codekingpro/portable-devtools

1# don't import any costly modules2import sys3import os4 5 6def warn_distutils_present():7    if 'distutils' not in sys.modules:8        return9    import warnings10 11    warnings.warn(12        "Distutils was imported before Setuptools, but importing Setuptools "13        "also replaces the `distutils` module in `sys.modules`. This may lead "14        "to undesirable behaviors or errors. To avoid these issues, avoid "15        "using distutils directly, ensure that setuptools is installed in the "16        "traditional way (e.g. not an editable install), and/or make sure "17        "that setuptools is always imported before distutils."18    )19 20 21def clear_distutils():22    if 'distutils' not in sys.modules:23        return24    import warnings25 26    warnings.warn("Setuptools is replacing distutils.")27    mods = [28        name29        for name in sys.modules30        if name == "distutils" or name.startswith("distutils.")31    ]32    for name in mods:33        del sys.modules[name]34 35 36def enabled():37    """38    Allow selection of distutils by environment variable.39    """40    which = os.environ.get('SETUPTOOLS_USE_DISTUTILS', 'local')41    return which == 'local'42 43 44def ensure_local_distutils():45    import importlib46 47    clear_distutils()48 49    # With the DistutilsMetaFinder in place,50    # perform an import to cause distutils to be51    # loaded from setuptools._distutils. Ref #2906.52    with shim():53        importlib.import_module('distutils')54 55    # check that submodules load as expected56    core = importlib.import_module('distutils.core')57    assert '_distutils' in core.__file__, core.__file__58    assert 'setuptools._distutils.log' not in sys.modules59 60 61def do_override():62    """63    Ensure that the local copy of distutils is preferred over stdlib.64 65    See https://github.com/pypa/setuptools/issues/417#issuecomment-39229840166    for more motivation.67    """68    if enabled():69        warn_distutils_present()70        ensure_local_distutils()71 72 73class _TrivialRe:74    def __init__(self, *patterns):75        self._patterns = patterns76 77    def match(self, string):78        return all(pat in string for pat in self._patterns)79 80 81class DistutilsMetaFinder:82    def find_spec(self, fullname, path, target=None):83        # optimization: only consider top level modules and those84        # found in the CPython test suite.85        if path is not None and not fullname.startswith('test.'):86            return None87 88        method_name = 'spec_for_{fullname}'.format(**locals())89        method = getattr(self, method_name, lambda: None)90        return method()91 92    def spec_for_distutils(self):93        if self.is_cpython():94            return None95 96        import importlib97        import importlib.abc98        import importlib.util99 100        try:101            mod = importlib.import_module('setuptools._distutils')102        except Exception:103            # There are a couple of cases where setuptools._distutils104            # may not be present:105            # - An older Setuptools without a local distutils is106            #   taking precedence. Ref #2957.107            # - Path manipulation during sitecustomize removes108            #   setuptools from the path but only after the hook109            #   has been loaded. Ref #2980.110            # In either case, fall back to stdlib behavior.111            return None112 113        class DistutilsLoader(importlib.abc.Loader):114            def create_module(self, spec):115                mod.__name__ = 'distutils'116                return mod117 118            def exec_module(self, module):119                pass120 121        return importlib.util.spec_from_loader(122            'distutils', DistutilsLoader(), origin=mod.__file__123        )124 125    @staticmethod126    def is_cpython():127        """128        Suppress supplying distutils for CPython (build and tests).129        Ref #2965 and #3007.130        """131        return os.path.isfile('pybuilddir.txt')132 133    def spec_for_pip(self):134        """135        Ensure stdlib distutils when running under pip.136        See pypa/pip#8761 for rationale.137        """138        if sys.version_info >= (3, 12) or self.pip_imported_during_build():139            return140        clear_distutils()141        self.spec_for_distutils = lambda: None142 143    @classmethod144    def pip_imported_during_build(cls):145        """146        Detect if pip is being imported in a build script. Ref #2355.147        """148        import traceback149 150        return any(151            cls.frame_file_is_setup(frame) for frame, line in traceback.walk_stack(None)152        )153 154    @staticmethod155    def frame_file_is_setup(frame):156        """157        Return True if the indicated frame suggests a setup.py file.158        """159        # some frames may not have __file__ (#2940)160        return frame.f_globals.get('__file__', '').endswith('setup.py')161 162    def spec_for_sensitive_tests(self):163        """164        Ensure stdlib distutils when running select tests under CPython.165 166        python/cpython#91169167        """168        clear_distutils()169        self.spec_for_distutils = lambda: None170 171    sensitive_tests = (172        [173            'test.test_distutils',174            'test.test_peg_generator',175            'test.test_importlib',176        ]177        if sys.version_info < (3, 10)178        else [179            'test.test_distutils',180        ]181    )182 183 184for name in DistutilsMetaFinder.sensitive_tests:185    setattr(186        DistutilsMetaFinder,187        f'spec_for_{name}',188        DistutilsMetaFinder.spec_for_sensitive_tests,189    )190 191 192DISTUTILS_FINDER = DistutilsMetaFinder()193 194 195def add_shim():196    DISTUTILS_FINDER in sys.meta_path or insert_shim()197 198 199class shim:200    def __enter__(self):201        insert_shim()202 203    def __exit__(self, exc, value, tb):204        _remove_shim()205 206 207def insert_shim():208    sys.meta_path.insert(0, DISTUTILS_FINDER)209 210 211def _remove_shim():212    try:213        sys.meta_path.remove(DISTUTILS_FINDER)214    except ValueError:215        pass216 217 218if sys.version_info < (3, 12):219    # DistutilsMetaFinder can only be disabled in Python < 3.12 (PEP 632)220    remove_shim = _remove_shim221