clang_tidy_git.py

#!/usr/bin/env python

import argparse
import json
import re
import subprocess
import sys

DEFAULT_FILE_PATTERN = r'.*\.[ch](pp)?'

# @@ -start,count +start,count @@
CHUNK_PATTERN = r'^@@\s+-\d+,\d+\s+\+(\d+),(\d+)\s+@@'


def transform_globs_into_regexes(globs):
    return [glob.replace('*', '.*').replace('?', '.') for glob in globs]


def get_file_patterns(globs, regexes):
    regexes += transform_globs_into_regexes(globs)
    if not regexes:
        regexes = [DEFAULT_FILE_PATTERN]
    return [re.compile(regex) for regex in regexes]


def git_diff(args):
    command = ['git', '--no-pager', 'diff', '--no-color'] + args
    try:
        return subprocess.check_output(command, stderr=subprocess.STDOUT)
    except OSError:
        _, e, _ = sys.exc_info()
        raise RuntimeError('Error executing git diff: {}'.format(e))


def get_changed_files(revision, paths, file_patterns):
    args = [
        '--diff-filter',
        'AMU',
        '--ignore-all-space',
        '--name-only',
        revision,
    ]
    output = git_diff(args + paths)

    files = []
    for line in output.split('\n'):
        for pattern in file_patterns:
            if pattern.match(line):
                files.append(line)

    return files


def get_changed_lines(revision, filename):
    output = git_diff(['--unified=0', revision, filename])
    changed_lines = []
    for chunk in re.finditer(CHUNK_PATTERN, output, re.MULTILINE):
        start = int(chunk.group(1))
        count = int(chunk.group(2))
        changed_lines.append([start, start + count])

    return dict(name=filename, lines=changed_lines)


def run_clang_tidy(clang_tidy_path, compile_commands_directory, extra_args,
                   line_filters):
    command = ['clang-tidy', '-p', compile_commands_directory]
    if line_filters:
        command.append("--line-filter='{}'".format(json.dumps(line_filters)))
    try:
        output = subprocess.check_output(command + extra_args)
    except OSError:
        _, e, _ = sys.exc_info()
        raise RuntimeError('Error executing clang-tidy: {}'.format(e))
    else:
        return output


def parse_options():
    parser = argparse.ArgumentParser(
        description='Run Clang-Tidy on your Git changes')
    parser.add_argument('-a', '--all', action='store_true')
    parser.add_argument('-c', '--clang-tidy-path', default='clang-tidy')
    parser.add_argument('--extra-args', nargs='+', default=[])
    parser.add_argument('-g', '--glob', nargs='+', default=[])
    parser.add_argument('-x', '--regex', nargs='+', default=[])
    parser.add_argument('-d', '--compile-commands-dir', default='.')
    parser.add_argument('-r', '--revision', default='HEAD')
    parser.add_argument('-p', '--paths', nargs='+', default=['.'])
    return parser.parse_args()


def main():
    options = parse_options()
    file_patterns = get_file_patterns(options.glob, options.regex)
    files = get_changed_files(options.revision, options.paths, file_patterns)

    line_filters = []
    if not options.all:
        for filename in files:
            line_filters.append(get_changed_lines(options.revision, filename))

    result = run_clang_tidy(options.clang_tidy_path,
                            options.compile_commands_dir, options.extra_args,
                            line_filters)

    print(result)


if __name__ == '__main__':
    main()