|
| 1 | +# don't import any costly modules |
| 2 | +import sys |
| 3 | +import os |
| 4 | + |
| 5 | + |
| 6 | +is_pypy = '__pypy__' in sys.builtin_module_names |
| 7 | + |
| 8 | + |
| 9 | +def warn_distutils_present(): |
| 10 | + if 'distutils' not in sys.modules: |
| 11 | + return |
| 12 | + if is_pypy and sys.version_info < (3, 7): |
| 13 | + # PyPy for 3.6 unconditionally imports distutils, so bypass the warning |
| 14 | + # https://foss.heptapod.net/pypy/pypy/-/blob/be829135bc0d758997b3566062999ee8b23872b4/lib-python/3/site.py#L250 |
| 15 | + return |
| 16 | + import warnings |
| 17 | + |
| 18 | + warnings.warn( |
| 19 | + "Distutils was imported before Setuptools, but importing Setuptools " |
| 20 | + "also replaces the `distutils` module in `sys.modules`. This may lead " |
| 21 | + "to undesirable behaviors or errors. To avoid these issues, avoid " |
| 22 | + "using distutils directly, ensure that setuptools is installed in the " |
| 23 | + "traditional way (e.g. not an editable install), and/or make sure " |
| 24 | + "that setuptools is always imported before distutils." |
| 25 | + ) |
| 26 | + |
| 27 | + |
| 28 | +def clear_distutils(): |
| 29 | + if 'distutils' not in sys.modules: |
| 30 | + return |
| 31 | + import warnings |
| 32 | + |
| 33 | + warnings.warn("Setuptools is replacing distutils.") |
| 34 | + mods = [ |
| 35 | + name |
| 36 | + for name in sys.modules |
| 37 | + if name == "distutils" or name.startswith("distutils.") |
| 38 | + ] |
| 39 | + for name in mods: |
| 40 | + del sys.modules[name] |
| 41 | + |
| 42 | + |
| 43 | +def enabled(): |
| 44 | + """ |
| 45 | + Allow selection of distutils by environment variable. |
| 46 | + """ |
| 47 | + which = os.environ.get('SETUPTOOLS_USE_DISTUTILS', 'local') |
| 48 | + return which == 'local' |
| 49 | + |
| 50 | + |
| 51 | +def ensure_local_distutils(): |
| 52 | + import importlib |
| 53 | + |
| 54 | + clear_distutils() |
| 55 | + |
| 56 | + # With the DistutilsMetaFinder in place, |
| 57 | + # perform an import to cause distutils to be |
| 58 | + # loaded from setuptools._distutils. Ref #2906. |
| 59 | + with shim(): |
| 60 | + importlib.import_module('distutils') |
| 61 | + |
| 62 | + # check that submodules load as expected |
| 63 | + core = importlib.import_module('distutils.core') |
| 64 | + assert '_distutils' in core.__file__, core.__file__ |
| 65 | + assert 'setuptools._distutils.log' not in sys.modules |
| 66 | + |
| 67 | + |
| 68 | +def do_override(): |
| 69 | + """ |
| 70 | + Ensure that the local copy of distutils is preferred over stdlib. |
| 71 | +
|
| 72 | + See https://github.com/pypa/setuptools/issues/417#issuecomment-392298401 |
| 73 | + for more motivation. |
| 74 | + """ |
| 75 | + if enabled(): |
| 76 | + warn_distutils_present() |
| 77 | + ensure_local_distutils() |
| 78 | + |
| 79 | + |
| 80 | +class _TrivialRe: |
| 81 | + def __init__(self, *patterns): |
| 82 | + self._patterns = patterns |
| 83 | + |
| 84 | + def match(self, string): |
| 85 | + return all(pat in string for pat in self._patterns) |
| 86 | + |
| 87 | + |
| 88 | +class DistutilsMetaFinder: |
| 89 | + def find_spec(self, fullname, path, target=None): |
| 90 | + # optimization: only consider top level modules and those |
| 91 | + # found in the CPython test suite. |
| 92 | + if path is not None and not fullname.startswith('test.'): |
| 93 | + return |
| 94 | + |
| 95 | + method_name = 'spec_for_{fullname}'.format(**locals()) |
| 96 | + method = getattr(self, method_name, lambda: None) |
| 97 | + return method() |
| 98 | + |
| 99 | + def spec_for_distutils(self): |
| 100 | + if self.is_cpython(): |
| 101 | + return |
| 102 | + |
| 103 | + import importlib |
| 104 | + import importlib.abc |
| 105 | + import importlib.util |
| 106 | + |
| 107 | + try: |
