mesonbuild/_pathlib.py

# Copyright 2021 The Meson development team

# 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

#     http://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.

'''
    This module soly exists to work around a pathlib.resolve bug on
    certain Windows systems:

    https://github.com/mesonbuild/meson/issues/7295
    https://bugs.python.org/issue31842

    It should **never** be used directly. Instead, it is automatically
    used when `import pathlib` is used. This is achieved by messing with
    `sys.modules['pathlib']` in mesonmain.

    Additionally, the sole purpose of this module is to work around a
    python bug. This only bugfixes to pathlib functions and classes are
    allowed here. Finally, this file should be removed once all upstream
    python bugs are fixed and it is OK to tell our users to "just upgrade
    python".
'''
from __future__ import annotations

import pathlib
import os
import platform

__all__ = [
    'PurePath',
    'PurePosixPath',
    'PureWindowsPath',
    'Path',
]

PurePath = pathlib.PurePath
PurePosixPath = pathlib.PurePosixPath
PureWindowsPath = pathlib.PureWindowsPath

# Only patch on platforms where the bug occurs
if platform.system().lower() in {'windows'}:
    # Can not directly inherit from pathlib.Path because the __new__
    # operator of pathlib.Path() returns a {Posix,Windows}Path object.
    class Path(type(pathlib.Path())):
        def resolve(self, strict: bool = False) -> 'Path':
            '''
                Work around a resolve bug on certain Windows systems:

                https://github.com/mesonbuild/meson/issues/7295
                https://bugs.python.org/issue31842
            '''

            try:
                return super().resolve(strict=strict)
            except OSError:
                return Path(os.path.normpath(self))
else:
    Path = pathlib.Path
    PosixPath = pathlib.PosixPath
    WindowsPath = pathlib.WindowsPath

    __all__ += [
        'PosixPath',
        'WindowsPath',
    ]