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 (VOID_TYPE_P (t))
2339 /* A pointer to incomplete type (other than cv void) can be
2340 dereferenced [expr.unary.op]/1 */
2341 error ("%qT is not a pointer-to-object type", type);
2342 return error_mark_node;
2344 else if (TREE_CODE (pointer) == ADDR_EXPR
2345 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2346 /* The POINTER was something like `&x'. We simplify `*&x' to
2348 return TREE_OPERAND (pointer, 0);
2351 tree ref = build1 (INDIRECT_REF, t, pointer);
2353 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2354 so that we get the proper error message if the result is used
2355 to assign to. Also, &* is supposed to be a no-op. */
2356 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2357 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2358 TREE_SIDE_EFFECTS (ref)
2359 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2363 /* `pointer' won't be an error_mark_node if we were given a
2364 pointer to member, so it's cool to check for this here. */
2365 else if (TYPE_PTR_TO_MEMBER_P (type))
2366 error ("invalid use of %qs on pointer to member", errorstring);
2367 else if (pointer != error_mark_node)
2370 error ("invalid type argument of %qs", errorstring);
2372 error ("invalid type argument");
2374 return error_mark_node;
2377 /* This handles expressions of the form "a[i]", which denotes
2380 This is logically equivalent in C to *(a+i), but we may do it differently.
2381 If A is a variable or a member, we generate a primitive ARRAY_REF.
2382 This avoids forcing the array out of registers, and can work on
2383 arrays that are not lvalues (for example, members of structures returned
2386 If INDEX is of some user-defined type, it must be converted to
2387 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2388 will inherit the type of the array, which will be some pointer type. */
2391 build_array_ref (tree array, tree idx)
2395 error ("subscript missing in array reference");
2396 return error_mark_node;
2399 if (TREE_TYPE (array) == error_mark_node
2400 || TREE_TYPE (idx) == error_mark_node)
2401 return error_mark_node;
2403 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2405 switch (TREE_CODE (array))
2409 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2410 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2411 TREE_OPERAND (array, 0), value);
2415 return build_conditional_expr
2416 (TREE_OPERAND (array, 0),
2417 build_array_ref (TREE_OPERAND (array, 1), idx),
2418 build_array_ref (TREE_OPERAND (array, 2), idx));
2424 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2428 warn_array_subscript_with_type_char (idx);
2430 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2432 error ("array subscript is not an integer");
2433 return error_mark_node;
2436 /* Apply integral promotions *after* noticing character types.
2437 (It is unclear why we do these promotions -- the standard
2438 does not say that we should. In fact, the natural thing would
2439 seem to be to convert IDX to ptrdiff_t; we're performing
2440 pointer arithmetic.) */
2441 idx = perform_integral_promotions (idx);
2443 /* An array that is indexed by a non-constant
2444 cannot be stored in a register; we must be able to do
2445 address arithmetic on its address.
2446 Likewise an array of elements of variable size. */
2447 if (TREE_CODE (idx) != INTEGER_CST
2448 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2449 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2452 if (!cxx_mark_addressable (array))
2453 return error_mark_node;
2456 /* An array that is indexed by a constant value which is not within
2457 the array bounds cannot be stored in a register either; because we
2458 would get a crash in store_bit_field/extract_bit_field when trying
2459 to access a non-existent part of the register. */
2460 if (TREE_CODE (idx) == INTEGER_CST
2461 && TYPE_DOMAIN (TREE_TYPE (array))
2462 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2464 if (!cxx_mark_addressable (array))
2465 return error_mark_node;
2468 if (pedantic && !lvalue_p (array))
2469 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2471 /* Note in C++ it is valid to subscript a `register' array, since
2472 it is valid to take the address of something with that
2473 storage specification. */
2477 while (TREE_CODE (foo) == COMPONENT_REF)
2478 foo = TREE_OPERAND (foo, 0);
2479 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2480 warning (OPT_Wextra, "subscripting array declared %<register%>");
2483 type = TREE_TYPE (TREE_TYPE (array));
2484 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2485 /* Array ref is const/volatile if the array elements are
2486 or if the array is.. */
2487 TREE_READONLY (rval)
2488 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2489 TREE_SIDE_EFFECTS (rval)
2490 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2491 TREE_THIS_VOLATILE (rval)
2492 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2493 return require_complete_type (fold_if_not_in_template (rval));
2497 tree ar = default_conversion (array);
2498 tree ind = default_conversion (idx);
2500 /* Put the integer in IND to simplify error checking. */
2501 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2508 if (ar == error_mark_node)
2511 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2513 error ("subscripted value is neither array nor pointer");
2514 return error_mark_node;
2516 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2518 error ("array subscript is not an integer");
2519 return error_mark_node;
2522 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2527 /* Resolve a pointer to member function. INSTANCE is the object
2528 instance to use, if the member points to a virtual member.
2530 This used to avoid checking for virtual functions if basetype
2531 has no virtual functions, according to an earlier ANSI draft.
2532 With the final ISO C++ rules, such an optimization is
2533 incorrect: A pointer to a derived member can be static_cast
2534 to pointer-to-base-member, as long as the dynamic object
2535 later has the right member. */
2538 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2540 if (TREE_CODE (function) == OFFSET_REF)
2541 function = TREE_OPERAND (function, 1);
2543 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2545 tree idx, delta, e1, e2, e3, vtbl, basetype;
2546 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2548 tree instance_ptr = *instance_ptrptr;
2549 tree instance_save_expr = 0;
2550 if (instance_ptr == error_mark_node)
2552 if (TREE_CODE (function) == PTRMEM_CST)
2554 /* Extracting the function address from a pmf is only
2555 allowed with -Wno-pmf-conversions. It only works for
2557 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2558 e1 = convert (fntype, e1);
2563 error ("object missing in use of %qE", function);
2564 return error_mark_node;
2568 if (TREE_SIDE_EFFECTS (instance_ptr))
2569 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2571 if (TREE_SIDE_EFFECTS (function))
2572 function = save_expr (function);
2574 /* Start by extracting all the information from the PMF itself. */
2575 e3 = pfn_from_ptrmemfunc (function);
2576 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2577 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2578 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2580 case ptrmemfunc_vbit_in_pfn:
2581 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2582 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2585 case ptrmemfunc_vbit_in_delta:
2586 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2587 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2594 /* Convert down to the right base before using the instance. A
2595 special case is that in a pointer to member of class C, C may
2596 be incomplete. In that case, the function will of course be
2597 a member of C, and no conversion is required. In fact,
2598 lookup_base will fail in that case, because incomplete
2599 classes do not have BINFOs. */
2600 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2601 if (!same_type_ignoring_top_level_qualifiers_p
2602 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2604 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2605 basetype, ba_check, NULL);
2606 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2608 if (instance_ptr == error_mark_node)
2609 return error_mark_node;
2611 /* ...and then the delta in the PMF. */
2612 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2613 instance_ptr, delta);
2615 /* Hand back the adjusted 'this' argument to our caller. */
2616 *instance_ptrptr = instance_ptr;
2618 /* Next extract the vtable pointer from the object. */
2619 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2621 vtbl = build_indirect_ref (vtbl, NULL);
2623 /* Finally, extract the function pointer from the vtable. */
2624 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2625 e2 = build_indirect_ref (e2, NULL);
2626 TREE_CONSTANT (e2) = 1;
2627 TREE_INVARIANT (e2) = 1;
2629 /* When using function descriptors, the address of the
2630 vtable entry is treated as a function pointer. */
2631 if (TARGET_VTABLE_USES_DESCRIPTORS)
2632 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2633 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2635 TREE_TYPE (e2) = TREE_TYPE (e3);
2636 e1 = build_conditional_expr (e1, e2, e3);
2638 /* Make sure this doesn't get evaluated first inside one of the
2639 branches of the COND_EXPR. */
2640 if (instance_save_expr)
2641 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2642 instance_save_expr, e1);
2650 build_function_call (tree function, tree params)
2652 tree fntype, fndecl;
2653 tree coerced_params;
2654 tree name = NULL_TREE;
2656 tree original = function;
2658 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2659 expressions, like those used for ObjC messenger dispatches. */
2660 function = objc_rewrite_function_call (function, params);
2662 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2663 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2664 if (TREE_CODE (function) == NOP_EXPR
2665 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2666 function = TREE_OPERAND (function, 0);
2668 if (TREE_CODE (function) == FUNCTION_DECL)
2670 name = DECL_NAME (function);
2672 mark_used (function);
2675 /* Convert anything with function type to a pointer-to-function. */
2676 if (pedantic && DECL_MAIN_P (function))
2677 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2679 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2680 (because calling an inline function does not mean the function
2681 needs to be separately compiled). */
2683 if (DECL_INLINE (function))
2684 function = inline_conversion (function);
2686 function = build_addr_func (function);
2692 function = build_addr_func (function);
2695 if (function == error_mark_node)
2696 return error_mark_node;
2698 fntype = TREE_TYPE (function);
2700 if (TYPE_PTRMEMFUNC_P (fntype))
2702 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2703 "function in %<%E (...)%>",
2705 return error_mark_node;
2708 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2709 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2711 if (!((TREE_CODE (fntype) == POINTER_TYPE
2712 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2714 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2716 error ("%qE cannot be used as a function", original);
2717 return error_mark_node;
2720 /* fntype now gets the type of function pointed to. */
2721 fntype = TREE_TYPE (fntype);
2723 /* Convert the parameters to the types declared in the
2724 function prototype, or apply default promotions. */
2726 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2727 params, fndecl, LOOKUP_NORMAL);
2728 if (coerced_params == error_mark_node)
2729 return error_mark_node;
2731 /* Check for errors in format strings and inappropriately
2734 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2735 TYPE_ARG_TYPES (fntype));
2737 return build_cxx_call (function, coerced_params);
2740 /* Convert the actual parameter expressions in the list VALUES
2741 to the types in the list TYPELIST.
2742 If parmdecls is exhausted, or when an element has NULL as its type,
2743 perform the default conversions.
2745 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2747 This is also where warnings about wrong number of args are generated.
2749 Return a list of expressions for the parameters as converted.
2751 Both VALUES and the returned value are chains of TREE_LIST nodes
2752 with the elements of the list in the TREE_VALUE slots of those nodes.
2754 In C++, unspecified trailing parameters can be filled in with their
2755 default arguments, if such were specified. Do so here. */
2758 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2760 tree typetail, valtail;
2761 tree result = NULL_TREE;
2762 const char *called_thing = 0;
2765 /* Argument passing is always copy-initialization. */
2766 flags |= LOOKUP_ONLYCONVERTING;
2770 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2772 if (DECL_NAME (fndecl) == NULL_TREE
2773 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2774 called_thing = "constructor";
2776 called_thing = "member function";
2779 called_thing = "function";
2782 for (valtail = values, typetail = typelist;
2784 valtail = TREE_CHAIN (valtail), i++)
2786 tree type = typetail ? TREE_VALUE (typetail) : 0;
2787 tree val = TREE_VALUE (valtail);
2789 if (val == error_mark_node || type == error_mark_node)
2790 return error_mark_node;
2792 if (type == void_type_node)
2796 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2797 error ("at this point in file");
2800 error ("too many arguments to function");
2801 /* In case anybody wants to know if this argument
2804 TREE_TYPE (tree_last (result)) = error_mark_node;
2808 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2809 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2810 if (TREE_CODE (val) == NOP_EXPR
2811 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2812 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2813 val = TREE_OPERAND (val, 0);
2815 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2817 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2818 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2819 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2820 val = decay_conversion (val);
2823 if (val == error_mark_node)
2824 return error_mark_node;
2828 /* Formal parm type is specified by a function prototype. */
2831 if (!COMPLETE_TYPE_P (complete_type (type)))
2834 error ("parameter %P of %qD has incomplete type %qT",
2837 error ("parameter %P has incomplete type %qT", i, type);
2838 parmval = error_mark_node;
2842 parmval = convert_for_initialization
2843 (NULL_TREE, type, val, flags,
2844 "argument passing", fndecl, i);
2845 parmval = convert_for_arg_passing (type, parmval);
2848 if (parmval == error_mark_node)
2849 return error_mark_node;
2851 result = tree_cons (NULL_TREE, parmval, result);
2855 if (fndecl && DECL_BUILT_IN (fndecl)
2856 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2857 /* Don't do ellipsis conversion for __built_in_constant_p
2858 as this will result in spurious warnings for non-POD
2860 val = require_complete_type (val);
2862 val = convert_arg_to_ellipsis (val);
2864 result = tree_cons (NULL_TREE, val, result);
2868 typetail = TREE_CHAIN (typetail);
2871 if (typetail != 0 && typetail != void_list_node)
2873 /* See if there are default arguments that can be used. */
2874 if (TREE_PURPOSE (typetail)
2875 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2877 for (; typetail != void_list_node; ++i)
2880 = convert_default_arg (TREE_VALUE (typetail),
2881 TREE_PURPOSE (typetail),
2884 if (parmval == error_mark_node)
2885 return error_mark_node;
2887 result = tree_cons (0, parmval, result);
2888 typetail = TREE_CHAIN (typetail);
2889 /* ends with `...'. */
2890 if (typetail == NULL_TREE)
2898 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2899 error ("at this point in file");
2902 error ("too few arguments to function");
2903 return error_mark_node;
2907 return nreverse (result);
2910 /* Build a binary-operation expression, after performing default
2911 conversions on the operands. CODE is the kind of expression to build. */
2914 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2915 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2924 if (processing_template_decl)
2926 if (type_dependent_expression_p (arg1)
2927 || type_dependent_expression_p (arg2))
2928 return build_min_nt (code, arg1, arg2);
2929 arg1 = build_non_dependent_expr (arg1);
2930 arg2 = build_non_dependent_expr (arg2);
2933 if (code == DOTSTAR_EXPR)
2934 expr = build_m_component_ref (arg1, arg2);
2936 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2939 /* Check for cases such as x+y<<z which users are likely to
2940 misinterpret. But don't warn about obj << x + y, since that is a
2941 common idiom for I/O. */
2942 if (warn_parentheses
2943 && !processing_template_decl
2944 && !error_operand_p (arg1)
2945 && !error_operand_p (arg2)
2946 && (code != LSHIFT_EXPR
2947 || !IS_AGGR_TYPE (TREE_TYPE (arg1))))
2948 warn_about_parentheses (code, arg1_code, arg2_code);
2950 if (processing_template_decl && expr != error_mark_node)
2951 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2956 /* Build a binary-operation expression without default conversions.
