1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
46 static tree pfn_from_ptrmemfunc (tree);
47 static tree convert_for_assignment (tree, tree, const char *, tree, int);
48 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
49 static tree rationalize_conditional_expr (enum tree_code, tree);
50 static int comp_ptr_ttypes_real (tree, tree, int);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
60 static tree convert_arguments (tree, tree, tree, int);
62 /* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
68 require_complete_type (tree value)
72 if (processing_template_decl || value == error_mark_node)
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
78 type = TREE_TYPE (value);
80 if (type == error_mark_node)
81 return error_mark_node;
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
87 if (complete_type_or_else (type, value))
90 return error_mark_node;
93 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
99 complete_type (tree type)
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
104 return error_mark_node;
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
110 tree t = complete_type (TREE_TYPE (type));
111 unsigned int needs_constructing, has_nontrivial_dtor;
112 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
115 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
117 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
120 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
121 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
124 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
125 instantiate_class_template (TYPE_MAIN_VARIANT (type));
130 /* Like complete_type, but issue an error if the TYPE cannot be completed.
131 VALUE is used for informative diagnostics.
132 Returns NULL_TREE if the type cannot be made complete. */
135 complete_type_or_else (tree type, tree value)
137 type = complete_type (type);
138 if (type == error_mark_node)
139 /* We already issued an error. */
141 else if (!COMPLETE_TYPE_P (type))
143 cxx_incomplete_type_diagnostic (value, type, 0);
150 /* Return truthvalue of whether type of EXP is instantiated. */
153 type_unknown_p (tree exp)
155 return (TREE_CODE (exp) == TREE_LIST
156 || TREE_TYPE (exp) == unknown_type_node);
160 /* Return the common type of two parameter lists.
161 We assume that comptypes has already been done and returned 1;
162 if that isn't so, this may crash.
164 As an optimization, free the space we allocate if the parameter
165 lists are already common. */
168 commonparms (tree p1, tree p2)
170 tree oldargs = p1, newargs, n;
174 len = list_length (p1);
175 newargs = tree_last (p1);
177 if (newargs == void_list_node)
186 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
191 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
193 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
195 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
198 else if (! TREE_PURPOSE (p1))
200 if (TREE_PURPOSE (p2))
202 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
208 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
210 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
212 if (TREE_VALUE (p1) != TREE_VALUE (p2))
215 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
218 TREE_VALUE (n) = TREE_VALUE (p1);
226 /* Given a type, perhaps copied for a typedef,
227 find the "original" version of it. */
229 original_type (tree t)
231 int quals = cp_type_quals (t);
232 while (t != error_mark_node
233 && TYPE_NAME (t) != NULL_TREE)
235 tree x = TYPE_NAME (t);
236 if (TREE_CODE (x) != TYPE_DECL)
238 x = DECL_ORIGINAL_TYPE (x);
243 return cp_build_qualified_type (t, quals);
246 /* T1 and T2 are arithmetic or enumeration types. Return the type
247 that will result from the "usual arithmetic conversions" on T1 and
248 T2 as described in [expr]. */
251 type_after_usual_arithmetic_conversions (tree t1, tree t2)
253 enum tree_code code1 = TREE_CODE (t1);
254 enum tree_code code2 = TREE_CODE (t2);
257 /* FIXME: Attributes. */
258 gcc_assert (ARITHMETIC_TYPE_P (t1)
259 || TREE_CODE (t1) == VECTOR_TYPE
260 || TREE_CODE (t1) == ENUMERAL_TYPE);
261 gcc_assert (ARITHMETIC_TYPE_P (t2)
262 || TREE_CODE (t2) == VECTOR_TYPE
263 || TREE_CODE (t2) == ENUMERAL_TYPE);
265 /* In what follows, we slightly generalize the rules given in [expr] so
266 as to deal with `long long' and `complex'. First, merge the
268 attributes = (*targetm.merge_type_attributes) (t1, t2);
270 /* If one type is complex, form the common type of the non-complex
271 components, then make that complex. Use T1 or T2 if it is the
273 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
275 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
276 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
278 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
280 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
281 return build_type_attribute_variant (t1, attributes);
282 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
283 return build_type_attribute_variant (t2, attributes);
285 return build_type_attribute_variant (build_complex_type (subtype),
289 if (code1 == VECTOR_TYPE)
291 /* When we get here we should have two vectors of the same size.
292 Just prefer the unsigned one if present. */
293 if (TYPE_UNSIGNED (t1))
294 return build_type_attribute_variant (t1, attributes);
296 return build_type_attribute_variant (t2, attributes);
299 /* If only one is real, use it as the result. */
300 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
301 return build_type_attribute_variant (t1, attributes);
302 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
303 return build_type_attribute_variant (t2, attributes);
305 /* Perform the integral promotions. */
306 if (code1 != REAL_TYPE)
308 t1 = type_promotes_to (t1);
309 t2 = type_promotes_to (t2);
312 /* Both real or both integers; use the one with greater precision. */
313 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
314 return build_type_attribute_variant (t1, attributes);
315 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
316 return build_type_attribute_variant (t2, attributes);
318 /* The types are the same; no need to do anything fancy. */
319 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
320 return build_type_attribute_variant (t1, attributes);
322 if (code1 != REAL_TYPE)
324 /* If one is a sizetype, use it so size_binop doesn't blow up. */
325 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
326 return build_type_attribute_variant (t1, attributes);
327 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
328 return build_type_attribute_variant (t2, attributes);
330 /* If one is unsigned long long, then convert the other to unsigned
332 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
333 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
334 return build_type_attribute_variant (long_long_unsigned_type_node,
336 /* If one is a long long, and the other is an unsigned long, and
337 long long can represent all the values of an unsigned long, then
338 convert to a long long. Otherwise, convert to an unsigned long
339 long. Otherwise, if either operand is long long, convert the
342 Since we're here, we know the TYPE_PRECISION is the same;
343 therefore converting to long long cannot represent all the values
344 of an unsigned long, so we choose unsigned long long in that
346 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
347 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
349 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
350 ? long_long_unsigned_type_node
351 : long_long_integer_type_node);
352 return build_type_attribute_variant (t, attributes);
355 /* Go through the same procedure, but for longs. */
356 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
357 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
358 return build_type_attribute_variant (long_unsigned_type_node,
360 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
361 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
363 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
364 ? long_unsigned_type_node : long_integer_type_node);
365 return build_type_attribute_variant (t, attributes);
367 /* Otherwise prefer the unsigned one. */
368 if (TYPE_UNSIGNED (t1))
369 return build_type_attribute_variant (t1, attributes);
371 return build_type_attribute_variant (t2, attributes);
375 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
376 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
377 return build_type_attribute_variant (long_double_type_node,
379 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
380 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
381 return build_type_attribute_variant (double_type_node,
383 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
384 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
385 return build_type_attribute_variant (float_type_node,
388 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
389 the standard C++ floating-point types. Logic earlier in this
390 function has already eliminated the possibility that
391 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
392 compelling reason to choose one or the other. */
393 return build_type_attribute_variant (t1, attributes);
397 /* Subroutine of composite_pointer_type to implement the recursive
398 case. See that function for documentation fo the parameters. */
401 composite_pointer_type_r (tree t1, tree t2, const char* location)
408 /* Determine the types pointed to by T1 and T2. */
409 if (TREE_CODE (t1) == POINTER_TYPE)
411 pointee1 = TREE_TYPE (t1);
412 pointee2 = TREE_TYPE (t2);
416 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
417 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
422 Otherwise, the composite pointer type is a pointer type
423 similar (_conv.qual_) to the type of one of the operands,
424 with a cv-qualification signature (_conv.qual_) that is the
425 union of the cv-qualification signatures of the operand
427 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
428 result_type = pointee1;
429 else if ((TREE_CODE (pointee1) == POINTER_TYPE
430 && TREE_CODE (pointee2) == POINTER_TYPE)
431 || (TYPE_PTR_TO_MEMBER_P (pointee1)
432 && TYPE_PTR_TO_MEMBER_P (pointee2)))
433 result_type = composite_pointer_type_r (pointee1, pointee2, location);
436 pedwarn ("%s between distinct pointer types %qT and %qT "
439 result_type = void_type_node;
441 result_type = cp_build_qualified_type (result_type,
442 (cp_type_quals (pointee1)
443 | cp_type_quals (pointee2)));
444 /* If the original types were pointers to members, so is the
446 if (TYPE_PTR_TO_MEMBER_P (t1))
448 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
449 TYPE_PTRMEM_CLASS_TYPE (t2)))
450 pedwarn ("%s between distinct pointer types %qT and %qT "
453 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
457 result_type = build_pointer_type (result_type);
459 /* Merge the attributes. */
460 attributes = (*targetm.merge_type_attributes) (t1, t2);
461 return build_type_attribute_variant (result_type, attributes);
464 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
465 ARG1 and ARG2 are the values with those types. The LOCATION is a
466 string describing the current location, in case an error occurs.
468 This routine also implements the computation of a common type for
469 pointers-to-members as per [expr.eq]. */
472 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
473 const char* location)
480 If one operand is a null pointer constant, the composite pointer
481 type is the type of the other operand. */
482 if (null_ptr_cst_p (arg1))
484 if (null_ptr_cst_p (arg2))
491 If one of the operands has type "pointer to cv1 void*", then
492 the other has type "pointer to cv2T", and the composite pointer
493 type is "pointer to cv12 void", where cv12 is the union of cv1
496 If either type is a pointer to void, make sure it is T1. */
497 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
505 /* Now, if T1 is a pointer to void, merge the qualifiers. */
506 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
511 if (pedantic && TYPE_PTRFN_P (t2))
512 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
513 "and pointer-to-function", location);
515 = cp_build_qualified_type (void_type_node,
516 (cp_type_quals (TREE_TYPE (t1))
517 | cp_type_quals (TREE_TYPE (t2))));
518 result_type = build_pointer_type (result_type);
519 /* Merge the attributes. */
520 attributes = (*targetm.merge_type_attributes) (t1, t2);
521 return build_type_attribute_variant (result_type, attributes);
524 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
525 && TREE_CODE (t2) == POINTER_TYPE)
527 if (objc_compare_types (t1, t2, -3, NULL_TREE))
531 /* [expr.eq] permits the application of a pointer conversion to
532 bring the pointers to a common type. */
533 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
534 && CLASS_TYPE_P (TREE_TYPE (t1))
535 && CLASS_TYPE_P (TREE_TYPE (t2))
536 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
539 class1 = TREE_TYPE (t1);
540 class2 = TREE_TYPE (t2);
542 if (DERIVED_FROM_P (class1, class2))
543 t2 = (build_pointer_type
544 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
545 else if (DERIVED_FROM_P (class2, class1))
546 t1 = (build_pointer_type
547 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
550 error ("%s between distinct pointer types %qT and %qT "
551 "lacks a cast", location, t1, t2);
552 return error_mark_node;
555 /* [expr.eq] permits the application of a pointer-to-member
556 conversion to change the class type of one of the types. */
557 else if (TYPE_PTR_TO_MEMBER_P (t1)
558 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
559 TYPE_PTRMEM_CLASS_TYPE (t2)))
561 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
562 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
564 if (DERIVED_FROM_P (class1, class2))
565 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
566 else if (DERIVED_FROM_P (class2, class1))
567 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
570 error ("%s between distinct pointer-to-member types %qT and %qT "
571 "lacks a cast", location, t1, t2);
572 return error_mark_node;
576 return composite_pointer_type_r (t1, t2, location);
579 /* Return the merged type of two types.
580 We assume that comptypes has already been done and returned 1;
581 if that isn't so, this may crash.
583 This just combines attributes and default arguments; any other
584 differences would cause the two types to compare unalike. */
587 merge_types (tree t1, tree t2)
589 enum tree_code code1;
590 enum tree_code code2;
593 /* Save time if the two types are the same. */
596 if (original_type (t1) == original_type (t2))
599 /* If one type is nonsense, use the other. */
600 if (t1 == error_mark_node)
602 if (t2 == error_mark_node)
605 /* Merge the attributes. */
606 attributes = (*targetm.merge_type_attributes) (t1, t2);
608 if (TYPE_PTRMEMFUNC_P (t1))
609 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
610 if (TYPE_PTRMEMFUNC_P (t2))
611 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
613 code1 = TREE_CODE (t1);
614 code2 = TREE_CODE (t2);
620 /* For two pointers, do this recursively on the target type. */
622 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
623 int quals = cp_type_quals (t1);
625 if (code1 == POINTER_TYPE)
626 t1 = build_pointer_type (target);
628 t1 = build_reference_type (target);
629 t1 = build_type_attribute_variant (t1, attributes);
630 t1 = cp_build_qualified_type (t1, quals);
632 if (TREE_CODE (target) == METHOD_TYPE)
633 t1 = build_ptrmemfunc_type (t1);
642 quals = cp_type_quals (t1);
643 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
644 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
645 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
647 t1 = cp_build_qualified_type (t1, quals);
653 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
654 /* Save space: see if the result is identical to one of the args. */
655 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
656 return build_type_attribute_variant (t1, attributes);
657 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
658 return build_type_attribute_variant (t2, attributes);
659 /* Merge the element types, and have a size if either arg has one. */
660 t1 = build_cplus_array_type
661 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
666 /* Function types: prefer the one that specified arg types.
667 If both do, merge the arg types. Also merge the return types. */
669 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
670 tree p1 = TYPE_ARG_TYPES (t1);
671 tree p2 = TYPE_ARG_TYPES (t2);
674 /* Save space: see if the result is identical to one of the args. */
675 if (valtype == TREE_TYPE (t1) && ! p2)
676 return cp_build_type_attribute_variant (t1, attributes);
677 if (valtype == TREE_TYPE (t2) && ! p1)
678 return cp_build_type_attribute_variant (t2, attributes);
680 /* Simple way if one arg fails to specify argument types. */
681 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
683 rval = build_function_type (valtype, p2);
684 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
685 rval = build_exception_variant (rval, raises);
686 return cp_build_type_attribute_variant (rval, attributes);
688 raises = TYPE_RAISES_EXCEPTIONS (t1);
689 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
691 rval = build_function_type (valtype, p1);
693 rval = build_exception_variant (rval, raises);
694 return cp_build_type_attribute_variant (rval, attributes);
697 rval = build_function_type (valtype, commonparms (p1, p2));
698 t1 = build_exception_variant (rval, raises);
704 /* Get this value the long way, since TYPE_METHOD_BASETYPE
705 is just the main variant of this. */
706 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
707 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
710 /* If this was a member function type, get back to the
711 original type of type member function (i.e., without
712 the class instance variable up front. */
713 t1 = build_function_type (TREE_TYPE (t1),
714 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
715 t2 = build_function_type (TREE_TYPE (t2),
716 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
717 t3 = merge_types (t1, t2);
718 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
719 TYPE_ARG_TYPES (t3));
720 t1 = build_exception_variant (t3, raises);
725 /* There is no need to merge attributes into a TYPENAME_TYPE.
726 When the type is instantiated it will have whatever
727 attributes result from the instantiation. */
733 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
735 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
738 return cp_build_type_attribute_variant (t1, attributes);
741 /* Return the common type of two types.
742 We assume that comptypes has already been done and returned 1;
743 if that isn't so, this may crash.
745 This is the type for the result of most arithmetic operations
746 if the operands have the given two types. */
749 common_type (tree t1, tree t2)
751 enum tree_code code1;
752 enum tree_code code2;
754 /* If one type is nonsense, bail. */
755 if (t1 == error_mark_node || t2 == error_mark_node)
756 return error_mark_node;
758 code1 = TREE_CODE (t1);
759 code2 = TREE_CODE (t2);
761 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
762 || code1 == VECTOR_TYPE)
763 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
764 || code2 == VECTOR_TYPE))
765 return type_after_usual_arithmetic_conversions (t1, t2);
767 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
768 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
769 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
770 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
776 /* Compare two exception specifier types for exactness or subsetness, if
777 allowed. Returns false for mismatch, true for match (same, or
780 [except.spec] "If a class X ... objects of class X or any class publicly
781 and unambiguously derived from X. Similarly, if a pointer type Y * ...
782 exceptions of type Y * or that are pointers to any type publicly and
783 unambiguously derived from Y. Otherwise a function only allows exceptions
784 that have the same type ..."
785 This does not mention cv qualifiers and is different to what throw
786 [except.throw] and catch [except.catch] will do. They will ignore the
787 top level cv qualifiers, and allow qualifiers in the pointer to class
790 We implement the letter of the standard. */
793 comp_except_types (tree a, tree b, bool exact)
795 if (same_type_p (a, b))
799 if (cp_type_quals (a) || cp_type_quals (b))
802 if (TREE_CODE (a) == POINTER_TYPE
803 && TREE_CODE (b) == POINTER_TYPE)
807 if (cp_type_quals (a) || cp_type_quals (b))
811 if (TREE_CODE (a) != RECORD_TYPE
812 || TREE_CODE (b) != RECORD_TYPE)
815 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
821 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
822 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
823 otherwise it must be exact. Exception lists are unordered, but
824 we've already filtered out duplicates. Most lists will be in order,
825 we should try to make use of that. */
828 comp_except_specs (tree t1, tree t2, bool exact)
837 if (t1 == NULL_TREE) /* T1 is ... */
838 return t2 == NULL_TREE || !exact;
839 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
840 return t2 != NULL_TREE && !TREE_VALUE (t2);
841 if (t2 == NULL_TREE) /* T2 is ... */
843 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
846 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
847 Count how many we find, to determine exactness. For exact matching and
848 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
850 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
852 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
854 tree a = TREE_VALUE (probe);
855 tree b = TREE_VALUE (t2);
857 if (comp_except_types (a, b, exact))
859 if (probe == base && exact)
860 base = TREE_CHAIN (probe);
865 if (probe == NULL_TREE)
868 return !exact || base == NULL_TREE || length == list_length (t1);
871 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
872 [] can match [size]. */
875 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
884 /* The type of the array elements must be the same. */
885 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
888 d1 = TYPE_DOMAIN (t1);
889 d2 = TYPE_DOMAIN (t2);
894 /* If one of the arrays is dimensionless, and the other has a
895 dimension, they are of different types. However, it is valid to
903 declarations for an array object can specify
904 array types that differ by the presence or absence of a major
905 array bound (_dcl.array_). */
907 return allow_redeclaration;
909 /* Check that the dimensions are the same. */
911 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
913 max1 = TYPE_MAX_VALUE (d1);
914 max2 = TYPE_MAX_VALUE (d2);
915 if (processing_template_decl && !abi_version_at_least (2)
916 && !value_dependent_expression_p (max1)
917 && !value_dependent_expression_p (max2))
919 /* With abi-1 we do not fold non-dependent array bounds, (and
920 consequently mangle them incorrectly). We must therefore
921 fold them here, to verify the domains have the same
927 if (!cp_tree_equal (max1, max2))
933 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
934 is a bitwise-or of the COMPARE_* flags. */
937 comptypes (tree t1, tree t2, int strict)
942 /* Suppress errors caused by previously reported errors. */
943 if (t1 == error_mark_node || t2 == error_mark_node)
946 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
948 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
949 current instantiation. */
950 if (TREE_CODE (t1) == TYPENAME_TYPE)
952 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
954 if (resolved != error_mark_node)
958 if (TREE_CODE (t2) == TYPENAME_TYPE)
960 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
962 if (resolved != error_mark_node)
966 /* If either type is the internal version of sizetype, use the
968 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
969 && TYPE_ORIG_SIZE_TYPE (t1))
970 t1 = TYPE_ORIG_SIZE_TYPE (t1);
972 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
973 && TYPE_ORIG_SIZE_TYPE (t2))
974 t2 = TYPE_ORIG_SIZE_TYPE (t2);
976 if (TYPE_PTRMEMFUNC_P (t1))
977 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
978 if (TYPE_PTRMEMFUNC_P (t2))
979 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
981 /* Different classes of types can't be compatible. */
982 if (TREE_CODE (t1) != TREE_CODE (t2))
985 /* Qualifiers must match. For array types, we will check when we
986 recur on the array element types. */
987 if (TREE_CODE (t1) != ARRAY_TYPE
988 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
990 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
993 /* Allow for two different type nodes which have essentially the same
994 definition. Note that we already checked for equality of the type
995 qualifiers (just above). */
997 if (TREE_CODE (t1) != ARRAY_TYPE
998 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
1001 /* Compare the types. Break out if they could be the same. */
1002 switch (TREE_CODE (t1))
1004 case TEMPLATE_TEMPLATE_PARM:
1005 case BOUND_TEMPLATE_TEMPLATE_PARM:
1006 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1007 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1009 if (!comp_template_parms
1010 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1011 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1013 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1015 /* Don't check inheritance. */
1016 strict = COMPARE_STRICT;
1021 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1022 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1023 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1024 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1027 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1029 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1035 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1036 strict & ~COMPARE_REDECLARATION))
1038 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1043 case REFERENCE_TYPE:
1044 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1045 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1046 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1052 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1054 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1059 /* Target types must match incl. qualifiers. */
1060 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1064 case TEMPLATE_TYPE_PARM:
1065 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1066 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1071 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1072 TYPENAME_TYPE_FULLNAME (t2)))
1074 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1078 case UNBOUND_CLASS_TEMPLATE:
1079 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1081 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1086 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1091 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1092 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1100 /* If we get here, we know that from a target independent POV the
1101 types are the same. Make sure the target attributes are also
1103 return targetm.comp_type_attributes (t1, t2);
1106 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1109 at_least_as_qualified_p (tree type1, tree type2)
1111 int q1 = cp_type_quals (type1);
1112 int q2 = cp_type_quals (type2);
1114 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1115 return (q1 & q2) == q2;
1118 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1119 more cv-qualified that TYPE1, and 0 otherwise. */
1122 comp_cv_qualification (tree type1, tree type2)
1124 int q1 = cp_type_quals (type1);
1125 int q2 = cp_type_quals (type2);
1130 if ((q1 & q2) == q2)
1132 else if ((q1 & q2) == q1)
1138 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1139 subset of the cv-qualification signature of TYPE2, and the types
1140 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1143 comp_cv_qual_signature (tree type1, tree type2)
1145 if (comp_ptr_ttypes_real (type2, type1, -1))
1147 else if (comp_ptr_ttypes_real (type1, type2, -1))
1153 /* If two types share a common base type, return that basetype.
