Add Python style checker to system/bt

[style]

# http://google.github.io/styleguide/pyguide.html

based_on_style: google

indent_width: 4

[Hook Scripts]

aosp_first = ${REPO_ROOT}/frameworks/base/tools/aosp/aosp_sha.sh ${PREUPLOAD_COMMIT} ".*$"

yapf_hook = ./tools/scripts/yapf_checker.py

#!/usr/bin/env python3

#

#   Copyright 2019 - The Android Open Source Project

#

#   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 logging

import os

import subprocess

import sys

PYTHONPATH_KEY = 'PYTHONPATH'

COMMIT_ID_ENV_KEY = 'PREUPLOAD_COMMIT'

ANDROID_BUILD_TOP_KEY = 'ANDROID_BUILD_TOP'

DEFAULT_YAPF_DIR = 'external/yapf'

GIT_COMMAND = ['git', 'diff-tree', '--no-commit-id', '--name-only']

def main():

    """

    A Python commit formatter using YAPF

    Caveat: if you modify a file, the entire file will be formatted, instead of

            the diff

    :return:

    """

    if COMMIT_ID_ENV_KEY not in os.environ:

        logging.error('Missing PREUPLOAD_COMMIT in environment.')

        exit(1)

    if ANDROID_BUILD_TOP_KEY not in os.environ:

        logging.error('Missing ANDROID_BUILD_TOP in environment.')

        exit(1)

    # Gather changed Python files

    commit_id = os.environ[COMMIT_ID_ENV_KEY]

    full_git_command = GIT_COMMAND + ['-r', commit_id]

    files = subprocess.check_output(full_git_command).decode(

        'utf-8').splitlines()

    full_files = [os.path.abspath(f) for f in files if f.endswith('.py')]

    if not full_files:

        return

    # Find yapf in Android code tree

    yapf_dir = os.path.join(os.environ[ANDROID_BUILD_TOP_KEY], DEFAULT_YAPF_DIR)

    yapf_binary = os.path.join(yapf_dir, 'yapf')

    # Run YAPF

    full_yapf_command = [

        "%s=$%s:%s" % (PYTHONPATH_KEY, PYTHONPATH_KEY, yapf_dir), 'python3',

        yapf_binary, '-d', '-p'

    ] + full_files

    environment = os.environ.copy()

    environment[PYTHONPATH_KEY] = environment[PYTHONPATH_KEY] + ":" + yapf_dir

    result = subprocess.run(

        full_yapf_command[1:],

        env=environment,

        stderr=subprocess.STDOUT,

        stdout=subprocess.PIPE)

    if result.returncode != 0 or result.stdout:

        logging.error(result.stdout.decode('utf-8').strip())

        logging.error('INVALID FORMATTING, return code %d', result.returncode)

        logging.error('To re-run the format command:\n\n'

                      '    %s\n' % ' '.join(full_yapf_command))

        yapf_inplace_format = ' '.join([

            "%s=$%s:%s" % (PYTHONPATH_KEY, PYTHONPATH_KEY,

                           yapf_dir), 'python3', yapf_binary, '-p', '-i'

        ] + full_files)

        logging.error('If this is a legitimate format error, please run:\n\n'

                      '    %s\n' % yapf_inplace_format)

        logging.error(

            'CAVEAT: Currently, this format the entire Python file if you modify even part of it'

        )

        exit(1)

if __name__ == '__main__':

    main()