teufel-pre-push

#!/usr/bin/python3

import os
import shutil
import subprocess
import sys


def empty_revision():
    return '0000000000000000000000000000000000000000'


def is_file_formatted_correctly(filename, repo_file):
    with open('{0}-formatted'.format(filename), 'w') as formatted_contents_file, open(filename, 'r') as in_contents:
        subprocess.call(['clang-format', '-style=file', '--assume-filename={0}'.format(repo_file)], stdin=in_contents,stdout=formatted_contents_file)
    diff = subprocess.call(['diff', '-u', filename, formatted_contents_file.name])
    is_correct = not bool(diff)

    return is_correct


def get_old_revision_locally():
    parent = subprocess.check_output(["git", "describe", "--abbrev=0", "--all", "HEAD~1"]).decode().strip()
    revisions = subprocess.check_output(["git", "rev-list", "--reverse", "{0}..HEAD".format(parent)]).decode()

    if len(revisions) == 0:
        print("Hook warning: There is no revision to push; pushing anyway...")
        sys.exit(0)

    old_revision = subprocess.check_output(["git", "rev-parse", "{0}~1".format(revisions.split()[0])]).decode().strip()
    return old_revision


def get_filenames_between_revisions(old_revision, new_revision):
    filenames = []

    try:
        FNULL = open(os.devnull, 'w')
        filenames = subprocess.check_output(
            ['git', 'diff-tree', '--no-commit-id', '--name-only', '-r', new_revision, old_revision], stderr=FNULL)
    except subprocess.CalledProcessError:
        print("Hook warning: it seems that the remote branch is not related to the branch you want to push")
        old_revision = get_old_revision_locally()
        print("old revision=", old_revision, "new revision=", new_revision)
        filenames = subprocess.check_output(
            ['git', 'diff-tree', '--no-commit-id', '--name-only', '-r', new_revision, old_revision])

    if len(filenames) == 0:
        print("Hook warning: there is no difference in content between new and old revisions; pushing anyway...")
        sys.exit(0)

    source_filenames = []

    for f in filenames.split():
        f = f.decode()
        if f.endswith('.c') or f.endswith('.cpp') or f.endswith('.h') or f.endswith('.hpp'):
            source_filenames.append(f.strip())

    return source_filenames


def hook(old_revision, new_revision):
    if old_revision == empty_revision():
        old_revision = get_old_revision_locally()

    filenames_between_revisions = get_filenames_between_revisions(
        old_revision, new_revision)

    result = True

    for f in filenames_between_revisions:
        if not os.path.isfile(f):
            continue  # File has been deleted from the repository

        tmp_filename = '.clang-format-check/{0}'.format(f)
        dirname = os.path.dirname(tmp_filename)
        try:
            os.makedirs(dirname)
        except:
            pass
        with open(tmp_filename, 'w') as temp_file:
            subprocess.check_call(['git', 'show', '{0}:{1}'.format(new_revision, f)], stdout=temp_file)

        if not is_file_formatted_correctly(tmp_filename, f):
            result = False

    return result

if __name__ == '__main__':

    line = ''
    for l in sys.stdin:
        line = l

    new_revision = ''
    old_revision = ''

    if line == '':
        new_revision = subprocess.check_output(["git", "rev-parse", "HEAD"]).decode().strip()
        old_revision = empty_revision()
    else:
        new_revision = line.split()[1]
        old_revision = line.split()[3]

    if new_revision == empty_revision():
        print("new revision is empty, you might be deleting a remote branch; pushing anyway...")
        sys.exit(0)

    result = False
    try:
        result = hook(old_revision, new_revision)
    except OSError as e:
        print('OSError reports: {} (exit code {}); is clang-format installed?'.format(e.strerror, e.errno))

    if os.path.isdir('.clang-format-check'):
        shutil.rmtree('.clang-format-check')

    if result:
        sys.exit(0)
    else:
        sys.exit(1)