1154 If there is not a unique most-derived base type, this function
1155 returns ERROR_MARK_NODE. */
1158 common_base_type (tree tt1, tree tt2)
1160 tree best = NULL_TREE;
1163 /* If one is a baseclass of another, that's good enough. */
1164 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1166 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1169 /* Otherwise, try to find a unique baseclass of TT1
1170 that is shared by TT2, and follow that down. */
1171 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1173 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1174 tree trial = common_base_type (basetype, tt2);
1178 if (trial == error_mark_node)
1180 if (best == NULL_TREE)
1182 else if (best != trial)
1183 return error_mark_node;
1188 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1190 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1191 tree trial = common_base_type (tt1, basetype);
1195 if (trial == error_mark_node)
1197 if (best == NULL_TREE)
1199 else if (best != trial)
1200 return error_mark_node;
1206 /* Subroutines of `comptypes'. */
1208 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1209 equivalent in the sense that functions with those parameter types
1210 can have equivalent types. The two lists must be equivalent,
1211 element by element. */
1214 compparms (tree parms1, tree parms2)
1218 /* An unspecified parmlist matches any specified parmlist
1219 whose argument types don't need default promotions. */
1221 for (t1 = parms1, t2 = parms2;
1223 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1225 /* If one parmlist is shorter than the other,
1226 they fail to match. */
1229 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1236 /* Process a sizeof or alignof expression where the operand is a
1240 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1245 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1246 if (type == error_mark_node)
1247 return error_mark_node;
1249 type = non_reference (type);
1250 if (TREE_CODE (type) == METHOD_TYPE)
1252 if (complain && (pedantic || warn_pointer_arith))
1253 pedwarn ("invalid application of %qs to a member function",
1254 operator_name_info[(int) op].name);
1255 value = size_one_node;
1258 dependent_p = dependent_type_p (type);
1260 complete_type (type);
1262 /* VLA types will have a non-constant size. In the body of an
1263 uninstantiated template, we don't need to try to compute the
1264 value, because the sizeof expression is not an integral
1265 constant expression in that case. And, if we do try to
1266 compute the value, we'll likely end up with SAVE_EXPRs, which
1267 the template substitution machinery does not expect to see. */
1268 || (processing_template_decl
1269 && COMPLETE_TYPE_P (type)
1270 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1272 value = build_min (op, size_type_node, type);
1273 TREE_READONLY (value) = 1;
1277 return c_sizeof_or_alignof_type (complete_type (type),
1282 /* Process a sizeof expression where the operand is an expression. */
1285 cxx_sizeof_expr (tree e)
1287 if (e == error_mark_node)
1288 return error_mark_node;
1290 if (processing_template_decl)
1292 e = build_min (SIZEOF_EXPR, size_type_node, e);
1293 TREE_SIDE_EFFECTS (e) = 0;
1294 TREE_READONLY (e) = 1;
1299 if (TREE_CODE (e) == COMPONENT_REF
1300 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1301 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1303 error ("invalid application of %<sizeof%> to a bit-field");
1306 else if (is_overloaded_fn (e))
1308 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1312 else if (type_unknown_p (e))
1314 cxx_incomplete_type_error (e, TREE_TYPE (e));
1320 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1323 /* Implement the __alignof keyword: Return the minimum required
1324 alignment of E, measured in bytes. For VAR_DECL's and
1325 FIELD_DECL's return DECL_ALIGN (which can be set from an
1326 "aligned" __attribute__ specification). */
1329 cxx_alignof_expr (tree e)
1333 if (e == error_mark_node)
1334 return error_mark_node;
1336 if (processing_template_decl)
1338 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1339 TREE_SIDE_EFFECTS (e) = 0;
1340 TREE_READONLY (e) = 1;
1345 if (TREE_CODE (e) == VAR_DECL)
1346 t = size_int (DECL_ALIGN_UNIT (e));
1347 else if (TREE_CODE (e) == COMPONENT_REF
1348 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1349 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1351 error ("invalid application of %<__alignof%> to a bit-field");
1354 else if (TREE_CODE (e) == COMPONENT_REF
1355 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1356 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1357 else if (is_overloaded_fn (e))
1359 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1363 else if (type_unknown_p (e))
1365 cxx_incomplete_type_error (e, TREE_TYPE (e));
1369 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1371 return fold_convert (size_type_node, t);
1374 /* Process a sizeof or alignof expression E with code OP where the operand
1375 is an expression. */
1378 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1380 if (op == SIZEOF_EXPR)
1381 return cxx_sizeof_expr (e);
1383 return cxx_alignof_expr (e);
1386 /* EXPR is being used in a context that is not a function call.
1391 The expression can be used only as the left-hand operand of a
1392 member function call.
1394 [expr.mptr.operator]
1396 If the result of .* or ->* is a function, then that result can be
1397 used only as the operand for the function call operator ().
1399 by issuing an error message if appropriate. Returns true iff EXPR
1400 violates these rules. */
1403 invalid_nonstatic_memfn_p (tree expr)
1405 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1407 error ("invalid use of non-static member function");
1413 /* If EXP is a reference to a bitfield, and the type of EXP does not
1414 match the declared type of the bitfield, return the declared type
1415 of the bitfield. Otherwise, return NULL_TREE. */
1418 is_bitfield_expr_with_lowered_type (tree exp)
1420 switch (TREE_CODE (exp))
1423 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1425 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1428 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1432 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1438 field = TREE_OPERAND (exp, 1);
1439 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1441 if (same_type_ignoring_top_level_qualifiers_p
1442 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1444 return DECL_BIT_FIELD_TYPE (field);
1452 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1453 bitfield with a lowered type, the type of EXP is returned, rather
1457 unlowered_expr_type (tree exp)
1461 type = is_bitfield_expr_with_lowered_type (exp);
1463 type = TREE_TYPE (exp);
1468 /* Perform the conversions in [expr] that apply when an lvalue appears
1469 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1470 function-to-pointer conversions. In addition, manifest constants
1471 are replaced by their values, and bitfield references are converted
1472 to their declared types.
1474 Although the returned value is being used as an rvalue, this
1475 function does not wrap the returned expression in a
1476 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1477 that the return value is no longer an lvalue. */
1480 decay_conversion (tree exp)
1483 enum tree_code code;
1485 type = TREE_TYPE (exp);
1486 if (type == error_mark_node)
1487 return error_mark_node;
1489 if (type_unknown_p (exp))
1491 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1492 return error_mark_node;
1495 exp = decl_constant_value (exp);
1496 if (error_operand_p (exp))
1497 return error_mark_node;
1499 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1500 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1501 code = TREE_CODE (type);
1502 if (code == VOID_TYPE)
1504 error ("void value not ignored as it ought to be");
1505 return error_mark_node;
1507 if (invalid_nonstatic_memfn_p (exp))
1508 return error_mark_node;
1509 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1510 return build_unary_op (ADDR_EXPR, exp, 0);
1511 if (code == ARRAY_TYPE)
1516 if (TREE_CODE (exp) == INDIRECT_REF)
1517 return build_nop (build_pointer_type (TREE_TYPE (type)),
1518 TREE_OPERAND (exp, 0));
1520 if (TREE_CODE (exp) == COMPOUND_EXPR)
1522 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1523 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1524 TREE_OPERAND (exp, 0), op1);
1528 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1530 error ("invalid use of non-lvalue array");
1531 return error_mark_node;
1534 ptrtype = build_pointer_type (TREE_TYPE (type));
1536 if (TREE_CODE (exp) == VAR_DECL)
1538 if (!cxx_mark_addressable (exp))
1539 return error_mark_node;
1540 adr = build_nop (ptrtype, build_address (exp));
1543 /* This way is better for a COMPONENT_REF since it can
1544 simplify the offset for a component. */
1545 adr = build_unary_op (ADDR_EXPR, exp, 1);
1546 return cp_convert (ptrtype, adr);
1549 /* If a bitfield is used in a context where integral promotion
1550 applies, then the caller is expected to have used
1551 default_conversion. That function promotes bitfields correctly
1552 before calling this function. At this point, if we have a
1553 bitfield referenced, we may assume that is not subject to
1554 promotion, and that, therefore, the type of the resulting rvalue
1555 is the declared type of the bitfield. */
1556 exp = convert_bitfield_to_declared_type (exp);
1558 /* We do not call rvalue() here because we do not want to wrap EXP
1559 in a NON_LVALUE_EXPR. */
1563 Non-class rvalues always have cv-unqualified types. */
1564 type = TREE_TYPE (exp);
1565 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1566 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1571 /* Perform prepatory conversions, as part of the "usual arithmetic
1572 conversions". In particular, as per [expr]:
1574 Whenever an lvalue expression appears as an operand of an
1575 operator that expects the rvalue for that operand, the
1576 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1577 standard conversions are applied to convert the expression to an
1580 In addition, we perform integral promotions here, as those are
1581 applied to both operands to a binary operator before determining
1582 what additional conversions should apply. */
1585 default_conversion (tree exp)
1587 /* Perform the integral promotions first so that bitfield
1588 expressions (which may promote to "int", even if the bitfield is
1589 declared "unsigned") are promoted correctly. */
1590 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1591 exp = perform_integral_promotions (exp);
1592 /* Perform the other conversions. */
1593 exp = decay_conversion (exp);
1598 /* EXPR is an expression with an integral or enumeration type.
1599 Perform the integral promotions in [conv.prom], and return the
1603 perform_integral_promotions (tree expr)
1610 If the bitfield has an enumerated type, it is treated as any
1611 other value of that type for promotion purposes. */
1612 type = is_bitfield_expr_with_lowered_type (expr);
1613 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1614 type = TREE_TYPE (expr);
1615 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1616 promoted_type = type_promotes_to (type);
1617 if (type != promoted_type)
1618 expr = cp_convert (promoted_type, expr);
1622 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1626 inline_conversion (tree exp)
1628 if (TREE_CODE (exp) == FUNCTION_DECL)
1629 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1634 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1635 decay_conversion to one. */
1638 string_conv_p (tree totype, tree exp, int warn)
1642 if (TREE_CODE (totype) != POINTER_TYPE)
1645 t = TREE_TYPE (totype);
1646 if (!same_type_p (t, char_type_node)
1647 && !same_type_p (t, wchar_type_node))
1650 if (TREE_CODE (exp) == STRING_CST)
1652 /* Make sure that we don't try to convert between char and wchar_t. */
1653 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1658 /* Is this a string constant which has decayed to 'const char *'? */
1659 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1660 if (!same_type_p (TREE_TYPE (exp), t))
1663 if (TREE_CODE (exp) != ADDR_EXPR
1664 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1668 /* This warning is not very useful, as it complains about printf. */
1670 warning (OPT_Wwrite_strings,
1671 "deprecated conversion from string constant to %qT",
1677 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1678 can, for example, use as an lvalue. This code used to be in
1679 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1680 expressions, where we're dealing with aggregates. But now it's again only
1681 called from unary_complex_lvalue. The case (in particular) that led to
1682 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1686 rationalize_conditional_expr (enum tree_code code, tree t)
1688 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1689 the first operand is always the one to be used if both operands
1690 are equal, so we know what conditional expression this used to be. */
1691 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1693 tree op0 = TREE_OPERAND (t, 0);
1694 tree op1 = TREE_OPERAND (t, 1);
1696 /* The following code is incorrect if either operand side-effects. */
1697 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1698 && !TREE_SIDE_EFFECTS (op1));
1700 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1701 ? LE_EXPR : GE_EXPR),
1702 op0, TREE_CODE (op0),
1703 op1, TREE_CODE (op1),
1704 /*overloaded_p=*/NULL),
1705 build_unary_op (code, op0, 0),
1706 build_unary_op (code, op1, 0));
1710 build_conditional_expr (TREE_OPERAND (t, 0),
1711 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1712 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1715 /* Given the TYPE of an anonymous union field inside T, return the
1716 FIELD_DECL for the field. If not found return NULL_TREE. Because
1717 anonymous unions can nest, we must also search all anonymous unions
1718 that are directly reachable. */
1721 lookup_anon_field (tree t, tree type)
1725 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1727 if (TREE_STATIC (field))
1729 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1732 /* If we find it directly, return the field. */
1733 if (DECL_NAME (field) == NULL_TREE
1734 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1739 /* Otherwise, it could be nested, search harder. */
1740 if (DECL_NAME (field) == NULL_TREE
1741 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1743 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1751 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1752 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1753 non-NULL, it indicates the path to the base used to name MEMBER.
1754 If PRESERVE_REFERENCE is true, the expression returned will have
1755 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1756 returned will have the type referred to by the reference.
1758 This function does not perform access control; that is either done
1759 earlier by the parser when the name of MEMBER is resolved to MEMBER
1760 itself, or later when overload resolution selects one of the
1761 functions indicated by MEMBER. */
1764 build_class_member_access_expr (tree object, tree member,
1765 tree access_path, bool preserve_reference)
1769 tree result = NULL_TREE;
1771 if (error_operand_p (object) || error_operand_p (member))
1772 return error_mark_node;
1774 gcc_assert (DECL_P (member) || BASELINK_P (member));
1778 The type of the first expression shall be "class object" (of a
1780 object_type = TREE_TYPE (object);
1781 if (!currently_open_class (object_type)
1782 && !complete_type_or_else (object_type, object))
1783 return error_mark_node;
1784 if (!CLASS_TYPE_P (object_type))
1786 error ("request for member %qD in %qE, which is of non-class type %qT",
1787 member, object, object_type);
1788 return error_mark_node;
1791 /* The standard does not seem to actually say that MEMBER must be a
1792 member of OBJECT_TYPE. However, that is clearly what is
1794 if (DECL_P (member))
1796 member_scope = DECL_CLASS_CONTEXT (member);
1798 if (TREE_DEPRECATED (member))
1799 warn_deprecated_use (member);
1802 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1803 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1804 presently be the anonymous union. Go outwards until we find a
1805 type related to OBJECT_TYPE. */
1806 while (ANON_AGGR_TYPE_P (member_scope)
1807 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1809 member_scope = TYPE_CONTEXT (member_scope);
1810 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1812 if (TREE_CODE (member) == FIELD_DECL)
1813 error ("invalid use of nonstatic data member %qE", member);
1815 error ("%qD is not a member of %qT", member, object_type);
1816 return error_mark_node;
1819 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1820 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1821 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1823 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1825 object = build_indirect_ref (temp, NULL);
1828 /* In [expr.ref], there is an explicit list of the valid choices for
1829 MEMBER. We check for each of those cases here. */
1830 if (TREE_CODE (member) == VAR_DECL)
1832 /* A static data member. */
1834 /* If OBJECT has side-effects, they are supposed to occur. */
1835 if (TREE_SIDE_EFFECTS (object))
1836 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1838 else if (TREE_CODE (member) == FIELD_DECL)
1840 /* A non-static data member. */
1845 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1846 && integer_zerop (TREE_OPERAND (object, 0)));
1848 /* Convert OBJECT to the type of MEMBER. */
1849 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1850 TYPE_MAIN_VARIANT (member_scope)))
1855 binfo = lookup_base (access_path ? access_path : object_type,
1856 member_scope, ba_unique, &kind);
1857 if (binfo == error_mark_node)
1858 return error_mark_node;
1860 /* It is invalid to try to get to a virtual base of a
1861 NULL object. The most common cause is invalid use of
1863 if (null_object_p && kind == bk_via_virtual)
1865 error ("invalid access to non-static data member %qD of "
1868 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1869 return error_mark_node;
1872 /* Convert to the base. */
1873 object = build_base_path (PLUS_EXPR, object, binfo,
1875 /* If we found the base successfully then we should be able
1876 to convert to it successfully. */
1877 gcc_assert (object != error_mark_node);
1880 /* Complain about other invalid uses of offsetof, even though they will
1881 give the right answer. Note that we complain whether or not they
1882 actually used the offsetof macro, since there's no way to know at this
1883 point. So we just give a warning, instead of a pedwarn. */
1884 /* Do not produce this warning for base class field references, because
1885 we know for a fact that didn't come from offsetof. This does occur
1886 in various testsuite cases where a null object is passed where a
1887 vtable access is required. */
1888 if (null_object_p && warn_invalid_offsetof
1889 && CLASSTYPE_NON_POD_P (object_type)
1890 && !DECL_FIELD_IS_BASE (member)
1891 && !skip_evaluation)
1893 warning (0, "invalid access to non-static data member %qD of NULL object",
1895 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1898 /* If MEMBER is from an anonymous aggregate, we have converted
1899 OBJECT so that it refers to the class containing the
1900 anonymous union. Generate a reference to the anonymous union
1901 itself, and recur to find MEMBER. */
1902 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1903 /* When this code is called from build_field_call, the
1904 object already has the type of the anonymous union.
1905 That is because the COMPONENT_REF was already
1906 constructed, and was then disassembled before calling
1907 build_field_call. After the function-call code is
1908 cleaned up, this waste can be eliminated. */
1909 && (!same_type_ignoring_top_level_qualifiers_p
1910 (TREE_TYPE (object), DECL_CONTEXT (member))))
1912 tree anonymous_union;
1914 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1915 DECL_CONTEXT (member));
1916 object = build_class_member_access_expr (object,
1918 /*access_path=*/NULL_TREE,
1919 preserve_reference);
1922 /* Compute the type of the field, as described in [expr.ref]. */
1923 type_quals = TYPE_UNQUALIFIED;
1924 member_type = TREE_TYPE (member);
1925 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1927 type_quals = (cp_type_quals (member_type)
1928 | cp_type_quals (object_type));
1930 /* A field is const (volatile) if the enclosing object, or the
1931 field itself, is const (volatile). But, a mutable field is
1932 not const, even within a const object. */
1933 if (DECL_MUTABLE_P (member))
1934 type_quals &= ~TYPE_QUAL_CONST;
1935 member_type = cp_build_qualified_type (member_type, type_quals);
1938 result = build3 (COMPONENT_REF, member_type, object, member,
1940 result = fold_if_not_in_template (result);
1942 /* Mark the expression const or volatile, as appropriate. Even
1943 though we've dealt with the type above, we still have to mark the
1944 expression itself. */
1945 if (type_quals & TYPE_QUAL_CONST)
1946 TREE_READONLY (result) = 1;
1947 if (type_quals & TYPE_QUAL_VOLATILE)
1948 TREE_THIS_VOLATILE (result) = 1;
1950 else if (BASELINK_P (member))
1952 /* The member is a (possibly overloaded) member function. */
1956 /* If the MEMBER is exactly one static member function, then we
1957 know the type of the expression. Otherwise, we must wait
1958 until overload resolution has been performed. */
1959 functions = BASELINK_FUNCTIONS (member);
1960 if (TREE_CODE (functions) == FUNCTION_DECL
1961 && DECL_STATIC_FUNCTION_P (functions))
1962 type = TREE_TYPE (functions);
1964 type = unknown_type_node;
1965 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1966 base. That will happen when the function is called. */
1967 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1969 else if (TREE_CODE (member) == CONST_DECL)
1971 /* The member is an enumerator. */
1973 /* If OBJECT has side-effects, they are supposed to occur. */
1974 if (TREE_SIDE_EFFECTS (object))
1975 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1980 error ("invalid use of %qD", member);
1981 return error_mark_node;
1984 if (!preserve_reference)
1987 If E2 is declared to have type "reference to T", then ... the
1988 type of E1.E2 is T. */
1989 result = convert_from_reference (result);
1994 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1995 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1998 lookup_destructor (tree object, tree scope, tree dtor_name)
2000 tree object_type = TREE_TYPE (object);
2001 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2004 if (scope && !check_dtor_name (scope, dtor_type))
2006 error ("qualified type %qT does not match destructor name ~%qT",
2008 return error_mark_node;
2010 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2012 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2013 TYPE_MAIN_VARIANT (object_type), dtor_type);
2014 return error_mark_node;
2016 expr = lookup_member (dtor_type, complete_dtor_identifier,
2017 /*protect=*/1, /*want_type=*/false);
2018 expr = (adjust_result_of_qualified_name_lookup
2019 (expr, dtor_type, object_type));
2023 /* An expression of the form "A::template B" has been resolved to
2024 DECL. Issue a diagnostic if B is not a template or template
2028 check_template_keyword (tree decl)
2030 /* The standard says:
2034 If a name prefixed by the keyword template is not a member
2035 template, the program is ill-formed.
