check-style

#!/usr/bin/env python2

# Copyright(c) 2016 Intel Corporation
#
# Licensed under the Apache License, Version 2.0(the "License")
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import argparse
import difflib
import os
import re
import string
import subprocess
import sys


def get_root_dir():
    cmd = ['git', 'rev-parse', '--show-toplevel']
    process = subprocess.Popen(cmd, stdout=subprocess.PIPE,
            stderr=None, stdin=subprocess.PIPE)
    stdout, stderr = process.communicate()
    if process.returncode != 0:
        return None
    return stdout.splitlines()[0]

def get_files():
    files = None
    cmd = ['git', 'ls-files']
    process = subprocess.Popen(cmd, stdout=subprocess.PIPE,
            stderr=None, stdin=subprocess.PIPE)
    stdout, stderr = process.communicate()
    if process.returncode != 0:
        return None
    return list(filter(lambda x: x.endswith(b".c") or x.endswith(b".h"), stdout.splitlines()))

def print_diff(filename, clang_output):
    with open(filename) as f:
        print "\n".join(difflib.unified_diff(map(lambda x: x[:-1], f.readlines()),
            clang_output.splitlines(), fromfile=filename, tofile=filename))

def check_style(files, only_print):
    cmd = ['clang-format', '-style=file']

    if not only_print:
        cmd.append("-i")

    for f in files:
        cmd.append(f)
        process = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                stderr=None, stdin=subprocess.PIPE)
        stdout, stderr = process.communicate()
        if process.returncode != 0:
            sys.exit(process.returncode)

        if only_print:
            print_diff(f, stdout)
        cmd.pop()

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description=
                                     'Format the files in the repository according '
                                     'with iotivity-lite code style.')
    parser.add_argument('-p', action='store_true', default=False,
                        help='Only print the changes')

    args = parser.parse_args()
    current_dir = os.getcwd()
    root_dir = get_root_dir()

    os.chdir(root_dir)
    check_style(get_files(), args.p)
    os.chdir(current_dir)