dnl CF_POSIX_C_SOURCE version: 10 updated: 2018/06/20 20:23:13
dnl -----------------
dnl Define _POSIX_C_SOURCE to the given level, and _POSIX_SOURCE if needed.
dnl
dnl	POSIX.1-1990				_POSIX_SOURCE
dnl	POSIX.1-1990 and			_POSIX_SOURCE and
dnl		POSIX.2-1992 C-Language			_POSIX_C_SOURCE=2
dnl		Bindings Option
dnl	POSIX.1b-1993				_POSIX_C_SOURCE=199309L
dnl	POSIX.1c-1996				_POSIX_C_SOURCE=199506L
dnl	X/Open 2000				_POSIX_C_SOURCE=200112L
dnl
dnl Parameters:
dnl	$1 is the nominal value for _POSIX_C_SOURCE
AC_DEFUN([CF_POSIX_C_SOURCE],
[
cf_POSIX_C_SOURCE=ifelse([$1],,199506L,[$1])

cf_save_CFLAGS="$CFLAGS"
cf_save_CPPFLAGS="$CPPFLAGS"

CF_REMOVE_DEFINE(cf_trim_CFLAGS,$cf_save_CFLAGS,_POSIX_C_SOURCE)
CF_REMOVE_DEFINE(cf_trim_CPPFLAGS,$cf_save_CPPFLAGS,_POSIX_C_SOURCE)

AC_CACHE_CHECK(if we should define _POSIX_C_SOURCE,cf_cv_posix_c_source,[
	CF_MSG_LOG(if the symbol is already defined go no further)
	AC_TRY_COMPILE([#include <sys/types.h>],[
#ifndef _POSIX_C_SOURCE
make an error
#endif],
	[cf_cv_posix_c_source=no],
	[cf_want_posix_source=no
	 case .$cf_POSIX_C_SOURCE in
	 (.[[12]]??*)
		cf_cv_posix_c_source="-D_POSIX_C_SOURCE=$cf_POSIX_C_SOURCE"
		;;
	 (.2)
		cf_cv_posix_c_source="-D_POSIX_C_SOURCE=$cf_POSIX_C_SOURCE"
		cf_want_posix_source=yes
		;;
	 (.*)
		cf_want_posix_source=yes
		;;
	 esac
	 if test "$cf_want_posix_source" = yes ; then
		AC_TRY_COMPILE([#include <sys/types.h>],[
#ifdef _POSIX_SOURCE
make an error
#endif],[],
		cf_cv_posix_c_source="$cf_cv_posix_c_source -D_POSIX_SOURCE")
	 fi
	 CF_MSG_LOG(ifdef from value $cf_POSIX_C_SOURCE)
	 CFLAGS="$cf_trim_CFLAGS"
	 CPPFLAGS="$cf_trim_CPPFLAGS"
	 CF_APPEND_TEXT(CPPFLAGS,$cf_cv_posix_c_source)
	 CF_MSG_LOG(if the second compile does not leave our definition intact error)
	 AC_TRY_COMPILE([#include <sys/types.h>],[
#ifndef _POSIX_C_SOURCE
make an error
#endif],,
	 [cf_cv_posix_c_source=no])
	 CFLAGS="$cf_save_CFLAGS"
	 CPPFLAGS="$cf_save_CPPFLAGS"
	])
])

if test "$cf_cv_posix_c_source" != no ; then
	CFLAGS="$cf_trim_CFLAGS"
	CPPFLAGS="$cf_trim_CPPFLAGS"
	CF_ADD_CFLAGS($cf_cv_posix_c_source)
fi

])dnl
