Add _PyStaticType_ClearWeakRefs().

Author: ericsnowcurrently

Include/internal/pycore_typeobject.h

@@ -70,6 +70,7 @@ extern PyStatus _PyTypes_InitSlotDefs(void);
 
 extern int _PyStaticType_InitBuiltin(PyTypeObject *type);
 extern static_builtin_state * _PyStaticType_GetState(PyTypeObject *);
+extern void _PyStaticType_ClearWeakRefs(PyTypeObject *type);
 extern void _PyStaticType_Dealloc(PyTypeObject *type);
 
 

Objects/typeobject.c

@@ -140,7 +140,7 @@ static_builtin_state_clear(PyTypeObject *self)
 
     static_builtin_state *state = static_builtin_state_get(interp, self);
     state->type = NULL;
-    /* state->tp_weaklist should already have been cleared out. */
+    assert(state->tp_weaklist == NULL);  // It was already cleared out.
     static_builtin_index_clear(self);
 
     assert(interp->types.num_builtins_initialized > 0);
@@ -4358,6 +4358,7 @@ _PyStaticType_Dealloc(PyTypeObject *type)
     type->tp_flags &= ~Py_TPFLAGS_READY;
 
     if (type->tp_flags & _Py_TPFLAGS_STATIC_BUILTIN) {
+        _PyStaticType_ClearWeakRefs(type);
         static_builtin_state_clear(type);
         /* We leave _Py_TPFLAGS_STATIC_BUILTIN set on tp_flags. */
     }

Objects/weakrefobject.c

@@ -1018,3 +1018,19 @@ PyObject_ClearWeakRefs(PyObject *object)
         PyErr_Restore(err_type, err_value, err_tb);
     }
 }
+
+/* This function is called by _PyStaticType_Dealloc() to clear weak references.
+ *
+ * This is called at the end of runtime finalization, so we can just
+ * wipe out the type's weaklist.  We don't bother with callbacks
+ * or anything else.
+ */
+void
+_PyStaticType_ClearWeakRefs(PyTypeObject *type)
+{
+    static_builtin_state *state = _PyStaticType_GetState(type);
+    PyObject **list = _PyStaticType_GET_WEAKREFS_LISTPTR(state);
+    while (*list != NULL) {
+        clear_weakref((PyWeakReference *)*list);
+    }
+}