| 108 | + mod = importlib.import_module('setuptools._distutils') |
| 109 | + except Exception: |
| 110 | + # There are a couple of cases where setuptools._distutils |
| 111 | + # may not be present: |
| 112 | + # - An older Setuptools without a local distutils is |
| 113 | + # taking precedence. Ref #2957. |
| 114 | + # - Path manipulation during sitecustomize removes |
| 115 | + # setuptools from the path but only after the hook |
| 116 | + # has been loaded. Ref #2980. |
| 117 | + # In either case, fall back to stdlib behavior. |
| 118 | + return |
| 119 | + |
| 120 | + class DistutilsLoader(importlib.abc.Loader): |
| 121 | + def create_module(self, spec): |
| 122 | + mod.__name__ = 'distutils' |
| 123 | + return mod |
| 124 | + |
| 125 | + def exec_module(self, module): |
| 126 | + pass |
| 127 | + |
| 128 | + return importlib.util.spec_from_loader( |
| 129 | + 'distutils', DistutilsLoader(), origin=mod.__file__ |
| 130 | + ) |
| 131 | + |
| 132 | + @staticmethod |
| 133 | + def is_cpython(): |
| 134 | + """ |
| 135 | + Suppress supplying distutils for CPython (build and tests). |
| 136 | + Ref #2965 and #3007. |
| 137 | + """ |
| 138 | + return os.path.isfile('pybuilddir.txt') |
| 139 | + |
| 140 | + def spec_for_pip(self): |
| 141 | + """ |
| 142 | + Ensure stdlib distutils when running under pip. |
| 143 | + See pypa/pip#8761 for rationale. |
| 144 | + """ |
| 145 | + if self.pip_imported_during_build(): |
| 146 | + return |
| 147 | + clear_distutils() |
| 148 | + self.spec_for_distutils = lambda: None |
| 149 | + |
| 150 | + @classmethod |
| 151 | + def pip_imported_during_build(cls): |
| 152 | + """ |
| 153 | + Detect if pip is being imported in a build script. Ref #2355. |
| 154 | + """ |
| 155 | + import traceback |
| 156 | + |
| 157 | + return any( |
| 158 | + cls.frame_file_is_setup(frame) for frame, line in traceback.walk_stack(None) |
| 159 | + ) |
| 160 | + |
| 161 | + @staticmethod |
| 162 | + def frame_file_is_setup(frame): |
| 163 | + """ |
| 164 | + Return True if the indicated frame suggests a setup.py file. |
| 165 | + """ |
| 166 | + # some frames may not have __file__ (#2940) |
| 167 | + return frame.f_globals.get('__file__', '').endswith('setup.py') |
| 168 | + |
| 169 | + def spec_for_sensitive_tests(self): |
| 170 | + """ |
| 171 | + Ensure stdlib distutils when running select tests under CPython. |
| 172 | +
|
| 173 | + python/cpython#91169 |
| 174 | + """ |
| 175 | + clear_distutils() |
| 176 | + self.spec_for_distutils = lambda: None |
| 177 | + |
| 178 | + sensitive_tests = ( |
| 179 | + [ |
| 180 | + 'test.test_distutils', |
| 181 | + 'test.test_peg_generator', |
| 182 | + 'test.test_importlib', |
| 183 | + ] |
| 184 | + if sys.version_info < (3, 10) |
| 185 | + else [ |
| 186 | + 'test.test_distutils', |
| 187 | + ] |
| 188 | + ) |
| 189 | + |
| 190 | + |
| 191 | +for name in DistutilsMetaFinder.sensitive_tests: |
| 192 | + setattr( |
| 193 | + DistutilsMetaFinder, |
| 194 | + f'spec_for_{name}', |
| 195 | + DistutilsMetaFinder.spec_for_sensitive_tests, |
| 196 | + ) |
| 197 | + |
| 198 | + |
| 199 | +DISTUTILS_FINDER = DistutilsMetaFinder() |
| 200 | + |
| 201 | + |
| 202 | +def add_shim(): |
| 203 | + DISTUTILS_FINDER in sys.meta_path or insert_shim() |
| 204 | + |
| 205 | + |
| 206 | +class shim: |
| 207 | + def __enter__(self): |
| 208 | + insert_shim() |
| 209 | + |
| 210 | + def __exit__(self, exc, value, tb): |
| 211 | + remove_shim() |
| 212 | + |
| 213 | + |
| 214 | +def insert_shim(): |
| 215 | + sys.meta_path.insert(0, DISTUTILS_FINDER) |
| 216 | + |
| 217 | + |
| 218 | +def remove_shim(): |
| 219 | + try: |
| 220 | + sys.meta_path.remove(DISTUTILS_FINDER) |
| 221 | + except ValueError: |
| 222 | + pass |
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