2957 CODE is the kind of expression to build.
2958 This function differs from `build' in several ways:
2959 the data type of the result is computed and recorded in it,
2960 warnings are generated if arg data types are invalid,
2961 special handling for addition and subtraction of pointers is known,
2962 and some optimization is done (operations on narrow ints
2963 are done in the narrower type when that gives the same result).
2964 Constant folding is also done before the result is returned.
2966 Note that the operands will never have enumeral types
2967 because either they have just had the default conversions performed
2968 or they have both just been converted to some other type in which
2969 the arithmetic is to be done.
2971 C++: must do special pointer arithmetic when implementing
2972 multiple inheritance, and deal with pointer to member functions. */
2975 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2976 int convert_p ATTRIBUTE_UNUSED)
2979 enum tree_code code0, code1;
2981 const char *invalid_op_diag;
2983 /* Expression code to give to the expression when it is built.
2984 Normally this is CODE, which is what the caller asked for,
2985 but in some special cases we change it. */
2986 enum tree_code resultcode = code;
2988 /* Data type in which the computation is to be performed.
2989 In the simplest cases this is the common type of the arguments. */
2990 tree result_type = NULL;
2992 /* Nonzero means operands have already been type-converted
2993 in whatever way is necessary.
2994 Zero means they need to be converted to RESULT_TYPE. */
2997 /* Nonzero means create the expression with this type, rather than
2999 tree build_type = 0;
3001 /* Nonzero means after finally constructing the expression
3002 convert it to this type. */
3003 tree final_type = 0;
3007 /* Nonzero if this is an operation like MIN or MAX which can
3008 safely be computed in short if both args are promoted shorts.
3009 Also implies COMMON.
3010 -1 indicates a bitwise operation; this makes a difference
3011 in the exact conditions for when it is safe to do the operation
3012 in a narrower mode. */
3015 /* Nonzero if this is a comparison operation;
3016 if both args are promoted shorts, compare the original shorts.
3017 Also implies COMMON. */
3018 int short_compare = 0;
3020 /* Nonzero if this is a right-shift operation, which can be computed on the
3021 original short and then promoted if the operand is a promoted short. */
3022 int short_shift = 0;
3024 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3027 /* True if both operands have arithmetic type. */
3028 bool arithmetic_types_p;
3030 /* Apply default conversions. */
3034 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3035 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3036 || code == TRUTH_XOR_EXPR)
3038 if (!really_overloaded_fn (op0))
3039 op0 = decay_conversion (op0);
3040 if (!really_overloaded_fn (op1))
3041 op1 = decay_conversion (op1);
3045 if (!really_overloaded_fn (op0))
3046 op0 = default_conversion (op0);
3047 if (!really_overloaded_fn (op1))
3048 op1 = default_conversion (op1);
3051 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3052 STRIP_TYPE_NOPS (op0);
3053 STRIP_TYPE_NOPS (op1);
3055 /* DTRT if one side is an overloaded function, but complain about it. */
3056 if (type_unknown_p (op0))
3058 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3059 if (t != error_mark_node)
3061 pedwarn ("assuming cast to type %qT from overloaded function",
3066 if (type_unknown_p (op1))
3068 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3069 if (t != error_mark_node)
3071 pedwarn ("assuming cast to type %qT from overloaded function",
3077 type0 = TREE_TYPE (op0);
3078 type1 = TREE_TYPE (op1);
3080 /* The expression codes of the data types of the arguments tell us
3081 whether the arguments are integers, floating, pointers, etc. */
3082 code0 = TREE_CODE (type0);
3083 code1 = TREE_CODE (type1);
3085 /* If an error was already reported for one of the arguments,
3086 avoid reporting another error. */
3088 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3089 return error_mark_node;
3091 if ((invalid_op_diag
3092 = targetm.invalid_binary_op (code, type0, type1)))
3094 error (invalid_op_diag);
3095 return error_mark_node;
3101 /* Subtraction of two similar pointers.
3102 We must subtract them as integers, then divide by object size. */
3103 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3104 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3106 return pointer_diff (op0, op1, common_type (type0, type1));
3107 /* In all other cases except pointer - int, the usual arithmetic
3109 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3114 /* The pointer - int case is just like pointer + int; fall
3117 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3118 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3122 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3123 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3124 if (processing_template_decl)
3126 result_type = TREE_TYPE (ptr_operand);
3129 return cp_pointer_int_sum (code,
3140 case TRUNC_DIV_EXPR:
3142 case FLOOR_DIV_EXPR:
3143 case ROUND_DIV_EXPR:
3144 case EXACT_DIV_EXPR:
3145 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3146 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3147 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3148 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3150 enum tree_code tcode0 = code0, tcode1 = code1;
3152 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3153 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3154 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3155 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3157 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3158 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3159 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3160 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3162 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3163 resultcode = RDIV_EXPR;
3165 /* When dividing two signed integers, we have to promote to int.
3166 unless we divide by a constant != -1. Note that default
3167 conversion will have been performed on the operands at this
3168 point, so we have to dig out the original type to find out if
3170 shorten = ((TREE_CODE (op0) == NOP_EXPR
3171 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3172 || (TREE_CODE (op1) == INTEGER_CST
3173 && ! integer_all_onesp (op1)));
3182 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3183 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3187 case TRUNC_MOD_EXPR:
3188 case FLOOR_MOD_EXPR:
3189 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3190 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3191 else if (code1 == REAL_TYPE && real_zerop (op1))
3192 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3194 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3196 /* Although it would be tempting to shorten always here, that loses
3197 on some targets, since the modulo instruction is undefined if the
3198 quotient can't be represented in the computation mode. We shorten
3199 only if unsigned or if dividing by something we know != -1. */
3200 shorten = ((TREE_CODE (op0) == NOP_EXPR
3201 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3202 || (TREE_CODE (op1) == INTEGER_CST
3203 && ! integer_all_onesp (op1)));
3208 case TRUTH_ANDIF_EXPR:
3209 case TRUTH_ORIF_EXPR:
3210 case TRUTH_AND_EXPR:
3212 result_type = boolean_type_node;
3215 /* Shift operations: result has same type as first operand;
3216 always convert second operand to int.
3217 Also set SHORT_SHIFT if shifting rightward. */
3220 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3222 result_type = type0;
3223 if (TREE_CODE (op1) == INTEGER_CST)
3225 if (tree_int_cst_lt (op1, integer_zero_node))
3226 warning (0, "right shift count is negative");
3229 if (! integer_zerop (op1))
3231 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3232 warning (0, "right shift count >= width of type");
3235 /* Convert the shift-count to an integer, regardless of
3236 size of value being shifted. */
3237 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3238 op1 = cp_convert (integer_type_node, op1);
3239 /* Avoid converting op1 to result_type later. */
3245 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3247 result_type = type0;
3248 if (TREE_CODE (op1) == INTEGER_CST)
3250 if (tree_int_cst_lt (op1, integer_zero_node))
3251 warning (0, "left shift count is negative");
3252 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3253 warning (0, "left shift count >= width of type");
3255 /* Convert the shift-count to an integer, regardless of
3256 size of value being shifted. */
3257 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3258 op1 = cp_convert (integer_type_node, op1);
3259 /* Avoid converting op1 to result_type later. */
3266 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3268 result_type = type0;
3269 if (TREE_CODE (op1) == INTEGER_CST)
3271 if (tree_int_cst_lt (op1, integer_zero_node))
3272 warning (0, "%s rotate count is negative",
3273 (code == LROTATE_EXPR) ? "left" : "right");
3274 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3275 warning (0, "%s rotate count >= width of type",
3276 (code == LROTATE_EXPR) ? "left" : "right");
3278 /* Convert the shift-count to an integer, regardless of
3279 size of value being shifted. */
3280 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3281 op1 = cp_convert (integer_type_node, op1);
3287 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3288 warning (OPT_Wfloat_equal,
3289 "comparing floating point with == or != is unsafe");
3290 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3291 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3292 warning (OPT_Waddress,
3293 "comparison with string literal results in unspecified behaviour");
3295 build_type = boolean_type_node;
3296 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3297 || code0 == COMPLEX_TYPE)
3298 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3299 || code1 == COMPLEX_TYPE))
3301 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3302 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3303 result_type = composite_pointer_type (type0, type1, op0, op1,
3305 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3306 && null_ptr_cst_p (op1))
3307 result_type = type0;
3308 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3309 && null_ptr_cst_p (op0))
3310 result_type = type1;
3311 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3313 result_type = type0;
3314 error ("ISO C++ forbids comparison between pointer and integer");
3316 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3318 result_type = type1;
3319 error ("ISO C++ forbids comparison between pointer and integer");
3321 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3323 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3324 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3325 result_type = TREE_TYPE (op0);
3327 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3328 return cp_build_binary_op (code, op1, op0);
3329 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3330 && same_type_p (type0, type1))
3332 /* E will be the final comparison. */
3334 /* E1 and E2 are for scratch. */
3342 if (TREE_SIDE_EFFECTS (op0))
3343 op0 = save_expr (op0);
3344 if (TREE_SIDE_EFFECTS (op1))
3345 op1 = save_expr (op1);
3350 && (!op0.pfn || op0.delta == op1.delta))
3352 The reason for the `!op0.pfn' bit is that a NULL
3353 pointer-to-member is any member with a zero PFN; the
3354 DELTA field is unspecified. */
3355 pfn0 = pfn_from_ptrmemfunc (op0);
3356 pfn1 = pfn_from_ptrmemfunc (op1);
3357 delta0 = build_ptrmemfunc_access_expr (op0,
3359 delta1 = build_ptrmemfunc_access_expr (op1,
3361 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3362 e2 = cp_build_binary_op (EQ_EXPR,
3364 cp_convert (TREE_TYPE (pfn0),
3365 integer_zero_node));
3366 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3367 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3368 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3369 if (code == EQ_EXPR)
3371 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3375 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3376 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3378 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3379 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3387 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3388 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3390 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3391 result_type = composite_pointer_type (type0, type1, op0, op1,
3399 if (TREE_CODE (orig_op0) == STRING_CST
3400 || TREE_CODE (orig_op1) == STRING_CST)
3401 warning (OPT_Waddress,
3402 "comparison with string literal results in unspecified behaviour");
3404 build_type = boolean_type_node;
3405 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3406 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3408 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3409 result_type = composite_pointer_type (type0, type1, op0, op1,
3411 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3412 && integer_zerop (op1))
3413 result_type = type0;
3414 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3415 && integer_zerop (op0))
3416 result_type = type1;
3417 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3419 result_type = type0;
3420 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3422 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3424 result_type = type1;
3425 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3429 case UNORDERED_EXPR:
3436 build_type = integer_type_node;
3437 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3439 error ("unordered comparison on non-floating point argument");
3440 return error_mark_node;
3449 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3450 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3451 || code1 == COMPLEX_TYPE)))
3452 arithmetic_types_p = 1;
3455 arithmetic_types_p = 0;
3456 /* Vector arithmetic is only allowed when both sides are vectors. */
3457 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3459 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3460 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3463 binary_op_error (code);
3464 return error_mark_node;
3466 arithmetic_types_p = 1;
3469 /* Determine the RESULT_TYPE, if it is not already known. */
3471 && arithmetic_types_p
3472 && (shorten || common || short_compare))
3473 result_type = common_type (type0, type1);
3477 error ("invalid operands of types %qT and %qT to binary %qO",
3478 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3479 return error_mark_node;
3482 /* If we're in a template, the only thing we need to know is the
3484 if (processing_template_decl)
3485 return build2 (resultcode,
3486 build_type ? build_type : result_type,
3489 if (arithmetic_types_p)
3491 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3493 /* For certain operations (which identify themselves by shorten != 0)
3494 if both args were extended from the same smaller type,
3495 do the arithmetic in that type and then extend.
3497 shorten !=0 and !=1 indicates a bitwise operation.
3498 For them, this optimization is safe only if
3499 both args are zero-extended or both are sign-extended.
3500 Otherwise, we might change the result.
3501 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3502 but calculated in (unsigned short) it would be (unsigned short)-1. */
3504 if (shorten && none_complex)
3506 int unsigned0, unsigned1;
3507 tree arg0 = get_narrower (op0, &unsigned0);
3508 tree arg1 = get_narrower (op1, &unsigned1);
3509 /* UNS is 1 if the operation to be done is an unsigned one. */
3510 int uns = TYPE_UNSIGNED (result_type);
3513 final_type = result_type;
3515 /* Handle the case that OP0 does not *contain* a conversion
3516 but it *requires* conversion to FINAL_TYPE. */
3518 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3519 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3520 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3521 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3523 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3525 /* For bitwise operations, signedness of nominal type
3526 does not matter. Consider only how operands were extended. */
3530 /* Note that in all three cases below we refrain from optimizing
3531 an unsigned operation on sign-extended args.
3532 That would not be valid. */
3534 /* Both args variable: if both extended in same way
3535 from same width, do it in that width.
3536 Do it unsigned if args were zero-extended. */
3537 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3538 < TYPE_PRECISION (result_type))
3539 && (TYPE_PRECISION (TREE_TYPE (arg1))
3540 == TYPE_PRECISION (TREE_TYPE (arg0)))
3541 && unsigned0 == unsigned1
3542 && (unsigned0 || !uns))
3543 result_type = c_common_signed_or_unsigned_type
3544 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3545 else if (TREE_CODE (arg0) == INTEGER_CST
3546 && (unsigned1 || !uns)
3547 && (TYPE_PRECISION (TREE_TYPE (arg1))
3548 < TYPE_PRECISION (result_type))
3549 && (type = c_common_signed_or_unsigned_type
3550 (unsigned1, TREE_TYPE (arg1)),
3551 int_fits_type_p (arg0, type)))
3553 else if (TREE_CODE (arg1) == INTEGER_CST
3554 && (unsigned0 || !uns)
3555 && (TYPE_PRECISION (TREE_TYPE (arg0))
3556 < TYPE_PRECISION (result_type))
3557 && (type = c_common_signed_or_unsigned_type
3558 (unsigned0, TREE_TYPE (arg0)),
3559 int_fits_type_p (arg1, type)))
3563 /* Shifts can be shortened if shifting right. */
3568 tree arg0 = get_narrower (op0, &unsigned_arg);
3570 final_type = result_type;
3572 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3573 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3575 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3576 /* We can shorten only if the shift count is less than the
3577 number of bits in the smaller type size. */
3578 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3579 /* If arg is sign-extended and then unsigned-shifted,
3580 we can simulate this with a signed shift in arg's type
3581 only if the extended result is at least twice as wide
3582 as the arg. Otherwise, the shift could use up all the
3583 ones made by sign-extension and bring in zeros.
