target() {
	if [ $# -lt 1 ]
	then
		echo "target setting: required argument missing" 1>&2
		exit 1
	fi
	if [ -n "$TARGET" ]
	then
		echo "Error: target specified more than once" 1>&2
		exit 1
	fi
	if [ ! -f "cfgmagic/target.$1" ]
	then
		echo "Error: target $1 not known" 1>&2
		exit 1
	fi
	# looks good, proceed
	TARGET="$1"
	. "cfgmagic/target.$1"
	. cfgmagic/post-target
}

feature() {
	if [ $# -lt 1 ]
	then
		echo "feature setting: required argument missing" 1>&2
		exit 1
	fi
	if [ -z "$TARGET" ]
	then
		echo "Please specify the target before any features" 1>&2
		exit 1
	fi
	if [ ! -f "cfgmagic/feature.$1" ]
	then
		echo "Error: feature $1 not known" 1>&2
		exit 1
	fi
	# looks good, proceed
	. "cfgmagic/feature.$1"
}

export_to_c() {
	while [ $# != 0 ]
	do
		case "$c_export_list" in
			*" $1 "* | *" $1")
				;;
			*)
				c_export_list="$c_export_list $1"
				;;
		esac
		shift
	done
}

export_to_mk() {
	while [ $# != 0 ]
	do
		case "$mk_export_list" in
			*" $1 "* | *" $1")
				;;
			*)
				mk_export_list="$mk_export_list $1"
				;;
		esac
		shift
	done
}

export_to_m4() {
	while [ $# != 0 ]
	do
		case "$m4_export_list" in
			*" $1 "* | *" $1")
				;;
			*)
				m4_export_list="$m4_export_list $1"
				;;
		esac
		shift
	done
}