Simplify PyObject_ClearManagedDict

python · markshannon · Apr 2, 2024 · Feb 3, 2024 · Feb 4, 2024 · Feb 21, 2024
commit 895a94460a1e9cb1f6e29a8453fc5b2c4e700ddd
diff --git a/Include/internal/pycore_object.h b/Include/internal/pycore_object.h
@@ -650,6 +650,7 @@ _PyObject_InlineValues(PyObject *obj)
 {
     assert(Py_TYPE(obj)->tp_flags & Py_TPFLAGS_INLINE_VALUES);
     assert(Py_TYPE(obj)->tp_flags & Py_TPFLAGS_MANAGED_DICT);
+    assert(Py_TYPE(obj)->tp_basicsize == sizeof(PyObject));
     return (PyDictValues *)((char *)obj + sizeof(PyObject));
 }
 

@@ -6850,30 +6850,16 @@ PyObject_VisitManagedDict(PyObject *obj, visitproc visit, void *arg)
 void
 PyObject_ClearManagedDict(PyObject *obj)
 {
-    PyTypeObject *tp = Py_TYPE(obj);
     assert(_PyObject_InlineValuesConsistencyCheck(obj));
+    PyTypeObject *tp = Py_TYPE(obj);
+    Py_CLEAR(_PyObject_ManagedDictPointer(obj)->dict);
     if (tp->tp_flags & Py_TPFLAGS_INLINE_VALUES) {
-        PyManagedDictPointer *managed_dict = _PyObject_ManagedDictPointer(obj);
         PyDictValues *values = _PyObject_InlineValues(obj);
         if (values->valid) {
-            PyDictObject *dict = (PyDictObject *)managed_dict->dict;
-            if (dict) {
-                assert(dict->ma_values == values);
-                dict->ma_values = copy_values(values);
-                values->valid = 0;
-                _PyDict_CheckConsistency((PyObject *)dict, 1);
-            }
-            else {
-                for (Py_ssize_t i = 0; i < values->capacity; i++) {
-                    Py_CLEAR(values->values[i]);
-                }
-                return;
+            for (Py_ssize_t i = 0; i < values->capacity; i++) {
+                Py_CLEAR(values->values[i]);
             }
         }
-        Py_CLEAR(managed_dict->dict);
-    }
-    else if (tp->tp_flags & Py_TPFLAGS_MANAGED_DICT) {
-        Py_CLEAR(_PyObject_ManagedDictPointer(obj)->dict);
     }
     assert(_PyObject_InlineValuesConsistencyCheck(obj));
 }

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
@@ -1998,6 +1998,10 @@ subtype_clear(PyObject *self)
         if ((base->tp_flags & Py_TPFLAGS_MANAGED_DICT) == 0) {
             PyObject_ClearManagedDict(self);
         }
+        else {
+            assert((base->tp_flags & Py_TPFLAGS_INLINE_VALUES) ==
+                   (type->tp_flags & Py_TPFLAGS_INLINE_VALUES));
+        }
     }
     else if (type->tp_dictoffset != base->tp_dictoffset) {
         PyObject **dictptr = _PyObject_ComputedDictPointer(self);