tools/moveconfig.py

#!/usr/bin/env python2
#
# Author: Masahiro Yamada <yamada.masahiro@socionext.com>
#
# SPDX-License-Identifier:	GPL-2.0+
#

"""
Move config options from headers to defconfig files.

Since Kconfig was introduced to U-Boot, we have worked on moving
config options from headers to Kconfig (defconfig).

This tool intends to help this tremendous work.


Usage
-----

This tool takes one input file.  (let's say 'recipe' file here.)
The recipe describes the list of config options you want to move.
Each line takes the form:
<config_name> <type> <default>
(the fields must be separated with whitespaces.)

<config_name> is the name of config option.

<type> is the type of the option.  It must be one of bool, tristate,
string, int, and hex.

<default> is the default value of the option.  It must be appropriate
value corresponding to the option type.  It must be either y or n for
the bool type.  Tristate options can also take m (although U-Boot has
not supported the module feature).

You can add two or more lines in the recipe file, so you can move
multiple options at once.

Let's say, for example, you want to move CONFIG_CMD_USB and
CONFIG_SYS_TEXT_BASE.

The type should be bool, hex, respectively.  So, the recipe file
should look like this:

  $ cat recipe
  CONFIG_CMD_USB bool n
  CONFIG_SYS_TEXT_BASE hex 0x00000000

Next you must edit the Kconfig to add the menu entries for the configs
you are moving.

And then run this tool giving the file name of the recipe

  $ tools/moveconfig.py recipe

The tool walks through all the defconfig files to move the config
options specified by the recipe file.

The log is also displayed on the terminal.

Each line is printed in the format
<defconfig_name>   :  <action>

<defconfig_name> is the name of the defconfig
(without the suffix _defconfig).

<action> shows what the tool did for that defconfig.
It looks like one of the followings:

 - Move 'CONFIG_... '
   This config option was moved to the defconfig

 - Default value 'CONFIG_...'.  Do nothing.
   The value of this option is the same as default.
   We do not have to add it to the defconfig.

 - 'CONFIG_...' already exists in Kconfig.  Do nothing.
   This config option is already defined in Kconfig.
   We do not need/want to touch it.

 - Undefined.  Do nothing.
   This config option was not found in the config header.
   Nothing to do.

 - Failed to process.  Skip.
   An error occurred during processing this defconfig.  Skipped.
   (If -e option is passed, the tool exits immediately on error.)

Finally, you will be asked, Clean up headers? [y/n]:

If you say 'y' here, the unnecessary config defines are removed
from the config headers (include/configs/*.h).
It just uses the regex method, so you should not rely on it.
Just in case, please do 'git diff' to see what happened.


How does it works?
------------------

This tool runs configuration and builds include/autoconf.mk for every
defconfig.  The config options defined in Kconfig appear in the .config
file (unless they are hidden because of unmet dependency.)
On the other hand, the config options defined by board headers are seen
in include/autoconf.mk.  The tool looks for the specified options in both
of them to decide the appropriate action for the options.  If the option
is found in the .config or the value is the same as the specified default,
the option does not need to be touched.  If the option is found in
include/autoconf.mk, but not in the .config, and the value is different
from the default, the tools adds the option to the defconfig.

For faster processing, this tool handles multi-threading.  It creates
separate build directories where the out-of-tree build is run.  The
temporary build directories are automatically created and deleted as
needed.  The number of threads are chosen based on the number of the CPU
cores of your system although you can change it via -j (--jobs) option.


Toolchains
----------

Appropriate toolchain are necessary to generate include/autoconf.mk
for all the architectures supported by U-Boot.  Most of them are available
at the kernel.org site, some are not provided by kernel.org.

The default per-arch CROSS_COMPILE used by this tool is specified by
the list below, CROSS_COMPILE.  You may wish to update the list to
use your own.  Instead of modifying the list directly, you can give
them via environments.