3584 We can't optimize that case at all, but in most machines
3585 it never happens because available widths are 2**N. */
3586 && (!TYPE_UNSIGNED (final_type)
3588 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3589 <= TYPE_PRECISION (result_type))))
3591 /* Do an unsigned shift if the operand was zero-extended. */
3593 = c_common_signed_or_unsigned_type (unsigned_arg,
3595 /* Convert value-to-be-shifted to that type. */
3596 if (TREE_TYPE (op0) != result_type)
3597 op0 = cp_convert (result_type, op0);
3602 /* Comparison operations are shortened too but differently.
3603 They identify themselves by setting short_compare = 1. */
3607 /* Don't write &op0, etc., because that would prevent op0
3608 from being kept in a register.
3609 Instead, make copies of the our local variables and
3610 pass the copies by reference, then copy them back afterward. */
3611 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3612 enum tree_code xresultcode = resultcode;
3614 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3616 return cp_convert (boolean_type_node, val);
3617 op0 = xop0, op1 = xop1;
3619 resultcode = xresultcode;
3622 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3623 && warn_sign_compare
3624 /* Do not warn until the template is instantiated; we cannot
3625 bound the ranges of the arguments until that point. */
3626 && !processing_template_decl)
3628 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3629 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3631 int unsignedp0, unsignedp1;
3632 tree primop0 = get_narrower (op0, &unsignedp0);
3633 tree primop1 = get_narrower (op1, &unsignedp1);
3635 /* Check for comparison of different enum types. */
3636 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3637 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3638 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3639 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3641 warning (0, "comparison between types %q#T and %q#T",
3642 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3645 /* Give warnings for comparisons between signed and unsigned
3646 quantities that may fail. */
3647 /* Do the checking based on the original operand trees, so that
3648 casts will be considered, but default promotions won't be. */
3650 /* Do not warn if the comparison is being done in a signed type,
3651 since the signed type will only be chosen if it can represent
3652 all the values of the unsigned type. */
3653 if (!TYPE_UNSIGNED (result_type))
3655 /* Do not warn if both operands are unsigned. */
3656 else if (op0_signed == op1_signed)
3658 /* Do not warn if the signed quantity is an unsuffixed
3659 integer literal (or some static constant expression
3660 involving such literals or a conditional expression
3661 involving such literals) and it is non-negative. */
3662 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3663 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3665 /* Do not warn if the comparison is an equality operation,
3666 the unsigned quantity is an integral constant and it does
3667 not use the most significant bit of result_type. */
3668 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3669 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3670 && int_fits_type_p (orig_op1, c_common_signed_type
3672 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3673 && int_fits_type_p (orig_op0, c_common_signed_type
3677 warning (0, "comparison between signed and unsigned integer expressions");
3679 /* Warn if two unsigned values are being compared in a size
3680 larger than their original size, and one (and only one) is the
3681 result of a `~' operator. This comparison will always fail.
3683 Also warn if one operand is a constant, and the constant does not
3684 have all bits set that are set in the ~ operand when it is
3687 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3688 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3690 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3691 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3692 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3693 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3695 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3698 HOST_WIDE_INT constant, mask;
3702 if (host_integerp (primop0, 0))
3705 unsignedp = unsignedp1;
3706 constant = tree_low_cst (primop0, 0);
3711 unsignedp = unsignedp0;
3712 constant = tree_low_cst (primop1, 0);
3715 bits = TYPE_PRECISION (TREE_TYPE (primop));
3716 if (bits < TYPE_PRECISION (result_type)
3717 && bits < HOST_BITS_PER_LONG && unsignedp)
3719 mask = (~ (HOST_WIDE_INT) 0) << bits;
3720 if ((mask & constant) != mask)
3721 warning (0, "comparison of promoted ~unsigned with constant");
3724 else if (unsignedp0 && unsignedp1
3725 && (TYPE_PRECISION (TREE_TYPE (primop0))
3726 < TYPE_PRECISION (result_type))
3727 && (TYPE_PRECISION (TREE_TYPE (primop1))
3728 < TYPE_PRECISION (result_type)))
3729 warning (0, "comparison of promoted ~unsigned with unsigned");
3734 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3735 Then the expression will be built.
3736 It will be given type FINAL_TYPE if that is nonzero;
3737 otherwise, it will be given type RESULT_TYPE. */
3739 /* Issue warnings about peculiar, but valid, uses of NULL. */
3740 if (/* It's reasonable to use pointer values as operands of &&
3741 and ||, so NULL is no exception. */
3742 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3743 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3744 (orig_op0 == null_node
3745 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3746 /* Or vice versa. */
3747 || (orig_op1 == null_node
3748 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3749 /* Or, both are NULL and the operation was not a comparison. */
3750 || (orig_op0 == null_node && orig_op1 == null_node
3751 && code != EQ_EXPR && code != NE_EXPR)))
3752 /* Some sort of arithmetic operation involving NULL was
3753 performed. Note that pointer-difference and pointer-addition
3754 have already been handled above, and so we don't end up here in
3756 warning (0, "NULL used in arithmetic");
3760 if (TREE_TYPE (op0) != result_type)
3761 op0 = cp_convert (result_type, op0);
3762 if (TREE_TYPE (op1) != result_type)
3763 op1 = cp_convert (result_type, op1);
3765 if (op0 == error_mark_node || op1 == error_mark_node)
3766 return error_mark_node;
3769 if (build_type == NULL_TREE)
3770 build_type = result_type;
3772 result = build2 (resultcode, build_type, op0, op1);
3773 result = fold_if_not_in_template (result);
3774 if (final_type != 0)
3775 result = cp_convert (final_type, result);
3777 if (TREE_OVERFLOW_P (result)
3778 && !TREE_OVERFLOW_P (op0)
3779 && !TREE_OVERFLOW_P (op1))
3780 overflow_warning (result);
3785 /* Return a tree for the sum or difference (RESULTCODE says which)
3786 of pointer PTROP and integer INTOP. */
3789 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3791 tree res_type = TREE_TYPE (ptrop);
3793 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3794 in certain circumstance (when it's valid to do so). So we need
3795 to make sure it's complete. We don't need to check here, if we
3796 can actually complete it at all, as those checks will be done in
3797 pointer_int_sum() anyway. */
3798 complete_type (TREE_TYPE (res_type));
3800 return pointer_int_sum (resultcode, ptrop,
3801 fold_if_not_in_template (intop));
3804 /* Return a tree for the difference of pointers OP0 and OP1.
3805 The resulting tree has type int. */
3808 pointer_diff (tree op0, tree op1, tree ptrtype)
3811 tree restype = ptrdiff_type_node;
3812 tree target_type = TREE_TYPE (ptrtype);
3814 if (!complete_type_or_else (target_type, NULL_TREE))
3815 return error_mark_node;
3817 if (pedantic || warn_pointer_arith)
3819 if (TREE_CODE (target_type) == VOID_TYPE)
3820 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3821 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3822 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3823 if (TREE_CODE (target_type) == METHOD_TYPE)
3824 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3827 /* First do the subtraction as integers;
3828 then drop through to build the divide operator. */
3830 op0 = cp_build_binary_op (MINUS_EXPR,
3831 cp_convert (restype, op0),
3832 cp_convert (restype, op1));
3834 /* This generates an error if op1 is a pointer to an incomplete type. */
3835 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3836 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3838 op1 = (TYPE_PTROB_P (ptrtype)
3839 ? size_in_bytes (target_type)
3840 : integer_one_node);
3842 /* Do the division. */
3844 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3845 return fold_if_not_in_template (result);
3848 /* Construct and perhaps optimize a tree representation
3849 for a unary operation. CODE, a tree_code, specifies the operation
3850 and XARG is the operand. */
3853 build_x_unary_op (enum tree_code code, tree xarg)
3855 tree orig_expr = xarg;
3859 if (processing_template_decl)
3861 if (type_dependent_expression_p (xarg))
3862 return build_min_nt (code, xarg, NULL_TREE);
3864 xarg = build_non_dependent_expr (xarg);
3869 /* [expr.unary.op] says:
3871 The address of an object of incomplete type can be taken.
3873 (And is just the ordinary address operator, not an overloaded
3874 "operator &".) However, if the type is a template
3875 specialization, we must complete the type at this point so that
3876 an overloaded "operator &" will be available if required. */
3877 if (code == ADDR_EXPR
3878 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3879 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3880 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3881 || (TREE_CODE (xarg) == OFFSET_REF)))
3882 /* Don't look for a function. */;
3884 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3885 /*overloaded_p=*/NULL);
3886 if (!exp && code == ADDR_EXPR)
3888 /* A pointer to member-function can be formed only by saying
3890 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3891 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3893 if (TREE_CODE (xarg) != OFFSET_REF
3894 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3896 error ("invalid use of %qE to form a pointer-to-member-function",
3898 if (TREE_CODE (xarg) != OFFSET_REF)
3899 inform (" a qualified-id is required");
3900 return error_mark_node;
3904 error ("parentheses around %qE cannot be used to form a"
3905 " pointer-to-member-function",
3907 PTRMEM_OK_P (xarg) = 1;
3911 if (TREE_CODE (xarg) == OFFSET_REF)
3913 ptrmem = PTRMEM_OK_P (xarg);
3915 if (!ptrmem && !flag_ms_extensions
3916 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3918 /* A single non-static member, make sure we don't allow a
3919 pointer-to-member. */
3920 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3921 TREE_OPERAND (xarg, 0),
3922 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3923 PTRMEM_OK_P (xarg) = ptrmem;
3926 else if (TREE_CODE (xarg) == TARGET_EXPR)
3927 warning (0, "taking address of temporary");
3928 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3931 if (processing_template_decl && exp != error_mark_node)
3932 exp = build_min_non_dep (code, exp, orig_expr,
3933 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3934 if (TREE_CODE (exp) == ADDR_EXPR)
3935 PTRMEM_OK_P (exp) = ptrmem;
3939 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3940 constants, where a null value is represented by an INTEGER_CST of
3944 cp_truthvalue_conversion (tree expr)
3946 tree type = TREE_TYPE (expr);
3947 if (TYPE_PTRMEM_P (type))
3948 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3950 return c_common_truthvalue_conversion (expr);
3953 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3956 condition_conversion (tree expr)
3959 if (processing_template_decl)
3961 t = perform_implicit_conversion (boolean_type_node, expr);
3962 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3966 /* Return an ADDR_EXPR giving the address of T. This function
3967 attempts no optimizations or simplifications; it is a low-level
3971 build_address (tree t)
3975 if (error_operand_p (t) || !cxx_mark_addressable (t))
3976 return error_mark_node;
3978 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3983 /* Return a NOP_EXPR converting EXPR to TYPE. */
3986 build_nop (tree type, tree expr)
3988 if (type == error_mark_node || error_operand_p (expr))
3990 return build1 (NOP_EXPR, type, expr);
3993 /* C++: Must handle pointers to members.
3995 Perhaps type instantiation should be extended to handle conversion
3996 from aggregates to types we don't yet know we want? (Or are those
3997 cases typically errors which should be reported?)