2037 DR 228 removed the restriction that the template be a member
2040 DR 96, if accepted would add the further restriction that explicit
2041 template arguments must be provided if the template keyword is
2042 used, but, as of 2005-10-16, that DR is still in "drafting". If
2043 this DR is accepted, then the semantic checks here can be
2044 simplified, as the entity named must in fact be a template
2045 specialization, rather than, as at present, a set of overloaded
2046 functions containing at least one template function. */
2047 if (TREE_CODE (decl) != TEMPLATE_DECL
2048 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2050 if (!is_overloaded_fn (decl))
2051 pedwarn ("%qD is not a template", decl);
2056 if (BASELINK_P (fns))
2057 fns = BASELINK_FUNCTIONS (fns);
2060 tree fn = OVL_CURRENT (fns);
2061 if (TREE_CODE (fn) == TEMPLATE_DECL
2062 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2064 if (TREE_CODE (fn) == FUNCTION_DECL
2065 && DECL_USE_TEMPLATE (fn)
2066 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2068 fns = OVL_NEXT (fns);
2071 pedwarn ("%qD is not a template", decl);
2076 /* This function is called by the parser to process a class member
2077 access expression of the form OBJECT.NAME. NAME is a node used by
2078 the parser to represent a name; it is not yet a DECL. It may,
2079 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2080 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2081 there is no reason to do the lookup twice, so the parser keeps the
2082 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2083 be a template via the use of the "A::template B" syntax. */
2086 finish_class_member_access_expr (tree object, tree name, bool template_p)
2091 tree access_path = NULL_TREE;
2092 tree orig_object = object;
2093 tree orig_name = name;
2095 if (object == error_mark_node || name == error_mark_node)
2096 return error_mark_node;
2098 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2099 if (!objc_is_public (object, name))
2100 return error_mark_node;
2102 object_type = TREE_TYPE (object);
2104 if (processing_template_decl)
2106 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2107 dependent_type_p (object_type)
2108 /* If NAME is just an IDENTIFIER_NODE, then the expression
2110 || TREE_CODE (object) == IDENTIFIER_NODE
2111 /* If NAME is "f<args>", where either 'f' or 'args' is
2112 dependent, then the expression is dependent. */
2113 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2114 && dependent_template_id_p (TREE_OPERAND (name, 0),
2115 TREE_OPERAND (name, 1)))
2116 /* If NAME is "T::X" where "T" is dependent, then the
2117 expression is dependent. */
2118 || (TREE_CODE (name) == SCOPE_REF
2119 && TYPE_P (TREE_OPERAND (name, 0))
2120 && dependent_type_p (TREE_OPERAND (name, 0))))
2121 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2122 object = build_non_dependent_expr (object);
2127 The type of the first expression shall be "class object" (of a
2129 if (!currently_open_class (object_type)
2130 && !complete_type_or_else (object_type, object))
2131 return error_mark_node;
2132 if (!CLASS_TYPE_P (object_type))
2134 error ("request for member %qD in %qE, which is of non-class type %qT",
2135 name, object, object_type);
2136 return error_mark_node;
2139 if (BASELINK_P (name))
2140 /* A member function that has already been looked up. */
2144 bool is_template_id = false;
2145 tree template_args = NULL_TREE;
2148 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2150 is_template_id = true;
2151 template_args = TREE_OPERAND (name, 1);
2152 name = TREE_OPERAND (name, 0);
2154 if (TREE_CODE (name) == OVERLOAD)
2155 name = DECL_NAME (get_first_fn (name));
2156 else if (DECL_P (name))
2157 name = DECL_NAME (name);
2160 if (TREE_CODE (name) == SCOPE_REF)
2162 /* A qualified name. The qualifying class or namespace `S'
2163 has already been looked up; it is either a TYPE or a
2165 scope = TREE_OPERAND (name, 0);
2166 name = TREE_OPERAND (name, 1);
2168 /* If SCOPE is a namespace, then the qualified name does not
2169 name a member of OBJECT_TYPE. */
2170 if (TREE_CODE (scope) == NAMESPACE_DECL)
2172 error ("%<%D::%D%> is not a member of %qT",
2173 scope, name, object_type);
2174 return error_mark_node;
2177 gcc_assert (CLASS_TYPE_P (scope));
2178 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2179 || TREE_CODE (name) == BIT_NOT_EXPR);
2181 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2182 access_path = lookup_base (object_type, scope, ba_check, NULL);
2183 if (access_path == error_mark_node)
2184 return error_mark_node;
2187 error ("%qT is not a base of %qT", scope, object_type);
2188 return error_mark_node;
2194 access_path = object_type;
2197 if (TREE_CODE (name) == BIT_NOT_EXPR)
2198 member = lookup_destructor (object, scope, name);
2201 /* Look up the member. */
2202 member = lookup_member (access_path, name, /*protect=*/1,
2203 /*want_type=*/false);
2204 if (member == NULL_TREE)
2206 error ("%qD has no member named %qE", object_type, name);
2207 return error_mark_node;
2209 if (member == error_mark_node)
2210 return error_mark_node;
2215 tree template = member;
2217 if (BASELINK_P (template))
2218 template = lookup_template_function (template, template_args);
2221 error ("%qD is not a member template function", name);
2222 return error_mark_node;
2227 if (TREE_DEPRECATED (member))
2228 warn_deprecated_use (member);
2231 check_template_keyword (member);
2233 expr = build_class_member_access_expr (object, member, access_path,
2234 /*preserve_reference=*/false);
2235 if (processing_template_decl && expr != error_mark_node)
2237 if (BASELINK_P (member))
2239 if (TREE_CODE (orig_name) == SCOPE_REF)
2240 BASELINK_QUALIFIED_P (member) = 1;
2243 return build_min_non_dep (COMPONENT_REF, expr,
2244 orig_object, orig_name,
2251 /* Return an expression for the MEMBER_NAME field in the internal
2252 representation of PTRMEM, a pointer-to-member function. (Each
2253 pointer-to-member function type gets its own RECORD_TYPE so it is
2254 more convenient to access the fields by name than by FIELD_DECL.)
2255 This routine converts the NAME to a FIELD_DECL and then creates the
2256 node for the complete expression. */
2259 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2265 /* This code is a stripped down version of
2266 build_class_member_access_expr. It does not work to use that
2267 routine directly because it expects the object to be of class
2269 ptrmem_type = TREE_TYPE (ptrmem);
2270 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2271 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2272 /*want_type=*/false);
2273 member_type = cp_build_qualified_type (TREE_TYPE (member),
2274 cp_type_quals (ptrmem_type));
2275 return fold_build3 (COMPONENT_REF, member_type,
2276 ptrmem, member, NULL_TREE);
2279 /* Given an expression PTR for a pointer, return an expression
2280 for the value pointed to.
2281 ERRORSTRING is the name of the operator to appear in error messages.
2283 This function may need to overload OPERATOR_FNNAME.
2284 Must also handle REFERENCE_TYPEs for C++. */
2287 build_x_indirect_ref (tree expr, const char *errorstring)
2289 tree orig_expr = expr;
2292 if (processing_template_decl)
2294 if (type_dependent_expression_p (expr))
2295 return build_min_nt (INDIRECT_REF, expr);
2296 expr = build_non_dependent_expr (expr);
2299 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2300 NULL_TREE, /*overloaded_p=*/NULL);
2302 rval = build_indirect_ref (expr, errorstring);
2304 if (processing_template_decl && rval != error_mark_node)
2305 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2311 build_indirect_ref (tree ptr, const char *errorstring)
2315 if (ptr == error_mark_node)
2316 return error_mark_node;
2318 if (ptr == current_class_ptr)
2319 return current_class_ref;
2321 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2322 ? ptr : decay_conversion (ptr));
2323 type = TREE_TYPE (pointer);
2325 if (POINTER_TYPE_P (type))
2329 If the type of the expression is "pointer to T," the type
2330 of the result is "T."
2332 We must use the canonical variant because certain parts of
2333 the back end, like fold, do pointer comparisons between
2335 tree t = canonical_type_variant (TREE_TYPE (type));
2337 if (TREE_CODE (ptr) == CONVERT_EXPR
2338 || TREE_CODE (ptr) == NOP_EXPR
2339 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2341 /* If a warning is issued, mark it to avoid duplicates from
2342 the backend. This only needs to be done at
2343 warn_strict_aliasing > 2. */
2344 if (warn_strict_aliasing > 2)
2345 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2346 type, TREE_OPERAND (ptr, 0)))
2347 TREE_NO_WARNING (ptr) = 1;
2350 if (VOID_TYPE_P (t))
2352 /* A pointer to incomplete type (other than cv void) can be
2353 dereferenced [expr.unary.op]/1 */
2354 error ("%qT is not a pointer-to-object type", type);
2355 return error_mark_node;
2357 else if (TREE_CODE (pointer) == ADDR_EXPR
2358 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2359 /* The POINTER was something like `&x'. We simplify `*&x' to
2361 return TREE_OPERAND (pointer, 0);
2364 tree ref = build1 (INDIRECT_REF, t, pointer);
2366 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2367 so that we get the proper error message if the result is used
2368 to assign to. Also, &* is supposed to be a no-op. */
2369 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2370 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2371 TREE_SIDE_EFFECTS (ref)
2372 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2376 /* `pointer' won't be an error_mark_node if we were given a
2377 pointer to member, so it's cool to check for this here. */
2378 else if (TYPE_PTR_TO_MEMBER_P (type))
2379 error ("invalid use of %qs on pointer to member", errorstring);
2380 else if (pointer != error_mark_node)
2383 error ("invalid type argument of %qs", errorstring);
2385 error ("invalid type argument");
2387 return error_mark_node;
2390 /* This handles expressions of the form "a[i]", which denotes
2393 This is logically equivalent in C to *(a+i), but we may do it differently.
2394 If A is a variable or a member, we generate a primitive ARRAY_REF.
2395 This avoids forcing the array out of registers, and can work on
2396 arrays that are not lvalues (for example, members of structures returned
2399 If INDEX is of some user-defined type, it must be converted to
2400 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2401 will inherit the type of the array, which will be some pointer type. */
2404 build_array_ref (tree array, tree idx)
2408 error ("subscript missing in array reference");
2409 return error_mark_node;
2412 if (TREE_TYPE (array) == error_mark_node
2413 || TREE_TYPE (idx) == error_mark_node)
2414 return error_mark_node;
2416 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2418 switch (TREE_CODE (array))
2422 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2423 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2424 TREE_OPERAND (array, 0), value);
2428 return build_conditional_expr
2429 (TREE_OPERAND (array, 0),
2430 build_array_ref (TREE_OPERAND (array, 1), idx),
2431 build_array_ref (TREE_OPERAND (array, 2), idx));
2437 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2441 warn_array_subscript_with_type_char (idx);
2443 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2445 error ("array subscript is not an integer");
2446 return error_mark_node;
2449 /* Apply integral promotions *after* noticing character types.
2450 (It is unclear why we do these promotions -- the standard
2451 does not say that we should. In fact, the natural thing would
2452 seem to be to convert IDX to ptrdiff_t; we're performing
2453 pointer arithmetic.) */
2454 idx = perform_integral_promotions (idx);
2456 /* An array that is indexed by a non-constant
2457 cannot be stored in a register; we must be able to do
2458 address arithmetic on its address.
2459 Likewise an array of elements of variable size. */
2460 if (TREE_CODE (idx) != INTEGER_CST
2461 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2462 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2465 if (!cxx_mark_addressable (array))
2466 return error_mark_node;
2469 /* An array that is indexed by a constant value which is not within
2470 the array bounds cannot be stored in a register either; because we
2471 would get a crash in store_bit_field/extract_bit_field when trying
2472 to access a non-existent part of the register. */
2473 if (TREE_CODE (idx) == INTEGER_CST
2474 && TYPE_DOMAIN (TREE_TYPE (array))
2475 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2477 if (!cxx_mark_addressable (array))
2478 return error_mark_node;
2481 if (pedantic && !lvalue_p (array))
2482 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2484 /* Note in C++ it is valid to subscript a `register' array, since
2485 it is valid to take the address of something with that
2486 storage specification. */
2490 while (TREE_CODE (foo) == COMPONENT_REF)
2491 foo = TREE_OPERAND (foo, 0);
2492 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2493 warning (OPT_Wextra, "subscripting array declared %<register%>");
2496 type = TREE_TYPE (TREE_TYPE (array));
2497 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2498 /* Array ref is const/volatile if the array elements are
2499 or if the array is.. */
2500 TREE_READONLY (rval)
2501 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2502 TREE_SIDE_EFFECTS (rval)
2503 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2504 TREE_THIS_VOLATILE (rval)
2505 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2506 return require_complete_type (fold_if_not_in_template (rval));
2510 tree ar = default_conversion (array);
2511 tree ind = default_conversion (idx);
2513 /* Put the integer in IND to simplify error checking. */
2514 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2521 if (ar == error_mark_node)
2524 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2526 error ("subscripted value is neither array nor pointer");
2527 return error_mark_node;
2529 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2531 error ("array subscript is not an integer");
2532 return error_mark_node;
2535 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2540 /* Resolve a pointer to member function. INSTANCE is the object
2541 instance to use, if the member points to a virtual member.
2543 This used to avoid checking for virtual functions if basetype
2544 has no virtual functions, according to an earlier ANSI draft.
2545 With the final ISO C++ rules, such an optimization is
2546 incorrect: A pointer to a derived member can be static_cast
2547 to pointer-to-base-member, as long as the dynamic object
2548 later has the right member. */
2551 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2553 if (TREE_CODE (function) == OFFSET_REF)
2554 function = TREE_OPERAND (function, 1);
2556 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2558 tree idx, delta, e1, e2, e3, vtbl, basetype;
2559 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2561 tree instance_ptr = *instance_ptrptr;
2562 tree instance_save_expr = 0;
2563 if (instance_ptr == error_mark_node)
2565 if (TREE_CODE (function) == PTRMEM_CST)
2567 /* Extracting the function address from a pmf is only
2568 allowed with -Wno-pmf-conversions. It only works for
2570 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2571 e1 = convert (fntype, e1);
2576 error ("object missing in use of %qE", function);
2577 return error_mark_node;
2581 if (TREE_SIDE_EFFECTS (instance_ptr))
2582 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2584 if (TREE_SIDE_EFFECTS (function))
2585 function = save_expr (function);
2587 /* Start by extracting all the information from the PMF itself. */
2588 e3 = pfn_from_ptrmemfunc (function);
2589 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2590 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2591 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2593 case ptrmemfunc_vbit_in_pfn:
2594 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2595 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2598 case ptrmemfunc_vbit_in_delta:
2599 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2600 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2607 /* Convert down to the right base before using the instance. A
2608 special case is that in a pointer to member of class C, C may
2609 be incomplete. In that case, the function will of course be
2610 a member of C, and no conversion is required. In fact,
2611 lookup_base will fail in that case, because incomplete
2612 classes do not have BINFOs. */
2613 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2614 if (!same_type_ignoring_top_level_qualifiers_p
2615 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2617 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2618 basetype, ba_check, NULL);
2619 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2621 if (instance_ptr == error_mark_node)
2622 return error_mark_node;
2624 /* ...and then the delta in the PMF. */
2625 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2626 instance_ptr, delta);
2628 /* Hand back the adjusted 'this' argument to our caller. */
2629 *instance_ptrptr = instance_ptr;
2631 /* Next extract the vtable pointer from the object. */
2632 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2634 vtbl = build_indirect_ref (vtbl, NULL);
2636 /* Finally, extract the function pointer from the vtable. */
2637 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2638 e2 = build_indirect_ref (e2, NULL);
2639 TREE_CONSTANT (e2) = 1;
2640 TREE_INVARIANT (e2) = 1;
2642 /* When using function descriptors, the address of the
2643 vtable entry is treated as a function pointer. */
2644 if (TARGET_VTABLE_USES_DESCRIPTORS)
2645 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2646 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2648 TREE_TYPE (e2) = TREE_TYPE (e3);
2649 e1 = build_conditional_expr (e1, e2, e3);
2651 /* Make sure this doesn't get evaluated first inside one of the
2652 branches of the COND_EXPR. */
2653 if (instance_save_expr)
2654 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2655 instance_save_expr, e1);
2663 build_function_call (tree function, tree params)
2665 tree fntype, fndecl;
2666 tree coerced_params;
2667 tree name = NULL_TREE;
2669 tree original = function;
2671 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2672 expressions, like those used for ObjC messenger dispatches. */
2673 function = objc_rewrite_function_call (function, params);
2675 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2676 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2677 if (TREE_CODE (function) == NOP_EXPR
2678 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2679 function = TREE_OPERAND (function, 0);
2681 if (TREE_CODE (function) == FUNCTION_DECL)
2683 name = DECL_NAME (function);
2685 mark_used (function);
2688 /* Convert anything with function type to a pointer-to-function. */
2689 if (pedantic && DECL_MAIN_P (function))
2690 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2692 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2693 (because calling an inline function does not mean the function
2694 needs to be separately compiled). */
2696 if (DECL_INLINE (function))
2697 function = inline_conversion (function);
2699 function = build_addr_func (function);
2705 function = build_addr_func (function);
2708 if (function == error_mark_node)
2709 return error_mark_node;
2711 fntype = TREE_TYPE (function);
2713 if (TYPE_PTRMEMFUNC_P (fntype))
2715 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2716 "function in %<%E (...)%>",
2718 return error_mark_node;
2721 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2722 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2724 if (!((TREE_CODE (fntype) == POINTER_TYPE
2725 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2727 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2729 error ("%qE cannot be used as a function", original);
2730 return error_mark_node;
2733 /* fntype now gets the type of function pointed to. */
2734 fntype = TREE_TYPE (fntype);
2736 /* Convert the parameters to the types declared in the
2737 function prototype, or apply default promotions. */
2739 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2740 params, fndecl, LOOKUP_NORMAL);
2741 if (coerced_params == error_mark_node)
2742 return error_mark_node;
2744 /* Check for errors in format strings and inappropriately
2747 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2748 TYPE_ARG_TYPES (fntype));
2750 return build_cxx_call (function, coerced_params);
2753 /* Convert the actual parameter expressions in the list VALUES
2754 to the types in the list TYPELIST.
2755 If parmdecls is exhausted, or when an element has NULL as its type,
2756 perform the default conversions.
2758 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2760 This is also where warnings about wrong number of args are generated.
2762 Return a list of expressions for the parameters as converted.
2764 Both VALUES and the returned value are chains of TREE_LIST nodes
2765 with the elements of the list in the TREE_VALUE slots of those nodes.