Available options
-----------------

 -c, --color
   Surround each portion of the log with escape sequences to display it
   in color on the terminal.

 -d, --defconfigs
  Specify a file containing a list of defconfigs to move

 -n, --dry-run
   Peform a trial run that does not make any changes.  It is useful to
   see what is going to happen before one actually runs it.

 -e, --exit-on-error
   Exit immediately if Make exits with a non-zero status while processing
   a defconfig file.

 -H, --headers-only
   Only cleanup the headers; skip the defconfig processing

 -j, --jobs
   Specify the number of threads to run simultaneously.  If not specified,
   the number of threads is the same as the number of CPU cores.

To see the complete list of supported options, run

  $ tools/moveconfig.py -h

"""

import fnmatch
import multiprocessing
import optparse
import os
import re
import shutil
import subprocess
import sys
import tempfile
import time

SHOW_GNU_MAKE = 'scripts/show-gnu-make'
SLEEP_TIME=0.03

# Here is the list of cross-tools I use.
# Most of them are available at kernel.org
# (https://www.kernel.org/pub/tools/crosstool/files/bin/), except the followings:
# arc: https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/releases
# blackfin: http://sourceforge.net/projects/adi-toolchain/files/
# nds32: http://osdk.andestech.com/packages/
# nios2: https://sourcery.mentor.com/GNUToolchain/subscription42545
# sh: http://sourcery.mentor.com/public/gnu_toolchain/sh-linux-gnu
CROSS_COMPILE = {
    'arc': 'arc-linux-',
    'aarch64': 'aarch64-linux-',
    'arm': 'arm-unknown-linux-gnueabi-',
    'avr32': 'avr32-linux-',
    'blackfin': 'bfin-elf-',
    'm68k': 'm68k-linux-',
    'microblaze': 'microblaze-linux-',
    'mips': 'mips-linux-',
    'nds32': 'nds32le-linux-',
    'nios2': 'nios2-linux-gnu-',
    'openrisc': 'or32-linux-',
    'powerpc': 'powerpc-linux-',
    'sh': 'sh-linux-gnu-',
    'sparc': 'sparc-linux-',
    'x86': 'i386-linux-'
}

STATE_IDLE = 0
STATE_DEFCONFIG = 1
STATE_AUTOCONF = 2
STATE_SAVEDEFCONFIG = 3

ACTION_MOVE = 0
ACTION_DEFAULT_VALUE = 1
ACTION_ALREADY_EXIST = 2
ACTION_UNDEFINED = 3

COLOR_BLACK        = '0;30'
COLOR_RED          = '0;31'
COLOR_GREEN        = '0;32'
COLOR_BROWN        = '0;33'
COLOR_BLUE         = '0;34'
COLOR_PURPLE       = '0;35'
COLOR_CYAN         = '0;36'
COLOR_LIGHT_GRAY   = '0;37'
COLOR_DARK_GRAY    = '1;30'
COLOR_LIGHT_RED    = '1;31'
COLOR_LIGHT_GREEN  = '1;32'
COLOR_YELLOW       = '1;33'
COLOR_LIGHT_BLUE   = '1;34'
COLOR_LIGHT_PURPLE = '1;35'
COLOR_LIGHT_CYAN   = '1;36'
COLOR_WHITE        = '1;37'

### helper functions ###
def get_devnull():
    """Get the file object of '/dev/null' device."""
    try:
        devnull = subprocess.DEVNULL # py3k
    except AttributeError:
        devnull = open(os.devnull, 'wb')
    return devnull

def check_top_directory():
    """Exit if we are not at the top of source directory."""
    for f in ('README', 'Licenses'):
        if not os.path.exists(f):
            sys.exit('Please run at the top of source directory.')

def get_make_cmd():
    """Get the command name of GNU Make.

