dnl CF_XOPEN_SOURCE version: 42 updated: 2012/01/07 08:26:49
dnl ---------------
dnl Try to get _XOPEN_SOURCE defined properly that we can use POSIX functions,
dnl or adapt to the vendor's definitions to get equivalent functionality,
dnl without losing the common non-POSIX features.
dnl
dnl Parameters:
dnl	$1 is the nominal value for _XOPEN_SOURCE
dnl	$2 is the nominal value for _POSIX_C_SOURCE
AC_DEFUN([CF_XOPEN_SOURCE],[

cf_XOPEN_SOURCE=ifelse([$1],,500,[$1])
cf_POSIX_C_SOURCE=ifelse([$2],,199506L,[$2])
cf_xopen_source=

case $host_os in #(vi
aix[[4-7]]*) #(vi
	cf_xopen_source="-D_ALL_SOURCE"
	;;
cygwin) #(vi
	cf_XOPEN_SOURCE=600
	;;
darwin[[0-8]].*) #(vi
	cf_xopen_source="-D_APPLE_C_SOURCE"
	;;
darwin*) #(vi
	cf_xopen_source="-D_DARWIN_C_SOURCE"
	cf_XOPEN_SOURCE=
	;;
freebsd*|dragonfly*) #(vi
	# 5.x headers associate
	#	_XOPEN_SOURCE=600 with _POSIX_C_SOURCE=200112L
	#	_XOPEN_SOURCE=500 with _POSIX_C_SOURCE=199506L
	cf_POSIX_C_SOURCE=200112L
	cf_XOPEN_SOURCE=600
	cf_xopen_source="-D_BSD_TYPES -D__BSD_VISIBLE -D_POSIX_C_SOURCE=$cf_POSIX_C_SOURCE -D_XOPEN_SOURCE=$cf_XOPEN_SOURCE"
	;;
hpux11*) #(vi
	cf_xopen_source="-D_HPUX_SOURCE -D_XOPEN_SOURCE=500"
	;;
hpux*) #(vi
	cf_xopen_source="-D_HPUX_SOURCE"
	;;
irix[[56]].*) #(vi
	cf_xopen_source="-D_SGI_SOURCE"
	cf_XOPEN_SOURCE=
	;;
linux*|gnu*|mint*|k*bsd*-gnu) #(vi
	CF_GNU_SOURCE
	;;
mirbsd*) #(vi
	# setting _XOPEN_SOURCE or _POSIX_SOURCE breaks <sys/select.h> and other headers which use u_int / u_short types
	cf_XOPEN_SOURCE=
	CF_POSIX_C_SOURCE($cf_POSIX_C_SOURCE)
	;;
netbsd*) #(vi
	cf_xopen_source="-D_NETBSD_SOURCE" # setting _XOPEN_SOURCE breaks IPv6 for lynx on NetBSD 1.6, breaks xterm, is not needed for ncursesw
	;;
openbsd[[4-9]]*) #(vi
	# setting _XOPEN_SOURCE lower than 500 breaks g++ compile with wchar.h, needed for ncursesw
	cf_xopen_source="-D_BSD_SOURCE"
	cf_XOPEN_SOURCE=600
	;;
openbsd*) #(vi
	# setting _XOPEN_SOURCE breaks xterm on OpenBSD 2.8, is not needed for ncursesw
	;;
osf[[45]]*) #(vi
	cf_xopen_source="-D_OSF_SOURCE"
	;;
nto-qnx*) #(vi
	cf_xopen_source="-D_QNX_SOURCE"
	;;
sco*) #(vi
	# setting _XOPEN_SOURCE breaks Lynx on SCO Unix / OpenServer
	;;
solaris2.*) #(vi
	cf_xopen_source="-D__EXTENSIONS__"
	;;
*)
	CF_TRY_XOPEN_SOURCE
	CF_POSIX_C_SOURCE($cf_POSIX_C_SOURCE)
	;;
esac

if test -n "$cf_xopen_source" ; then
	CF_ADD_CFLAGS($cf_xopen_source)
fi

dnl In anything but the default case, we may have system-specific setting
dnl which is still not guaranteed to provide all of the entrypoints that
dnl _XOPEN_SOURCE would yield.
if test -n "$cf_XOPEN_SOURCE" && test -z "$cf_cv_xopen_source" ; then
	AC_MSG_CHECKING(if _XOPEN_SOURCE really is set)
	AC_TRY_COMPILE([#include <stdlib.h>],[
#ifndef _XOPEN_SOURCE
make an error
#endif],
	[cf_XOPEN_SOURCE_set=yes],
	[cf_XOPEN_SOURCE_set=no])
	AC_MSG_RESULT($cf_XOPEN_SOURCE_set)
	if test $cf_XOPEN_SOURCE_set = yes
	then
		AC_TRY_COMPILE([#include <stdlib.h>],[
#if (_XOPEN_SOURCE - 0) < $cf_XOPEN_SOURCE
make an error
#endif],
		[cf_XOPEN_SOURCE_set_ok=yes],
		[cf_XOPEN_SOURCE_set_ok=no])
		if test $cf_XOPEN_SOURCE_set_ok = no
		then
			AC_MSG_WARN(_XOPEN_SOURCE is lower than requested)
		fi
	else
		CF_TRY_XOPEN_SOURCE
	fi
fi
])