3999 NOCONVERT nonzero suppresses the default promotions
4000 (such as from short to int). */
4003 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4005 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4008 const char *errstring = NULL;
4010 const char *invalid_op_diag;
4012 if (arg == error_mark_node)
4013 return error_mark_node;
4015 if ((invalid_op_diag
4016 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4021 error (invalid_op_diag);
4022 return error_mark_node;
4027 case UNARY_PLUS_EXPR:
4030 int flags = WANT_ARITH | WANT_ENUM;
4031 /* Unary plus (but not unary minus) is allowed on pointers. */
4032 if (code == UNARY_PLUS_EXPR)
4033 flags |= WANT_POINTER;
4034 arg = build_expr_type_conversion (flags, arg, true);
4036 errstring = (code == NEGATE_EXPR
4037 ? "wrong type argument to unary minus"
4038 : "wrong type argument to unary plus");
4041 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4042 arg = perform_integral_promotions (arg);
4044 /* Make sure the result is not an lvalue: a unary plus or minus
4045 expression is always a rvalue. */
4052 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4056 arg = default_conversion (arg);
4058 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4061 errstring = "wrong type argument to bit-complement";
4062 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4063 arg = perform_integral_promotions (arg);
4067 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4068 errstring = "wrong type argument to abs";
4069 else if (!noconvert)
4070 arg = default_conversion (arg);
4074 /* Conjugating a real value is a no-op, but allow it anyway. */
4075 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4076 errstring = "wrong type argument to conjugation";
4077 else if (!noconvert)
4078 arg = default_conversion (arg);
4081 case TRUTH_NOT_EXPR:
4082 arg = perform_implicit_conversion (boolean_type_node, arg);
4083 val = invert_truthvalue (arg);
4084 if (arg != error_mark_node)
4086 errstring = "in argument to unary !";
4093 if (TREE_CODE (arg) == COMPLEX_CST)
4094 return TREE_REALPART (arg);
4095 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4097 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4098 return fold_if_not_in_template (arg);
4104 if (TREE_CODE (arg) == COMPLEX_CST)
4105 return TREE_IMAGPART (arg);
4106 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4108 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4109 return fold_if_not_in_template (arg);
4112 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4114 case PREINCREMENT_EXPR:
4115 case POSTINCREMENT_EXPR:
4116 case PREDECREMENT_EXPR:
4117 case POSTDECREMENT_EXPR:
4118 /* Handle complex lvalues (when permitted)
4119 by reduction to simpler cases. */
4121 val = unary_complex_lvalue (code, arg);
4125 /* Increment or decrement the real part of the value,
4126 and don't change the imaginary part. */
4127 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4131 arg = stabilize_reference (arg);
4132 real = build_unary_op (REALPART_EXPR, arg, 1);
4133 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4134 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4135 build_unary_op (code, real, 1), imag);
4138 /* Report invalid types. */
4140 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4143 if (code == PREINCREMENT_EXPR)
4144 errstring ="no pre-increment operator for type";
4145 else if (code == POSTINCREMENT_EXPR)
4146 errstring ="no post-increment operator for type";
4147 else if (code == PREDECREMENT_EXPR)
4148 errstring ="no pre-decrement operator for type";
4150 errstring ="no post-decrement operator for type";
4154 /* Report something read-only. */
4156 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4157 || TREE_READONLY (arg))
4158 readonly_error (arg, ((code == PREINCREMENT_EXPR
4159 || code == POSTINCREMENT_EXPR)
4160 ? "increment" : "decrement"),
4166 tree result_type = TREE_TYPE (arg);
4168 declared_type = unlowered_expr_type (arg);
4170 arg = get_unwidened (arg, 0);
4171 argtype = TREE_TYPE (arg);
4173 /* ARM $5.2.5 last annotation says this should be forbidden. */
4174 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4175 pedwarn ("ISO C++ forbids %sing an enum",
4176 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4177 ? "increment" : "decrement");
4179 /* Compute the increment. */
4181 if (TREE_CODE (argtype) == POINTER_TYPE)
4183 tree type = complete_type (TREE_TYPE (argtype));
4185 if (!COMPLETE_OR_VOID_TYPE_P (type))
4186 error ("cannot %s a pointer to incomplete type %qT",
4187 ((code == PREINCREMENT_EXPR
4188 || code == POSTINCREMENT_EXPR)
4189 ? "increment" : "decrement"), TREE_TYPE (argtype));
4190 else if ((pedantic || warn_pointer_arith)
4191 && !TYPE_PTROB_P (argtype))
4192 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
4193 ((code == PREINCREMENT_EXPR
4194 || code == POSTINCREMENT_EXPR)
4195 ? "increment" : "decrement"), argtype);
4196 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4199 inc = integer_one_node;
4201 inc = cp_convert (argtype, inc);
4203 /* Handle incrementing a cast-expression. */
4205 switch (TREE_CODE (arg))
4210 case FIX_TRUNC_EXPR:
4211 case FIX_FLOOR_EXPR:
4212 case FIX_ROUND_EXPR:
4215 tree incremented, modify, value, compound;
4216 if (! lvalue_p (arg) && pedantic)
4217 pedwarn ("cast to non-reference type used as lvalue");
4218 arg = stabilize_reference (arg);
4219 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4222 value = save_expr (arg);
4223 incremented = build2 (((code == PREINCREMENT_EXPR
4224 || code == POSTINCREMENT_EXPR)
4225 ? PLUS_EXPR : MINUS_EXPR),
4226 argtype, value, inc);
4228 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4229 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4232 /* Eliminate warning about unused result of + or -. */
4233 TREE_NO_WARNING (compound) = 1;
4241 /* Complain about anything else that is not a true lvalue. */
4242 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4243 || code == POSTINCREMENT_EXPR)
4244 ? lv_increment : lv_decrement)))
4245 return error_mark_node;
4247 /* Forbid using -- on `bool'. */
4248 if (same_type_p (declared_type, boolean_type_node))
4250 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4252 error ("invalid use of %<--%> on bool variable %qD", arg);
4253 return error_mark_node;
4255 val = boolean_increment (code, arg);
4258 val = build2 (code, TREE_TYPE (arg), arg, inc);
4260 TREE_SIDE_EFFECTS (val) = 1;
4261 return cp_convert (result_type, val);
4265 /* Note that this operation never does default_conversion
4266 regardless of NOCONVERT. */
4268 argtype = lvalue_type (arg);
4270 if (TREE_CODE (arg) == OFFSET_REF)
4273 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4275 tree type = build_pointer_type (TREE_TYPE (argtype));
4276 arg = build1 (CONVERT_EXPR, type, arg);
4279 else if (pedantic && DECL_MAIN_P (arg))
4281 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4283 /* Let &* cancel out to simplify resulting code. */
4284 if (TREE_CODE (arg) == INDIRECT_REF)
4286 /* We don't need to have `current_class_ptr' wrapped in a
4287 NON_LVALUE_EXPR node. */
4288 if (arg == current_class_ref)
4289 return current_class_ptr;
4291 arg = TREE_OPERAND (arg, 0);
4292 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4294 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4295 arg = build1 (CONVERT_EXPR, type, arg);
4298 /* Don't let this be an lvalue. */
4303 /* Uninstantiated types are all functions. Taking the
4304 address of a function is a no-op, so just return the
4307 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4308 || !IDENTIFIER_OPNAME_P (arg));
4310 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4311 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4313 /* They're trying to take the address of a unique non-static
4314 member function. This is ill-formed (except in MS-land),
4315 but let's try to DTRT.
4316 Note: We only handle unique functions here because we don't
4317 want to complain if there's a static overload; non-unique
4318 cases will be handled by instantiate_type. But we need to
4319 handle this case here to allow casts on the resulting PMF.
4320 We could defer this in non-MS mode, but it's easier to give
4321 a useful error here. */
4323 /* Inside constant member functions, the `this' pointer
4324 contains an extra const qualifier. TYPE_MAIN_VARIANT
4325 is used here to remove this const from the diagnostics
4326 and the created OFFSET_REF. */
4327 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4328 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4331 if (! flag_ms_extensions)
4333 tree name = DECL_NAME (fn);
4334 if (current_class_type
4335 && TREE_OPERAND (arg, 0) == current_class_ref)
4336 /* An expression like &memfn. */
4337 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4338 " or parenthesized non-static member function to form"
4339 " a pointer to member function. Say %<&%T::%D%>",
4342 pedwarn ("ISO C++ forbids taking the address of a bound member"
4343 " function to form a pointer to member function."
4347 arg = build_offset_ref (base, fn, /*address_p=*/true);
4351 if (type_unknown_p (arg))
4352 return build1 (ADDR_EXPR, unknown_type_node, arg);
4354 /* Handle complex lvalues (when permitted)
4355 by reduction to simpler cases. */
4356 val = unary_complex_lvalue (code, arg);
4360 switch (TREE_CODE (arg))
4365 case FIX_TRUNC_EXPR:
4366 case FIX_FLOOR_EXPR:
4367 case FIX_ROUND_EXPR:
4369 if (! lvalue_p (arg) && pedantic)
4370 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4374 arg = BASELINK_FUNCTIONS (arg);
4378 arg = OVL_CURRENT (arg);
4382 /* Turn a reference to a non-static data member into a
4383 pointer-to-member. */
4388 if (!PTRMEM_OK_P (arg))
4389 return build_unary_op (code, arg, 0);
4391 t = TREE_OPERAND (arg, 1);
4392 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4394 error ("cannot create pointer to reference member %qD", t);
4395 return error_mark_node;
4398 type = build_ptrmem_type (context_for_name_lookup (t),
4400 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4408 /* Anything not already handled and not a true memory reference
4410 if (TREE_CODE (argtype) != FUNCTION_TYPE
4411 && TREE_CODE (argtype) != METHOD_TYPE
4412 && TREE_CODE (arg) != OFFSET_REF
4413 && !lvalue_or_else (arg, lv_addressof))
4414 return error_mark_node;
4416 if (argtype != error_mark_node)
4417 argtype = build_pointer_type (argtype);
4419 /* In a template, we are processing a non-dependent expression
4420 so we can just form an ADDR_EXPR with the correct type. */
4421 if (processing_template_decl)
4423 val = build_address (arg);
4424 if (TREE_CODE (arg) == OFFSET_REF)
4425 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4429 if (TREE_CODE (arg) != COMPONENT_REF)
4431 val = build_address (arg);
4432 if (TREE_CODE (arg) == OFFSET_REF)
4433 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4435 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4437 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4439 /* We can only get here with a single static member
4441 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4442 && DECL_STATIC_FUNCTION_P (fn));
4444 val = build_address (fn);
4445 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4446 /* Do not lose object's side effects. */
4447 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4448 TREE_OPERAND (arg, 0), val);
4450 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4452 error ("attempt to take address of bit-field structure member %qD",
4453 TREE_OPERAND (arg, 1));
4454 return error_mark_node;
4458 tree object = TREE_OPERAND (arg, 0);
4459 tree field = TREE_OPERAND (arg, 1);
4460 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4461 (TREE_TYPE (object), decl_type_context (field)));
4462 val = build_address (arg);
4465 if (TREE_CODE (argtype) == POINTER_TYPE
4466 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4468 build_ptrmemfunc_type (argtype);
4469 val = build_ptrmemfunc (argtype, val, 0,
4470 /*c_cast_p=*/false);
4482 argtype = TREE_TYPE (arg);
4483 return fold_if_not_in_template (build1 (code, argtype, arg));
4486 error ("%s", errstring);
4487 return error_mark_node;
4490 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4491 for certain kinds of expressions which are not really lvalues
4492 but which we can accept as lvalues.
4494 If ARG is not a kind of expression we can handle, return
4498 unary_complex_lvalue (enum tree_code code, tree arg)
4500 /* Inside a template, making these kinds of adjustments is
4501 pointless; we are only concerned with the type of the
4503 if (processing_template_decl)
4506 /* Handle (a, b) used as an "lvalue". */
4507 if (TREE_CODE (arg) == COMPOUND_EXPR)
4509 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4510 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4511 TREE_OPERAND (arg, 0), real_result);
4514 /* Handle (a ? b : c) used as an "lvalue". */
4515 if (TREE_CODE (arg) == COND_EXPR
4516 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4517 return rationalize_conditional_expr (code, arg);
4519 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4520 if (TREE_CODE (arg) == MODIFY_EXPR
4521 || TREE_CODE (arg) == PREINCREMENT_EXPR
4522 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4524 tree lvalue = TREE_OPERAND (arg, 0);
4525 if (TREE_SIDE_EFFECTS (lvalue))
4527 lvalue = stabilize_reference (lvalue);
4528 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4529 lvalue, TREE_OPERAND (arg, 1));
4531 return unary_complex_lvalue
4532 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4535 if (code != ADDR_EXPR)
4538 /* Handle (a = b) used as an "lvalue" for `&'. */
4539 if (TREE_CODE (arg) == MODIFY_EXPR
4540 || TREE_CODE (arg) == INIT_EXPR)
4542 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4543 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4545 TREE_NO_WARNING (arg) = 1;
4549 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4550 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4551 || TREE_CODE (arg) == OFFSET_REF)
4554 /* We permit compiler to make function calls returning
4555 objects of aggregate type look like lvalues. */
4559 if (TREE_CODE (targ) == SAVE_EXPR)
4560 targ = TREE_OPERAND (targ, 0);
4562 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4564 if (TREE_CODE (arg) == SAVE_EXPR)
4567 targ = build_cplus_new (TREE_TYPE (arg), arg);
4568 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4571 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4572 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4573 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4576 /* Don't let anything else be handled specially. */
4580 /* Mark EXP saying that we need to be able to take the
4581 address of it; it should not be allocated in a register.
