build/depfile_path_to_relative.py

#!/usr/bin/env fuchsia-vendored-python
# Copyright 2021 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import os
import subprocess
import sys


def main():
    parser = argparse.ArgumentParser(
        description="Executes a command, then rewrites the depfile, converts all absolute paths to relative"
    )
    parser.add_argument(
        "--depfile", help="Path to the depfile to rewrite", required=True
    )
    parser.add_argument(
        "command", nargs="+", help="Positional args for the command to run"
    )
    args = parser.parse_args()

    retval = subprocess.call(args.command)
    if retval != 0:
        return retval

    lines = []
    with open(args.depfile, "r") as f:
        for line in f:
            lines.append(" ".join(os.path.relpath(p) for p in line.split()))
    with open(args.depfile, "w") as f:
        f.write("\n".join(lines))


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