libdot/bin/clang-format

#!/usr/bin/env python3
# Copyright 2025 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Run clang-format with the right settings."""

import functools
from pathlib import Path
import platform
import subprocess
import sys
from typing import Iterable

import libdot


@functools.cache
def get_manifest_name() -> str:
    """The path on the server for this program."""
    osname = platform.system()
    try:
        shortname = {
            "Linux": "linux",
            "Darwin": "mac",
            "Windows": "win",
        }[osname]
    except KeyError as e:
        raise RuntimeError(f"Unknown OS {osname}") from e
    return f"clang-format/{shortname}"


@functools.cache
def get_manifest_spec() -> libdot.Artifact:
    """Get the manifest entry for this file."""
    return libdot.fetch_manifest_lookup(
        libdot.DIR / "fetch.json", get_manifest_name()
    )


@functools.cache
def binary_path() -> Path:
    """Get path to the local binary."""
    spec = get_manifest_spec()
    objname = spec.url.rsplit("/", 1)[-1]
    sfx = ".exe" if platform.system() == "Windows" else ""
    return libdot.BIN_DIR / f".clang-format.{objname}{sfx}"


def setup() -> None:
    """Download & update our copy."""
    path = binary_path()
    if path.exists():
        return

    for p in libdot.BIN_DIR.glob(".clang-format.*"):
        p.unlink()

    # Download & unpack the archive.
    libdot.fetch_manifest_spec(get_manifest_spec(), path)
    path.chmod(0o755)


def run(argv: Iterable[str] = (), **kwargs) -> subprocess.CompletedProcess:
    """Run the tool directly."""
    setup()

    cmd = [binary_path()] + list(argv)
    return libdot.run(cmd, **kwargs)


def perform(
    argv: Iterable[str] = (),
    paths: Iterable[str] = (),
    fix: bool = False,
    gerrit_comments_file: bool = None,
) -> None:
    """Run high level tool logic."""
    del gerrit_comments_file

    argv = list(argv)
    paths = list(paths)

    argv += ["-style=file"]
    if fix:
        argv += ["-i"]
    else:
        argv += ["--dry-run"]

    # TODO(vapier): Add support for Gerrit comments.

    result = run(argv + paths, check=False)
    return result.returncode == 0


def get_parser() -> libdot.ArgumentParser:
    """Get a command line parser."""
    parser = libdot.ArgumentParser(description=__doc__, short_options=False)
    parser.add_argument(
        "--fix",
        action="store_true",
        help="Fix formatting issues.",
    )
    return parser


def main(argv: list[str]) -> int:
    """The main func!"""
    parser = get_parser()
    opts, args = parser.parse_known_args(argv)
    return 0 if perform(args, fix=opts.fix) else 1


if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))