fix extract_paths

sisyphus/hash.py

@@ -44,6 +44,19 @@ def get_object_state(obj):
     Comment: Maybe obj.__reduce__() is a better idea? is it stable for hashing?
     """
 
+    # Note: sis_hash_helper does not call get_object_state in these cases.
+    # However, other code might (e.g. extract_paths),
+    # so we keep consistent to the behavior of sis_hash_helper.
+    if obj is None:
+        return None
+    if isinstance(obj, (bool, int, float, complex, str)):
+        return obj
+    if isfunction(obj) or isclass(obj):
+        # Note: sis_hash_helper does not call get_object_state in these cases.
+        # However, other code might (e.g. extract_paths),
+        # so we keep consistent to the behavior of sis_hash_helper.
+        return obj.__module__, obj.__qualname__
+
     if isinstance(obj, pathlib.PurePath):
         # pathlib paths have a somewhat technical internal state
         # ('_drv', '_root', '_parts', '_str', '_hash', '_pparts', '_cached_cparts'),
@@ -58,18 +71,14 @@ def get_object_state(obj):
     else:
         args = None
 
-    if hasattr(obj, "__sis_state__") and not isinstance(obj, type):
+    if hasattr(obj, "__sis_state__"):
         state = obj.__sis_state__()
     # Note: Since Python 3.11, there is a default object.__getstate__.
     # However, this default object.__getstate__ is not correct for some native types, e.g. _functools.partial.
     # https://github.com/rwth-i6/sisyphus/issues/207
     # https://github.com/python/cpython/issues/125094
     # Thus, only use __getstate__ if it is not the default object.__getstate__.
-    elif (
-        hasattr(obj, "__getstate__")
-        and obj.__class__.__getstate__ is not getattr(object, "__getstate__", None)
-        and not isinstance(obj, type)
-    ):
+    elif hasattr(obj, "__getstate__") and obj.__class__.__getstate__ is not getattr(object, "__getstate__", None):
         state = obj.__getstate__()
     else:
         state = _getmembers(obj)

sisyphus/tools.py

@@ -85,6 +85,10 @@ def extract_paths(args: Any) -> Set:
         if id(obj) in visited_obj_ids:
             continue
         visited_obj_ids[id(obj)] = obj
+        if obj is None:
+            continue
+        if isinstance(obj, (bool, int, float, complex, str)):
+            continue
         if isinstance(obj, Block) or isinstance(obj, enum.Enum):
             continue
         if hasattr(obj, "_sis_path") and obj._sis_path is True and not type(obj) is type:

tests/hash_unittest.py

@@ -23,6 +23,22 @@ def d():
         self.assertEqual(sis_hash_helper(b), b"(function, (tuple, (str, '" + __name__.encode() + b"'), (str, 'b')))")
         self.assertRaises(AssertionError, sis_hash_helper, c)
 
+    def test_get_object_state_cls(self):
+        # Note: the hash of a class currently does not depend on get_object_state,
+        # but there is special logic in sis_hash_helper for classes,
+        # thus it doesn't really matter for the hash what is being returned here.
+        # However, this is used by extract_paths, so we test it here.
+        s = get_object_state(str)
+        self.assertEqual(s, ("builtins", "str"))
+
+    def test_get_object_state_function(self):
+        # Note: the hash of a function currently does not depend on get_object_state,
+        # but there is special logic in sis_hash_helper for functions,
+        # thus it doesn't really matter for the hash what is being returned here.
+        # However, this is used by extract_paths, so we test it here.
+        s = get_object_state(b)
+        self.assertEqual(s, (b.__module__, b.__name__))
+
     def test_enum(self):
         self.assertEqual(
             sis_hash_helper(MyEnum.Entry1),