109 lines
3.5 KiB
C
109 lines
3.5 KiB
C
/* A substitute for POSIX 2008 <stddef.h>, for platforms that have issues.
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Copyright (C) 2009-2015 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, see <http://www.gnu.org/licenses/>. */
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/* Written by Eric Blake. */
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/*
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* POSIX 2008 <stddef.h> for platforms that have issues.
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* <http://www.opengroup.org/susv3xbd/stddef.h.html>
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*/
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#if __GNUC__ >= 3
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@PRAGMA_SYSTEM_HEADER@
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#endif
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@PRAGMA_COLUMNS@
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#if defined __need_wchar_t || defined __need_size_t \
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|| defined __need_ptrdiff_t || defined __need_NULL \
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|| defined __need_wint_t
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/* Special invocation convention inside gcc header files. In
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particular, gcc provides a version of <stddef.h> that blindly
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redefines NULL even when __need_wint_t was defined, even though
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wint_t is not normally provided by <stddef.h>. Hence, we must
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remember if special invocation has ever been used to obtain wint_t,
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in which case we need to clean up NULL yet again. */
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# if !(defined _@GUARD_PREFIX@_STDDEF_H && defined _GL_STDDEF_WINT_T)
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# ifdef __need_wint_t
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# define _GL_STDDEF_WINT_T
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# endif
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# @INCLUDE_NEXT@ @NEXT_STDDEF_H@
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# endif
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#else
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/* Normal invocation convention. */
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# ifndef _@GUARD_PREFIX@_STDDEF_H
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/* The include_next requires a split double-inclusion guard. */
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# @INCLUDE_NEXT@ @NEXT_STDDEF_H@
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/* On NetBSD 5.0, the definition of NULL lacks proper parentheses. */
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# if (@REPLACE_NULL@ \
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&& (!defined _@GUARD_PREFIX@_STDDEF_H || defined _GL_STDDEF_WINT_T))
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# undef NULL
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# ifdef __cplusplus
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/* ISO C++ says that the macro NULL must expand to an integer constant
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expression, hence '((void *) 0)' is not allowed in C++. */
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# if __GNUG__ >= 3
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/* GNU C++ has a __null macro that behaves like an integer ('int' or
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'long') but has the same size as a pointer. Use that, to avoid
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warnings. */
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# define NULL __null
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# else
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# define NULL 0L
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# endif
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# else
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# define NULL ((void *) 0)
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# endif
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# endif
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# ifndef _@GUARD_PREFIX@_STDDEF_H
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# define _@GUARD_PREFIX@_STDDEF_H
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/* Some platforms lack wchar_t. */
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#if !@HAVE_WCHAR_T@
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# define wchar_t int
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#endif
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/* Some platforms lack max_align_t. */
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#if !@HAVE_MAX_ALIGN_T@
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/* On the x86, the maximum storage alignment of double, long, etc. is 4,
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but GCC's C11 ABI for x86 says that max_align_t has an alignment of 8,
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and the C11 standard allows this. Work around this problem by
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using __alignof__ (which returns 8 for double) rather than _Alignof
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(which returns 4), and align each union member accordingly. */
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# ifdef __GNUC__
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# define _GL_STDDEF_ALIGNAS(type) \
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__attribute__ ((__aligned__ (__alignof__ (type))))
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# else
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# define _GL_STDDEF_ALIGNAS(type) /* */
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# endif
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typedef union
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{
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char *__p _GL_STDDEF_ALIGNAS (char *);
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double __d _GL_STDDEF_ALIGNAS (double);
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long double __ld _GL_STDDEF_ALIGNAS (long double);
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long int __i _GL_STDDEF_ALIGNAS (long int);
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} max_align_t;
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#endif
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# endif /* _@GUARD_PREFIX@_STDDEF_H */
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# endif /* _@GUARD_PREFIX@_STDDEF_H */
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#endif /* __need_XXX */
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