GNUStep building with python.

i sometimes forget how to build GNUStep code.
following is code.

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys
import os
import re

if __name__ == '__main__':
    if len(sys.argv) != 3:
        print 'invalid arguments'
        sys.exit(1)
    print 'compiling starts'

    opt_array = ['-fconstant-string-class=NSConstantString',
                 '-IC:\GNUstep\GNUstep\System\Library\Headers',
                 '-LC:\GNUstep\GNUstep\System\Library\Libraries',
                 '-lgnustep-base',
                 '-lobjc'
                 ]

    base_dir = os.getcwd()
    filter = re.compile('\.m$')
    linker = []
    input = sys.argv[1]
    output = sys.argv[2]

    for dirpath, dirnames, filenames in os.walk(base_dir):
         for filename in filenames:
             if filter.search(filename):
                 if filename == input:
                     continue
                 filename, ext = filename.split('.')
                 filename = os.path.join(dirpath, filename)
                 action = 'gcc -O %s -c %s.%s -o %s.o' %\
                     ((' ').join(opt_array), filename, ext, filename)
                 print action
                 linker.append("%s.o" % filename)
                 os.system(action)

         break
    action = "gcc -O %s %s %s -o %s" %\
        ((' ').join(linker), input, (' ').join(opt_array),output)
    print action
    os.system(action)
    print 'compiling ends'