| 1 | # Check for stdalign.h that conforms to C11. |
| 2 | |
| 3 | dnl Copyright 2011-2012 Free Software Foundation, Inc. |
| 4 | dnl This file is free software; the Free Software Foundation |
| 5 | dnl gives unlimited permission to copy and/or distribute it, |
| 6 | dnl with or without modifications, as long as this notice is preserved. |
| 7 | |
| 8 | # Prepare for substituting <stdalign.h> if it is not supported. |
| 9 | |
| 10 | AC_DEFUN([gl_STDALIGN_H], |
| 11 | [ |
| 12 | AC_CACHE_CHECK([for working stdalign.h], |
| 13 | [gl_cv_header_working_stdalign_h], |
| 14 | [AC_COMPILE_IFELSE( |
| 15 | [AC_LANG_PROGRAM( |
| 16 | [[#include <stdalign.h> |
| 17 | int align_int = alignof (int) + _Alignof (double); |
| 18 | |
| 19 | /* Test _Alignas only on platforms where gnulib can help. */ |
| 20 | #if \ |
| 21 | (__GNUC__ || __IBMC__ || __IBMCPP__ \ |
| 22 | || 0x5110 <= __SUNPRO_C || 1300 <= _MSC_VER) |
| 23 | int alignas (8) alignas_int = 1; |
| 24 | #endif |
| 25 | ]])], |
| 26 | [gl_cv_header_working_stdalign_h=yes], |
| 27 | [gl_cv_header_working_stdalign_h=no])]) |
| 28 | |
| 29 | if test $gl_cv_header_working_stdalign_h = yes; then |
| 30 | STDALIGN_H='' |
| 31 | else |
| 32 | STDALIGN_H='stdalign.h' |
| 33 | fi |
| 34 | |
| 35 | AC_SUBST([STDALIGN_H]) |
| 36 | AM_CONDITIONAL([GL_GENERATE_STDALIGN_H], [test -n "$STDALIGN_H"]) |
| 37 | ]) |