    U-Boot needs GNU Make for building, but the command name is not
    necessarily "make". (for example, "gmake" on FreeBSD).
    Returns the most appropriate command name on your system.
    """
    process = subprocess.Popen([SHOW_GNU_MAKE], stdout=subprocess.PIPE)
    ret = process.communicate()
    if process.returncode:
        sys.exit('GNU Make not found')
    return ret[0].rstrip()

def color_text(color_enabled, color, string):
    """Return colored string."""
    if color_enabled:
        return '\033[' + color + 'm' + string + '\033[0m'
    else:
        return string

def log_msg(color_enabled, color, defconfig, msg):
    """Return the formated line for the log."""
    return defconfig[:-len('_defconfig')].ljust(37) + ': ' + \
        color_text(color_enabled, color, msg) + '\n'

def update_cross_compile():
    """Update per-arch CROSS_COMPILE via enviroment variables

    The default CROSS_COMPILE values are available
    in the CROSS_COMPILE list above.

    You can override them via enviroment variables
    CROSS_COMPILE_{ARCH}.

    For example, if you want to override toolchain prefixes
    for ARM and PowerPC, you can do as follows in your shell:

    export CROSS_COMPILE_ARM=...
    export CROSS_COMPILE_POWERPC=...
    """
    archs = []

    for arch in os.listdir('arch'):
        if os.path.exists(os.path.join('arch', arch, 'Makefile')):
            archs.append(arch)

    # arm64 is a special case
    archs.append('aarch64')

    for arch in archs:
        env = 'CROSS_COMPILE_' + arch.upper()
        cross_compile = os.environ.get(env)
        if cross_compile:
            CROSS_COMPILE[arch] = cross_compile

def cleanup_one_header(header_path, patterns, dry_run):
    """Clean regex-matched lines away from a file.

    Arguments:
      header_path: path to the cleaned file.
      patterns: list of regex patterns.  Any lines matching to these
                patterns are deleted.
      dry_run: make no changes, but still display log.
    """
    with open(header_path) as f:
        lines = f.readlines()

    matched = []
    for i, line in enumerate(lines):
        for pattern in patterns:
            m = pattern.search(line)
            if m:
                print '%s: %s: %s' % (header_path, i + 1, line),
                matched.append(i)
                break

    if dry_run or not matched:
        return

    with open(header_path, 'w') as f:
        for i, line in enumerate(lines):
            if not i in matched:
                f.write(line)

def cleanup_headers(config_attrs, dry_run):
    """Delete config defines from board headers.

    Arguments:
      config_attrs: A list of dictionaris, each of them includes the name,
                    the type, and the default value of the target config.
      dry_run: make no changes, but still display log.
    """
    while True:
        choice = raw_input('Clean up headers? [y/n]: ').lower()
        print choice
        if choice == 'y' or choice == 'n':
            break

    if choice == 'n':
        return

    patterns = []
    for config_attr in config_attrs:
        config = config_attr['config']
        patterns.append(re.compile(r'#\s*define\s+%s\W' % config))
        patterns.append(re.compile(r'#\s*undef\s+%s\W' % config))

    for dir in 'include', 'arch', 'board':
        for (dirpath, dirnames, filenames) in os.walk(dir):
            for filename in filenames:
                if not fnmatch.fnmatch(filename, '*~'):
                    cleanup_one_header(os.path.join(dirpath, filename),
                                       patterns, dry_run)

### classes ###
class KconfigParser:

    """A parser of .config and include/autoconf.mk."""

    re_arch = re.compile(r'CONFIG_SYS_ARCH="(.*)"')
    re_cpu = re.compile(r'CONFIG_SYS_CPU="(.*)"')

    def __init__(self, config_attrs, options, build_dir):
        """Create a new parser.

        Arguments:
          config_attrs: A list of dictionaris, each of them includes the name,
                        the type, and the default value of the target config.
          options: option flags.
          build_dir: Build directory.
        """
        self.config_attrs = config_attrs
        self.options = options
        self.build_dir = build_dir

    def get_cross_compile(self):
        """Parse .config file and return CROSS_COMPILE.

