tools/bazel/convert_driver_subsys.py

# Copyright 2025 The Pigweed Authors
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy of
# the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations under
# the License.
"""Batch-translates Zephyr's driver/ directory and subsys/ directory to Bazel."""

import argparse
from pathlib import Path
import sys

import driver_subsys_cmake_to_bazel


def find_zephyr_root(path: Path) -> Path:
    """Finds the Zephyr root directory from a subdirectory path."""
    for parent_dir in path.parents:
        if parent_dir.name == 'zephyr':
            return parent_dir
    raise ValueError('Input path is not inside zephyr tree')


def main():
    """Main entry point."""
    parser = argparse.ArgumentParser(
        description=(
            'Batch-convert Zephyr driver or subsys CMakeLists.txt files to'
            ' BUILD.bazel'
        )
    )
    parser.add_argument(
        '--start_dir',
        required=True,
        help='Top-level SoC directory to start conversion, e.g. subsys/logging',
    )
    parser.add_argument(
        '--output_dir',
        required=True,
        help='Output directory to hold converted BUILD.bazel files',
    )
    args = parser.parse_args()

    start_path = Path(args.start_dir)
    output_path = Path(args.output_dir)

    try:
        any_cmake_file = next(start_path.rglob('CMakeLists.txt'))
        zephyr_root = find_zephyr_root(any_cmake_file)
    except (StopIteration, ValueError) as e:
        print(
            f"Error: No CMakeLists.txt found in '{args.start_dir}' "
            "or it's not a Zephyr directory.",
            file=sys.stderr,
        )
        print(f'Details: {e}', file=sys.stderr)
        sys.exit(1)

    driver_root = zephyr_root / 'drivers'
    subsys_root = zephyr_root / 'subsys'

    if start_path.parent != driver_root and start_path.parent != subsys_root:
        print(
            f"Warning: '{start_path}' is not a top-level driver or subsys "
            'directory e.g. subsys/logging. Converted Bazel rules may miss '
            'common files in the parent directory.'
        )

    cmake_files = sorted(list(start_path.rglob('CMakeLists.txt')))

    for cmake_file in cmake_files:
        cmake_dir = cmake_file.parent

        relative_dir = cmake_dir.relative_to(start_path)
        output_dir = output_path / relative_dir
        output_dir.mkdir(parents=True, exist_ok=True)
        output_file = output_dir / 'BUILD.bazel'

        print(f'Converting {cmake_file} to {output_file}...')

        with open(cmake_file, 'r', encoding='utf-8') as f:
            cmake_content = f.read()

        target_name = cmake_dir.name

        bazel_content = (
            driver_subsys_cmake_to_bazel.convert_cmakelists_to_bazel(
                cmake_content,
                target_name,
            )
        )

        with open(output_file, 'w', encoding='utf-8') as f:
            f.write(bazel_content)

    print('\nConversion complete.')


if __name__ == '__main__':
    main()