2767 In C++, unspecified trailing parameters can be filled in with their
2768 default arguments, if such were specified. Do so here. */
2771 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2773 tree typetail, valtail;
2774 tree result = NULL_TREE;
2775 const char *called_thing = 0;
2778 /* Argument passing is always copy-initialization. */
2779 flags |= LOOKUP_ONLYCONVERTING;
2783 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2785 if (DECL_NAME (fndecl) == NULL_TREE
2786 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2787 called_thing = "constructor";
2789 called_thing = "member function";
2792 called_thing = "function";
2795 for (valtail = values, typetail = typelist;
2797 valtail = TREE_CHAIN (valtail), i++)
2799 tree type = typetail ? TREE_VALUE (typetail) : 0;
2800 tree val = TREE_VALUE (valtail);
2802 if (val == error_mark_node || type == error_mark_node)
2803 return error_mark_node;
2805 if (type == void_type_node)
2809 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2810 error ("at this point in file");
2813 error ("too many arguments to function");
2814 /* In case anybody wants to know if this argument
2817 TREE_TYPE (tree_last (result)) = error_mark_node;
2821 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2822 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2823 if (TREE_CODE (val) == NOP_EXPR
2824 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2825 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2826 val = TREE_OPERAND (val, 0);
2828 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2830 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2831 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2832 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2833 val = decay_conversion (val);
2836 if (val == error_mark_node)
2837 return error_mark_node;
2841 /* Formal parm type is specified by a function prototype. */
2844 if (!COMPLETE_TYPE_P (complete_type (type)))
2847 error ("parameter %P of %qD has incomplete type %qT",
2850 error ("parameter %P has incomplete type %qT", i, type);
2851 parmval = error_mark_node;
2855 parmval = convert_for_initialization
2856 (NULL_TREE, type, val, flags,
2857 "argument passing", fndecl, i);
2858 parmval = convert_for_arg_passing (type, parmval);
2861 if (parmval == error_mark_node)
2862 return error_mark_node;
2864 result = tree_cons (NULL_TREE, parmval, result);
2868 if (fndecl && DECL_BUILT_IN (fndecl)
2869 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2870 /* Don't do ellipsis conversion for __built_in_constant_p
2871 as this will result in spurious warnings for non-POD
2873 val = require_complete_type (val);
2875 val = convert_arg_to_ellipsis (val);
2877 result = tree_cons (NULL_TREE, val, result);
2881 typetail = TREE_CHAIN (typetail);
2884 if (typetail != 0 && typetail != void_list_node)
2886 /* See if there are default arguments that can be used. */
2887 if (TREE_PURPOSE (typetail)
2888 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2890 for (; typetail != void_list_node; ++i)
2893 = convert_default_arg (TREE_VALUE (typetail),
2894 TREE_PURPOSE (typetail),
2897 if (parmval == error_mark_node)
2898 return error_mark_node;
2900 result = tree_cons (0, parmval, result);
2901 typetail = TREE_CHAIN (typetail);
2902 /* ends with `...'. */
2903 if (typetail == NULL_TREE)
2911 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2912 error ("at this point in file");
2915 error ("too few arguments to function");
2916 return error_mark_node;
2920 return nreverse (result);
2923 /* Build a binary-operation expression, after performing default
2924 conversions on the operands. CODE is the kind of expression to build. */
2927 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2928 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2937 if (processing_template_decl)
2939 if (type_dependent_expression_p (arg1)
2940 || type_dependent_expression_p (arg2))
2941 return build_min_nt (code, arg1, arg2);
2942 arg1 = build_non_dependent_expr (arg1);
2943 arg2 = build_non_dependent_expr (arg2);
2946 if (code == DOTSTAR_EXPR)
2947 expr = build_m_component_ref (arg1, arg2);
2949 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2952 /* Check for cases such as x+y<<z which users are likely to
2953 misinterpret. But don't warn about obj << x + y, since that is a
2954 common idiom for I/O. */
2955 if (warn_parentheses
2956 && !processing_template_decl
2957 && !error_operand_p (arg1)
2958 && !error_operand_p (arg2)
2959 && (code != LSHIFT_EXPR
2960 || !IS_AGGR_TYPE (TREE_TYPE (arg1))))
2961 warn_about_parentheses (code, arg1_code, arg2_code);
2963 if (processing_template_decl && expr != error_mark_node)
2964 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2969 /* Build a binary-operation expression without default conversions.
2970 CODE is the kind of expression to build.
2971 This function differs from `build' in several ways:
2972 the data type of the result is computed and recorded in it,
2973 warnings are generated if arg data types are invalid,
2974 special handling for addition and subtraction of pointers is known,
2975 and some optimization is done (operations on narrow ints
2976 are done in the narrower type when that gives the same result).
2977 Constant folding is also done before the result is returned.
2979 Note that the operands will never have enumeral types
2980 because either they have just had the default conversions performed
2981 or they have both just been converted to some other type in which
2982 the arithmetic is to be done.
2984 C++: must do special pointer arithmetic when implementing
2985 multiple inheritance, and deal with pointer to member functions. */
2988 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2989 int convert_p ATTRIBUTE_UNUSED)
2992 enum tree_code code0, code1;
2994 const char *invalid_op_diag;
2996 /* Expression code to give to the expression when it is built.
2997 Normally this is CODE, which is what the caller asked for,
2998 but in some special cases we change it. */
2999 enum tree_code resultcode = code;
3001 /* Data type in which the computation is to be performed.
3002 In the simplest cases this is the common type of the arguments. */
3003 tree result_type = NULL;
3005 /* Nonzero means operands have already been type-converted
3006 in whatever way is necessary.
3007 Zero means they need to be converted to RESULT_TYPE. */
3010 /* Nonzero means create the expression with this type, rather than
3012 tree build_type = 0;
3014 /* Nonzero means after finally constructing the expression
3015 convert it to this type. */
3016 tree final_type = 0;
3020 /* Nonzero if this is an operation like MIN or MAX which can
3021 safely be computed in short if both args are promoted shorts.
3022 Also implies COMMON.
3023 -1 indicates a bitwise operation; this makes a difference
3024 in the exact conditions for when it is safe to do the operation
3025 in a narrower mode. */
3028 /* Nonzero if this is a comparison operation;
3029 if both args are promoted shorts, compare the original shorts.
3030 Also implies COMMON. */
3031 int short_compare = 0;
3033 /* Nonzero if this is a right-shift operation, which can be computed on the
3034 original short and then promoted if the operand is a promoted short. */
3035 int short_shift = 0;
3037 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3040 /* True if both operands have arithmetic type. */
3041 bool arithmetic_types_p;
3043 /* Apply default conversions. */
3047 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3048 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3049 || code == TRUTH_XOR_EXPR)
3051 if (!really_overloaded_fn (op0))
3052 op0 = decay_conversion (op0);
3053 if (!really_overloaded_fn (op1))
3054 op1 = decay_conversion (op1);
3058 if (!really_overloaded_fn (op0))
3059 op0 = default_conversion (op0);
3060 if (!really_overloaded_fn (op1))
3061 op1 = default_conversion (op1);
3064 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3065 STRIP_TYPE_NOPS (op0);
3066 STRIP_TYPE_NOPS (op1);
3068 /* DTRT if one side is an overloaded function, but complain about it. */
3069 if (type_unknown_p (op0))
3071 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3072 if (t != error_mark_node)
3074 pedwarn ("assuming cast to type %qT from overloaded function",
3079 if (type_unknown_p (op1))
3081 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3082 if (t != error_mark_node)
3084 pedwarn ("assuming cast to type %qT from overloaded function",
3090 type0 = TREE_TYPE (op0);
3091 type1 = TREE_TYPE (op1);
3093 /* The expression codes of the data types of the arguments tell us
3094 whether the arguments are integers, floating, pointers, etc. */
3095 code0 = TREE_CODE (type0);
3096 code1 = TREE_CODE (type1);
3098 /* If an error was already reported for one of the arguments,
3099 avoid reporting another error. */
3101 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3102 return error_mark_node;
3104 if ((invalid_op_diag
3105 = targetm.invalid_binary_op (code, type0, type1)))
3107 error (invalid_op_diag);
3108 return error_mark_node;
3114 /* Subtraction of two similar pointers.
3115 We must subtract them as integers, then divide by object size. */
3116 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3117 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3119 return pointer_diff (op0, op1, common_type (type0, type1));
3120 /* In all other cases except pointer - int, the usual arithmetic
3122 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3127 /* The pointer - int case is just like pointer + int; fall
3130 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3131 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3135 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3136 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3137 if (processing_template_decl)
3139 result_type = TREE_TYPE (ptr_operand);
3142 return cp_pointer_int_sum (code,
3153 case TRUNC_DIV_EXPR:
3155 case FLOOR_DIV_EXPR:
3156 case ROUND_DIV_EXPR:
3157 case EXACT_DIV_EXPR:
3158 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3159 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3160 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3161 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3163 enum tree_code tcode0 = code0, tcode1 = code1;
3165 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3166 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3167 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3168 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3170 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3171 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3172 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3173 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3175 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3176 resultcode = RDIV_EXPR;
3178 /* When dividing two signed integers, we have to promote to int.
3179 unless we divide by a constant != -1. Note that default
3180 conversion will have been performed on the operands at this
3181 point, so we have to dig out the original type to find out if
3183 shorten = ((TREE_CODE (op0) == NOP_EXPR
3184 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3185 || (TREE_CODE (op1) == INTEGER_CST
3186 && ! integer_all_onesp (op1)));
3195 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3196 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3200 case TRUNC_MOD_EXPR:
3201 case FLOOR_MOD_EXPR:
3202 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3203 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3204 else if (code1 == REAL_TYPE && real_zerop (op1))
3205 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3207 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3209 /* Although it would be tempting to shorten always here, that loses
3210 on some targets, since the modulo instruction is undefined if the
3211 quotient can't be represented in the computation mode. We shorten
3212 only if unsigned or if dividing by something we know != -1. */
3213 shorten = ((TREE_CODE (op0) == NOP_EXPR
3214 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3215 || (TREE_CODE (op1) == INTEGER_CST
3216 && ! integer_all_onesp (op1)));
3221 case TRUTH_ANDIF_EXPR:
3222 case TRUTH_ORIF_EXPR:
3223 case TRUTH_AND_EXPR:
3225 result_type = boolean_type_node;
3228 /* Shift operations: result has same type as first operand;
3229 always convert second operand to int.
3230 Also set SHORT_SHIFT if shifting rightward. */
3233 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3235 result_type = type0;
3236 if (TREE_CODE (op1) == INTEGER_CST)
3238 if (tree_int_cst_lt (op1, integer_zero_node))
3239 warning (0, "right shift count is negative");
3242 if (! integer_zerop (op1))
3244 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3245 warning (0, "right shift count >= width of type");
3248 /* Convert the shift-count to an integer, regardless of
3249 size of value being shifted. */
3250 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3251 op1 = cp_convert (integer_type_node, op1);
3252 /* Avoid converting op1 to result_type later. */
3258 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3260 result_type = type0;
3261 if (TREE_CODE (op1) == INTEGER_CST)
3263 if (tree_int_cst_lt (op1, integer_zero_node))
3264 warning (0, "left shift count is negative");
3265 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3266 warning (0, "left shift count >= width of type");
3268 /* Convert the shift-count to an integer, regardless of
3269 size of value being shifted. */
3270 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3271 op1 = cp_convert (integer_type_node, op1);
3272 /* Avoid converting op1 to result_type later. */
3279 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3281 result_type = type0;
3282 if (TREE_CODE (op1) == INTEGER_CST)
3284 if (tree_int_cst_lt (op1, integer_zero_node))
3285 warning (0, "%s rotate count is negative",
3286 (code == LROTATE_EXPR) ? "left" : "right");
3287 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3288 warning (0, "%s rotate count >= width of type",
3289 (code == LROTATE_EXPR) ? "left" : "right");
3291 /* Convert the shift-count to an integer, regardless of
3292 size of value being shifted. */
3293 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3294 op1 = cp_convert (integer_type_node, op1);
3300 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3301 warning (OPT_Wfloat_equal,
3302 "comparing floating point with == or != is unsafe");
3303 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3304 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3305 warning (OPT_Waddress,
3306 "comparison with string literal results in unspecified behaviour");
3308 build_type = boolean_type_node;
3309 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3310 || code0 == COMPLEX_TYPE)
3311 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3312 || code1 == COMPLEX_TYPE))
3314 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3315 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3316 result_type = composite_pointer_type (type0, type1, op0, op1,
3318 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3319 && null_ptr_cst_p (op1))
3320 result_type = type0;
3321 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3322 && null_ptr_cst_p (op0))
3323 result_type = type1;
3324 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3326 result_type = type0;
3327 error ("ISO C++ forbids comparison between pointer and integer");
3329 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3331 result_type = type1;
3332 error ("ISO C++ forbids comparison between pointer and integer");
3334 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3336 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3337 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3338 result_type = TREE_TYPE (op0);
3340 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3341 return cp_build_binary_op (code, op1, op0);
3342 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3343 && same_type_p (type0, type1))
3345 /* E will be the final comparison. */
3347 /* E1 and E2 are for scratch. */
3355 if (TREE_SIDE_EFFECTS (op0))
3356 op0 = save_expr (op0);
3357 if (TREE_SIDE_EFFECTS (op1))
3358 op1 = save_expr (op1);
3363 && (!op0.pfn || op0.delta == op1.delta))
3365 The reason for the `!op0.pfn' bit is that a NULL
3366 pointer-to-member is any member with a zero PFN; the
3367 DELTA field is unspecified. */
3368 pfn0 = pfn_from_ptrmemfunc (op0);
3369 pfn1 = pfn_from_ptrmemfunc (op1);
3370 delta0 = build_ptrmemfunc_access_expr (op0,
3372 delta1 = build_ptrmemfunc_access_expr (op1,
3374 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3375 e2 = cp_build_binary_op (EQ_EXPR,
3377 cp_convert (TREE_TYPE (pfn0),
3378 integer_zero_node));
3379 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3380 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3381 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3382 if (code == EQ_EXPR)
3384 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3388 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3389 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3391 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3392 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3400 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3401 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3403 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3404 result_type = composite_pointer_type (type0, type1, op0, op1,
3412 if (TREE_CODE (orig_op0) == STRING_CST
3413 || TREE_CODE (orig_op1) == STRING_CST)
3414 warning (OPT_Waddress,
3415 "comparison with string literal results in unspecified behaviour");
3417 build_type = boolean_type_node;
3418 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3419 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3421 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3422 result_type = composite_pointer_type (type0, type1, op0, op1,
3424 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3425 && integer_zerop (op1))
3426 result_type = type0;
3427 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3428 && integer_zerop (op0))
3429 result_type = type1;
3430 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3432 result_type = type0;
3433 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3435 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3437 result_type = type1;
3438 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3442 case UNORDERED_EXPR:
3449 build_type = integer_type_node;
3450 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3452 error ("unordered comparison on non-floating point argument");
3453 return error_mark_node;
3462 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3463 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3464 || code1 == COMPLEX_TYPE)))
3465 arithmetic_types_p = 1;
3468 arithmetic_types_p = 0;
3469 /* Vector arithmetic is only allowed when both sides are vectors. */
3470 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3472 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3473 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3476 binary_op_error (code);
3477 return error_mark_node;
3479 arithmetic_types_p = 1;
3482 /* Determine the RESULT_TYPE, if it is not already known. */
3484 && arithmetic_types_p
3485 && (shorten || common || short_compare))
3486 result_type = common_type (type0, type1);
3490 error ("invalid operands of types %qT and %qT to binary %qO",
3491 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3492 return error_mark_node;
3495 /* If we're in a template, the only thing we need to know is the
3497 if (processing_template_decl)
3498 return build2 (resultcode,
3499 build_type ? build_type : result_type,
3502 if (arithmetic_types_p)
3504 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3506 /* For certain operations (which identify themselves by shorten != 0)
3507 if both args were extended from the same smaller type,
3508 do the arithmetic in that type and then extend.
3510 shorten !=0 and !=1 indicates a bitwise operation.
3511 For them, this optimization is safe only if
3512 both args are zero-extended or both are sign-extended.
3513 Otherwise, we might change the result.
3514 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3515 but calculated in (unsigned short) it would be (unsigned short)-1. */
3517 if (shorten && none_complex)
3519 int unsigned0, unsigned1;
3520 tree arg0 = get_narrower (op0, &unsigned0);
3521 tree arg1 = get_narrower (op1, &unsigned1);
3522 /* UNS is 1 if the operation to be done is an unsigned one. */
3523 int uns = TYPE_UNSIGNED (result_type);
3526 final_type = result_type;
3528 /* Handle the case that OP0 does not *contain* a conversion
3529 but it *requires* conversion to FINAL_TYPE. */
3531 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3532 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3533 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3534 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3536 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3538 /* For bitwise operations, signedness of nominal type
3539 does not matter. Consider only how operands were extended. */
3543 /* Note that in all three cases below we refrain from optimizing
3544 an unsigned operation on sign-extended args.
3545 That would not be valid. */
3547 /* Both args variable: if both extended in same way
3548 from same width, do it in that width.
3549 Do it unsigned if args were zero-extended. */
3550 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3551 < TYPE_PRECISION (result_type))
3552 && (TYPE_PRECISION (TREE_TYPE (arg1))
3553 == TYPE_PRECISION (TREE_TYPE (arg0)))
3554 && unsigned0 == unsigned1
3555 && (unsigned0 || !uns))
3556 result_type = c_common_signed_or_unsigned_type
3557 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3558 else if (TREE_CODE (arg0) == INTEGER_CST
3559 && (unsigned1 || !uns)
3560 && (TYPE_PRECISION (TREE_TYPE (arg1))
3561 < TYPE_PRECISION (result_type))
3562 && (type = c_common_signed_or_unsigned_type
3563 (unsigned1, TREE_TYPE (arg1)),
3564 int_fits_type_p (arg0, type)))
3566 else if (TREE_CODE (arg1) == INTEGER_CST
3567 && (unsigned0 || !uns)
3568 && (TYPE_PRECISION (TREE_TYPE (arg0))
3569 < TYPE_PRECISION (result_type))
3570 && (type = c_common_signed_or_unsigned_type
3571 (unsigned0, TREE_TYPE (arg0)),
3572 int_fits_type_p (arg1, type)))
3576 /* Shifts can be shortened if shifting right. */
3581 tree arg0 = get_narrower (op0, &unsigned_arg);
3583 final_type = result_type;
3585 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3586 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3588 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3589 /* We can shorten only if the shift count is less than the
3590 number of bits in the smaller type size. */
3591 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3592 /* If arg is sign-extended and then unsigned-shifted,
3593 we can simulate this with a signed shift in arg's type
3594 only if the extended result is at least twice as wide
3595 as the arg. Otherwise, the shift could use up all the
3596 ones made by sign-extension and bring in zeros.
3597 We can't optimize that case at all, but in most machines
3598 it never happens because available widths are 2**N. */
3599 && (!TYPE_UNSIGNED (final_type)
3601 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3602 <= TYPE_PRECISION (result_type))))
3604 /* Do an unsigned shift if the operand was zero-extended. */
3606 = c_common_signed_or_unsigned_type (unsigned_arg,
3608 /* Convert value-to-be-shifted to that type. */
3609 if (TREE_TYPE (op0) != result_type)
3610 op0 = cp_convert (result_type, op0);
3615 /* Comparison operations are shortened too but differently.
3616 They identify themselves by setting short_compare = 1. */
3620 /* Don't write &op0, etc., because that would prevent op0
3621 from being kept in a register.
3622 Instead, make copies of the our local variables and
3623 pass the copies by reference, then copy them back afterward. */
3624 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3625 enum tree_code xresultcode = resultcode;
3627 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3629 return cp_convert (boolean_type_node, val);
3630 op0 = xop0, op1 = xop1;
3632 resultcode = xresultcode;
3635 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3636 && warn_sign_compare
3637 /* Do not warn until the template is instantiated; we cannot
3638 bound the ranges of the arguments until that point. */
3639 && !processing_template_decl)
3641 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3642 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3644 int unsignedp0, unsignedp1;
3645 tree primop0 = get_narrower (op0, &unsignedp0);
3646 tree primop1 = get_narrower (op1, &unsignedp1);
3648 /* Check for comparison of different enum types. */
3649 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3650 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3651 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3652 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3654 warning (0, "comparison between types %q#T and %q#T",
3655 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3658 /* Give warnings for comparisons between signed and unsigned
3659 quantities that may fail. */
3660 /* Do the checking based on the original operand trees, so that
3661 casts will be considered, but default promotions won't be. */
3663 /* Do not warn if the comparison is being done in a signed type,
3664 since the signed type will only be chosen if it can represent
3665 all the values of the unsigned type. */
3666 if (!TYPE_UNSIGNED (result_type))
3668 /* Do not warn if both operands are unsigned. */
3669 else if (op0_signed == op1_signed)
3671 /* Do not warn if the signed quantity is an unsuffixed
3672 integer literal (or some static constant expression
3673 involving such literals or a conditional expression
3674 involving such literals) and it is non-negative. */
3675 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3676 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3678 /* Do not warn if the comparison is an equality operation,
3679 the unsigned quantity is an integral constant and it does
3680 not use the most significant bit of result_type. */
3681 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3682 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3683 && int_fits_type_p (orig_op1, c_common_signed_type
3685 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3686 && int_fits_type_p (orig_op0, c_common_signed_type
3690 warning (0, "comparison between signed and unsigned integer expressions");
3692 /* Warn if two unsigned values are being compared in a size
3693 larger than their original size, and one (and only one) is the
3694 result of a `~' operator. This comparison will always fail.
