Mercurial > gnulib
view m4/stdalign.m4 @ 17249:e542fd46ad6f
maint: update all copyright year number ranges
Run "make update-copyright". Compare to commit 1602f0a from last year.
Signed-off-by: Eric Blake <eblake@redhat.com>
author | Eric Blake <eblake@redhat.com> |
---|---|
date | Tue, 01 Jan 2013 00:50:58 +0000 |
parents | 1031e29cf9ff |
children | 7524d97ae56f |
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# Check for stdalign.h that conforms to C11. dnl Copyright 2011-2013 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. # Prepare for substituting <stdalign.h> if it is not supported. AC_DEFUN([gl_STDALIGN_H], [ AC_CACHE_CHECK([for working stdalign.h], [gl_cv_header_working_stdalign_h], [AC_COMPILE_IFELSE( [AC_LANG_PROGRAM( [[#include <stdalign.h> #include <stddef.h> /* Test that alignof yields a result consistent with offsetof. This catches GCC bug 52023 <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>. */ #ifdef __cplusplus template <class t> struct alignof_helper { char a; t b; }; # define ao(type) offsetof (alignof_helper<type>, b) #else # define ao(type) offsetof (struct { char a; type b; }, b) #endif char test_double[ao (double) % _Alignof (double) == 0 ? 1 : -1]; char test_long[ao (long int) % _Alignof (long int) == 0 ? 1 : -1]; char test_alignof[alignof (double) == _Alignof (double) ? 1 : -1]; /* Test _Alignas only on platforms where gnulib can help. */ #if \ (__GNUC__ || __IBMC__ || __IBMCPP__ \ || 0x5110 <= __SUNPRO_C || 1300 <= _MSC_VER) int alignas (8) alignas_int = 1; char test_alignas[_Alignof (alignas_int) == 8 ? 1 : -1]; #endif ]])], [gl_cv_header_working_stdalign_h=yes], [gl_cv_header_working_stdalign_h=no])]) if test $gl_cv_header_working_stdalign_h = yes; then STDALIGN_H='' else STDALIGN_H='stdalign.h' fi AC_SUBST([STDALIGN_H]) AM_CONDITIONAL([GL_GENERATE_STDALIGN_H], [test -n "$STDALIGN_H"]) ])