4582 Value is true if successful.
4584 C++: we do not allow `current_class_ptr' to be addressable. */
4587 cxx_mark_addressable (tree exp)
4592 switch (TREE_CODE (x))
4599 x = TREE_OPERAND (x, 0);
4603 if (x == current_class_ptr)
4605 error ("cannot take the address of %<this%>, which is an rvalue expression");
4606 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4612 /* Caller should not be trying to mark initialized
4613 constant fields addressable. */
4614 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4615 || DECL_IN_AGGR_P (x) == 0
4617 || DECL_EXTERNAL (x));
4622 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4623 && !DECL_ARTIFICIAL (x))
4625 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4628 ("address of explicit register variable %qD requested", x);
4631 else if (extra_warnings)
4633 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4635 TREE_ADDRESSABLE (x) = 1;
4639 TREE_ADDRESSABLE (x) = 1;
4643 TREE_ADDRESSABLE (x) = 1;
4647 TREE_ADDRESSABLE (x) = 1;
4648 cxx_mark_addressable (TREE_OPERAND (x, 0));
4656 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4659 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4661 tree orig_ifexp = ifexp;
4662 tree orig_op1 = op1;
4663 tree orig_op2 = op2;
4666 if (processing_template_decl)
4668 /* The standard says that the expression is type-dependent if
4669 IFEXP is type-dependent, even though the eventual type of the
4670 expression doesn't dependent on IFEXP. */
4671 if (type_dependent_expression_p (ifexp)
4672 /* As a GNU extension, the middle operand may be omitted. */
4673 || (op1 && type_dependent_expression_p (op1))
4674 || type_dependent_expression_p (op2))
4675 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4676 ifexp = build_non_dependent_expr (ifexp);
4678 op1 = build_non_dependent_expr (op1);
4679 op2 = build_non_dependent_expr (op2);
4682 expr = build_conditional_expr (ifexp, op1, op2);
4683 if (processing_template_decl && expr != error_mark_node)
4684 return build_min_non_dep (COND_EXPR, expr,
4685 orig_ifexp, orig_op1, orig_op2);
4689 /* Given a list of expressions, return a compound expression
4690 that performs them all and returns the value of the last of them. */
4692 tree build_x_compound_expr_from_list (tree list, const char *msg)
4694 tree expr = TREE_VALUE (list);
4696 if (TREE_CHAIN (list))
4699 pedwarn ("%s expression list treated as compound expression", msg);
4701 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4702 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4708 /* Handle overloading of the ',' operator when needed. */
4711 build_x_compound_expr (tree op1, tree op2)
4714 tree orig_op1 = op1;
4715 tree orig_op2 = op2;
4717 if (processing_template_decl)
4719 if (type_dependent_expression_p (op1)
4720 || type_dependent_expression_p (op2))
4721 return build_min_nt (COMPOUND_EXPR, op1, op2);
4722 op1 = build_non_dependent_expr (op1);
4723 op2 = build_non_dependent_expr (op2);
4726 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4727 /*overloaded_p=*/NULL);
4729 result = build_compound_expr (op1, op2);
4731 if (processing_template_decl && result != error_mark_node)
4732 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4737 /* Build a compound expression. */
4740 build_compound_expr (tree lhs, tree rhs)
4742 lhs = convert_to_void (lhs, "left-hand operand of comma");
4744 if (lhs == error_mark_node || rhs == error_mark_node)
4745 return error_mark_node;
4747 if (TREE_CODE (rhs) == TARGET_EXPR)
4749 /* If the rhs is a TARGET_EXPR, then build the compound
4750 expression inside the target_expr's initializer. This
4751 helps the compiler to eliminate unnecessary temporaries. */
4752 tree init = TREE_OPERAND (rhs, 1);
4754 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4755 TREE_OPERAND (rhs, 1) = init;
4760 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4763 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4764 casts away constness. DIAG_FN gives the function to call if we
4765 need to issue a diagnostic; if it is NULL, no diagnostic will be
4766 issued. DESCRIPTION explains what operation is taking place. */
4769 check_for_casting_away_constness (tree src_type, tree dest_type,
4770 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4771 const char *description)
4773 if (diag_fn && casts_away_constness (src_type, dest_type))
4774 diag_fn ("%s from type %qT to type %qT casts away constness",
4775 description, src_type, dest_type);
4778 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4779 (another pointer-to-member type in the same hierarchy) and return
4780 the converted expression. If ALLOW_INVERSE_P is permitted, a
4781 pointer-to-derived may be converted to pointer-to-base; otherwise,
4782 only the other direction is permitted. If C_CAST_P is true, this
4783 conversion is taking place as part of a C-style cast. */
4786 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4789 if (TYPE_PTRMEM_P (type))
4793 if (TREE_CODE (expr) == PTRMEM_CST)
4794 expr = cplus_expand_constant (expr);
4795 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4796 TYPE_PTRMEM_CLASS_TYPE (type),
4799 if (!integer_zerop (delta))
4800 expr = cp_build_binary_op (PLUS_EXPR,
4801 build_nop (ptrdiff_type_node, expr),
4803 return build_nop (type, expr);
4806 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4807 allow_inverse_p, c_cast_p);
4810 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4811 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4812 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4815 ignore_overflows (tree expr, tree orig)
4817 if (TREE_CODE (expr) == INTEGER_CST
4818 && CONSTANT_CLASS_P (orig)
4819 && TREE_CODE (orig) != STRING_CST
4820 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4821 || TREE_CONSTANT_OVERFLOW (expr)
4822 != TREE_CONSTANT_OVERFLOW (orig)))
4824 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4825 /* Ensure constant sharing. */
4826 expr = build_int_cst_wide (TREE_TYPE (expr),
4827 TREE_INT_CST_LOW (expr),
4828 TREE_INT_CST_HIGH (expr));
4831 /* Avoid clobbering a shared constant. */
4832 expr = copy_node (expr);
4833 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4834 TREE_CONSTANT_OVERFLOW (expr)
4835 = TREE_CONSTANT_OVERFLOW (orig);
4841 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4842 this static_cast is being attempted as one of the possible casts
4843 allowed by a C-style cast. (In that case, accessibility of base
4844 classes is not considered, and it is OK to cast away
4845 constness.) Return the result of the cast. *VALID_P is set to
4846 indicate whether or not the cast was valid. */
4849 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4855 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4858 /* Assume the cast is valid. */
4861 intype = TREE_TYPE (expr);
4863 /* Save casted types in the function's used types hash table. */
4864 used_types_insert (type);
4866 /* Determine what to do when casting away constness. */
4869 /* C-style casts are allowed to cast away constness. With
4870 WARN_CAST_QUAL, we still want to issue a warning. */
4871 diag_fn = warn_cast_qual ? warning0 : NULL;
4876 /* A static_cast may not cast away constness. */
4878 desc = "static_cast";
4881 /* [expr.static.cast]
4883 An lvalue of type "cv1 B", where B is a class type, can be cast
4884 to type "reference to cv2 D", where D is a class derived (clause
4885 _class.derived_) from B, if a valid standard conversion from
4886 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4887 same cv-qualification as, or greater cv-qualification than, cv1,
4888 and B is not a virtual base class of D. */
4889 /* We check this case before checking the validity of "TYPE t =
4890 EXPR;" below because for this case:
4893 struct D : public B { D(const B&); };
4895 void f() { static_cast<const D&>(b); }
4897 we want to avoid constructing a new D. The standard is not
4898 completely clear about this issue, but our interpretation is
4899 consistent with other compilers. */
4900 if (TREE_CODE (type) == REFERENCE_TYPE
4901 && CLASS_TYPE_P (TREE_TYPE (type))
4902 && CLASS_TYPE_P (intype)
4903 && real_lvalue_p (expr)
4904 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4905 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4906 build_pointer_type (TYPE_MAIN_VARIANT
4907 (TREE_TYPE (type))))
4909 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4913 /* There is a standard conversion from "D*" to "B*" even if "B"
4914 is ambiguous or inaccessible. If this is really a
4915 static_cast, then we check both for inaccessibility and
4916 ambiguity. However, if this is a static_cast being performed
4917 because the user wrote a C-style cast, then accessibility is
4919 base = lookup_base (TREE_TYPE (type), intype,
4920 c_cast_p ? ba_unique : ba_check,
4923 /* Convert from "B*" to "D*". This function will check that "B"
4924 is not a virtual base of "D". */
4925 expr = build_base_path (MINUS_EXPR, build_address (expr),
4926 base, /*nonnull=*/false);
4927 /* Convert the pointer to a reference -- but then remember that
4928 there are no expressions with reference type in C++. */
4929 return convert_from_reference (build_nop (type, expr));
4934 /* [expr.static.cast]
4936 An expression e can be explicitly converted to a type T using a
4937 static_cast of the form static_cast<T>(e) if the declaration T
4938 t(e);" is well-formed, for some invented temporary variable
4940 result = perform_direct_initialization_if_possible (type, expr,
4944 result = convert_from_reference (result);
4946 /* Ignore any integer overflow caused by the cast. */
4947 result = ignore_overflows (result, orig);
4949 /* [expr.static.cast]
4951 If T is a reference type, the result is an lvalue; otherwise,
4952 the result is an rvalue. */
4953 if (TREE_CODE (type) != REFERENCE_TYPE)
4954 result = rvalue (result);
4958 /* [expr.static.cast]
4960 Any expression can be explicitly converted to type cv void. */
4961 if (TREE_CODE (type) == VOID_TYPE)
4962 return convert_to_void (expr, /*implicit=*/NULL);
4964 /* [expr.static.cast]
4966 The inverse of any standard conversion sequence (clause _conv_),
4967 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4968 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4969 (_conv.bool_) conversions, can be performed explicitly using
4970 static_cast subject to the restriction that the explicit
4971 conversion does not cast away constness (_expr.const.cast_), and
4972 the following additional rules for specific cases: */
4973 /* For reference, the conversions not excluded are: integral
4974 promotions, floating point promotion, integral conversions,
4975 floating point conversions, floating-integral conversions,
4976 pointer conversions, and pointer to member conversions. */
4979 A value of integral _or enumeration_ type can be explicitly
4980 converted to an enumeration type. */
4981 /* The effect of all that is that any conversion between any two
4982 types which are integral, floating, or enumeration types can be
4984 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4985 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4987 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4989 /* Ignore any integer overflow caused by the cast. */
4990 expr = ignore_overflows (expr, orig);
4994 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4995 && CLASS_TYPE_P (TREE_TYPE (type))
4996 && CLASS_TYPE_P (TREE_TYPE (intype))
4997 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4998 (TREE_TYPE (intype))),
4999 build_pointer_type (TYPE_MAIN_VARIANT
5000 (TREE_TYPE (type)))))
5005 check_for_casting_away_constness (intype, type, diag_fn, desc);
5006 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5007 c_cast_p ? ba_unique : ba_check,
5009 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5012 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5013 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5020 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5021 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5023 if (TYPE_PTRMEM_P (type))
5025 t1 = (build_ptrmem_type
5027 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5028 t2 = (build_ptrmem_type
5030 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5037 if (can_convert (t1, t2))
5040 check_for_casting_away_constness (intype, type, diag_fn,
5042 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5047 /* [expr.static.cast]
5049 An rvalue of type "pointer to cv void" can be explicitly
5050 converted to a pointer to object type. A value of type pointer
5051 to object converted to "pointer to cv void" and back to the
5052 original pointer type will have its original value. */
5053 if (TREE_CODE (intype) == POINTER_TYPE
5054 && VOID_TYPE_P (TREE_TYPE (intype))
5055 && TYPE_PTROB_P (type))
5058 check_for_casting_away_constness (intype, type, diag_fn, desc);
5059 return build_nop (type, expr);
5063 return error_mark_node;
5066 /* Return an expression representing static_cast<TYPE>(EXPR). */
5069 build_static_cast (tree type, tree expr)
5074 if (type == error_mark_node || expr == error_mark_node)
5075 return error_mark_node;
5077 if (processing_template_decl)
5079 expr = build_min (STATIC_CAST_EXPR, type, expr);
5080 /* We don't know if it will or will not have side effects. */
5081 TREE_SIDE_EFFECTS (expr) = 1;
5082 return convert_from_reference (expr);
5085 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5086 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5087 if (TREE_CODE (type) != REFERENCE_TYPE
5088 && TREE_CODE (expr) == NOP_EXPR
5089 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5090 expr = TREE_OPERAND (expr, 0);
5092 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5096 error ("invalid static_cast from type %qT to type %qT",
5097 TREE_TYPE (expr), type);
5098 return error_mark_node;
5101 /* EXPR is an expression with member function or pointer-to-member
5102 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5103 not permitted by ISO C++, but we accept it in some modes. If we
5104 are not in one of those modes, issue a diagnostic. Return the
5105 converted expression. */
5108 convert_member_func_to_ptr (tree type, tree expr)
5113 intype = TREE_TYPE (expr);
5114 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5115 || TREE_CODE (intype) == METHOD_TYPE);
5117 if (pedantic || warn_pmf2ptr)
5118 pedwarn ("converting from %qT to %qT", intype, type);
5120 if (TREE_CODE (intype) == METHOD_TYPE)
5121 expr = build_addr_func (expr);
5122 else if (TREE_CODE (expr) == PTRMEM_CST)
5123 expr = build_address (PTRMEM_CST_MEMBER (expr));
5126 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5127 decl = build_address (decl);
5128 expr = get_member_function_from_ptrfunc (&decl, expr);
5131 return build_nop (type, expr);
5134 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5135 If C_CAST_P is true, this reinterpret cast is being done as part of
5136 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5137 indicate whether or not reinterpret_cast was valid. */
5140 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5145 /* Assume the cast is invalid. */
5149 if (type == error_mark_node || error_operand_p (expr))
5150 return error_mark_node;
5152 intype = TREE_TYPE (expr);
5154 /* Save casted types in the function's used types hash table. */
5155 used_types_insert (type);
5157 /* [expr.reinterpret.cast]
5158 An lvalue expression of type T1 can be cast to the type
5159 "reference to T2" if an expression of type "pointer to T1" can be
5160 explicitly converted to the type "pointer to T2" using a
5161 reinterpret_cast. */
5162 if (TREE_CODE (type) == REFERENCE_TYPE)
5164 if (! real_lvalue_p (expr))
5166 error ("invalid cast of an rvalue expression of type "
5169 return error_mark_node;
5172 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5173 "B" are related class types; the reinterpret_cast does not
5174 adjust the pointer. */
5175 if (TYPE_PTR_P (intype)
5176 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5177 COMPARE_BASE | COMPARE_DERIVED)))
5178 warning (0, "casting %qT to %qT does not dereference pointer",
5181 expr = build_unary_op (ADDR_EXPR, expr, 0);
5182 if (expr != error_mark_node)
5183 expr = build_reinterpret_cast_1
5184 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5186 if (expr != error_mark_node)
5187 expr = build_indirect_ref (expr, 0);
5191 /* As a G++ extension, we consider conversions from member
5192 functions, and pointers to member functions to
5193 pointer-to-function and pointer-to-void types. If
5194 -Wno-pmf-conversions has not been specified,
5195 convert_member_func_to_ptr will issue an error message. */
5196 if ((TYPE_PTRMEMFUNC_P (intype)
5197 || TREE_CODE (intype) == METHOD_TYPE)
5198 && TYPE_PTR_P (type)
5199 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5200 || VOID_TYPE_P (TREE_TYPE (type))))
5201 return convert_member_func_to_ptr (type, expr);
5203 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5204 array-to-pointer, and function-to-pointer conversions are