        Returns:
          A string storing the compiler prefix for the architecture.
        """
        arch = ''
        cpu = ''
        dotconfig = os.path.join(self.build_dir, '.config')
        for line in open(dotconfig):
            m = self.re_arch.match(line)
            if m:
                arch = m.group(1)
                continue
            m = self.re_cpu.match(line)
            if m:
                cpu = m.group(1)

        assert arch, 'Error: arch is not defined in %s' % defconfig

        # fix-up for aarch64
        if arch == 'arm' and cpu == 'armv8':
            arch = 'aarch64'

        return CROSS_COMPILE.get(arch, '')

    def parse_one_config(self, config_attr, defconfig_lines, autoconf_lines):
        """Parse .config, defconfig, include/autoconf.mk for one config.

        This function looks for the config options in the lines from
        defconfig, .config, and include/autoconf.mk in order to decide
        which action should be taken for this defconfig.

        Arguments:
          config_attr: A dictionary including the name, the type,
                       and the default value of the target config.
          defconfig_lines: lines from the original defconfig file.
          autoconf_lines: lines from the include/autoconf.mk file.

        Returns:
          A tupple of the action for this defconfig and the line
          matched for the config.
        """
        config = config_attr['config']
        not_set = '# %s is not set' % config

        if config_attr['type'] in ('bool', 'tristate') and \
           config_attr['default'] == 'n':
            default = not_set
        else:
            default = config + '=' + config_attr['default']

        for line in defconfig_lines:
            line = line.rstrip()
            if line.startswith(config + '=') or line == not_set:
                return (ACTION_ALREADY_EXIST, line)

        if config_attr['type'] in ('bool', 'tristate'):
            value = not_set
        else:
            value = '(undefined)'

        for line in autoconf_lines:
            line = line.rstrip()
            if line.startswith(config + '='):
                value = line
                break

        if value == default:
            action = ACTION_DEFAULT_VALUE
        elif value == '(undefined)':
            action = ACTION_UNDEFINED
        else:
            action = ACTION_MOVE

        return (action, value)

    def update_defconfig(self, defconfig):
        """Parse files for the config options and update the defconfig.

        This function parses the given defconfig, the generated .config
        and include/autoconf.mk searching the target options.
        Move the config option(s) to the defconfig or do nothing if unneeded.
        Also, display the log to show what happened to this defconfig.

        Arguments:
          defconfig: defconfig name.
        """

        defconfig_path = os.path.join('configs', defconfig)
        dotconfig_path = os.path.join(self.build_dir, '.config')
        autoconf_path = os.path.join(self.build_dir, 'include', 'autoconf.mk')
        results = []

        with open(defconfig_path) as f:
            defconfig_lines = f.readlines()

        with open(autoconf_path) as f:
            autoconf_lines = f.readlines()

        for config_attr in self.config_attrs:
            result = self.parse_one_config(config_attr, defconfig_lines,
                                           autoconf_lines)
            results.append(result)

        log = ''

        for (action, value) in results:
            if action == ACTION_MOVE:
                actlog = "Move '%s'" % value
                log_color = COLOR_LIGHT_GREEN
            elif action == ACTION_DEFAULT_VALUE:
                actlog = "Default value '%s'.  Do nothing." % value
                log_color = COLOR_LIGHT_BLUE
            elif action == ACTION_ALREADY_EXIST:
                actlog = "'%s' already defined in Kconfig.  Do nothing." % value
                log_color = COLOR_LIGHT_PURPLE
            elif action == ACTION_UNDEFINED:
                actlog = "Undefined.  Do nothing."
                log_color = COLOR_DARK_GRAY
            else:
                sys.exit("Internal Error. This should not happen.")

            log += log_msg(self.options.color, log_color, defconfig, actlog)

        # Some threads are running in parallel.
        # Print log in one shot to not mix up logs from different threads.
        print log,

        if not self.options.dry_run:
            with open(dotconfig_path, 'a') as f:
                for (action, value) in results:
                    if action == ACTION_MOVE:
                        f.write(value + '\n')

        os.remove(os.path.join(self.build_dir, 'include', 'config', 'auto.conf'))
        os.remove(autoconf_path)

class Slot:

    """A slot to store a subprocess.

