#!/usr/bin/env python3

# Copyright 2026 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import subprocess
import pathlib
import sys
import tempfile

from rustc_wrapper import (
    PrepareRustEnvForExecution,
    LoadRustEnvAndFlags,
    HandleReturnCode,
)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--clippy-driver', required=True, type=pathlib.Path)
    parser.add_argument(
        '--rustc-env-and-flags', type=pathlib.Path, required=True
    )
    parser.add_argument('--build-stamp-file', type=pathlib.Path, required=True)
    args = parser.parse_args()

    (rustenv, rustflags) = LoadRustEnvAndFlags(args.rustc_env_and_flags)
    PrepareRustEnvForExecution(rustenv)

    # `clippy-driver` should not write any files into the build directory
    # (e.g. into `out/`).
    #
    # `--emit=metadata` asks Clippy to only emit `.rmeta`.  This:
    # * Matches how `cargo clippy` invokes `clippy-driver` - see
    #   https://crrev.com/c/7316228/17#message-fa234861e30ee37399388ca5a6a048822b658833
    # * Seems sufficient for triggering Clippy lints.
    # * Avoids performance overhead (and general ickiness) of also building
    #   `.rlib` from within `clippy-driver`.
    assert not [x for x in rustflags if x.startswith("--emit")]
    assert not [x for x in rustflags if x.startswith("-o")]
    assert not [x for x in rustflags if x.startswith("--out-dir")]
    temp_dir = tempfile.TemporaryDirectory()
    rustflags += ["--out-dir", temp_dir.name]
    rustflags += ["--emit=metadata"]

    r = subprocess.run(
        [args.clippy_driver, *rustflags], env=rustenv, check=False
    )
    if r.returncode != 0:
        print(
            "NOTE: See `//docs/rust/clippy.md` for more Clippy info.",
            file=sys.stderr,
        )
        HandleReturnCode(r, args.rustc_env_and_flags)
        assert (
            False
        )  # `HandleReturnCode` should call `sys.exit` for non-0 code.

    args.build_stamp_file.touch()
    return 0


if __name__ == '__main__':
    sys.exit(main())