3696 Also warn if one operand is a constant, and the constant does not
3697 have all bits set that are set in the ~ operand when it is
3700 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3701 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3703 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3704 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3705 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3706 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3708 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3711 HOST_WIDE_INT constant, mask;
3715 if (host_integerp (primop0, 0))
3718 unsignedp = unsignedp1;
3719 constant = tree_low_cst (primop0, 0);
3724 unsignedp = unsignedp0;
3725 constant = tree_low_cst (primop1, 0);
3728 bits = TYPE_PRECISION (TREE_TYPE (primop));
3729 if (bits < TYPE_PRECISION (result_type)
3730 && bits < HOST_BITS_PER_LONG && unsignedp)
3732 mask = (~ (HOST_WIDE_INT) 0) << bits;
3733 if ((mask & constant) != mask)
3734 warning (0, "comparison of promoted ~unsigned with constant");
3737 else if (unsignedp0 && unsignedp1
3738 && (TYPE_PRECISION (TREE_TYPE (primop0))
3739 < TYPE_PRECISION (result_type))
3740 && (TYPE_PRECISION (TREE_TYPE (primop1))
3741 < TYPE_PRECISION (result_type)))
3742 warning (0, "comparison of promoted ~unsigned with unsigned");
3747 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3748 Then the expression will be built.
3749 It will be given type FINAL_TYPE if that is nonzero;
3750 otherwise, it will be given type RESULT_TYPE. */
3752 /* Issue warnings about peculiar, but valid, uses of NULL. */
3753 if (/* It's reasonable to use pointer values as operands of &&
3754 and ||, so NULL is no exception. */
3755 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3756 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3757 (orig_op0 == null_node
3758 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3759 /* Or vice versa. */
3760 || (orig_op1 == null_node
3761 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3762 /* Or, both are NULL and the operation was not a comparison. */
3763 || (orig_op0 == null_node && orig_op1 == null_node
3764 && code != EQ_EXPR && code != NE_EXPR)))
3765 /* Some sort of arithmetic operation involving NULL was
3766 performed. Note that pointer-difference and pointer-addition
3767 have already been handled above, and so we don't end up here in
3769 warning (0, "NULL used in arithmetic");
3773 if (TREE_TYPE (op0) != result_type)
3774 op0 = cp_convert (result_type, op0);
3775 if (TREE_TYPE (op1) != result_type)
3776 op1 = cp_convert (result_type, op1);
3778 if (op0 == error_mark_node || op1 == error_mark_node)
3779 return error_mark_node;
3782 if (build_type == NULL_TREE)
3783 build_type = result_type;
3785 result = build2 (resultcode, build_type, op0, op1);
3786 result = fold_if_not_in_template (result);
3787 if (final_type != 0)
3788 result = cp_convert (final_type, result);
3790 if (TREE_OVERFLOW_P (result)
3791 && !TREE_OVERFLOW_P (op0)
3792 && !TREE_OVERFLOW_P (op1))
3793 overflow_warning (result);
3798 /* Return a tree for the sum or difference (RESULTCODE says which)
3799 of pointer PTROP and integer INTOP. */
3802 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3804 tree res_type = TREE_TYPE (ptrop);
3806 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3807 in certain circumstance (when it's valid to do so). So we need
3808 to make sure it's complete. We don't need to check here, if we
3809 can actually complete it at all, as those checks will be done in
3810 pointer_int_sum() anyway. */
3811 complete_type (TREE_TYPE (res_type));
3813 return pointer_int_sum (resultcode, ptrop,
3814 fold_if_not_in_template (intop));
3817 /* Return a tree for the difference of pointers OP0 and OP1.
3818 The resulting tree has type int. */
3821 pointer_diff (tree op0, tree op1, tree ptrtype)
3824 tree restype = ptrdiff_type_node;
3825 tree target_type = TREE_TYPE (ptrtype);
3827 if (!complete_type_or_else (target_type, NULL_TREE))
3828 return error_mark_node;
3830 if (pedantic || warn_pointer_arith)
3832 if (TREE_CODE (target_type) == VOID_TYPE)
3833 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3834 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3835 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3836 if (TREE_CODE (target_type) == METHOD_TYPE)
3837 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3840 /* First do the subtraction as integers;
3841 then drop through to build the divide operator. */
3843 op0 = cp_build_binary_op (MINUS_EXPR,
3844 cp_convert (restype, op0),
3845 cp_convert (restype, op1));
3847 /* This generates an error if op1 is a pointer to an incomplete type. */
3848 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3849 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3851 op1 = (TYPE_PTROB_P (ptrtype)
3852 ? size_in_bytes (target_type)
3853 : integer_one_node);
3855 /* Do the division. */
3857 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3858 return fold_if_not_in_template (result);
3861 /* Construct and perhaps optimize a tree representation
3862 for a unary operation. CODE, a tree_code, specifies the operation
3863 and XARG is the operand. */
3866 build_x_unary_op (enum tree_code code, tree xarg)
3868 tree orig_expr = xarg;
3872 if (processing_template_decl)
3874 if (type_dependent_expression_p (xarg))
3875 return build_min_nt (code, xarg, NULL_TREE);
3877 xarg = build_non_dependent_expr (xarg);
3882 /* [expr.unary.op] says:
3884 The address of an object of incomplete type can be taken.
3886 (And is just the ordinary address operator, not an overloaded
3887 "operator &".) However, if the type is a template
3888 specialization, we must complete the type at this point so that
3889 an overloaded "operator &" will be available if required. */
3890 if (code == ADDR_EXPR
3891 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3892 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3893 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3894 || (TREE_CODE (xarg) == OFFSET_REF)))
3895 /* Don't look for a function. */;
3897 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3898 /*overloaded_p=*/NULL);
3899 if (!exp && code == ADDR_EXPR)
3901 /* A pointer to member-function can be formed only by saying
3903 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3904 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3906 if (TREE_CODE (xarg) != OFFSET_REF
3907 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3909 error ("invalid use of %qE to form a pointer-to-member-function",
3911 if (TREE_CODE (xarg) != OFFSET_REF)
3912 inform (" a qualified-id is required");
3913 return error_mark_node;
3917 error ("parentheses around %qE cannot be used to form a"
3918 " pointer-to-member-function",
3920 PTRMEM_OK_P (xarg) = 1;
3924 if (TREE_CODE (xarg) == OFFSET_REF)
3926 ptrmem = PTRMEM_OK_P (xarg);
3928 if (!ptrmem && !flag_ms_extensions
3929 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3931 /* A single non-static member, make sure we don't allow a
3932 pointer-to-member. */
3933 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3934 TREE_OPERAND (xarg, 0),
3935 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3936 PTRMEM_OK_P (xarg) = ptrmem;
3939 else if (TREE_CODE (xarg) == TARGET_EXPR)
3940 warning (0, "taking address of temporary");
3941 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3944 if (processing_template_decl && exp != error_mark_node)
3945 exp = build_min_non_dep (code, exp, orig_expr,
3946 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3947 if (TREE_CODE (exp) == ADDR_EXPR)
3948 PTRMEM_OK_P (exp) = ptrmem;
3952 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3953 constants, where a null value is represented by an INTEGER_CST of
3957 cp_truthvalue_conversion (tree expr)
3959 tree type = TREE_TYPE (expr);
3960 if (TYPE_PTRMEM_P (type))
3961 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3963 return c_common_truthvalue_conversion (expr);
3966 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3969 condition_conversion (tree expr)
3972 if (processing_template_decl)
3974 t = perform_implicit_conversion (boolean_type_node, expr);
3975 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3979 /* Return an ADDR_EXPR giving the address of T. This function
3980 attempts no optimizations or simplifications; it is a low-level
3984 build_address (tree t)
3988 if (error_operand_p (t) || !cxx_mark_addressable (t))
3989 return error_mark_node;
3991 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3996 /* Return a NOP_EXPR converting EXPR to TYPE. */
3999 build_nop (tree type, tree expr)
4001 if (type == error_mark_node || error_operand_p (expr))
4003 return build1 (NOP_EXPR, type, expr);
4006 /* C++: Must handle pointers to members.
4008 Perhaps type instantiation should be extended to handle conversion
4009 from aggregates to types we don't yet know we want? (Or are those
4010 cases typically errors which should be reported?)
4012 NOCONVERT nonzero suppresses the default promotions
4013 (such as from short to int). */
4016 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4018 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4021 const char *errstring = NULL;
4023 const char *invalid_op_diag;
4025 if (arg == error_mark_node)
4026 return error_mark_node;
4028 if ((invalid_op_diag
4029 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4034 error (invalid_op_diag);
4035 return error_mark_node;
4040 case UNARY_PLUS_EXPR:
4043 int flags = WANT_ARITH | WANT_ENUM;
4044 /* Unary plus (but not unary minus) is allowed on pointers. */
4045 if (code == UNARY_PLUS_EXPR)
4046 flags |= WANT_POINTER;
4047 arg = build_expr_type_conversion (flags, arg, true);
4049 errstring = (code == NEGATE_EXPR
4050 ? "wrong type argument to unary minus"
4051 : "wrong type argument to unary plus");
4054 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4055 arg = perform_integral_promotions (arg);
4057 /* Make sure the result is not an lvalue: a unary plus or minus
4058 expression is always a rvalue. */
4065 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4069 arg = default_conversion (arg);
4071 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4074 errstring = "wrong type argument to bit-complement";
4075 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4076 arg = perform_integral_promotions (arg);
4080 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4081 errstring = "wrong type argument to abs";
4082 else if (!noconvert)
4083 arg = default_conversion (arg);
4087 /* Conjugating a real value is a no-op, but allow it anyway. */
4088 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4089 errstring = "wrong type argument to conjugation";
4090 else if (!noconvert)
4091 arg = default_conversion (arg);
4094 case TRUTH_NOT_EXPR:
4095 arg = perform_implicit_conversion (boolean_type_node, arg);
4096 val = invert_truthvalue (arg);
4097 if (arg != error_mark_node)
4099 errstring = "in argument to unary !";
4106 if (TREE_CODE (arg) == COMPLEX_CST)
4107 return TREE_REALPART (arg);
4108 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4110 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4111 return fold_if_not_in_template (arg);
4117 if (TREE_CODE (arg) == COMPLEX_CST)
4118 return TREE_IMAGPART (arg);
4119 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4121 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4122 return fold_if_not_in_template (arg);
4125 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4127 case PREINCREMENT_EXPR:
4128 case POSTINCREMENT_EXPR:
4129 case PREDECREMENT_EXPR:
4130 case POSTDECREMENT_EXPR:
4131 /* Handle complex lvalues (when permitted)
4132 by reduction to simpler cases. */
4134 val = unary_complex_lvalue (code, arg);
4138 /* Increment or decrement the real part of the value,
4139 and don't change the imaginary part. */
4140 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4144 arg = stabilize_reference (arg);
4145 real = build_unary_op (REALPART_EXPR, arg, 1);
4146 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4147 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4148 build_unary_op (code, real, 1), imag);
4151 /* Report invalid types. */
4153 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4156 if (code == PREINCREMENT_EXPR)
4157 errstring ="no pre-increment operator for type";
4158 else if (code == POSTINCREMENT_EXPR)
4159 errstring ="no post-increment operator for type";
4160 else if (code == PREDECREMENT_EXPR)
4161 errstring ="no pre-decrement operator for type";
4163 errstring ="no post-decrement operator for type";
4167 /* Report something read-only. */
4169 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4170 || TREE_READONLY (arg))
4171 readonly_error (arg, ((code == PREINCREMENT_EXPR
4172 || code == POSTINCREMENT_EXPR)
4173 ? "increment" : "decrement"),
4179 tree result_type = TREE_TYPE (arg);
4181 declared_type = unlowered_expr_type (arg);
4183 arg = get_unwidened (arg, 0);
4184 argtype = TREE_TYPE (arg);
4186 /* ARM $5.2.5 last annotation says this should be forbidden. */
4187 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4188 pedwarn ("ISO C++ forbids %sing an enum",
4189 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4190 ? "increment" : "decrement");
4192 /* Compute the increment. */
4194 if (TREE_CODE (argtype) == POINTER_TYPE)
4196 tree type = complete_type (TREE_TYPE (argtype));
4198 if (!COMPLETE_OR_VOID_TYPE_P (type))
4199 error ("cannot %s a pointer to incomplete type %qT",
4200 ((code == PREINCREMENT_EXPR
4201 || code == POSTINCREMENT_EXPR)
4202 ? "increment" : "decrement"), TREE_TYPE (argtype));
4203 else if ((pedantic || warn_pointer_arith)
4204 && !TYPE_PTROB_P (argtype))
4205 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
4206 ((code == PREINCREMENT_EXPR
4207 || code == POSTINCREMENT_EXPR)
4208 ? "increment" : "decrement"), argtype);
4209 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4212 inc = integer_one_node;
4214 inc = cp_convert (argtype, inc);
4216 /* Handle incrementing a cast-expression. */
4218 switch (TREE_CODE (arg))
4223 case FIX_TRUNC_EXPR:
4224 case FIX_FLOOR_EXPR:
4225 case FIX_ROUND_EXPR:
4228 tree incremented, modify, value, compound;
4229 if (! lvalue_p (arg) && pedantic)
4230 pedwarn ("cast to non-reference type used as lvalue");
4231 arg = stabilize_reference (arg);
4232 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4235 value = save_expr (arg);
4236 incremented = build2 (((code == PREINCREMENT_EXPR
4237 || code == POSTINCREMENT_EXPR)
4238 ? PLUS_EXPR : MINUS_EXPR),
4239 argtype, value, inc);
4241 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4242 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4245 /* Eliminate warning about unused result of + or -. */
4246 TREE_NO_WARNING (compound) = 1;
4254 /* Complain about anything else that is not a true lvalue. */
4255 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4256 || code == POSTINCREMENT_EXPR)
4257 ? lv_increment : lv_decrement)))
4258 return error_mark_node;
4260 /* Forbid using -- on `bool'. */
4261 if (same_type_p (declared_type, boolean_type_node))
4263 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4265 error ("invalid use of %<--%> on bool variable %qD", arg);
4266 return error_mark_node;
4268 val = boolean_increment (code, arg);
4271 val = build2 (code, TREE_TYPE (arg), arg, inc);
4273 TREE_SIDE_EFFECTS (val) = 1;
4274 return cp_convert (result_type, val);
4278 /* Note that this operation never does default_conversion
4279 regardless of NOCONVERT. */
4281 argtype = lvalue_type (arg);
4283 if (TREE_CODE (arg) == OFFSET_REF)
4286 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4288 tree type = build_pointer_type (TREE_TYPE (argtype));
4289 arg = build1 (CONVERT_EXPR, type, arg);
4292 else if (pedantic && DECL_MAIN_P (arg))
4294 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4296 /* Let &* cancel out to simplify resulting code. */
4297 if (TREE_CODE (arg) == INDIRECT_REF)
4299 /* We don't need to have `current_class_ptr' wrapped in a
4300 NON_LVALUE_EXPR node. */
4301 if (arg == current_class_ref)
4302 return current_class_ptr;
4304 arg = TREE_OPERAND (arg, 0);
4305 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4307 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4308 arg = build1 (CONVERT_EXPR, type, arg);
4311 /* Don't let this be an lvalue. */
4316 /* Uninstantiated types are all functions. Taking the
4317 address of a function is a no-op, so just return the
4320 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4321 || !IDENTIFIER_OPNAME_P (arg));
4323 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4324 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4326 /* They're trying to take the address of a unique non-static
4327 member function. This is ill-formed (except in MS-land),
4328 but let's try to DTRT.
4329 Note: We only handle unique functions here because we don't
4330 want to complain if there's a static overload; non-unique
4331 cases will be handled by instantiate_type. But we need to
4332 handle this case here to allow casts on the resulting PMF.
4333 We could defer this in non-MS mode, but it's easier to give
4334 a useful error here. */
4336 /* Inside constant member functions, the `this' pointer
4337 contains an extra const qualifier. TYPE_MAIN_VARIANT
4338 is used here to remove this const from the diagnostics
4339 and the created OFFSET_REF. */
4340 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4341 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4344 if (! flag_ms_extensions)
4346 tree name = DECL_NAME (fn);
4347 if (current_class_type
4348 && TREE_OPERAND (arg, 0) == current_class_ref)
4349 /* An expression like &memfn. */
4350 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4351 " or parenthesized non-static member function to form"
4352 " a pointer to member function. Say %<&%T::%D%>",
4355 pedwarn ("ISO C++ forbids taking the address of a bound member"
4356 " function to form a pointer to member function."
4360 arg = build_offset_ref (base, fn, /*address_p=*/true);
4364 if (type_unknown_p (arg))
4365 return build1 (ADDR_EXPR, unknown_type_node, arg);
4367 /* Handle complex lvalues (when permitted)
4368 by reduction to simpler cases. */
4369 val = unary_complex_lvalue (code, arg);
4373 switch (TREE_CODE (arg))
4378 case FIX_TRUNC_EXPR:
4379 case FIX_FLOOR_EXPR:
4380 case FIX_ROUND_EXPR:
4382 if (! lvalue_p (arg) && pedantic)
4383 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4387 arg = BASELINK_FUNCTIONS (arg);
4391 arg = OVL_CURRENT (arg);
4395 /* Turn a reference to a non-static data member into a
4396 pointer-to-member. */
4401 if (!PTRMEM_OK_P (arg))
4402 return build_unary_op (code, arg, 0);
4404 t = TREE_OPERAND (arg, 1);
4405 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4407 error ("cannot create pointer to reference member %qD", t);
4408 return error_mark_node;
4411 type = build_ptrmem_type (context_for_name_lookup (t),
4413 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4421 /* Anything not already handled and not a true memory reference
4423 if (TREE_CODE (argtype) != FUNCTION_TYPE
4424 && TREE_CODE (argtype) != METHOD_TYPE
4425 && TREE_CODE (arg) != OFFSET_REF
4426 && !lvalue_or_else (arg, lv_addressof))
4427 return error_mark_node;
4429 if (argtype != error_mark_node)
4430 argtype = build_pointer_type (argtype);
4432 /* In a template, we are processing a non-dependent expression
4433 so we can just form an ADDR_EXPR with the correct type. */
4434 if (processing_template_decl)
4436 val = build_address (arg);
4437 if (TREE_CODE (arg) == OFFSET_REF)
4438 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4442 if (TREE_CODE (arg) != COMPONENT_REF)
4444 val = build_address (arg);
4445 if (TREE_CODE (arg) == OFFSET_REF)
4446 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4448 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4450 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4452 /* We can only get here with a single static member
4454 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4455 && DECL_STATIC_FUNCTION_P (fn));
4457 val = build_address (fn);
4458 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4459 /* Do not lose object's side effects. */
4460 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4461 TREE_OPERAND (arg, 0), val);
4463 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4465 error ("attempt to take address of bit-field structure member %qD",
4466 TREE_OPERAND (arg, 1));
4467 return error_mark_node;
4471 tree object = TREE_OPERAND (arg, 0);
4472 tree field = TREE_OPERAND (arg, 1);
4473 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4474 (TREE_TYPE (object), decl_type_context (field)));
4475 val = build_address (arg);
4478 if (TREE_CODE (argtype) == POINTER_TYPE
4479 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4481 build_ptrmemfunc_type (argtype);
4482 val = build_ptrmemfunc (argtype, val, 0,
4483 /*c_cast_p=*/false);
4495 argtype = TREE_TYPE (arg);
4496 return fold_if_not_in_template (build1 (code, argtype, arg));
4499 error ("%s", errstring);
4500 return error_mark_node;
4503 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4504 for certain kinds of expressions which are not really lvalues
4505 but which we can accept as lvalues.