    Each instance of this class handles one subprocess.
    This class is useful to control multiple threads
    for faster processing.
    """

    def __init__(self, config_attrs, options, devnull, make_cmd):
        """Create a new process slot.

        Arguments:
          config_attrs: A list of dictionaris, each of them includes the name,
                        the type, and the default value of the target config.
          options: option flags.
          devnull: A file object of '/dev/null'.
          make_cmd: command name of GNU Make.
        """
        self.options = options
        self.build_dir = tempfile.mkdtemp()
        self.devnull = devnull
        self.make_cmd = (make_cmd, 'O=' + self.build_dir)
        self.parser = KconfigParser(config_attrs, options, self.build_dir)
        self.state = STATE_IDLE
        self.failed_boards = []

    def __del__(self):
        """Delete the working directory

        This function makes sure the temporary directory is cleaned away
        even if Python suddenly dies due to error.  It should be done in here
        because it is guranteed the destructor is always invoked when the
        instance of the class gets unreferenced.

        If the subprocess is still running, wait until it finishes.
        """
        if self.state != STATE_IDLE:
            while self.ps.poll() == None:
                pass
        shutil.rmtree(self.build_dir)

    def add(self, defconfig):
        """Assign a new subprocess for defconfig and add it to the slot.

        If the slot is vacant, create a new subprocess for processing the
        given defconfig and add it to the slot.  Just returns False if
        the slot is occupied (i.e. the current subprocess is still running).

        Arguments:
          defconfig: defconfig name.

        Returns:
          Return True on success or False on failure
        """
        if self.state != STATE_IDLE:
            return False
        cmd = list(self.make_cmd)
        cmd.append(defconfig)
        self.ps = subprocess.Popen(cmd, stdout=self.devnull)
        self.defconfig = defconfig
        self.state = STATE_DEFCONFIG
        return True

    def poll(self):
        """Check the status of the subprocess and handle it as needed.

        Returns True if the slot is vacant (i.e. in idle state).
        If the configuration is successfully finished, assign a new
        subprocess to build include/autoconf.mk.
        If include/autoconf.mk is generated, invoke the parser to
        parse the .config and the include/autoconf.mk, and then set the
        slot back to the idle state.

        Returns:
          Return True if the subprocess is terminated, False otherwise
        """
        if self.state == STATE_IDLE:
            return True

        if self.ps.poll() == None:
            return False

        if self.ps.poll() != 0:

            print >> sys.stderr, log_msg(self.options.color,
                                         COLOR_LIGHT_RED,
                                         self.defconfig,
                                         "failed to process.")
            if self.options.exit_on_error:
                sys.exit("Exit on error.")
            else:
                # If --exit-on-error flag is not set,
                # skip this board and continue.
                # Record the failed board.
                self.failed_boards.append(self.defconfig)
                self.state = STATE_IDLE
                return True

        if self.state == STATE_AUTOCONF:
            self.parser.update_defconfig(self.defconfig)

            """Save off the defconfig in a consistent way"""
            cmd = list(self.make_cmd)
            cmd.append('savedefconfig')
            self.ps = subprocess.Popen(cmd, stdout=self.devnull,
                                       stderr=self.devnull)
            self.state = STATE_SAVEDEFCONFIG
            return False

        if self.state == STATE_SAVEDEFCONFIG:
            defconfig_path = os.path.join(self.build_dir, 'defconfig')
            shutil.move(defconfig_path,
                        os.path.join('configs', self.defconfig))
            self.state = STATE_IDLE
            return True

        cross_compile = self.parser.get_cross_compile()
        cmd = list(self.make_cmd)
        if cross_compile:
            cmd.append('CROSS_COMPILE=%s' % cross_compile)
        cmd.append('KCONFIG_IGNORE_DUPLICATES=1')
        cmd.append('include/config/auto.conf')
        self.ps = subprocess.Popen(cmd, stdout=self.devnull)
        self.state = STATE_AUTOCONF
        return False

    def get_failed_boards(self):
        """Returns a list of failed boards (defconfigs) in this slot.
        """
        return self.failed_boards

class Slots:

