inspect.getfile: Don't crash on classes without '__module__' attribute #20372

Some classes defined in C may not have the '__module__' attribute, so
we now handle this case to avoid having unexepected AttributeError.

Lib/inspect.py

@@ -516,6 +516,7 @@ def getfile(object):
             return object.__file__
         raise TypeError('{!r} is a built-in module'.format(object))
     if isclass(object):
+        if hasattr(object, '__module__'):
             object = sys.modules.get(object.__module__)
             if hasattr(object, '__file__'):
                 return object.__file__

Lib/test/test_inspect.py

@@ -319,6 +319,16 @@ class TestRetrievingSourceCode(GetSourceBase):
     def test_getfile(self):
         self.assertEqual(inspect.getfile(mod.StupidGit), mod.__file__)
 
+    def test_getfile_class_without_module(self):
+        class CM(type):
+            @property
+            def __module__(cls):
+                raise AttributeError
+        class C(metaclass=CM):
+            pass
+        with self.assertRaises(TypeError):
+            inspect.getfile(C)
+
     def test_getmodule_recursion(self):
         from types import ModuleType
         name = '__inspect_dummy'