Issue #14605: Expose importlib.abc.FileLoader and

importlib.machinery.(FileFinder, SourceFileLoader,
_SourcelessFileLoader, ExtensionFileLoader).

This exposes all of importlib's mechanisms that will become public on
the sys module.

Lib/importlib/test/extension/test_case_sensitivity.py

@@ -1,3 +1,4 @@
+import imp
 import sys
 from test import support
 import unittest
@@ -13,8 +14,10 @@ class ExtensionModuleCaseSensitivityTest(unittest.TestCase):
         good_name = ext_util.NAME
         bad_name = good_name.upper()
         assert good_name != bad_name
-        finder = _bootstrap._FileFinder(ext_util.PATH,
-                                        _bootstrap._ExtensionFinderDetails())
+        finder = _bootstrap.FileFinder(ext_util.PATH,
+                                        (_bootstrap.ExtensionFileLoader,
+                                            _bootstrap._suffix_list(imp.C_EXTENSION),
+                                            False))
         return finder.find_module(bad_name)
 
     def test_case_sensitive(self):

Lib/importlib/test/extension/test_finder.py

@@ -2,6 +2,7 @@ from importlib import _bootstrap
 from .. import abc
 from . import util
 
+import imp
 import unittest
 
 class FinderTests(abc.FinderTests):
@@ -9,8 +10,10 @@ class FinderTests(abc.FinderTests):
     """Test the finder for extension modules."""
 
     def find_module(self, fullname):
-        importer = _bootstrap._FileFinder(util.PATH,
-                                          _bootstrap._ExtensionFinderDetails())
+        importer = _bootstrap.FileFinder(util.PATH,
+                                          (_bootstrap.ExtensionFileLoader,
+                                              _bootstrap._suffix_list(imp.C_EXTENSION),
+                                              False))
         return importer.find_module(fullname)
 
     def test_module(self):

Lib/importlib/test/extension/test_loader.py

@@ -12,7 +12,7 @@ class LoaderTests(abc.LoaderTests):
     """Test load_module() for extension modules."""
 
     def load_module(self, fullname):
-        loader = _bootstrap._ExtensionFileLoader(ext_util.NAME,
+        loader = _bootstrap.ExtensionFileLoader(ext_util.NAME,
                                                 ext_util.FILEPATH)
         return loader.load_module(fullname)
 
@@ -25,7 +25,7 @@ class LoaderTests(abc.LoaderTests):
                 self.assertEqual(getattr(module, attr), value)
             self.assertTrue(ext_util.NAME in sys.modules)
             self.assertTrue(isinstance(module.__loader__,
-                                    _bootstrap._ExtensionFileLoader))
+                                    _bootstrap.ExtensionFileLoader))
 
     def test_package(self):
         # Extensions are not found in packages.

Lib/importlib/test/extension/test_path_hook.py

@@ -14,7 +14,8 @@ class PathHookTests(unittest.TestCase):
     # XXX Should it only work for directories containing an extension module?
 
     def hook(self, entry):
-        return _bootstrap._file_path_hook(entry)
+        return _bootstrap.FileFinder.path_hook((_bootstrap.ExtensionFileLoader,
+            _bootstrap._suffix_list(imp.C_EXTENSION), False))(entry)
 
     def test_success(self):
         # Path hook should handle a directory where a known extension module