    """Controller of the array of subprocess slots."""

    def __init__(self, config_attrs, options):
        """Create a new slots controller.

        Arguments:
          config_attrs: A list of dictionaris containing the name, the type,
                        and the default value of the target CONFIG.
          options: option flags.
        """
        self.options = options
        self.slots = []
        devnull = get_devnull()
        make_cmd = get_make_cmd()
        for i in range(options.jobs):
            self.slots.append(Slot(config_attrs, options, devnull, make_cmd))

    def add(self, defconfig):
        """Add a new subprocess if a vacant slot is found.

        Arguments:
          defconfig: defconfig name to be put into.

        Returns:
          Return True on success or False on failure
        """
        for slot in self.slots:
            if slot.add(defconfig):
                return True
        return False

    def available(self):
        """Check if there is a vacant slot.

        Returns:
          Return True if at lease one vacant slot is found, False otherwise.
        """
        for slot in self.slots:
            if slot.poll():
                return True
        return False

    def empty(self):
        """Check if all slots are vacant.

        Returns:
          Return True if all the slots are vacant, False otherwise.
        """
        ret = True
        for slot in self.slots:
            if not slot.poll():
                ret = False
        return ret

    def show_failed_boards(self):
        """Display all of the failed boards (defconfigs)."""
        failed_boards = []

        for slot in self.slots:
            failed_boards += slot.get_failed_boards()

        if len(failed_boards) > 0:
            msg = [ "The following boards were not processed due to error:" ]
            msg += failed_boards
            for line in msg:
                print >> sys.stderr, color_text(self.options.color,
                                                COLOR_LIGHT_RED, line)

            with open('moveconfig.failed', 'w') as f:
                for board in failed_boards:
                    f.write(board + '\n')

def move_config(config_attrs, options):
    """Move config options to defconfig files.

    Arguments:
      config_attrs: A list of dictionaris, each of them includes the name,
                    the type, and the default value of the target config.
      options: option flags
    """
    if len(config_attrs) == 0:
        print 'Nothing to do. exit.'
        sys.exit(0)

    print 'Move the following CONFIG options (jobs: %d)' % options.jobs
    for config_attr in config_attrs:
        print '  %s (type: %s, default: %s)' % (config_attr['config'],
                                                config_attr['type'],
                                                config_attr['default'])

    if options.defconfigs:
        defconfigs = [line.strip() for line in open(options.defconfigs)]
        for i, defconfig in enumerate(defconfigs):
            if not defconfig.endswith('_defconfig'):
                defconfigs[i] = defconfig + '_defconfig'
            if not os.path.exists(os.path.join('configs', defconfigs[i])):
                sys.exit('%s - defconfig does not exist. Stopping.' %
                         defconfigs[i])
    else:
        # All the defconfig files to be processed
        defconfigs = []
        for (dirpath, dirnames, filenames) in os.walk('configs'):
            dirpath = dirpath[len('configs') + 1:]
            for filename in fnmatch.filter(filenames, '*_defconfig'):
                defconfigs.append(os.path.join(dirpath, filename))

    slots = Slots(config_attrs, options)

    # Main loop to process defconfig files:
    #  Add a new subprocess into a vacant slot.
    #  Sleep if there is no available slot.
    for defconfig in defconfigs:
        while not slots.add(defconfig):
            while not slots.available():
                # No available slot: sleep for a while
                time.sleep(SLEEP_TIME)

    # wait until all the subprocesses finish
    while not slots.empty():
        time.sleep(SLEEP_TIME)

    slots.show_failed_boards()

def bad_recipe(filename, linenum, msg):
    """Print error message with the file name and the line number and exit."""
    sys.exit("%s: line %d: error : " % (filename, linenum) + msg)

def parse_recipe(filename):
    """Parse the recipe file and retrieve the config attributes.

