#! /usr/bin/env python
# vim: set fileencoding=utf-8 :
# Copyright (C) 2010 by Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

import getopt
import re
import os
import subprocess
import sys

# This prevents including a timestamp in the .config which makes comparing a
# bit easier.
os.environ['KCONFIG_NOTIMESTAMP'] = 'Yes, please'

re_interesting = re.compile(r'^(# )?CONFIG_')

opts, args = getopt.getopt(sys.argv[1:], '', ['arch=', 'src='])

src = ''
arch = 'arm'

for o, a in opts:
    if o == '--arch':
        arch = a
    elif o == '--src':
        src = a

configdir = os.path.join(src, 'arch', arch, 'configs')

def all_defconfigs():
    lc = len(configdir)
    for root, dirs, files in os.walk(configdir):
        root = root[lc + 1:]
        for f in filter(lambda s: s.endswith('_defconfig'), files):
            yield os.path.join(root, f)

if not args:
    args = all_defconfigs()

for target in args:
    defconfig_src = os.path.join(configdir, target)

    subprocess.check_call(['make', '-s', 'ARCH=%s' % arch, target])
    origconfig = list(open('.config'))
    config = list(origconfig)
    config_size = os.stat('.config').st_size

    i = 0

    while i < len(config):
        mo = re_interesting.match(config[i])
        if mo:
            defconfig = open(defconfig_src, 'w')
            defconfig.writelines(config[:i])
            defconfig.writelines(config[i + 1:])
            defconfig.close()
            subprocess.check_call(['make', '-s', 'ARCH=%s' % arch, target])
            if os.stat('.config').st_size == config_size and list(open('.config')) == origconfig:
                print '-%s' % config[i][:-1]
                del config[i]
            else:
                print ' %s' % config[i][:-1]
                i += 1
        else:
            del config[i]

    defconfig = open(defconfig_src, 'w')
    defconfig.writelines(config)
    defconfig.close()