5206 expr = decay_conversion (expr);
5208 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5209 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5210 if (TREE_CODE (expr) == NOP_EXPR
5211 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5212 expr = TREE_OPERAND (expr, 0);
5214 if (error_operand_p (expr))
5215 return error_mark_node;
5217 intype = TREE_TYPE (expr);
5219 /* [expr.reinterpret.cast]
5220 A pointer can be converted to any integral type large enough to
5222 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5224 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5225 pedwarn ("cast from %qT to %qT loses precision",
5228 /* [expr.reinterpret.cast]
5229 A value of integral or enumeration type can be explicitly
5230 converted to a pointer. */
5231 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5234 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5235 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5236 return fold_if_not_in_template (build_nop (type, expr));
5237 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5238 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5243 check_for_casting_away_constness (intype, type, error,
5244 "reinterpret_cast");
5245 /* Warn about possible alignment problems. */
5246 if (STRICT_ALIGNMENT && warn_cast_align
5247 && !VOID_TYPE_P (type)
5248 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5249 && COMPLETE_TYPE_P (TREE_TYPE (type))
5250 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5251 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5252 warning (0, "cast from %qT to %qT increases required alignment of "
5256 /* We need to strip nops here, because the frontend likes to
5257 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5259 strict_aliasing_warning (intype, type, sexpr);
5261 return fold_if_not_in_template (build_nop (type, expr));
5263 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5264 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5267 /* Only issue a warning, as we have always supported this
5268 where possible, and it is necessary in some cases. DR 195
5269 addresses this issue, but as of 2004/10/26 is still in
5271 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5272 return fold_if_not_in_template (build_nop (type, expr));
5274 else if (TREE_CODE (type) == VECTOR_TYPE)
5275 return fold_if_not_in_template (convert_to_vector (type, expr));
5276 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5277 return fold_if_not_in_template (convert_to_integer (type, expr));
5282 error ("invalid cast from type %qT to type %qT", intype, type);
5283 return error_mark_node;
5286 return cp_convert (type, expr);
5290 build_reinterpret_cast (tree type, tree expr)
5292 if (type == error_mark_node || expr == error_mark_node)
5293 return error_mark_node;
5295 if (processing_template_decl)
5297 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5299 if (!TREE_SIDE_EFFECTS (t)
5300 && type_dependent_expression_p (expr))
5301 /* There might turn out to be side effects inside expr. */
5302 TREE_SIDE_EFFECTS (t) = 1;
5303 return convert_from_reference (t);
5306 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5310 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5311 return an appropriate expression. Otherwise, return
5312 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5313 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5314 performing a C-style cast, its value upon return will indicate
5315 whether or not the conversion succeeded. */
5318 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5322 tree reference_type;
5324 /* Callers are responsible for handling error_mark_node as a
5325 destination type. */
5326 gcc_assert (dst_type != error_mark_node);
5327 /* In a template, callers should be building syntactic
5328 representations of casts, not using this machinery. */
5329 gcc_assert (!processing_template_decl);
5331 /* Assume the conversion is invalid. */
5335 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5338 error ("invalid use of const_cast with type %qT, "
5339 "which is not a pointer, "
5340 "reference, nor a pointer-to-data-member type", dst_type);
5341 return error_mark_node;
5344 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5347 error ("invalid use of const_cast with type %qT, which is a pointer "
5348 "or reference to a function type", dst_type);
5349 return error_mark_node;
5352 /* Save casted types in the function's used types hash table. */
5353 used_types_insert (dst_type);
5355 src_type = TREE_TYPE (expr);
5356 /* Expressions do not really have reference types. */
5357 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5358 src_type = TREE_TYPE (src_type);
5360 /* [expr.const.cast]
5362 An lvalue of type T1 can be explicitly converted to an lvalue of
5363 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5364 types) if a pointer to T1 can be explicitly converted to the type
5365 pointer to T2 using a const_cast. */
5366 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5368 reference_type = dst_type;
5369 if (! real_lvalue_p (expr))
5372 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5373 src_type, dst_type);
5374 return error_mark_node;
5376 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5377 src_type = build_pointer_type (src_type);
5381 reference_type = NULL_TREE;
5382 /* If the destination type is not a reference type, the
5383 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5384 conversions are performed. */
5385 src_type = type_decays_to (src_type);
5386 if (src_type == error_mark_node)
5387 return error_mark_node;
5390 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5391 && comp_ptr_ttypes_const (dst_type, src_type))
5396 /* This cast is actually a C-style cast. Issue a warning if
5397 the user is making a potentially unsafe cast. */
5399 check_for_casting_away_constness (src_type, dst_type,
5405 expr = build_unary_op (ADDR_EXPR, expr, 0);
5406 expr = build_nop (reference_type, expr);
5407 return convert_from_reference (expr);
5411 expr = decay_conversion (expr);
5412 /* build_c_cast puts on a NOP_EXPR to make the result not an
5413 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5414 non-lvalue context. */
5415 if (TREE_CODE (expr) == NOP_EXPR
5416 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5417 expr = TREE_OPERAND (expr, 0);
5418 return build_nop (dst_type, expr);
5423 error ("invalid const_cast from type %qT to type %qT",
5424 src_type, dst_type);
5425 return error_mark_node;
5429 build_const_cast (tree type, tree expr)
5431 if (type == error_mark_node || error_operand_p (expr))
5432 return error_mark_node;
5434 if (processing_template_decl)
5436 tree t = build_min (CONST_CAST_EXPR, type, expr);
5438 if (!TREE_SIDE_EFFECTS (t)
5439 && type_dependent_expression_p (expr))
5440 /* There might turn out to be side effects inside expr. */
5441 TREE_SIDE_EFFECTS (t) = 1;
5442 return convert_from_reference (t);
5445 return build_const_cast_1 (type, expr, /*complain=*/true,
5449 /* Build an expression representing an explicit C-style cast to type
5450 TYPE of expression EXPR. */
5453 build_c_cast (tree type, tree expr)
5459 if (type == error_mark_node || error_operand_p (expr))
5460 return error_mark_node;
5462 if (processing_template_decl)
5464 tree t = build_min (CAST_EXPR, type,
5465 tree_cons (NULL_TREE, value, NULL_TREE));
5466 /* We don't know if it will or will not have side effects. */
5467 TREE_SIDE_EFFECTS (t) = 1;
5468 return convert_from_reference (t);
5471 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5472 'Class') should always be retained, because this information aids
5473 in method lookup. */
5474 if (objc_is_object_ptr (type)
5475 && objc_is_object_ptr (TREE_TYPE (expr)))
5476 return build_nop (type, expr);
5478 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5479 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5480 if (TREE_CODE (type) != REFERENCE_TYPE
5481 && TREE_CODE (value) == NOP_EXPR
5482 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5483 value = TREE_OPERAND (value, 0);
5485 if (TREE_CODE (type) == ARRAY_TYPE)
5487 /* Allow casting from T1* to T2[] because Cfront allows it.
5488 NIHCL uses it. It is not valid ISO C++ however. */
5489 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5491 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5492 type = build_pointer_type (TREE_TYPE (type));
5496 error ("ISO C++ forbids casting to an array type %qT", type);
5497 return error_mark_node;
5501 if (TREE_CODE (type) == FUNCTION_TYPE
5502 || TREE_CODE (type) == METHOD_TYPE)
5504 error ("invalid cast to function type %qT", type);
5505 return error_mark_node;
5508 /* A C-style cast can be a const_cast. */
5509 result = build_const_cast_1 (type, value, /*complain=*/false,
5514 /* Or a static cast. */
5515 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5517 /* Or a reinterpret_cast. */
5519 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5521 /* The static_cast or reinterpret_cast may be followed by a
5524 /* A valid cast may result in errors if, for example, a
5525 conversion to am ambiguous base class is required. */
5526 && !error_operand_p (result))
5530 /* Non-class rvalues always have cv-unqualified type. */
5531 if (!CLASS_TYPE_P (type))
5532 type = TYPE_MAIN_VARIANT (type);
5533 result_type = TREE_TYPE (result);
5534 if (!CLASS_TYPE_P (result_type))
5535 result_type = TYPE_MAIN_VARIANT (result_type);
5536 /* If the type of RESULT does not match TYPE, perform a
5537 const_cast to make it match. If the static_cast or
5538 reinterpret_cast succeeded, we will differ by at most
5539 cv-qualification, so the follow-on const_cast is guaranteed
5541 if (!same_type_p (non_reference (type), non_reference (result_type)))
5543 result = build_const_cast_1 (type, result, false, &valid_p);
5544 gcc_assert (valid_p);
5549 return error_mark_node;
5552 /* Build an assignment expression of lvalue LHS from value RHS.
5553 MODIFYCODE is the code for a binary operator that we use
5554 to combine the old value of LHS with RHS to get the new value.
5555 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5557 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5560 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5564 tree lhstype = TREE_TYPE (lhs);
5565 tree olhstype = lhstype;
5566 tree olhs = NULL_TREE;
5567 bool plain_assign = (modifycode == NOP_EXPR);
5569 /* Avoid duplicate error messages from operands that had errors. */
5570 if (error_operand_p (lhs) || error_operand_p (rhs))
5571 return error_mark_node;
5573 /* Handle control structure constructs used as "lvalues". */
5574 switch (TREE_CODE (lhs))
5576 /* Handle --foo = 5; as these are valid constructs in C++. */
5577 case PREDECREMENT_EXPR:
5578 case PREINCREMENT_EXPR:
5579 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5580 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5581 stabilize_reference (TREE_OPERAND (lhs, 0)),
5582 TREE_OPERAND (lhs, 1));
5583 return build2 (COMPOUND_EXPR, lhstype,
5585 build_modify_expr (TREE_OPERAND (lhs, 0),
5588 /* Handle (a, b) used as an "lvalue". */
5590 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5592 if (newrhs == error_mark_node)
5593 return error_mark_node;
5594 return build2 (COMPOUND_EXPR, lhstype,
5595 TREE_OPERAND (lhs, 0), newrhs);
5598 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5599 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5600 stabilize_reference (TREE_OPERAND (lhs, 0)),
5601 TREE_OPERAND (lhs, 1));
5602 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5603 if (newrhs == error_mark_node)
5604 return error_mark_node;
5605 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5609 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5610 when neither operand has side-effects. */
5611 if (!lvalue_or_else (lhs, lv_assign))
5612 return error_mark_node;
5614 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5615 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5617 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5618 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5620 TREE_OPERAND (lhs, 0),
5621 TREE_OPERAND (lhs, 1)),
5622 TREE_OPERAND (lhs, 0),
5623 TREE_OPERAND (lhs, 1));
5626 /* Handle (a ? b : c) used as an "lvalue". */
5629 /* Produce (a ? (b = rhs) : (c = rhs))
5630 except that the RHS goes through a save-expr
5631 so the code to compute it is only emitted once. */
5633 tree preeval = NULL_TREE;
5635 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5637 error ("void value not ignored as it ought to be");
5638 return error_mark_node;
5641 rhs = stabilize_expr (rhs, &preeval);
5643 /* Check this here to avoid odd errors when trying to convert
5644 a throw to the type of the COND_EXPR. */
5645 if (!lvalue_or_else (lhs, lv_assign))
5646 return error_mark_node;
5648 cond = build_conditional_expr
5649 (TREE_OPERAND (lhs, 0),
5650 build_modify_expr (TREE_OPERAND (lhs, 1),
5652 build_modify_expr (TREE_OPERAND (lhs, 2),
5655 if (cond == error_mark_node)
5657 /* Make sure the code to compute the rhs comes out
5658 before the split. */
5660 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5668 if (modifycode == INIT_EXPR)
5670 if (TREE_CODE (rhs) == CONSTRUCTOR)
5672 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5673 /* Call convert to generate an error; see PR 11063. */
5674 rhs = convert (lhstype, rhs);
5675 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5676 TREE_SIDE_EFFECTS (result) = 1;
5679 else if (! IS_AGGR_TYPE (lhstype))
5680 /* Do the default thing. */;
5683 result = build_special_member_call (lhs, complete_ctor_identifier,
5684 build_tree_list (NULL_TREE, rhs),
5685 lhstype, LOOKUP_NORMAL);
5686 if (result == NULL_TREE)
5687 return error_mark_node;
5693 lhs = require_complete_type (lhs);
5694 if (lhs == error_mark_node)
5695 return error_mark_node;
5697 if (modifycode == NOP_EXPR)
5699 /* `operator=' is not an inheritable operator. */
5700 if (! IS_AGGR_TYPE (lhstype))
5701 /* Do the default thing. */;
5704 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5705 lhs, rhs, make_node (NOP_EXPR),
5706 /*overloaded_p=*/NULL);
5707 if (result == NULL_TREE)
5708 return error_mark_node;
5715 /* A binary op has been requested. Combine the old LHS
5716 value with the RHS producing the value we should actually
5717 store into the LHS. */
5719 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5720 lhs = stabilize_reference (lhs);
5721 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5722 if (newrhs == error_mark_node)
5724 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5725 TREE_TYPE (lhs), TREE_TYPE (rhs));
5726 return error_mark_node;
5729 /* Now it looks like a plain assignment. */
5730 modifycode = NOP_EXPR;
5732 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5733 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5736 /* The left-hand side must be an lvalue. */
5737 if (!lvalue_or_else (lhs, lv_assign))
5738 return error_mark_node;
5740 /* Warn about modifying something that is `const'. Don't warn if
5741 this is initialization. */
5742 if (modifycode != INIT_EXPR
5743 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5744 /* Functions are not modifiable, even though they are
5746 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5747 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5748 /* If it's an aggregate and any field is const, then it is
5749 effectively const. */
5750 || (CLASS_TYPE_P (lhstype)
5751 && C_TYPE_FIELDS_READONLY (lhstype))))
5752 readonly_error (lhs, "assignment", 0);
5754 /* If storing into a structure or union member, it has probably been
5755 given type `int'. Compute the type that would go with the actual
5756 amount of storage the member occupies. */
5758 if (TREE_CODE (lhs) == COMPONENT_REF
5759 && (TREE_CODE (lhstype) == INTEGER_TYPE
5760 || TREE_CODE (lhstype) == REAL_TYPE
5761 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5763 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5765 /* If storing in a field that is in actuality a short or narrower
5766 than one, we must store in the field in its actual type. */
5768 if (lhstype != TREE_TYPE (lhs))
5770 /* Avoid warnings converting integral types back into enums for
5772 if (TREE_CODE (lhstype) == INTEGER_TYPE
5773 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5775 if (TREE_SIDE_EFFECTS (lhs))
5776 lhs = stabilize_reference (lhs);
5779 lhs = copy_node (lhs);
5780 TREE_TYPE (lhs) = lhstype;
5784 /* Convert new value to destination type. */
5786 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5790 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5791 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5793 error ("incompatible types in assignment of %qT to %qT",
5794 TREE_TYPE (rhs), lhstype);
5795 return error_mark_node;
5798 /* Allow array assignment in compiler-generated code. */
5799 if (! DECL_ARTIFICIAL (current_function_decl))
5801 /* This routine is used for both initialization and assignment.