4507 If ARG is not a kind of expression we can handle, return
4511 unary_complex_lvalue (enum tree_code code, tree arg)
4513 /* Inside a template, making these kinds of adjustments is
4514 pointless; we are only concerned with the type of the
4516 if (processing_template_decl)
4519 /* Handle (a, b) used as an "lvalue". */
4520 if (TREE_CODE (arg) == COMPOUND_EXPR)
4522 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4523 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4524 TREE_OPERAND (arg, 0), real_result);
4527 /* Handle (a ? b : c) used as an "lvalue". */
4528 if (TREE_CODE (arg) == COND_EXPR
4529 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4530 return rationalize_conditional_expr (code, arg);
4532 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4533 if (TREE_CODE (arg) == MODIFY_EXPR
4534 || TREE_CODE (arg) == PREINCREMENT_EXPR
4535 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4537 tree lvalue = TREE_OPERAND (arg, 0);
4538 if (TREE_SIDE_EFFECTS (lvalue))
4540 lvalue = stabilize_reference (lvalue);
4541 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4542 lvalue, TREE_OPERAND (arg, 1));
4544 return unary_complex_lvalue
4545 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4548 if (code != ADDR_EXPR)
4551 /* Handle (a = b) used as an "lvalue" for `&'. */
4552 if (TREE_CODE (arg) == MODIFY_EXPR
4553 || TREE_CODE (arg) == INIT_EXPR)
4555 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4556 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4558 TREE_NO_WARNING (arg) = 1;
4562 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4563 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4564 || TREE_CODE (arg) == OFFSET_REF)
4567 /* We permit compiler to make function calls returning
4568 objects of aggregate type look like lvalues. */
4572 if (TREE_CODE (targ) == SAVE_EXPR)
4573 targ = TREE_OPERAND (targ, 0);
4575 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4577 if (TREE_CODE (arg) == SAVE_EXPR)
4580 targ = build_cplus_new (TREE_TYPE (arg), arg);
4581 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4584 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4585 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4586 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4589 /* Don't let anything else be handled specially. */
4593 /* Mark EXP saying that we need to be able to take the
4594 address of it; it should not be allocated in a register.
4595 Value is true if successful.
4597 C++: we do not allow `current_class_ptr' to be addressable. */
4600 cxx_mark_addressable (tree exp)
4605 switch (TREE_CODE (x))
4612 x = TREE_OPERAND (x, 0);
4616 if (x == current_class_ptr)
4618 error ("cannot take the address of %<this%>, which is an rvalue expression");
4619 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4625 /* Caller should not be trying to mark initialized
4626 constant fields addressable. */
4627 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4628 || DECL_IN_AGGR_P (x) == 0
4630 || DECL_EXTERNAL (x));
4635 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4636 && !DECL_ARTIFICIAL (x))
4638 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4641 ("address of explicit register variable %qD requested", x);
4644 else if (extra_warnings)
4646 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4648 TREE_ADDRESSABLE (x) = 1;
4652 TREE_ADDRESSABLE (x) = 1;
4656 TREE_ADDRESSABLE (x) = 1;
4660 TREE_ADDRESSABLE (x) = 1;
4661 cxx_mark_addressable (TREE_OPERAND (x, 0));
4669 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4672 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4674 tree orig_ifexp = ifexp;
4675 tree orig_op1 = op1;
4676 tree orig_op2 = op2;
4679 if (processing_template_decl)
4681 /* The standard says that the expression is type-dependent if
4682 IFEXP is type-dependent, even though the eventual type of the
4683 expression doesn't dependent on IFEXP. */
4684 if (type_dependent_expression_p (ifexp)
4685 /* As a GNU extension, the middle operand may be omitted. */
4686 || (op1 && type_dependent_expression_p (op1))
4687 || type_dependent_expression_p (op2))
4688 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4689 ifexp = build_non_dependent_expr (ifexp);
4691 op1 = build_non_dependent_expr (op1);
4692 op2 = build_non_dependent_expr (op2);
4695 expr = build_conditional_expr (ifexp, op1, op2);
4696 if (processing_template_decl && expr != error_mark_node)
4697 return build_min_non_dep (COND_EXPR, expr,
4698 orig_ifexp, orig_op1, orig_op2);
4702 /* Given a list of expressions, return a compound expression
4703 that performs them all and returns the value of the last of them. */
4705 tree build_x_compound_expr_from_list (tree list, const char *msg)
4707 tree expr = TREE_VALUE (list);
4709 if (TREE_CHAIN (list))
4712 pedwarn ("%s expression list treated as compound expression", msg);
4714 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4715 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4721 /* Handle overloading of the ',' operator when needed. */
4724 build_x_compound_expr (tree op1, tree op2)
4727 tree orig_op1 = op1;
4728 tree orig_op2 = op2;
4730 if (processing_template_decl)
4732 if (type_dependent_expression_p (op1)
4733 || type_dependent_expression_p (op2))
4734 return build_min_nt (COMPOUND_EXPR, op1, op2);
4735 op1 = build_non_dependent_expr (op1);
4736 op2 = build_non_dependent_expr (op2);
4739 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4740 /*overloaded_p=*/NULL);
4742 result = build_compound_expr (op1, op2);
4744 if (processing_template_decl && result != error_mark_node)
4745 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4750 /* Build a compound expression. */
4753 build_compound_expr (tree lhs, tree rhs)
4755 lhs = convert_to_void (lhs, "left-hand operand of comma");
4757 if (lhs == error_mark_node || rhs == error_mark_node)
4758 return error_mark_node;
4760 if (TREE_CODE (rhs) == TARGET_EXPR)
4762 /* If the rhs is a TARGET_EXPR, then build the compound
4763 expression inside the target_expr's initializer. This
4764 helps the compiler to eliminate unnecessary temporaries. */
4765 tree init = TREE_OPERAND (rhs, 1);
4767 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4768 TREE_OPERAND (rhs, 1) = init;
4773 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4776 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4777 casts away constness. DIAG_FN gives the function to call if we
4778 need to issue a diagnostic; if it is NULL, no diagnostic will be
4779 issued. DESCRIPTION explains what operation is taking place. */
4782 check_for_casting_away_constness (tree src_type, tree dest_type,
4783 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4784 const char *description)
4786 if (diag_fn && casts_away_constness (src_type, dest_type))
4787 diag_fn ("%s from type %qT to type %qT casts away constness",
4788 description, src_type, dest_type);
4791 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4792 (another pointer-to-member type in the same hierarchy) and return
4793 the converted expression. If ALLOW_INVERSE_P is permitted, a
4794 pointer-to-derived may be converted to pointer-to-base; otherwise,
4795 only the other direction is permitted. If C_CAST_P is true, this
4796 conversion is taking place as part of a C-style cast. */
4799 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4802 if (TYPE_PTRMEM_P (type))
4806 if (TREE_CODE (expr) == PTRMEM_CST)
4807 expr = cplus_expand_constant (expr);
4808 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4809 TYPE_PTRMEM_CLASS_TYPE (type),
4812 if (!integer_zerop (delta))
4813 expr = cp_build_binary_op (PLUS_EXPR,
4814 build_nop (ptrdiff_type_node, expr),
4816 return build_nop (type, expr);
4819 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4820 allow_inverse_p, c_cast_p);
4823 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4824 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4825 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4828 ignore_overflows (tree expr, tree orig)
4830 if (TREE_CODE (expr) == INTEGER_CST
4831 && CONSTANT_CLASS_P (orig)
4832 && TREE_CODE (orig) != STRING_CST
4833 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4834 || TREE_CONSTANT_OVERFLOW (expr)
4835 != TREE_CONSTANT_OVERFLOW (orig)))
4837 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4838 /* Ensure constant sharing. */
4839 expr = build_int_cst_wide (TREE_TYPE (expr),
4840 TREE_INT_CST_LOW (expr),
4841 TREE_INT_CST_HIGH (expr));
4844 /* Avoid clobbering a shared constant. */
4845 expr = copy_node (expr);
4846 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4847 TREE_CONSTANT_OVERFLOW (expr)
4848 = TREE_CONSTANT_OVERFLOW (orig);
4854 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4855 this static_cast is being attempted as one of the possible casts
4856 allowed by a C-style cast. (In that case, accessibility of base
4857 classes is not considered, and it is OK to cast away
4858 constness.) Return the result of the cast. *VALID_P is set to
4859 indicate whether or not the cast was valid. */
4862 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4868 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4871 /* Assume the cast is valid. */
4874 intype = TREE_TYPE (expr);
4876 /* Save casted types in the function's used types hash table. */
4877 used_types_insert (type);
4879 /* Determine what to do when casting away constness. */
4882 /* C-style casts are allowed to cast away constness. With
4883 WARN_CAST_QUAL, we still want to issue a warning. */
4884 diag_fn = warn_cast_qual ? warning0 : NULL;
4889 /* A static_cast may not cast away constness. */
4891 desc = "static_cast";
4894 /* [expr.static.cast]
4896 An lvalue of type "cv1 B", where B is a class type, can be cast
4897 to type "reference to cv2 D", where D is a class derived (clause
4898 _class.derived_) from B, if a valid standard conversion from
4899 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4900 same cv-qualification as, or greater cv-qualification than, cv1,
4901 and B is not a virtual base class of D. */
4902 /* We check this case before checking the validity of "TYPE t =
4903 EXPR;" below because for this case:
4906 struct D : public B { D(const B&); };
4908 void f() { static_cast<const D&>(b); }
4910 we want to avoid constructing a new D. The standard is not
4911 completely clear about this issue, but our interpretation is
4912 consistent with other compilers. */
4913 if (TREE_CODE (type) == REFERENCE_TYPE
4914 && CLASS_TYPE_P (TREE_TYPE (type))
4915 && CLASS_TYPE_P (intype)
4916 && real_lvalue_p (expr)
4917 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4918 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4919 build_pointer_type (TYPE_MAIN_VARIANT
4920 (TREE_TYPE (type))))
4922 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4926 /* There is a standard conversion from "D*" to "B*" even if "B"
4927 is ambiguous or inaccessible. If this is really a
4928 static_cast, then we check both for inaccessibility and
4929 ambiguity. However, if this is a static_cast being performed
4930 because the user wrote a C-style cast, then accessibility is
4932 base = lookup_base (TREE_TYPE (type), intype,
4933 c_cast_p ? ba_unique : ba_check,
4936 /* Convert from "B*" to "D*". This function will check that "B"
4937 is not a virtual base of "D". */
4938 expr = build_base_path (MINUS_EXPR, build_address (expr),
4939 base, /*nonnull=*/false);
4940 /* Convert the pointer to a reference -- but then remember that
4941 there are no expressions with reference type in C++. */
4942 return convert_from_reference (build_nop (type, expr));
4947 /* [expr.static.cast]
4949 An expression e can be explicitly converted to a type T using a
4950 static_cast of the form static_cast<T>(e) if the declaration T
4951 t(e);" is well-formed, for some invented temporary variable
4953 result = perform_direct_initialization_if_possible (type, expr,
4957 result = convert_from_reference (result);
4959 /* Ignore any integer overflow caused by the cast. */
4960 result = ignore_overflows (result, orig);
4962 /* [expr.static.cast]
4964 If T is a reference type, the result is an lvalue; otherwise,
4965 the result is an rvalue. */
4966 if (TREE_CODE (type) != REFERENCE_TYPE)
4967 result = rvalue (result);
4971 /* [expr.static.cast]
4973 Any expression can be explicitly converted to type cv void. */
4974 if (TREE_CODE (type) == VOID_TYPE)
4975 return convert_to_void (expr, /*implicit=*/NULL);
4977 /* [expr.static.cast]
4979 The inverse of any standard conversion sequence (clause _conv_),
4980 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4981 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4982 (_conv.bool_) conversions, can be performed explicitly using
4983 static_cast subject to the restriction that the explicit
4984 conversion does not cast away constness (_expr.const.cast_), and
4985 the following additional rules for specific cases: */
4986 /* For reference, the conversions not excluded are: integral
4987 promotions, floating point promotion, integral conversions,
4988 floating point conversions, floating-integral conversions,
4989 pointer conversions, and pointer to member conversions. */
4992 A value of integral _or enumeration_ type can be explicitly
4993 converted to an enumeration type. */
4994 /* The effect of all that is that any conversion between any two
4995 types which are integral, floating, or enumeration types can be
4997 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4998 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5000 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5002 /* Ignore any integer overflow caused by the cast. */
5003 expr = ignore_overflows (expr, orig);
5007 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5008 && CLASS_TYPE_P (TREE_TYPE (type))
5009 && CLASS_TYPE_P (TREE_TYPE (intype))
5010 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5011 (TREE_TYPE (intype))),
5012 build_pointer_type (TYPE_MAIN_VARIANT
5013 (TREE_TYPE (type)))))
5018 check_for_casting_away_constness (intype, type, diag_fn, desc);
5019 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5020 c_cast_p ? ba_unique : ba_check,
5022 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5025 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5026 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5033 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5034 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5036 if (TYPE_PTRMEM_P (type))
5038 t1 = (build_ptrmem_type
5040 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5041 t2 = (build_ptrmem_type
5043 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5050 if (can_convert (t1, t2))
5053 check_for_casting_away_constness (intype, type, diag_fn,
5055 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5060 /* [expr.static.cast]
5062 An rvalue of type "pointer to cv void" can be explicitly
5063 converted to a pointer to object type. A value of type pointer
5064 to object converted to "pointer to cv void" and back to the
5065 original pointer type will have its original value. */
5066 if (TREE_CODE (intype) == POINTER_TYPE
5067 && VOID_TYPE_P (TREE_TYPE (intype))
5068 && TYPE_PTROB_P (type))
5071 check_for_casting_away_constness (intype, type, diag_fn, desc);
5072 return build_nop (type, expr);
5076 return error_mark_node;
5079 /* Return an expression representing static_cast<TYPE>(EXPR). */
5082 build_static_cast (tree type, tree expr)
5087 if (type == error_mark_node || expr == error_mark_node)
5088 return error_mark_node;
5090 if (processing_template_decl)
5092 expr = build_min (STATIC_CAST_EXPR, type, expr);
5093 /* We don't know if it will or will not have side effects. */
5094 TREE_SIDE_EFFECTS (expr) = 1;
5095 return convert_from_reference (expr);
5098 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5099 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5100 if (TREE_CODE (type) != REFERENCE_TYPE
5101 && TREE_CODE (expr) == NOP_EXPR
5102 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5103 expr = TREE_OPERAND (expr, 0);
5105 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5109 error ("invalid static_cast from type %qT to type %qT",
5110 TREE_TYPE (expr), type);
5111 return error_mark_node;
5114 /* EXPR is an expression with member function or pointer-to-member
5115 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5116 not permitted by ISO C++, but we accept it in some modes. If we
5117 are not in one of those modes, issue a diagnostic. Return the
5118 converted expression. */
5121 convert_member_func_to_ptr (tree type, tree expr)
5126 intype = TREE_TYPE (expr);
5127 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5128 || TREE_CODE (intype) == METHOD_TYPE);
5130 if (pedantic || warn_pmf2ptr)
5131 pedwarn ("converting from %qT to %qT", intype, type);
5133 if (TREE_CODE (intype) == METHOD_TYPE)
5134 expr = build_addr_func (expr);
5135 else if (TREE_CODE (expr) == PTRMEM_CST)
5136 expr = build_address (PTRMEM_CST_MEMBER (expr));
5139 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5140 decl = build_address (decl);
5141 expr = get_member_function_from_ptrfunc (&decl, expr);
5144 return build_nop (type, expr);
5147 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5148 If C_CAST_P is true, this reinterpret cast is being done as part of
5149 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5150 indicate whether or not reinterpret_cast was valid. */
5153 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5158 /* Assume the cast is invalid. */
5162 if (type == error_mark_node || error_operand_p (expr))
5163 return error_mark_node;
5165 intype = TREE_TYPE (expr);
5167 /* Save casted types in the function's used types hash table. */
5168 used_types_insert (type);
5170 /* [expr.reinterpret.cast]
5171 An lvalue expression of type T1 can be cast to the type
5172 "reference to T2" if an expression of type "pointer to T1" can be
5173 explicitly converted to the type "pointer to T2" using a
5174 reinterpret_cast. */
5175 if (TREE_CODE (type) == REFERENCE_TYPE)
5177 if (! real_lvalue_p (expr))
5179 error ("invalid cast of an rvalue expression of type "
5182 return error_mark_node;
5185 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5186 "B" are related class types; the reinterpret_cast does not
5187 adjust the pointer. */
5188 if (TYPE_PTR_P (intype)
5189 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5190 COMPARE_BASE | COMPARE_DERIVED)))
5191 warning (0, "casting %qT to %qT does not dereference pointer",
5194 expr = build_unary_op (ADDR_EXPR, expr, 0);
5195 if (expr != error_mark_node)
5196 expr = build_reinterpret_cast_1
5197 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5199 if (expr != error_mark_node)
5200 expr = build_indirect_ref (expr, 0);
5204 /* As a G++ extension, we consider conversions from member
5205 functions, and pointers to member functions to
5206 pointer-to-function and pointer-to-void types. If
5207 -Wno-pmf-conversions has not been specified,
5208 convert_member_func_to_ptr will issue an error message. */
5209 if ((TYPE_PTRMEMFUNC_P (intype)
5210 || TREE_CODE (intype) == METHOD_TYPE)
5211 && TYPE_PTR_P (type)
5212 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5213 || VOID_TYPE_P (TREE_TYPE (type))))
5214 return convert_member_func_to_ptr (type, expr);
5216 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5217 array-to-pointer, and function-to-pointer conversions are
5219 expr = decay_conversion (expr);
5221 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5222 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5223 if (TREE_CODE (expr) == NOP_EXPR
5224 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5225 expr = TREE_OPERAND (expr, 0);
5227 if (error_operand_p (expr))
5228 return error_mark_node;
5230 intype = TREE_TYPE (expr);
5232 /* [expr.reinterpret.cast]
5233 A pointer can be converted to any integral type large enough to
5235 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5237 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5238 pedwarn ("cast from %qT to %qT loses precision",
5241 /* [expr.reinterpret.cast]
5242 A value of integral or enumeration type can be explicitly
5243 converted to a pointer. */
5244 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5247 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5248 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5249 return fold_if_not_in_template (build_nop (type, expr));
5250 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5251 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5256 check_for_casting_away_constness (intype, type, error,
5257 "reinterpret_cast");
5258 /* Warn about possible alignment problems. */
5259 if (STRICT_ALIGNMENT && warn_cast_align
5260 && !VOID_TYPE_P (type)
5261 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5262 && COMPLETE_TYPE_P (TREE_TYPE (type))
5263 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5264 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5265 warning (0, "cast from %qT to %qT increases required alignment of "
5269 /* We need to strip nops here, because the frontend likes to
5270 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5272 if (warn_strict_aliasing <= 2)
5273 strict_aliasing_warning (intype, type, sexpr);
5275 return fold_if_not_in_template (build_nop (type, expr));
5277 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5278 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5281 /* Only issue a warning, as we have always supported this
5282 where possible, and it is necessary in some cases. DR 195
5283 addresses this issue, but as of 2004/10/26 is still in
5285 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5286 return fold_if_not_in_template (build_nop (type, expr));
5288 else if (TREE_CODE (type) == VECTOR_TYPE)
5289 return fold_if_not_in_template (convert_to_vector (type, expr));
5290 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5291 return fold_if_not_in_template (convert_to_integer (type, expr));
5296 error ("invalid cast from type %qT to type %qT", intype, type);
5297 return error_mark_node;
5300 return cp_convert (type, expr);
5304 build_reinterpret_cast (tree type, tree expr)
5306 if (type == error_mark_node || expr == error_mark_node)
5307 return error_mark_node;
5309 if (processing_template_decl)
5311 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5313 if (!TREE_SIDE_EFFECTS (t)
5314 && type_dependent_expression_p (expr))
5315 /* There might turn out to be side effects inside expr. */
5316 TREE_SIDE_EFFECTS (t) = 1;
5317 return convert_from_reference (t);
5320 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5324 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5325 return an appropriate expression. Otherwise, return
5326 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5327 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5328 performing a C-style cast, its value upon return will indicate
5329 whether or not the conversion succeeded. */
5332 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5336 tree reference_type;
5338 /* Callers are responsible for handling error_mark_node as a
5339 destination type. */
5340 gcc_assert (dst_type != error_mark_node);
5341 /* In a template, callers should be building syntactic
5342 representations of casts, not using this machinery. */
5343 gcc_assert (!processing_template_decl);
5345 /* Assume the conversion is invalid. */
5349 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5352 error ("invalid use of const_cast with type %qT, "
5353 "which is not a pointer, "
5354 "reference, nor a pointer-to-data-member type", dst_type);
5355 return error_mark_node;
5358 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5361 error ("invalid use of const_cast with type %qT, which is a pointer "
5362 "or reference to a function type", dst_type);
5363 return error_mark_node;
5366 /* Save casted types in the function's used types hash table. */
5367 used_types_insert (dst_type);
5369 src_type = TREE_TYPE (expr);
5370 /* Expressions do not really have reference types. */
5371 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5372 src_type = TREE_TYPE (src_type);
5374 /* [expr.const.cast]
5376 An lvalue of type T1 can be explicitly converted to an lvalue of
5377 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5378 types) if a pointer to T1 can be explicitly converted to the type
5379 pointer to T2 using a const_cast. */
5380 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5382 reference_type = dst_type;
5383 if (! real_lvalue_p (expr))
5386 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5387 src_type, dst_type);
5388 return error_mark_node;
5390 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5391 src_type = build_pointer_type (src_type);
5395 reference_type = NULL_TREE;
5396 /* If the destination type is not a reference type, the
5397 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5398 conversions are performed. */
5399 src_type = type_decays_to (src_type);
5400 if (src_type == error_mark_node)
5401 return error_mark_node;
5404 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5405 && comp_ptr_ttypes_const (dst_type, src_type))
5410 /* This cast is actually a C-style cast. Issue a warning if
5411 the user is making a potentially unsafe cast. */
5413 check_for_casting_away_constness (src_type, dst_type,
5419 expr = build_unary_op (ADDR_EXPR, expr, 0);
5420 expr = build_nop (reference_type, expr);
5421 return convert_from_reference (expr);
5425 expr = decay_conversion (expr);
5426 /* build_c_cast puts on a NOP_EXPR to make the result not an
5427 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5428 non-lvalue context. */
5429 if (TREE_CODE (expr) == NOP_EXPR
5430 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5431 expr = TREE_OPERAND (expr, 0);
5432 return build_nop (dst_type, expr);
5437 error ("invalid const_cast from type %qT to type %qT",
5438 src_type, dst_type);
5439 return error_mark_node;
5443 build_const_cast (tree type, tree expr)
5445 if (type == error_mark_node || error_operand_p (expr))
5446 return error_mark_node;
5448 if (processing_template_decl)
5450 tree t = build_min (CONST_CAST_EXPR, type, expr);
5452 if (!TREE_SIDE_EFFECTS (t)
5453 && type_dependent_expression_p (expr))
5454 /* There might turn out to be side effects inside expr. */
5455 TREE_SIDE_EFFECTS (t) = 1;
5456 return convert_from_reference (t);
5459 return build_const_cast_1 (type, expr, /*complain=*/true,
5463 /* Build an expression representing an explicit C-style cast to type
5464 TYPE of expression EXPR. */
5467 build_c_cast (tree type, tree expr)
5473 if (type == error_mark_node || error_operand_p (expr))
5474 return error_mark_node;
5476 if (processing_template_decl)
5478 tree t = build_min (CAST_EXPR, type,
5479 tree_cons (NULL_TREE, value, NULL_TREE));
5480 /* We don't know if it will or will not have side effects. */
5481 TREE_SIDE_EFFECTS (t) = 1;
5482 return convert_from_reference (t);
5485 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5486 'Class') should always be retained, because this information aids
5487 in method lookup. */
5488 if (objc_is_object_ptr (type)
5489 && objc_is_object_ptr (TREE_TYPE (expr)))
5490 return build_nop (type, expr);
5492 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5493 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5494 if (TREE_CODE (type) != REFERENCE_TYPE
5495 && TREE_CODE (value) == NOP_EXPR
5496 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5497 value = TREE_OPERAND (value, 0);
5499 if (TREE_CODE (type) == ARRAY_TYPE)
5501 /* Allow casting from T1* to T2[] because Cfront allows it.
