Issue #19698: Remove exec_module() from the built-in and extension

module loaders.

Due to the fact that the call signatures for extension modules and
built-in modules does not allow for the specifying of what module to
initialize and that on Windows all extension modules are built-in
modules, work to clean up built-in and extension module initialization
will have to wait until Python 3.5. Because of this the semantics of
exec_module() would be incorrect, so removing the methods for now is
the best option; load_module() is still used as a fallback by
importlib and so this won't affect semantics.

Lib/test/test_importlib/builtin/test_loader.py

@@ -9,78 +9,6 @@ import types
 import unittest
 
 
-class ExecModTests(abc.LoaderTests):
-
-    """Test exec_module() for built-in modules."""
-
-    @classmethod
-    def setUpClass(cls):
-        cls.verification = {'__name__': 'errno', '__package__': '',
-                             '__loader__': cls.machinery.BuiltinImporter}
-
-    def verify(self, module):
-        """Verify that the module matches against what it should have."""
-        self.assertIsInstance(module, types.ModuleType)
-        for attr, value in self.verification.items():
-            self.assertEqual(getattr(module, attr), value)
-        self.assertIn(module.__name__, sys.modules)
-        self.assertTrue(hasattr(module, '__spec__'))
-        self.assertEqual(module.__spec__.origin, 'built-in')
-
-    def load_spec(self, name):
-        spec = self.machinery.ModuleSpec(name, self.machinery.BuiltinImporter,
-                                         origin='built-in')
-        module = types.ModuleType(name)
-        module.__spec__ = spec
-        self.machinery.BuiltinImporter.exec_module(module)
-        # Strictly not what exec_module() is supposed to do, but since
-        # _imp.init_builtin() does this we can't get around it.
-        return sys.modules[name]
-
-    def test_module(self):
-        # Common case.
-        with util.uncache(builtin_util.NAME):
-            module = self.load_spec(builtin_util.NAME)
-            self.verify(module)
-            self.assertIn('built-in', str(module))
-
-    # Built-in modules cannot be a package.
-    test_package = None
-
-    # Built-in modules cannot be a package.
-    test_lacking_parent = None
-
-    # Not way to force an import failure.
-    test_state_after_failure = None
-
-    def test_unloadable(self):
-        name = 'dssdsdfff'
-        assert name not in sys.builtin_module_names
-        with self.assertRaises(ImportError) as cm:
-            self.load_spec(name)
-        self.assertEqual(cm.exception.name, name)
-
-    def test_already_imported(self):
-        # Using the name of a module already imported but not a built-in should
-        # still fail.
-        module_name = 'builtin_reload_test'
-        assert module_name not in sys.builtin_module_names
-        with util.uncache(module_name):
-            module = types.ModuleType(module_name)
-            spec = self.machinery.ModuleSpec(module_name,
-                                             self.machinery.BuiltinImporter,
-                                             origin='built-in')
-            module.__spec__ = spec
-            sys.modules[module_name] = module
-        with self.assertRaises(ImportError) as cm:
-            self.machinery.BuiltinImporter.exec_module(module)
-        self.assertEqual(cm.exception.name, module_name)
-
-
-Frozen_ExecModTests, Source_ExecModTests = util.test_both(ExecModTests,
-        machinery=[frozen_machinery, source_machinery])
-
-
 class LoaderTests(abc.LoaderTests):
 
     """Test load_module() for built-in modules."""