use of $host_os in ltmain.in [1.4]

[libtool]

ltmain.in in 1.4 has:

    # On Cygwin there's no "real" PIC flag so we must build both object types
    case $host_os in
    cygwin* | mingw* | pw32* | os2*)
      pic_mode=default
      ;;
    esac

Taking a look at the generated libtool on Solaris 8/SPARC and AIX
4.3.2, $host_os is not defined anywhere. Is the above an error?

Later on I see:

  # libtool link mode
  link | relink)
    modename="$modename: link"
    case $host in
    *-*-cygwin* | *-*-mingw* | *-*-pw32* | *-*-os2*)

-- 
albert chin (address@hidden)