5502 NIHCL uses it. It is not valid ISO C++ however. */
5503 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5505 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5506 type = build_pointer_type (TREE_TYPE (type));
5510 error ("ISO C++ forbids casting to an array type %qT", type);
5511 return error_mark_node;
5515 if (TREE_CODE (type) == FUNCTION_TYPE
5516 || TREE_CODE (type) == METHOD_TYPE)
5518 error ("invalid cast to function type %qT", type);
5519 return error_mark_node;
5522 /* A C-style cast can be a const_cast. */
5523 result = build_const_cast_1 (type, value, /*complain=*/false,
5528 /* Or a static cast. */
5529 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5531 /* Or a reinterpret_cast. */
5533 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5535 /* The static_cast or reinterpret_cast may be followed by a
5538 /* A valid cast may result in errors if, for example, a
5539 conversion to am ambiguous base class is required. */
5540 && !error_operand_p (result))
5544 /* Non-class rvalues always have cv-unqualified type. */
5545 if (!CLASS_TYPE_P (type))
5546 type = TYPE_MAIN_VARIANT (type);
5547 result_type = TREE_TYPE (result);
5548 if (!CLASS_TYPE_P (result_type))
5549 result_type = TYPE_MAIN_VARIANT (result_type);
5550 /* If the type of RESULT does not match TYPE, perform a
5551 const_cast to make it match. If the static_cast or
5552 reinterpret_cast succeeded, we will differ by at most
5553 cv-qualification, so the follow-on const_cast is guaranteed
5555 if (!same_type_p (non_reference (type), non_reference (result_type)))
5557 result = build_const_cast_1 (type, result, false, &valid_p);
5558 gcc_assert (valid_p);
5563 return error_mark_node;
5566 /* Build an assignment expression of lvalue LHS from value RHS.
5567 MODIFYCODE is the code for a binary operator that we use
5568 to combine the old value of LHS with RHS to get the new value.
5569 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5571 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5574 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5578 tree lhstype = TREE_TYPE (lhs);
5579 tree olhstype = lhstype;
5580 tree olhs = NULL_TREE;
5581 bool plain_assign = (modifycode == NOP_EXPR);
5583 /* Avoid duplicate error messages from operands that had errors. */
5584 if (error_operand_p (lhs) || error_operand_p (rhs))
5585 return error_mark_node;
5587 /* Handle control structure constructs used as "lvalues". */
5588 switch (TREE_CODE (lhs))
5590 /* Handle --foo = 5; as these are valid constructs in C++. */
5591 case PREDECREMENT_EXPR:
5592 case PREINCREMENT_EXPR:
5593 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5594 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5595 stabilize_reference (TREE_OPERAND (lhs, 0)),
5596 TREE_OPERAND (lhs, 1));
5597 return build2 (COMPOUND_EXPR, lhstype,
5599 build_modify_expr (TREE_OPERAND (lhs, 0),
5602 /* Handle (a, b) used as an "lvalue". */
5604 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5606 if (newrhs == error_mark_node)
5607 return error_mark_node;
5608 return build2 (COMPOUND_EXPR, lhstype,
5609 TREE_OPERAND (lhs, 0), newrhs);
5612 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5613 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5614 stabilize_reference (TREE_OPERAND (lhs, 0)),
5615 TREE_OPERAND (lhs, 1));
5616 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5617 if (newrhs == error_mark_node)
5618 return error_mark_node;
5619 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5623 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5624 when neither operand has side-effects. */
5625 if (!lvalue_or_else (lhs, lv_assign))
5626 return error_mark_node;
5628 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5629 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5631 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5632 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5634 TREE_OPERAND (lhs, 0),
5635 TREE_OPERAND (lhs, 1)),
5636 TREE_OPERAND (lhs, 0),
5637 TREE_OPERAND (lhs, 1));
5640 /* Handle (a ? b : c) used as an "lvalue". */
5643 /* Produce (a ? (b = rhs) : (c = rhs))
5644 except that the RHS goes through a save-expr
5645 so the code to compute it is only emitted once. */
5647 tree preeval = NULL_TREE;
5649 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5651 error ("void value not ignored as it ought to be");
5652 return error_mark_node;
5655 rhs = stabilize_expr (rhs, &preeval);
5657 /* Check this here to avoid odd errors when trying to convert
5658 a throw to the type of the COND_EXPR. */
5659 if (!lvalue_or_else (lhs, lv_assign))
5660 return error_mark_node;
5662 cond = build_conditional_expr
5663 (TREE_OPERAND (lhs, 0),
5664 build_modify_expr (TREE_OPERAND (lhs, 1),
5666 build_modify_expr (TREE_OPERAND (lhs, 2),
5669 if (cond == error_mark_node)
5671 /* Make sure the code to compute the rhs comes out
5672 before the split. */
5674 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5682 if (modifycode == INIT_EXPR)
5684 if (TREE_CODE (rhs) == CONSTRUCTOR)
5686 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5687 /* Call convert to generate an error; see PR 11063. */
5688 rhs = convert (lhstype, rhs);
5689 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5690 TREE_SIDE_EFFECTS (result) = 1;
5693 else if (! IS_AGGR_TYPE (lhstype))
5694 /* Do the default thing. */;
5697 result = build_special_member_call (lhs, complete_ctor_identifier,
5698 build_tree_list (NULL_TREE, rhs),
5699 lhstype, LOOKUP_NORMAL);
5700 if (result == NULL_TREE)
5701 return error_mark_node;
5707 lhs = require_complete_type (lhs);
5708 if (lhs == error_mark_node)
5709 return error_mark_node;
5711 if (modifycode == NOP_EXPR)
5713 /* `operator=' is not an inheritable operator. */
5714 if (! IS_AGGR_TYPE (lhstype))
5715 /* Do the default thing. */;
5718 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5719 lhs, rhs, make_node (NOP_EXPR),
5720 /*overloaded_p=*/NULL);
5721 if (result == NULL_TREE)
5722 return error_mark_node;
5729 /* A binary op has been requested. Combine the old LHS
5730 value with the RHS producing the value we should actually
5731 store into the LHS. */
5733 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5734 lhs = stabilize_reference (lhs);
5735 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5736 if (newrhs == error_mark_node)
5738 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5739 TREE_TYPE (lhs), TREE_TYPE (rhs));
5740 return error_mark_node;
5743 /* Now it looks like a plain assignment. */
5744 modifycode = NOP_EXPR;
5746 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5747 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5750 /* The left-hand side must be an lvalue. */
5751 if (!lvalue_or_else (lhs, lv_assign))
5752 return error_mark_node;
5754 /* Warn about modifying something that is `const'. Don't warn if
5755 this is initialization. */
5756 if (modifycode != INIT_EXPR
5757 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5758 /* Functions are not modifiable, even though they are
5760 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5761 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5762 /* If it's an aggregate and any field is const, then it is
5763 effectively const. */
5764 || (CLASS_TYPE_P (lhstype)
5765 && C_TYPE_FIELDS_READONLY (lhstype))))
5766 readonly_error (lhs, "assignment", 0);
5768 /* If storing into a structure or union member, it has probably been
5769 given type `int'. Compute the type that would go with the actual
5770 amount of storage the member occupies. */
5772 if (TREE_CODE (lhs) == COMPONENT_REF
5773 && (TREE_CODE (lhstype) == INTEGER_TYPE
5774 || TREE_CODE (lhstype) == REAL_TYPE
5775 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5777 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5779 /* If storing in a field that is in actuality a short or narrower
5780 than one, we must store in the field in its actual type. */
5782 if (lhstype != TREE_TYPE (lhs))
5784 /* Avoid warnings converting integral types back into enums for
5786 if (TREE_CODE (lhstype) == INTEGER_TYPE
5787 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5789 if (TREE_SIDE_EFFECTS (lhs))
5790 lhs = stabilize_reference (lhs);
5793 lhs = copy_node (lhs);
5794 TREE_TYPE (lhs) = lhstype;
5798 /* Convert new value to destination type. */
5800 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5804 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5805 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5807 error ("incompatible types in assignment of %qT to %qT",
5808 TREE_TYPE (rhs), lhstype);
5809 return error_mark_node;
5812 /* Allow array assignment in compiler-generated code. */
5813 if (! DECL_ARTIFICIAL (current_function_decl))
5815 /* This routine is used for both initialization and assignment.
5816 Make sure the diagnostic message differentiates the context. */
5817 if (modifycode == INIT_EXPR)
5818 error ("array used as initializer");
5820 error ("invalid array assignment");
5821 return error_mark_node;
5824 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5825 ? 1 + (modifycode != INIT_EXPR): 0;
5826 return build_vec_init (lhs, NULL_TREE, newrhs,
5827 /*explicit_default_init_p=*/false,
5831 if (modifycode == INIT_EXPR)
5832 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5833 "initialization", NULL_TREE, 0);
5836 /* Avoid warnings on enum bit fields. */
5837 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5838 && TREE_CODE (lhstype) == INTEGER_TYPE)
5840 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5842 newrhs = convert_force (lhstype, newrhs, 0);
5845 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5847 if (TREE_CODE (newrhs) == CALL_EXPR
5848 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5849 newrhs = build_cplus_new (lhstype, newrhs);
5851 /* Can't initialize directly from a TARGET_EXPR, since that would
5852 cause the lhs to be constructed twice, and possibly result in
5853 accidental self-initialization. So we force the TARGET_EXPR to be
5854 expanded without a target. */
5855 if (TREE_CODE (newrhs) == TARGET_EXPR)
5856 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5857 TREE_OPERAND (newrhs, 0));
5860 if (newrhs == error_mark_node)
5861 return error_mark_node;
5863 if (c_dialect_objc () && flag_objc_gc)
5865 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5871 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5872 lhstype, lhs, newrhs);
5874 TREE_SIDE_EFFECTS (result) = 1;
5876 TREE_NO_WARNING (result) = 1;
5878 /* If we got the LHS in a different type for storing in,
5879 convert the result back to the nominal type of LHS
5880 so that the value we return always has the same type
5881 as the LHS argument. */
5883 if (olhstype == TREE_TYPE (result))
5887 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5888 TREE_NO_WARNING (result) = 1;
5891 return convert_for_assignment (olhstype, result, "assignment",
5896 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5898 if (processing_template_decl)
5899 return build_min_nt (MODOP_EXPR, lhs,
5900 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5902 if (modifycode != NOP_EXPR)
5904 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5905 make_node (modifycode),
5906 /*overloaded_p=*/NULL);
5909 TREE_NO_WARNING (rval) = 1;
5913 return build_modify_expr (lhs, modifycode, rhs);
5917 /* Get difference in deltas for different pointer to member function
5918 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5919 the conversion is invalid, the constant is zero. If
5920 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5921 If C_CAST_P is true this conversion is taking place as part of a
5924 Note that the naming of FROM and TO is kind of backwards; the return
5925 value is what we add to a TO in order to get a FROM. They are named
5926 this way because we call this function to find out how to convert from
5927 a pointer to member of FROM to a pointer to member of TO. */
5930 get_delta_difference (tree from, tree to,
5931 bool allow_inverse_p,
5938 /* Assume no conversion is required. */
5939 result = integer_zero_node;
5940 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5941 if (kind == bk_inaccessible || kind == bk_ambig)
5942 error (" in pointer to member function conversion");
5945 if (kind != bk_via_virtual)
5946 result = BINFO_OFFSET (binfo);
5949 tree virt_binfo = binfo_from_vbase (binfo);
5951 /* This is a reinterpret cast, we choose to do nothing. */
5952 if (allow_inverse_p)
5953 warning (0, "pointer to member cast via virtual base %qT",
5954 BINFO_TYPE (virt_binfo));
5956 error ("pointer to member conversion via virtual base %qT",
5957 BINFO_TYPE (virt_binfo));
5960 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5961 /* Pointer to member of incomplete class is permitted*/;
5962 else if (!allow_inverse_p)
5964 error_not_base_type (from, to);
5965 error (" in pointer to member conversion");
5969 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5972 if (kind != bk_via_virtual)
5973 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5976 /* This is a reinterpret cast, we choose to do nothing. */
5977 tree virt_binfo = binfo_from_vbase (binfo);
5979 warning (0, "pointer to member cast via virtual base %qT",
5980 BINFO_TYPE (virt_binfo));
5985 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5989 /* Return a constructor for the pointer-to-member-function TYPE using
5990 the other components as specified. */
5993 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5998 VEC(constructor_elt, gc) *v;
6000 /* Pull the FIELD_DECLs out of the type. */
6001 pfn_field = TYPE_FIELDS (type);
6002 delta_field = TREE_CHAIN (pfn_field);
6004 /* Make sure DELTA has the type we want. */
6005 delta = convert_and_check (delta_type_node, delta);
6007 /* Finish creating the initializer. */
6008 v = VEC_alloc(constructor_elt, gc, 2);
6009 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6010 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6011 u = build_constructor (type, v);
6012 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6013 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6014 TREE_STATIC (u) = (TREE_CONSTANT (u)
6015 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6017 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6022 /* Build a constructor for a pointer to member function. It can be
6023 used to initialize global variables, local variable, or used
6024 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6027 If FORCE is nonzero, then force this conversion, even if
6028 we would rather not do it. Usually set when using an explicit
6029 cast. A C-style cast is being processed iff C_CAST_P is true.
6031 Return error_mark_node, if something goes wrong. */
6034 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6040 if (error_operand_p (pfn))
6041 return error_mark_node;
6043 pfn_type = TREE_TYPE (pfn);
6044 to_type = build_ptrmemfunc_type (type);
6046 /* Handle multiple conversions of pointer to member functions. */
6047 if (TYPE_PTRMEMFUNC_P (pfn_type))
6049 tree delta = NULL_TREE;
6050 tree npfn = NULL_TREE;
6054 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6055 error ("invalid conversion to type %qT from type %qT",
6058 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6059 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6063 /* We don't have to do any conversion to convert a
6064 pointer-to-member to its own type. But, we don't want to
6065 just return a PTRMEM_CST if there's an explicit cast; that
6066 cast should make the expression an invalid template argument. */
6067 if (TREE_CODE (pfn) != PTRMEM_CST)
6069 if (same_type_p (to_type, pfn_type))
6071 else if (integer_zerop (n))
6072 return build_reinterpret_cast (to_type, pfn);
6075 if (TREE_SIDE_EFFECTS (pfn))
6076 pfn = save_expr (pfn);
6078 /* Obtain the function pointer and the current DELTA. */
6079 if (TREE_CODE (pfn) == PTRMEM_CST)
6080 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6083 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6084 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6087 /* Just adjust the DELTA field. */
6088 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6089 (TREE_TYPE (delta), ptrdiff_type_node));
6090 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6091 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6092 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6093 return build_ptrmemfunc1 (to_type, delta, npfn);
6096 /* Handle null pointer to member function conversions. */
6097 if (integer_zerop (pfn))
6099 pfn = build_c_cast (type, integer_zero_node);
6100 return build_ptrmemfunc1 (to_type,
6105 if (type_unknown_p (pfn))
6106 return instantiate_type (type, pfn, tf_warning_or_error);
6108 fn = TREE_OPERAND (pfn, 0);
6109 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6110 /* In a template, we will have preserved the
6112 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6113 return make_ptrmem_cst (to_type, fn);
6116 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6119 ??? There is no consistency as to the types returned for the above
6120 values. Some code acts as if it were a sizetype and some as if it were
6121 integer_type_node. */
6124 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6126 tree type = TREE_TYPE (cst);
6127 tree fn = PTRMEM_CST_MEMBER (cst);
6128 tree ptr_class, fn_class;
6130 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6132 /* The class that the function belongs to. */
6133 fn_class = DECL_CONTEXT (fn);
6135 /* The class that we're creating a pointer to member of. */
6136 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6138 /* First, calculate the adjustment to the function's class. */
6139 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6142 if (!DECL_VIRTUAL_P (fn))
6143 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6146 /* If we're dealing with a virtual function, we have to adjust 'this'
6147 again, to point to the base which provides the vtable entry for
6148 fn; the call will do the opposite adjustment. */
6149 tree orig_class = DECL_CONTEXT (fn);
6150 tree binfo = binfo_or_else (orig_class, fn_class);
6151 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6152 *delta, BINFO_OFFSET (binfo));
6153 *delta = fold_if_not_in_template (*delta);
6155 /* We set PFN to the vtable offset at which the function can be
6156 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6157 case delta is shifted left, and then incremented). */
6158 *pfn = DECL_VINDEX (fn);
6159 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6160 TYPE_SIZE_UNIT (vtable_entry_type));
6161 *pfn = fold_if_not_in_template (*pfn);
6163 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6165 case ptrmemfunc_vbit_in_pfn:
6166 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6168 *pfn = fold_if_not_in_template (*pfn);
6171 case ptrmemfunc_vbit_in_delta:
6172 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6173 *delta, integer_one_node);
6174 *delta = fold_if_not_in_template (*delta);
6175 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6176 *delta, integer_one_node);
6177 *delta = fold_if_not_in_template (*delta);
6184 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6185 *pfn = fold_if_not_in_template (*pfn);
6189 /* Return an expression for PFN from the pointer-to-member function
6193 pfn_from_ptrmemfunc (tree t)
6195 if (TREE_CODE (t) == PTRMEM_CST)
6200 expand_ptrmemfunc_cst (t, &delta, &pfn);
6205 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6208 /* Convert value RHS to type TYPE as preparation for an assignment to
6209 an lvalue of type TYPE. ERRTYPE is a string to use in error
6210 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6211 are doing the conversion in order to pass the PARMNUMth argument of
6215 convert_for_assignment (tree type, tree rhs,
6216 const char *errtype, tree fndecl, int parmnum)
6219 enum tree_code coder;
6221 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6222 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6223 rhs = TREE_OPERAND (rhs, 0);
6225 rhstype = TREE_TYPE (rhs);
6226 coder = TREE_CODE (rhstype);
6228 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6229 && vector_types_convertible_p (type, rhstype))
6230 return convert (type, rhs);
6232 if (rhs == error_mark_node || rhstype == error_mark_node)
6233 return error_mark_node;
6234 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6235 return error_mark_node;
6237 /* The RHS of an assignment cannot have void type. */
6238 if (coder == VOID_TYPE)
6240 error ("void value not ignored as it ought to be");
6241 return error_mark_node;
6244 /* Simplify the RHS if possible. */
6245 if (TREE_CODE (rhs) == CONST_DECL)
6246 rhs = DECL_INITIAL (rhs);
6248 if (c_dialect_objc ())
6251 tree rname = fndecl;
6253 if (!strcmp (errtype, "assignment"))
6255 else if (!strcmp (errtype, "initialization"))
6259 tree selector = objc_message_selector ();
6263 if (selector && parmno > 1)
6270 if (objc_compare_types (type, rhstype, parmno, rname))
6271 return convert (type, rhs);
6276 The expression is implicitly converted (clause _conv_) to the
6277 cv-unqualified type of the left operand.