5802 Make sure the diagnostic message differentiates the context. */
5803 if (modifycode == INIT_EXPR)
5804 error ("array used as initializer");
5806 error ("invalid array assignment");
5807 return error_mark_node;
5810 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5811 ? 1 + (modifycode != INIT_EXPR): 0;
5812 return build_vec_init (lhs, NULL_TREE, newrhs,
5813 /*explicit_default_init_p=*/false,
5817 if (modifycode == INIT_EXPR)
5818 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5819 "initialization", NULL_TREE, 0);
5822 /* Avoid warnings on enum bit fields. */
5823 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5824 && TREE_CODE (lhstype) == INTEGER_TYPE)
5826 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5828 newrhs = convert_force (lhstype, newrhs, 0);
5831 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5833 if (TREE_CODE (newrhs) == CALL_EXPR
5834 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5835 newrhs = build_cplus_new (lhstype, newrhs);
5837 /* Can't initialize directly from a TARGET_EXPR, since that would
5838 cause the lhs to be constructed twice, and possibly result in
5839 accidental self-initialization. So we force the TARGET_EXPR to be
5840 expanded without a target. */
5841 if (TREE_CODE (newrhs) == TARGET_EXPR)
5842 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5843 TREE_OPERAND (newrhs, 0));
5846 if (newrhs == error_mark_node)
5847 return error_mark_node;
5849 if (c_dialect_objc () && flag_objc_gc)
5851 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5857 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5858 lhstype, lhs, newrhs);
5860 TREE_SIDE_EFFECTS (result) = 1;
5862 TREE_NO_WARNING (result) = 1;
5864 /* If we got the LHS in a different type for storing in,
5865 convert the result back to the nominal type of LHS
5866 so that the value we return always has the same type
5867 as the LHS argument. */
5869 if (olhstype == TREE_TYPE (result))
5873 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5874 TREE_NO_WARNING (result) = 1;
5877 return convert_for_assignment (olhstype, result, "assignment",
5882 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5884 if (processing_template_decl)
5885 return build_min_nt (MODOP_EXPR, lhs,
5886 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5888 if (modifycode != NOP_EXPR)
5890 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5891 make_node (modifycode),
5892 /*overloaded_p=*/NULL);
5895 TREE_NO_WARNING (rval) = 1;
5899 return build_modify_expr (lhs, modifycode, rhs);
5903 /* Get difference in deltas for different pointer to member function
5904 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5905 the conversion is invalid, the constant is zero. If
5906 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5907 If C_CAST_P is true this conversion is taking place as part of a
5910 Note that the naming of FROM and TO is kind of backwards; the return
5911 value is what we add to a TO in order to get a FROM. They are named
5912 this way because we call this function to find out how to convert from
5913 a pointer to member of FROM to a pointer to member of TO. */
5916 get_delta_difference (tree from, tree to,
5917 bool allow_inverse_p,
5924 /* Assume no conversion is required. */
5925 result = integer_zero_node;
5926 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5927 if (kind == bk_inaccessible || kind == bk_ambig)
5928 error (" in pointer to member function conversion");
5931 if (kind != bk_via_virtual)
5932 result = BINFO_OFFSET (binfo);
5935 tree virt_binfo = binfo_from_vbase (binfo);
5937 /* This is a reinterpret cast, we choose to do nothing. */
5938 if (allow_inverse_p)
5939 warning (0, "pointer to member cast via virtual base %qT",
5940 BINFO_TYPE (virt_binfo));
5942 error ("pointer to member conversion via virtual base %qT",
5943 BINFO_TYPE (virt_binfo));
5946 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5947 /* Pointer to member of incomplete class is permitted*/;
5948 else if (!allow_inverse_p)
5950 error_not_base_type (from, to);
5951 error (" in pointer to member conversion");
5955 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5958 if (kind != bk_via_virtual)
5959 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5962 /* This is a reinterpret cast, we choose to do nothing. */
5963 tree virt_binfo = binfo_from_vbase (binfo);
5965 warning (0, "pointer to member cast via virtual base %qT",
5966 BINFO_TYPE (virt_binfo));
5971 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5975 /* Return a constructor for the pointer-to-member-function TYPE using
5976 the other components as specified. */
5979 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5984 VEC(constructor_elt, gc) *v;
5986 /* Pull the FIELD_DECLs out of the type. */
5987 pfn_field = TYPE_FIELDS (type);
5988 delta_field = TREE_CHAIN (pfn_field);
5990 /* Make sure DELTA has the type we want. */
5991 delta = convert_and_check (delta_type_node, delta);
5993 /* Finish creating the initializer. */
5994 v = VEC_alloc(constructor_elt, gc, 2);
5995 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
5996 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
5997 u = build_constructor (type, v);
5998 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5999 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6000 TREE_STATIC (u) = (TREE_CONSTANT (u)
6001 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6003 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6008 /* Build a constructor for a pointer to member function. It can be
6009 used to initialize global variables, local variable, or used
6010 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6013 If FORCE is nonzero, then force this conversion, even if
6014 we would rather not do it. Usually set when using an explicit
6015 cast. A C-style cast is being processed iff C_CAST_P is true.
6017 Return error_mark_node, if something goes wrong. */
6020 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6026 if (error_operand_p (pfn))
6027 return error_mark_node;
6029 pfn_type = TREE_TYPE (pfn);
6030 to_type = build_ptrmemfunc_type (type);
6032 /* Handle multiple conversions of pointer to member functions. */
6033 if (TYPE_PTRMEMFUNC_P (pfn_type))
6035 tree delta = NULL_TREE;
6036 tree npfn = NULL_TREE;
6040 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6041 error ("invalid conversion to type %qT from type %qT",
6044 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6045 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6049 /* We don't have to do any conversion to convert a
6050 pointer-to-member to its own type. But, we don't want to
6051 just return a PTRMEM_CST if there's an explicit cast; that
6052 cast should make the expression an invalid template argument. */
6053 if (TREE_CODE (pfn) != PTRMEM_CST)
6055 if (same_type_p (to_type, pfn_type))
6057 else if (integer_zerop (n))
6058 return build_reinterpret_cast (to_type, pfn);
6061 if (TREE_SIDE_EFFECTS (pfn))
6062 pfn = save_expr (pfn);
6064 /* Obtain the function pointer and the current DELTA. */
6065 if (TREE_CODE (pfn) == PTRMEM_CST)
6066 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6069 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6070 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6073 /* Just adjust the DELTA field. */
6074 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6075 (TREE_TYPE (delta), ptrdiff_type_node));
6076 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6077 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6078 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6079 return build_ptrmemfunc1 (to_type, delta, npfn);
6082 /* Handle null pointer to member function conversions. */
6083 if (integer_zerop (pfn))
6085 pfn = build_c_cast (type, integer_zero_node);
6086 return build_ptrmemfunc1 (to_type,
6091 if (type_unknown_p (pfn))
6092 return instantiate_type (type, pfn, tf_warning_or_error);
6094 fn = TREE_OPERAND (pfn, 0);
6095 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6096 /* In a template, we will have preserved the
6098 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6099 return make_ptrmem_cst (to_type, fn);
6102 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6105 ??? There is no consistency as to the types returned for the above
6106 values. Some code acts as if it were a sizetype and some as if it were
6107 integer_type_node. */
6110 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6112 tree type = TREE_TYPE (cst);
6113 tree fn = PTRMEM_CST_MEMBER (cst);
6114 tree ptr_class, fn_class;
6116 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6118 /* The class that the function belongs to. */
6119 fn_class = DECL_CONTEXT (fn);
6121 /* The class that we're creating a pointer to member of. */
6122 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6124 /* First, calculate the adjustment to the function's class. */
6125 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6128 if (!DECL_VIRTUAL_P (fn))
6129 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6132 /* If we're dealing with a virtual function, we have to adjust 'this'
6133 again, to point to the base which provides the vtable entry for
6134 fn; the call will do the opposite adjustment. */
6135 tree orig_class = DECL_CONTEXT (fn);
6136 tree binfo = binfo_or_else (orig_class, fn_class);
6137 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6138 *delta, BINFO_OFFSET (binfo));
6139 *delta = fold_if_not_in_template (*delta);
6141 /* We set PFN to the vtable offset at which the function can be
6142 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6143 case delta is shifted left, and then incremented). */
6144 *pfn = DECL_VINDEX (fn);
6145 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6146 TYPE_SIZE_UNIT (vtable_entry_type));
6147 *pfn = fold_if_not_in_template (*pfn);
6149 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6151 case ptrmemfunc_vbit_in_pfn:
6152 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6154 *pfn = fold_if_not_in_template (*pfn);
6157 case ptrmemfunc_vbit_in_delta:
6158 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6159 *delta, integer_one_node);
6160 *delta = fold_if_not_in_template (*delta);
6161 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6162 *delta, integer_one_node);
6163 *delta = fold_if_not_in_template (*delta);
6170 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6171 *pfn = fold_if_not_in_template (*pfn);
6175 /* Return an expression for PFN from the pointer-to-member function
6179 pfn_from_ptrmemfunc (tree t)
6181 if (TREE_CODE (t) == PTRMEM_CST)
6186 expand_ptrmemfunc_cst (t, &delta, &pfn);
6191 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6194 /* Convert value RHS to type TYPE as preparation for an assignment to
6195 an lvalue of type TYPE. ERRTYPE is a string to use in error
6196 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6197 are doing the conversion in order to pass the PARMNUMth argument of
6201 convert_for_assignment (tree type, tree rhs,
6202 const char *errtype, tree fndecl, int parmnum)
6205 enum tree_code coder;
6207 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6208 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6209 rhs = TREE_OPERAND (rhs, 0);
6211 rhstype = TREE_TYPE (rhs);
6212 coder = TREE_CODE (rhstype);
6214 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6215 && vector_types_convertible_p (type, rhstype))
6216 return convert (type, rhs);
6218 if (rhs == error_mark_node || rhstype == error_mark_node)
6219 return error_mark_node;
6220 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6221 return error_mark_node;
6223 /* The RHS of an assignment cannot have void type. */
6224 if (coder == VOID_TYPE)
6226 error ("void value not ignored as it ought to be");
6227 return error_mark_node;
6230 /* Simplify the RHS if possible. */
6231 if (TREE_CODE (rhs) == CONST_DECL)
6232 rhs = DECL_INITIAL (rhs);
6234 if (c_dialect_objc ())
6237 tree rname = fndecl;
6239 if (!strcmp (errtype, "assignment"))
6241 else if (!strcmp (errtype, "initialization"))
6245 tree selector = objc_message_selector ();
6249 if (selector && parmno > 1)
6256 if (objc_compare_types (type, rhstype, parmno, rname))
6257 return convert (type, rhs);
6262 The expression is implicitly converted (clause _conv_) to the
6263 cv-unqualified type of the left operand.
6265 We allow bad conversions here because by the time we get to this point
6266 we are committed to doing the conversion. If we end up doing a bad
6267 conversion, convert_like will complain. */
6268 if (!can_convert_arg_bad (type, rhstype, rhs))
6270 /* When -Wno-pmf-conversions is use, we just silently allow
6271 conversions from pointers-to-members to plain pointers. If
6272 the conversion doesn't work, cp_convert will complain. */
6274 && TYPE_PTR_P (type)
6275 && TYPE_PTRMEMFUNC_P (rhstype))
6276 rhs = cp_convert (strip_top_quals (type), rhs);
6279 /* If the right-hand side has unknown type, then it is an
6280 overloaded function. Call instantiate_type to get error
6282 if (rhstype == unknown_type_node)
6283 instantiate_type (type, rhs, tf_warning_or_error);
6285 error ("cannot convert %qT to %qT for argument %qP to %qD",
6286 rhstype, type, parmnum, fndecl);
6288 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6289 return error_mark_node;
6292 if (warn_missing_format_attribute)
6294 const enum tree_code codel = TREE_CODE (type);
6295 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6297 && check_missing_format_attribute (type, rhstype))
6298 warning (OPT_Wmissing_format_attribute,
6299 "%s might be a candidate for a format attribute",
6303 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6305 if (warn_parentheses
6306 && type == boolean_type_node
6307 && TREE_CODE (rhs) == MODIFY_EXPR
6308 && !TREE_NO_WARNING (rhs)
6309 && TREE_TYPE (rhs) != boolean_type_node)
6311 warning (OPT_Wparentheses,
6312 "suggest parentheses around assignment used as truth value");
6313 TREE_NO_WARNING (rhs) = 1;
6316 return perform_implicit_conversion (strip_top_quals (type), rhs);
6319 /* Convert RHS to be of type TYPE.
6320 If EXP is nonzero, it is the target of the initialization.
6321 ERRTYPE is a string to use in error messages.
6323 Two major differences between the behavior of
6324 `convert_for_assignment' and `convert_for_initialization'
6325 are that references are bashed in the former, while
6326 copied in the latter, and aggregates are assigned in
6327 the former (operator=) while initialized in the
6330 If using constructor make sure no conversion operator exists, if one does
6331 exist, an ambiguity exists.
6333 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6336 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6337 const char *errtype, tree fndecl, int parmnum)
6339 enum tree_code codel = TREE_CODE (type);
6341 enum tree_code coder;
6343 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6344 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6345 if (TREE_CODE (rhs) == NOP_EXPR
6346 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6347 && codel != REFERENCE_TYPE)
6348 rhs = TREE_OPERAND (rhs, 0);
6350 if (type == error_mark_node
6351 || rhs == error_mark_node
6352 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6353 return error_mark_node;
6355 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6356 && TREE_CODE (type) != ARRAY_TYPE
6357 && (TREE_CODE (type) != REFERENCE_TYPE
6358 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6359 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6360 && (TREE_CODE (type) != REFERENCE_TYPE
6361 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6362 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6363 rhs = decay_conversion (rhs);
6365 rhstype = TREE_TYPE (rhs);
6366 coder = TREE_CODE (rhstype);
6368 if (coder == ERROR_MARK)
6369 return error_mark_node;
6371 /* We accept references to incomplete types, so we can
6372 return here before checking if RHS is of complete type. */
6374 if (codel == REFERENCE_TYPE)
6376 /* This should eventually happen in convert_arguments. */
6377 int savew = 0, savee = 0;
6380 savew = warningcount, savee = errorcount;
6381 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6385 if (warningcount > savew)
6386 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6387 else if (errorcount > savee)
6388 error ("in passing argument %P of %q+D", parmnum, fndecl);
6394 exp = require_complete_type (exp);
6395 if (exp == error_mark_node)
6396 return error_mark_node;
6398 rhstype = non_reference (rhstype);
6400 type = complete_type (type);
6402 if (IS_AGGR_TYPE (type))
6403 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6405 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6408 /* If RETVAL is the address of, or a reference to, a local variable or
6409 temporary give an appropriate warning. */
6412 maybe_warn_about_returning_address_of_local (tree retval)
6414 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6415 tree whats_returned = retval;
6419 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6420 whats_returned = TREE_OPERAND (whats_returned, 1);
6421 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6422 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6423 || TREE_CODE (whats_returned) == NOP_EXPR)
6424 whats_returned = TREE_OPERAND (whats_returned, 0);
6429 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6431 whats_returned = TREE_OPERAND (whats_returned, 0);
6433 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6435 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6436 || TREE_CODE (whats_returned) == TARGET_EXPR)
6438 warning (0, "returning reference to temporary");
6441 if (TREE_CODE (whats_returned) == VAR_DECL
6442 && DECL_NAME (whats_returned)
6443 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6445 warning (0, "reference to non-lvalue returned");
6450 while (TREE_CODE (whats_returned) == COMPONENT_REF
6451 || TREE_CODE (whats_returned) == ARRAY_REF)
6452 whats_returned = TREE_OPERAND (whats_returned, 0);
6454 if (DECL_P (whats_returned)
6455 && DECL_NAME (whats_returned)
6456 && DECL_FUNCTION_SCOPE_P (whats_returned)
6457 && !(TREE_STATIC (whats_returned)
6458 || TREE_PUBLIC (whats_returned)))
6460 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6461 warning (0, "reference to local variable %q+D returned",
6464 warning (0, "address of local variable %q+D returned",
6470 /* Check that returning RETVAL from the current function is valid.
