Import <stdalign.h>

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.
bouyer-socketcan
kamil 2016-10-02 17:19:00 +00:00
parent 9e58801f20
commit 7db6ba3b08
3 changed files with 59 additions and 3 deletions

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@ -1,4 +1,4 @@
# $NetBSD: mi,v 1.2061 2016/10/02 13:09:24 kamil Exp $
# $NetBSD: mi,v 1.2062 2016/10/02 17:19:00 kamil Exp $
#
# Note: don't delete entries from here - mark them as "obsolete" instead.
./etc/mtree/set.comp comp-sys-root
@ -2739,6 +2739,7 @@
./usr/include/ssp/strings.h comp-c-include
./usr/include/ssp/unistd.h comp-c-include
./usr/include/stab.h comp-c-include
./usr/include/stdalign.h comp-c-include
./usr/include/stdarg.h comp-c-include
./usr/include/stdbool.h comp-c-include
./usr/include/stddef.h comp-c-include

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@ -1,4 +1,4 @@
# $NetBSD: Makefile,v 1.142 2016/10/02 13:09:24 kamil Exp $
# $NetBSD: Makefile,v 1.143 2016/10/02 17:19:00 kamil Exp $
# @(#)Makefile 8.2 (Berkeley) 1/4/94
# Doing a make includes builds /usr/include
@ -18,7 +18,7 @@ INCS= a.out.h aio.h ar.h assert.h atomic.h \
ndbm.h netconfig.h netdb.h netgroup.h nlist.h nl_types.h nsswitch.h \
paths.h pwd.h quota.h randomid.h ranlib.h re_comp.h regex.h regexp.h \
resolv.h res_update.h rmt.h sched.h search.h semaphore.h setjmp.h \
string.h sgtty.h signal.h spawn.h stab.h stddef.h stdio.h \
string.h sgtty.h signal.h spawn.h stab.h stdalign.h stddef.h stdio.h \
stdlib.h stdnoreturn.h strings.h stringlist.h struct.h sysexits.h \
tar.h time.h ttyent.h tzfile.h \
ucontext.h ulimit.h unistd.h util.h utime.h utmp.h utmpx.h uuid.h \

55
include/stdalign.h Normal file
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@ -0,0 +1,55 @@
/* $NetBSD: stdalign.h,v 1.1 2016/10/02 17:19:00 kamil Exp $ */
/*-
* Copyright (c) 2016 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Kamil Rytarowski.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _STDALIGN_H_
#define _STDALIGN_H_
/*-
* ISO/IEC 9899:201x 7.15 Alignment <stdalign.h>
* ISO/IEC N3242=11-0012 (C++1x) 18.10 Other runtime support 6.
* ISO/IEC N3797 (C++1y) 18.10 Other runtime support 7.
*/
#ifndef __alignas_is_defined
#if ((__cplusplus - 0) < 201103L)
#define alignas _Alignas
#endif
#define __alignas_is_defined 1
#endif /* __alignas_is_defined */
#ifndef __alignof_is_defined
#if ((__cplusplus - 0) < 201103L)
#define alignof _Alignof
#endif
#define __alignof_is_defined 1
#endif /* __alignof_is_defined */
#endif