    This function parses the given recipe file and gets the name,
    the type, and the default value of the target config options.

    Arguments:
      filename: path to file to be parsed.
    Returns:
      A list of dictionaris, each of them includes the name,
      the type, and the default value of the target config.
    """
    config_attrs = []
    linenum = 1

    for line in open(filename):
        tokens = line.split()
        if len(tokens) != 3:
            bad_recipe(filename, linenum,
                       "%d fields in this line.  Each line must contain 3 fields"
                       % len(tokens))

        (config, type, default) = tokens

        # prefix the option name with CONFIG_ if missing
        if not config.startswith('CONFIG_'):
            config = 'CONFIG_' + config

        # sanity check of default values
        if type == 'bool':
            if not default in ('y', 'n'):
                bad_recipe(filename, linenum,
                           "default for bool type must be either y or n")
        elif type == 'tristate':
            if not default in ('y', 'm', 'n'):
                bad_recipe(filename, linenum,
                           "default for tristate type must be y, m, or n")
        elif type == 'string':
            if default[0] != '"' or default[-1] != '"':
                bad_recipe(filename, linenum,
                           "default for string type must be surrounded by double-quotations")
        elif type == 'int':
            try:
                int(default)
            except:
                bad_recipe(filename, linenum,
                           "type is int, but default value is not decimal")
        elif type == 'hex':
            if len(default) < 2 or default[:2] != '0x':
                bad_recipe(filename, linenum,
                           "default for hex type must be prefixed with 0x")
            try:
                int(default, 16)
            except:
                bad_recipe(filename, linenum,
                           "type is hex, but default value is not hexadecimal")
        else:
            bad_recipe(filename, linenum,
                       "unsupported type '%s'. type must be one of bool, tristate, string, int, hex"
                       % type)

        config_attrs.append({'config': config, 'type': type, 'default': default})
        linenum += 1

    return config_attrs

def main():
    try:
        cpu_count = multiprocessing.cpu_count()
    except NotImplementedError:
        cpu_count = 1

    parser = optparse.OptionParser()
    # Add options here
    parser.add_option('-c', '--color', action='store_true', default=False,
                      help='display the log in color')
    parser.add_option('-d', '--defconfigs', type='string',
                      help='a file containing a list of defconfigs to move')
    parser.add_option('-n', '--dry-run', action='store_true', default=False,
                      help='perform a trial run (show log with no changes)')
    parser.add_option('-e', '--exit-on-error', action='store_true',
                      default=False,
                      help='exit immediately on any error')
    parser.add_option('-H', '--headers-only', dest='cleanup_headers_only',
                      action='store_true', default=False,
                      help='only cleanup the headers')
    parser.add_option('-j', '--jobs', type='int', default=cpu_count,
                      help='the number of jobs to run simultaneously')
    parser.usage += ' recipe_file\n\n' + \
                    'The recipe_file should describe config options you want to move.\n' + \
                    'Each line should contain config_name, type, default_value\n\n' + \
                    'Example:\n' + \
                    'CONFIG_FOO bool n\n' + \
                    'CONFIG_BAR int 100\n' + \
                    'CONFIG_BAZ string "hello"\n'

    (options, args) = parser.parse_args()

    if len(args) != 1:
        parser.print_usage()
        sys.exit(1)

    config_attrs = parse_recipe(args[0])

    update_cross_compile()

    check_top_directory()

    if not options.cleanup_headers_only:
        move_config(config_attrs, options)

    cleanup_headers(config_attrs, options.dry_run)

if __name__ == '__main__':
    main()