Mine

inherit kde

kde-split_do_unpack () {
    extractlist=""
    for stuff in ac{include,local}.m4 admin configure.in.{in,mid,bot}
                Makefile.am{,.in} ChangeLog AUTHORS COPYING NEWS README
                $KMMODULE
    do
        extractlist="$extractlist $KMNAME-$KMVER/$stuff"
    done

    tar -xjpf $KDESRC $extractlist
}

EXPORT_FUNCTIONS do_unpack