bpo-26579: Add object.__getstate__(). (GH-2821)

Copying and pickling instances of subclasses of builtin types
bytearray, set, frozenset, collections.OrderedDict, collections.deque,
weakref.WeakSet, and datetime.tzinfo now copies and pickles instance attributes
implemented as slots.

2 files changed, 10 insertions, 35 deletions

diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index b47f977..f78e261 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -1347,27 +1347,24 @@ deque_traverse(dequeobject *deque, visitproc visit, void *arg)
 static PyObject *
 deque_reduce(dequeobject *deque, PyObject *Py_UNUSED(ignored))
 {
-    PyObject *dict, *it;
+    PyObject *state, *it;
 
-    if (_PyObject_LookupAttr((PyObject *)deque, &_Py_ID(__dict__), &dict) < 0) {
+    state = _PyObject_GetState((PyObject *)deque);
+    if (state == NULL) {
         return NULL;
     }
-    if (dict == NULL) {
-        dict = Py_None;
-        Py_INCREF(dict);
-    }
 
     it = PyObject_GetIter((PyObject *)deque);
     if (it == NULL) {
-        Py_DECREF(dict);
+        Py_DECREF(state);
         return NULL;
     }
 
     if (deque->maxlen < 0) {
-        return Py_BuildValue("O()NN", Py_TYPE(deque), dict, it);
+        return Py_BuildValue("O()NN", Py_TYPE(deque), state, it);
     }
     else {
-        return Py_BuildValue("O(()n)NN", Py_TYPE(deque), deque->maxlen, dict, it);
+        return Py_BuildValue("O(()n)NN", Py_TYPE(deque), deque->maxlen, state, it);
     }
 }
 
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index ae97190..fc766c3 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -3736,9 +3736,8 @@ static PyObject *
 tzinfo_reduce(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
     PyObject *args, *state;
-    PyObject *getinitargs, *getstate;
+    PyObject *getinitargs;
     _Py_IDENTIFIER(__getinitargs__);
-    _Py_IDENTIFIER(__getstate__);
 
     if (_PyObject_LookupAttrId(self, &PyId___getinitargs__, &getinitargs) < 0) {
         return NULL;
@@ -3754,34 +3753,13 @@ tzinfo_reduce(PyObject *self, PyObject *Py_UNUSED(ignored))
         return NULL;
     }
 
-    if (_PyObject_LookupAttrId(self, &PyId___getstate__, &getstate) < 0) {
+    state = _PyObject_GetState(self);
+    if (state == NULL) {
         Py_DECREF(args);
         return NULL;
     }
-    if (getstate != NULL) {
-        state = PyObject_CallNoArgs(getstate);
-        Py_DECREF(getstate);
-        if (state == NULL) {
-            Py_DECREF(args);
-            return NULL;
-        }
-    }
-    else {
-        PyObject **dictptr;
-        state = Py_None;
-        dictptr = _PyObject_GetDictPtr(self);
-        if (dictptr && *dictptr && PyDict_GET_SIZE(*dictptr)) {
-            state = *dictptr;
-        }
-        Py_INCREF(state);
-    }
 
-    if (state == Py_None) {
-        Py_DECREF(state);
-        return Py_BuildValue("(ON)", Py_TYPE(self), args);
-    }
-    else
-        return Py_BuildValue("(ONN)", Py_TYPE(self), args, state);
+    return Py_BuildValue("(ONN)", Py_TYPE(self), args, state);
 }
 
 static PyMethodDef tzinfo_methods[] = {