6279 We allow bad conversions here because by the time we get to this point
6280 we are committed to doing the conversion. If we end up doing a bad
6281 conversion, convert_like will complain. */
6282 if (!can_convert_arg_bad (type, rhstype, rhs))
6284 /* When -Wno-pmf-conversions is use, we just silently allow
6285 conversions from pointers-to-members to plain pointers. If
6286 the conversion doesn't work, cp_convert will complain. */
6288 && TYPE_PTR_P (type)
6289 && TYPE_PTRMEMFUNC_P (rhstype))
6290 rhs = cp_convert (strip_top_quals (type), rhs);
6293 /* If the right-hand side has unknown type, then it is an
6294 overloaded function. Call instantiate_type to get error
6296 if (rhstype == unknown_type_node)
6297 instantiate_type (type, rhs, tf_warning_or_error);
6299 error ("cannot convert %qT to %qT for argument %qP to %qD",
6300 rhstype, type, parmnum, fndecl);
6302 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6303 return error_mark_node;
6306 if (warn_missing_format_attribute)
6308 const enum tree_code codel = TREE_CODE (type);
6309 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6311 && check_missing_format_attribute (type, rhstype))
6312 warning (OPT_Wmissing_format_attribute,
6313 "%s might be a candidate for a format attribute",
6317 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6319 if (warn_parentheses
6320 && type == boolean_type_node
6321 && TREE_CODE (rhs) == MODIFY_EXPR
6322 && !TREE_NO_WARNING (rhs)
6323 && TREE_TYPE (rhs) != boolean_type_node)
6325 warning (OPT_Wparentheses,
6326 "suggest parentheses around assignment used as truth value");
6327 TREE_NO_WARNING (rhs) = 1;
6330 return perform_implicit_conversion (strip_top_quals (type), rhs);
6333 /* Convert RHS to be of type TYPE.
6334 If EXP is nonzero, it is the target of the initialization.
6335 ERRTYPE is a string to use in error messages.
6337 Two major differences between the behavior of
6338 `convert_for_assignment' and `convert_for_initialization'
6339 are that references are bashed in the former, while
6340 copied in the latter, and aggregates are assigned in
6341 the former (operator=) while initialized in the
6344 If using constructor make sure no conversion operator exists, if one does
6345 exist, an ambiguity exists.
6347 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6350 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6351 const char *errtype, tree fndecl, int parmnum)
6353 enum tree_code codel = TREE_CODE (type);
6355 enum tree_code coder;
6357 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6358 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6359 if (TREE_CODE (rhs) == NOP_EXPR
6360 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6361 && codel != REFERENCE_TYPE)
6362 rhs = TREE_OPERAND (rhs, 0);
6364 if (type == error_mark_node
6365 || rhs == error_mark_node
6366 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6367 return error_mark_node;
6369 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6370 && TREE_CODE (type) != ARRAY_TYPE
6371 && (TREE_CODE (type) != REFERENCE_TYPE
6372 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6373 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6374 && (TREE_CODE (type) != REFERENCE_TYPE
6375 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6376 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6377 rhs = decay_conversion (rhs);
6379 rhstype = TREE_TYPE (rhs);
6380 coder = TREE_CODE (rhstype);
6382 if (coder == ERROR_MARK)
6383 return error_mark_node;
6385 /* We accept references to incomplete types, so we can
6386 return here before checking if RHS is of complete type. */
6388 if (codel == REFERENCE_TYPE)
6390 /* This should eventually happen in convert_arguments. */
6391 int savew = 0, savee = 0;
6394 savew = warningcount, savee = errorcount;
6395 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6399 if (warningcount > savew)
6400 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6401 else if (errorcount > savee)
6402 error ("in passing argument %P of %q+D", parmnum, fndecl);
6408 exp = require_complete_type (exp);
6409 if (exp == error_mark_node)
6410 return error_mark_node;
6412 rhstype = non_reference (rhstype);
6414 type = complete_type (type);
6416 if (IS_AGGR_TYPE (type))
6417 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6419 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6422 /* If RETVAL is the address of, or a reference to, a local variable or
6423 temporary give an appropriate warning. */
6426 maybe_warn_about_returning_address_of_local (tree retval)
6428 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6429 tree whats_returned = retval;
6433 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6434 whats_returned = TREE_OPERAND (whats_returned, 1);
6435 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6436 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6437 || TREE_CODE (whats_returned) == NOP_EXPR)
6438 whats_returned = TREE_OPERAND (whats_returned, 0);
6443 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6445 whats_returned = TREE_OPERAND (whats_returned, 0);
6447 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6449 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6450 || TREE_CODE (whats_returned) == TARGET_EXPR)
6452 warning (0, "returning reference to temporary");
6455 if (TREE_CODE (whats_returned) == VAR_DECL
6456 && DECL_NAME (whats_returned)
6457 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6459 warning (0, "reference to non-lvalue returned");
6464 while (TREE_CODE (whats_returned) == COMPONENT_REF
6465 || TREE_CODE (whats_returned) == ARRAY_REF)
6466 whats_returned = TREE_OPERAND (whats_returned, 0);
6468 if (DECL_P (whats_returned)
6469 && DECL_NAME (whats_returned)
6470 && DECL_FUNCTION_SCOPE_P (whats_returned)
6471 && !(TREE_STATIC (whats_returned)
6472 || TREE_PUBLIC (whats_returned)))
6474 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6475 warning (0, "reference to local variable %q+D returned",
6478 warning (0, "address of local variable %q+D returned",
6484 /* Check that returning RETVAL from the current function is valid.
6485 Return an expression explicitly showing all conversions required to
6486 change RETVAL into the function return type, and to assign it to
6487 the DECL_RESULT for the function. Set *NO_WARNING to true if
6488 code reaches end of non-void function warning shouldn't be issued
6489 on this RETURN_EXPR. */
6492 check_return_expr (tree retval, bool *no_warning)
6495 /* The type actually returned by the function, after any
6498 int fn_returns_value_p;
6500 *no_warning = false;
6502 /* A `volatile' function is one that isn't supposed to return, ever.
6503 (This is a G++ extension, used to get better code for functions
6504 that call the `volatile' function.) */
6505 if (TREE_THIS_VOLATILE (current_function_decl))
6506 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6508 /* Check for various simple errors. */
6509 if (DECL_DESTRUCTOR_P (current_function_decl))
6512 error ("returning a value from a destructor");
6515 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6517 if (in_function_try_handler)
6518 /* If a return statement appears in a handler of the
6519 function-try-block of a constructor, the program is ill-formed. */
6520 error ("cannot return from a handler of a function-try-block of a constructor");
6522 /* You can't return a value from a constructor. */
6523 error ("returning a value from a constructor");
6527 if (processing_template_decl)
6529 current_function_returns_value = 1;
6533 /* When no explicit return-value is given in a function with a named
6534 return value, the named return value is used. */
6535 result = DECL_RESULT (current_function_decl);
6536 valtype = TREE_TYPE (result);
6537 gcc_assert (valtype != NULL_TREE);
6538 fn_returns_value_p = !VOID_TYPE_P (valtype);
6539 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6542 /* Check for a return statement with no return value in a function
6543 that's supposed to return a value. */
6544 if (!retval && fn_returns_value_p)
6546 pedwarn ("return-statement with no value, in function returning %qT",
6548 /* Clear this, so finish_function won't say that we reach the
6549 end of a non-void function (which we don't, we gave a
6551 current_function_returns_null = 0;
6552 /* And signal caller that TREE_NO_WARNING should be set on the
6553 RETURN_EXPR to avoid control reaches end of non-void function
6554 warnings in tree-cfg.c. */
6557 /* Check for a return statement with a value in a function that
6558 isn't supposed to return a value. */
6559 else if (retval && !fn_returns_value_p)
6561 if (VOID_TYPE_P (TREE_TYPE (retval)))
6562 /* You can return a `void' value from a function of `void'
6563 type. In that case, we have to evaluate the expression for
6564 its side-effects. */
6565 finish_expr_stmt (retval);
6567 pedwarn ("return-statement with a value, in function "
6568 "returning 'void'");
6570 current_function_returns_null = 1;
6572 /* There's really no value to return, after all. */
6576 /* Remember that this function can sometimes return without a
6578 current_function_returns_null = 1;
6580 /* Remember that this function did return a value. */
6581 current_function_returns_value = 1;
6583 /* Check for erroneous operands -- but after giving ourselves a
6584 chance to provide an error about returning a value from a void
6586 if (error_operand_p (retval))
6588 current_function_return_value = error_mark_node;
6589 return error_mark_node;
6592 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6593 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6594 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6595 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6597 && null_ptr_cst_p (retval))
6598 warning (0, "%<operator new%> must not return NULL unless it is "
6599 "declared %<throw()%> (or -fcheck-new is in effect)");
6601 /* Effective C++ rule 15. See also start_function. */
6603 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6607 /* The function return type must be a reference to the current
6609 if (TREE_CODE (valtype) == REFERENCE_TYPE
6610 && same_type_ignoring_top_level_qualifiers_p
6611 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6613 /* Returning '*this' is obviously OK. */
6614 if (retval == current_class_ref)
6616 /* If we are calling a function whose return type is the same of
6617 the current class reference, it is ok. */
6618 else if (TREE_CODE (retval) == INDIRECT_REF
6619 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6624 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6627 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6629 [...] For a function with a class return type, if the expression
6630 in the return statement is the name of a local object, and the cv-
6631 unqualified type of the local object is the same as the function
6632 return type, an implementation is permitted to omit creating the tem-
6633 porary object to hold the function return value [...]
6635 So, if this is a value-returning function that always returns the same
6636 local variable, remember it.
6638 It might be nice to be more flexible, and choose the first suitable
6639 variable even if the function sometimes returns something else, but
6640 then we run the risk of clobbering the variable we chose if the other
6641 returned expression uses the chosen variable somehow. And people expect
6642 this restriction, anyway. (jason 2000-11-19)
6644 See finish_function and finalize_nrv for the rest of this optimization. */
6646 if (fn_returns_value_p && flag_elide_constructors)
6648 if (retval != NULL_TREE
6649 && (current_function_return_value == NULL_TREE
6650 || current_function_return_value == retval)
6651 && TREE_CODE (retval) == VAR_DECL
6652 && DECL_CONTEXT (retval) == current_function_decl
6653 && ! TREE_STATIC (retval)
6654 && ! DECL_ANON_UNION_VAR_P (retval)
6655 && (DECL_ALIGN (retval)
6656 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6657 && same_type_p ((TYPE_MAIN_VARIANT
6658 (TREE_TYPE (retval))),
6660 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6661 current_function_return_value = retval;
6663 current_function_return_value = error_mark_node;
6666 /* We don't need to do any conversions when there's nothing being
6671 /* Do any required conversions. */
6672 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6673 /* No conversions are required. */
6677 /* The type the function is declared to return. */
6678 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6680 /* The functype's return type will have been set to void, if it
6681 was an incomplete type. Just treat this as 'return;' */
6682 if (VOID_TYPE_P (functype))
6683 return error_mark_node;
6685 /* First convert the value to the function's return type, then
6686 to the type of return value's location to handle the
6687 case that functype is smaller than the valtype. */
6688 retval = convert_for_initialization
6689 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6690 "return", NULL_TREE, 0);
6691 retval = convert (valtype, retval);
6693 /* If the conversion failed, treat this just like `return;'. */
6694 if (retval == error_mark_node)
6696 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6697 else if (! current_function_returns_struct
6698 && TREE_CODE (retval) == TARGET_EXPR
6699 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6700 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6701 TREE_OPERAND (retval, 0));
6703 maybe_warn_about_returning_address_of_local (retval);
6706 /* Actually copy the value returned into the appropriate location. */
6707 if (retval && retval != result)
6708 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6714 /* Returns nonzero if the pointer-type FROM can be converted to the
6715 pointer-type TO via a qualification conversion. If CONSTP is -1,
6716 then we return nonzero if the pointers are similar, and the
6717 cv-qualification signature of FROM is a proper subset of that of TO.
6719 If CONSTP is positive, then all outer pointers have been
6723 comp_ptr_ttypes_real (tree to, tree from, int constp)
6725 bool to_more_cv_qualified = false;
6727 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6729 if (TREE_CODE (to) != TREE_CODE (from))
6732 if (TREE_CODE (from) == OFFSET_TYPE
6733 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6734 TYPE_OFFSET_BASETYPE (to)))
6737 /* Const and volatile mean something different for function types,
6738 so the usual checks are not appropriate. */
6739 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6741 /* In Objective-C++, some types may have been 'volatilized' by
6742 the compiler for EH; when comparing them here, the volatile
6743 qualification must be ignored. */
6744 bool objc_quals_match = objc_type_quals_match (to, from);
6746 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6749 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6753 to_more_cv_qualified = true;
6757 constp &= TYPE_READONLY (to);
6760 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6761 return ((constp >= 0 || to_more_cv_qualified)
6762 && same_type_ignoring_top_level_qualifiers_p (to, from));
6766 /* When comparing, say, char ** to char const **, this function takes
6767 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6768 types to this function. */
6771 comp_ptr_ttypes (tree to, tree from)
6773 return comp_ptr_ttypes_real (to, from, 1);
6776 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6777 type or inheritance-related types, regardless of cv-quals. */
6780 ptr_reasonably_similar (tree to, tree from)
6782 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6784 /* Any target type is similar enough to void. */
6785 if (TREE_CODE (to) == VOID_TYPE
6786 || TREE_CODE (from) == VOID_TYPE)
6789 if (TREE_CODE (to) != TREE_CODE (from))
6792 if (TREE_CODE (from) == OFFSET_TYPE
6793 && comptypes (TYPE_OFFSET_BASETYPE (to),
6794 TYPE_OFFSET_BASETYPE (from),
6795 COMPARE_BASE | COMPARE_DERIVED))
6798 if (TREE_CODE (to) == VECTOR_TYPE
6799 && vector_types_convertible_p (to, from))
6802 if (TREE_CODE (to) == INTEGER_TYPE
6803 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6806 if (TREE_CODE (to) == FUNCTION_TYPE)
6809 if (TREE_CODE (to) != POINTER_TYPE)
6811 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6812 COMPARE_BASE | COMPARE_DERIVED);
6816 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6817 pointer-to-member types) are the same, ignoring cv-qualification at
6821 comp_ptr_ttypes_const (tree to, tree from)
6823 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6825 if (TREE_CODE (to) != TREE_CODE (from))
6828 if (TREE_CODE (from) == OFFSET_TYPE
6829 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6830 TYPE_OFFSET_BASETYPE (to)))
6833 if (TREE_CODE (to) != POINTER_TYPE)
6834 return same_type_ignoring_top_level_qualifiers_p (to, from);
6838 /* Returns the type qualifiers for this type, including the qualifiers on the
6839 elements for an array type. */
6842 cp_type_quals (tree type)
6844 type = strip_array_types (type);
6845 if (type == error_mark_node)
6846 return TYPE_UNQUALIFIED;
6847 return TYPE_QUALS (type);
6850 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6854 cp_type_readonly (tree type)
6856 type = strip_array_types (type);
6857 return TYPE_READONLY (type);
6860 /* Returns nonzero if the TYPE contains a mutable member. */
6863 cp_has_mutable_p (tree type)
6865 type = strip_array_types (type);
6867 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6870 /* Apply the TYPE_QUALS to the new DECL. */
6872 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6874 tree type = TREE_TYPE (decl);
6876 if (type == error_mark_node)
6879 if (TREE_CODE (type) == FUNCTION_TYPE
6880 && type_quals != TYPE_UNQUALIFIED)
6882 /* This was an error in C++98 (cv-qualifiers cannot be added to
6883 a function type), but DR 295 makes the code well-formed by
6884 dropping the extra qualifiers. */
6887 tree bad_type = build_qualified_type (type, type_quals);
6888 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6892 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6896 /* Avoid setting TREE_READONLY incorrectly. */
6897 if (/* If the object has a constructor, the constructor may modify
6899 TYPE_NEEDS_CONSTRUCTING (type)
6900 /* If the type isn't complete, we don't know yet if it will need
6902 || !COMPLETE_TYPE_P (type)
6903 /* If the type has a mutable component, that component might be
6905 || TYPE_HAS_MUTABLE_P (type))
6906 type_quals &= ~TYPE_QUAL_CONST;
6908 c_apply_type_quals_to_decl (type_quals, decl);
6911 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6912 exemplar types such that casting T1 to T2 is casting away constness
6913 if and only if there is no implicit conversion from T1 to T2. */
6916 casts_away_constness_r (tree *t1, tree *t2)
6921 /* [expr.const.cast]
6923 For multi-level pointer to members and multi-level mixed pointers
6924 and pointers to members (conv.qual), the "member" aspect of a
6925 pointer to member level is ignored when determining if a const
6926 cv-qualifier has been cast away. */
6927 /* [expr.const.cast]
6929 For two pointer types:
6931 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6932 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6935 casting from X1 to X2 casts away constness if, for a non-pointer
6936 type T there does not exist an implicit conversion (clause
6939 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6943 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6944 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6945 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6947 *t1 = cp_build_qualified_type (void_type_node,
6948 cp_type_quals (*t1));
6949 *t2 = cp_build_qualified_type (void_type_node,
6950 cp_type_quals (*t2));
6954 quals1 = cp_type_quals (*t1);
6955 quals2 = cp_type_quals (*t2);
6957 if (TYPE_PTRMEM_P (*t1))
6958 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6960 *t1 = TREE_TYPE (*t1);
6961 if (TYPE_PTRMEM_P (*t2))
6962 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6964 *t2 = TREE_TYPE (*t2);
6966 casts_away_constness_r (t1, t2);
6967 *t1 = build_pointer_type (*t1);
6968 *t2 = build_pointer_type (*t2);
6969 *t1 = cp_build_qualified_type (*t1, quals1);
6970 *t2 = cp_build_qualified_type (*t2, quals2);
6973 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6977 casts_away_constness (tree t1, tree t2)
6979 if (TREE_CODE (t2) == REFERENCE_TYPE)
6981 /* [expr.const.cast]
6983 Casting from an lvalue of type T1 to an lvalue of type T2
6984 using a reference cast casts away constness if a cast from an
6985 rvalue of type "pointer to T1" to the type "pointer to T2"
6986 casts away constness. */
6987 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6988 return casts_away_constness (build_pointer_type (t1),
6989 build_pointer_type (TREE_TYPE (t2)));
6992 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6993 /* [expr.const.cast]
6995 Casting from an rvalue of type "pointer to data member of X
6996 of type T1" to the type "pointer to data member of Y of type
6997 T2" casts away constness if a cast from an rvalue of type
6998 "pointer to T1" to the type "pointer to T2" casts away
7000 return casts_away_constness
7001 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7002 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7004 /* Casting away constness is only something that makes sense for
7005 pointer or reference types. */
7006 if (TREE_CODE (t1) != POINTER_TYPE
7007 || TREE_CODE (t2) != POINTER_TYPE)
7010 /* Top-level qualifiers don't matter. */
7011 t1 = TYPE_MAIN_VARIANT (t1);
7012 t2 = TYPE_MAIN_VARIANT (t2);
7013 casts_away_constness_r (&t1, &t2);
7014 if (!can_convert (t2, t1))
7020 /* If T is a REFERENCE_TYPE return the type to which T refers.
7021 Otherwise, return T itself. */
7024 non_reference (tree t)
7026 if (TREE_CODE (t) == REFERENCE_TYPE)
7032 /* Return nonzero if REF is an lvalue valid for this language;
7033 otherwise, print an error message and return zero. USE says
7034 how the lvalue is being used and so selects the error message. */
7037 lvalue_or_else (tree ref, enum lvalue_use use)
7039 int win = lvalue_p (ref);