7db6ba3b08
This header conforms to the C11 standard Reference: ISO/IEC 9899:201x 7.15 Alignment <stdalign.h> According to ISO/IEC 9899:201x (draft) 7.15 Alignment <stdalign.h> defines four macros: - alignas which expands to _Alignas - alignof which expands to _Alignof - __alignas_is_defined and __alignof_is_defined which both expand to 1 The _Alignas declaration appears as one of the type specifiers to modify the alignment requirement of the object being declared. The _Alignof operator is used to query the alignment requirement of its operand type. ISO/IEC N3242=11-0012 (C++1x) and ISO/IEC N3797 (C++1y) both note a header <cstdalign> which defines only __alignas_is_defined and shall not define the alignas macro. It misses the alignof case as it's probably based on an older C1x draft, which defined only alignas. Assume that this is a bug in the standard and treat alignof the same way as alignas in C++11. Allow to define alignas and alignof in C++ prior the C++11 standard. It might be broken but a nonstandard C++ compiler might support C11-like _Alignas and _Alignof. Note that it's fatal for g++(1) v.5.4.
56 lines
2.1 KiB
C
56 lines
2.1 KiB
C
/* $NetBSD: stdalign.h,v 1.1 2016/10/02 17:19:00 kamil Exp $ */
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/*-
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* Copyright (c) 2016 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Kamil Rytarowski.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef _STDALIGN_H_
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#define _STDALIGN_H_
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/*-
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* ISO/IEC 9899:201x 7.15 Alignment <stdalign.h>
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* ISO/IEC N3242=11-0012 (C++1x) 18.10 Other runtime support 6.
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* ISO/IEC N3797 (C++1y) 18.10 Other runtime support 7.
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*/
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#ifndef __alignas_is_defined
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#if ((__cplusplus - 0) < 201103L)
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#define alignas _Alignas
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#endif
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#define __alignas_is_defined 1
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#endif /* __alignas_is_defined */
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#ifndef __alignof_is_defined
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#if ((__cplusplus - 0) < 201103L)
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#define alignof _Alignof
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#endif
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#define __alignof_is_defined 1
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#endif /* __alignof_is_defined */
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#endif
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