Tools/clangd/update-compile-commands-symlink-conf

#!/usr/bin/env python3

# Copyright (C) 2024 Igalia S.L.
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from __future__ import annotations
import re
import argparse
from pathlib import Path


# This warning is better placed in the code than in the template file, as
# otherwise it could be very confusing to people reading the template.
autogenerated_warning = b"""
# !!! Autogenerated by update-compile-commands-symlink-conf !!!
# ^ Removing this line will prevent this file from updating
#
# If you want to commit changes to the repository-committed template, edit
# Tools/clangd/update-compile-commands-symlink.conf.example
# ----------------------------------------------------------------------------

""".lstrip()

re_autogenerated = re.compile(rb"^# !!! Autogenerated .*", flags=re.MULTILINE)
assert re_autogenerated.match(autogenerated_warning)


def update_commands_conf(path_example: Path, path_dest: Path):
    current_bytes = None
    try:
        with open(path_dest, "rb") as f:
            current_bytes = f.read()
            is_autogenerated = re_autogenerated.match(current_bytes) is not None
            if not is_autogenerated and current_bytes != b"":
                return
    except FileNotFoundError:
        pass
    # Read the example and write it to `path_dest`.
    with open(path_example, "rb") as f:
        example_bytes = f.read()
    new_bytes = autogenerated_warning + example_bytes
    if new_bytes != current_bytes:
        with open(path_dest, "wb") as f:
            f.write(new_bytes)


def main():
    parser = argparse.ArgumentParser("update-compile-commands-symlink-conf",
        description="Creates or updates the update-compile-commands-symlink.conf file.")
    parser.add_argument("compile_commands_conf_example", type=Path)
    parser.add_argument("compile_commands_conf_dest", type=Path)
    args = parser.parse_args()
    update_commands_conf(path_example=args.compile_commands_conf_example,
        path_dest=args.compile_commands_conf_dest)


if __name__ == "__main__":
    main()