Rename _distutils_importer to _distutils_hack, as it supplies more than just an importer.

1 files changed, 45 insertions, 0 deletions

diff --git a/_distutils_hack/__init__.py b/_distutils_hack/__init__.py
new file mode 100644
index 00000000..3ad70100
--- /dev/null
+++ b/_distutils_hack/__init__.py
@@ -0,0 +1,45 @@
+import sys
+import os
+
+
+def enabled():
+    """
+    Allow selection of distutils by environment variable.
+    """
+    which = os.environ.get('SETUPTOOLS_USE_DISTUTILS', 'stdlib')
+    return which == 'local'
+
+
+class DistutilsMetaFinder:
+    def find_spec(self, fullname, path, target=None):
+        if path is not None or fullname != "distutils":
+            return None
+
+        return self.get_distutils_spec()
+
+    def get_distutils_spec(self):
+        import importlib.util
+
+        class DistutilsLoader(importlib.util.abc.Loader):
+
+            def create_module(self, spec):
+                return importlib.import_module('._distutils', 'setuptools')
+
+            def exec_module(self, module):
+                pass
+
+        return importlib.util.spec_from_loader('distutils', DistutilsLoader())
+
+
+DISTUTILS_FINDER = DistutilsMetaFinder()
+
+
+def add_shim():
+    sys.meta_path.insert(0, DISTUTILS_FINDER)
+
+
+def remove_shim():
+    try:
+        sys.path.remove(DISTUTILS_FINDER)
+    except ValueError:
+        pass