source: rtems-central/rtemsqual/util.py @ 4733ad3

# SPDX-License-Identifier: BSD-2-Clause
""" This module provides utility functions. """

# Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

import os
from typing import Any
import yaml


def load_config(config_filename: str) -> Any:
    """ Loads the configuration file with recursive includes. """
    class IncludeLoader(yaml.SafeLoader):  # pylint: disable=too-many-ancestors
        """ YAML loader customization to process custom include tags. """
        _filenames = [config_filename]

        def include(self, node):
            """ Processes the custom include tag. """
            container = IncludeLoader._filenames[0]
            dirname = os.path.dirname(container)
            filename = os.path.join(dirname, self.construct_scalar(node))
            IncludeLoader._filenames.insert(0, filename)
            with open(filename, "r") as included_file:
                data = yaml.load(included_file, IncludeLoader)
            IncludeLoader._filenames.pop()
            return data

    IncludeLoader.add_constructor("!include", IncludeLoader.include)
    with open(config_filename, "r") as config_file:
        return yaml.load(config_file.read(), Loader=IncludeLoader)