6471 Return an expression explicitly showing all conversions required to
6472 change RETVAL into the function return type, and to assign it to
6473 the DECL_RESULT for the function. Set *NO_WARNING to true if
6474 code reaches end of non-void function warning shouldn't be issued
6475 on this RETURN_EXPR. */
6478 check_return_expr (tree retval, bool *no_warning)
6481 /* The type actually returned by the function, after any
6484 int fn_returns_value_p;
6486 *no_warning = false;
6488 /* A `volatile' function is one that isn't supposed to return, ever.
6489 (This is a G++ extension, used to get better code for functions
6490 that call the `volatile' function.) */
6491 if (TREE_THIS_VOLATILE (current_function_decl))
6492 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6494 /* Check for various simple errors. */
6495 if (DECL_DESTRUCTOR_P (current_function_decl))
6498 error ("returning a value from a destructor");
6501 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6503 if (in_function_try_handler)
6504 /* If a return statement appears in a handler of the
6505 function-try-block of a constructor, the program is ill-formed. */
6506 error ("cannot return from a handler of a function-try-block of a constructor");
6508 /* You can't return a value from a constructor. */
6509 error ("returning a value from a constructor");
6513 if (processing_template_decl)
6515 current_function_returns_value = 1;
6519 /* When no explicit return-value is given in a function with a named
6520 return value, the named return value is used. */
6521 result = DECL_RESULT (current_function_decl);
6522 valtype = TREE_TYPE (result);
6523 gcc_assert (valtype != NULL_TREE);
6524 fn_returns_value_p = !VOID_TYPE_P (valtype);
6525 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6528 /* Check for a return statement with no return value in a function
6529 that's supposed to return a value. */
6530 if (!retval && fn_returns_value_p)
6532 pedwarn ("return-statement with no value, in function returning %qT",
6534 /* Clear this, so finish_function won't say that we reach the
6535 end of a non-void function (which we don't, we gave a
6537 current_function_returns_null = 0;
6538 /* And signal caller that TREE_NO_WARNING should be set on the
6539 RETURN_EXPR to avoid control reaches end of non-void function
6540 warnings in tree-cfg.c. */
6543 /* Check for a return statement with a value in a function that
6544 isn't supposed to return a value. */
6545 else if (retval && !fn_returns_value_p)
6547 if (VOID_TYPE_P (TREE_TYPE (retval)))
6548 /* You can return a `void' value from a function of `void'
6549 type. In that case, we have to evaluate the expression for
6550 its side-effects. */
6551 finish_expr_stmt (retval);
6553 pedwarn ("return-statement with a value, in function "
6554 "returning 'void'");
6556 current_function_returns_null = 1;
6558 /* There's really no value to return, after all. */
6562 /* Remember that this function can sometimes return without a
6564 current_function_returns_null = 1;
6566 /* Remember that this function did return a value. */
6567 current_function_returns_value = 1;
6569 /* Check for erroneous operands -- but after giving ourselves a
6570 chance to provide an error about returning a value from a void
6572 if (error_operand_p (retval))
6574 current_function_return_value = error_mark_node;
6575 return error_mark_node;
6578 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6579 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6580 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6581 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6583 && null_ptr_cst_p (retval))
6584 warning (0, "%<operator new%> must not return NULL unless it is "
6585 "declared %<throw()%> (or -fcheck-new is in effect)");
6587 /* Effective C++ rule 15. See also start_function. */
6589 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6593 /* The function return type must be a reference to the current
6595 if (TREE_CODE (valtype) == REFERENCE_TYPE
6596 && same_type_ignoring_top_level_qualifiers_p
6597 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6599 /* Returning '*this' is obviously OK. */
6600 if (retval == current_class_ref)
6602 /* If we are calling a function whose return type is the same of
6603 the current class reference, it is ok. */
6604 else if (TREE_CODE (retval) == INDIRECT_REF
6605 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6610 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6613 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6615 [...] For a function with a class return type, if the expression
6616 in the return statement is the name of a local object, and the cv-
6617 unqualified type of the local object is the same as the function
6618 return type, an implementation is permitted to omit creating the tem-
6619 porary object to hold the function return value [...]
6621 So, if this is a value-returning function that always returns the same
6622 local variable, remember it.
6624 It might be nice to be more flexible, and choose the first suitable
6625 variable even if the function sometimes returns something else, but
6626 then we run the risk of clobbering the variable we chose if the other
6627 returned expression uses the chosen variable somehow. And people expect
6628 this restriction, anyway. (jason 2000-11-19)
6630 See finish_function and finalize_nrv for the rest of this optimization. */
6632 if (fn_returns_value_p && flag_elide_constructors)
6634 if (retval != NULL_TREE
6635 && (current_function_return_value == NULL_TREE
6636 || current_function_return_value == retval)
6637 && TREE_CODE (retval) == VAR_DECL
6638 && DECL_CONTEXT (retval) == current_function_decl
6639 && ! TREE_STATIC (retval)
6640 && ! DECL_ANON_UNION_VAR_P (retval)
6641 && (DECL_ALIGN (retval)
6642 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6643 && same_type_p ((TYPE_MAIN_VARIANT
6644 (TREE_TYPE (retval))),
6646 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6647 current_function_return_value = retval;
6649 current_function_return_value = error_mark_node;
6652 /* We don't need to do any conversions when there's nothing being
6657 /* Do any required conversions. */
6658 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6659 /* No conversions are required. */
6663 /* The type the function is declared to return. */
6664 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6666 /* The functype's return type will have been set to void, if it
6667 was an incomplete type. Just treat this as 'return;' */
6668 if (VOID_TYPE_P (functype))
6669 return error_mark_node;
6671 /* First convert the value to the function's return type, then
6672 to the type of return value's location to handle the
6673 case that functype is smaller than the valtype. */
6674 retval = convert_for_initialization
6675 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6676 "return", NULL_TREE, 0);
6677 retval = convert (valtype, retval);
6679 /* If the conversion failed, treat this just like `return;'. */
6680 if (retval == error_mark_node)
6682 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6683 else if (! current_function_returns_struct
6684 && TREE_CODE (retval) == TARGET_EXPR
6685 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6686 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6687 TREE_OPERAND (retval, 0));
6689 maybe_warn_about_returning_address_of_local (retval);
6692 /* Actually copy the value returned into the appropriate location. */
6693 if (retval && retval != result)
6694 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6700 /* Returns nonzero if the pointer-type FROM can be converted to the
6701 pointer-type TO via a qualification conversion. If CONSTP is -1,
6702 then we return nonzero if the pointers are similar, and the
6703 cv-qualification signature of FROM is a proper subset of that of TO.
6705 If CONSTP is positive, then all outer pointers have been
6709 comp_ptr_ttypes_real (tree to, tree from, int constp)
6711 bool to_more_cv_qualified = false;
6713 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6715 if (TREE_CODE (to) != TREE_CODE (from))
6718 if (TREE_CODE (from) == OFFSET_TYPE
6719 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6720 TYPE_OFFSET_BASETYPE (to)))
6723 /* Const and volatile mean something different for function types,
6724 so the usual checks are not appropriate. */
6725 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6727 /* In Objective-C++, some types may have been 'volatilized' by
6728 the compiler for EH; when comparing them here, the volatile
6729 qualification must be ignored. */
6730 bool objc_quals_match = objc_type_quals_match (to, from);
6732 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6735 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6739 to_more_cv_qualified = true;
6743 constp &= TYPE_READONLY (to);
6746 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6747 return ((constp >= 0 || to_more_cv_qualified)
6748 && same_type_ignoring_top_level_qualifiers_p (to, from));
6752 /* When comparing, say, char ** to char const **, this function takes
6753 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6754 types to this function. */
6757 comp_ptr_ttypes (tree to, tree from)
6759 return comp_ptr_ttypes_real (to, from, 1);
6762 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6763 type or inheritance-related types, regardless of cv-quals. */
6766 ptr_reasonably_similar (tree to, tree from)
6768 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6770 /* Any target type is similar enough to void. */
6771 if (TREE_CODE (to) == VOID_TYPE
6772 || TREE_CODE (from) == VOID_TYPE)
6775 if (TREE_CODE (to) != TREE_CODE (from))
6778 if (TREE_CODE (from) == OFFSET_TYPE
6779 && comptypes (TYPE_OFFSET_BASETYPE (to),
6780 TYPE_OFFSET_BASETYPE (from),
6781 COMPARE_BASE | COMPARE_DERIVED))
6784 if (TREE_CODE (to) == VECTOR_TYPE
6785 && vector_types_convertible_p (to, from))
6788 if (TREE_CODE (to) == INTEGER_TYPE
6789 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6792 if (TREE_CODE (to) == FUNCTION_TYPE)
6795 if (TREE_CODE (to) != POINTER_TYPE)
6797 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6798 COMPARE_BASE | COMPARE_DERIVED);
6802 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6803 pointer-to-member types) are the same, ignoring cv-qualification at
6807 comp_ptr_ttypes_const (tree to, tree from)
6809 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6811 if (TREE_CODE (to) != TREE_CODE (from))
6814 if (TREE_CODE (from) == OFFSET_TYPE
6815 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6816 TYPE_OFFSET_BASETYPE (to)))
6819 if (TREE_CODE (to) != POINTER_TYPE)
6820 return same_type_ignoring_top_level_qualifiers_p (to, from);
6824 /* Returns the type qualifiers for this type, including the qualifiers on the
6825 elements for an array type. */
6828 cp_type_quals (tree type)
6830 type = strip_array_types (type);
6831 if (type == error_mark_node)
6832 return TYPE_UNQUALIFIED;
6833 return TYPE_QUALS (type);
6836 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6840 cp_type_readonly (tree type)
6842 type = strip_array_types (type);
6843 return TYPE_READONLY (type);
6846 /* Returns nonzero if the TYPE contains a mutable member. */
6849 cp_has_mutable_p (tree type)
6851 type = strip_array_types (type);
6853 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6856 /* Apply the TYPE_QUALS to the new DECL. */
6858 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6860 tree type = TREE_TYPE (decl);
6862 if (type == error_mark_node)
6865 if (TREE_CODE (type) == FUNCTION_TYPE
6866 && type_quals != TYPE_UNQUALIFIED)
6868 /* This was an error in C++98 (cv-qualifiers cannot be added to
6869 a function type), but DR 295 makes the code well-formed by
6870 dropping the extra qualifiers. */
6873 tree bad_type = build_qualified_type (type, type_quals);
6874 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6878 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6882 /* Avoid setting TREE_READONLY incorrectly. */
6883 if (/* If the object has a constructor, the constructor may modify
6885 TYPE_NEEDS_CONSTRUCTING (type)
6886 /* If the type isn't complete, we don't know yet if it will need
6888 || !COMPLETE_TYPE_P (type)
6889 /* If the type has a mutable component, that component might be
6891 || TYPE_HAS_MUTABLE_P (type))
6892 type_quals &= ~TYPE_QUAL_CONST;
6894 c_apply_type_quals_to_decl (type_quals, decl);
6897 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6898 exemplar types such that casting T1 to T2 is casting away constness
6899 if and only if there is no implicit conversion from T1 to T2. */
6902 casts_away_constness_r (tree *t1, tree *t2)
6907 /* [expr.const.cast]
6909 For multi-level pointer to members and multi-level mixed pointers
6910 and pointers to members (conv.qual), the "member" aspect of a
6911 pointer to member level is ignored when determining if a const
6912 cv-qualifier has been cast away. */
6913 /* [expr.const.cast]
6915 For two pointer types:
6917 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6918 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6921 casting from X1 to X2 casts away constness if, for a non-pointer
6922 type T there does not exist an implicit conversion (clause
6925 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6929 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6930 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6931 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6933 *t1 = cp_build_qualified_type (void_type_node,
6934 cp_type_quals (*t1));
6935 *t2 = cp_build_qualified_type (void_type_node,
6936 cp_type_quals (*t2));
6940 quals1 = cp_type_quals (*t1);
6941 quals2 = cp_type_quals (*t2);
6943 if (TYPE_PTRMEM_P (*t1))
6944 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6946 *t1 = TREE_TYPE (*t1);
6947 if (TYPE_PTRMEM_P (*t2))
6948 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6950 *t2 = TREE_TYPE (*t2);
6952 casts_away_constness_r (t1, t2);
6953 *t1 = build_pointer_type (*t1);
6954 *t2 = build_pointer_type (*t2);
6955 *t1 = cp_build_qualified_type (*t1, quals1);
6956 *t2 = cp_build_qualified_type (*t2, quals2);
6959 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6963 casts_away_constness (tree t1, tree t2)
6965 if (TREE_CODE (t2) == REFERENCE_TYPE)
6967 /* [expr.const.cast]
6969 Casting from an lvalue of type T1 to an lvalue of type T2
6970 using a reference cast casts away constness if a cast from an
6971 rvalue of type "pointer to T1" to the type "pointer to T2"
6972 casts away constness. */
6973 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6974 return casts_away_constness (build_pointer_type (t1),
6975 build_pointer_type (TREE_TYPE (t2)));
6978 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6979 /* [expr.const.cast]
6981 Casting from an rvalue of type "pointer to data member of X
6982 of type T1" to the type "pointer to data member of Y of type
6983 T2" casts away constness if a cast from an rvalue of type
6984 "pointer to T1" to the type "pointer to T2" casts away
6986 return casts_away_constness
6987 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6988 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6990 /* Casting away constness is only something that makes sense for
6991 pointer or reference types. */
6992 if (TREE_CODE (t1) != POINTER_TYPE
6993 || TREE_CODE (t2) != POINTER_TYPE)
6996 /* Top-level qualifiers don't matter. */
6997 t1 = TYPE_MAIN_VARIANT (t1);
6998 t2 = TYPE_MAIN_VARIANT (t2);
6999 casts_away_constness_r (&t1, &t2);
7000 if (!can_convert (t2, t1))
7006 /* If T is a REFERENCE_TYPE return the type to which T refers.
7007 Otherwise, return T itself. */
7010 non_reference (tree t)
7012 if (TREE_CODE (t) == REFERENCE_TYPE)
7018 /* Return nonzero if REF is an lvalue valid for this language;
7019 otherwise, print an error message and return zero. USE says
7020 how the lvalue is being used and so selects the error message. */
7023 lvalue_or_else (tree ref, enum lvalue_use use)
7025 int win = lvalue_p (ref);