Revert "clear weakrefs unconditionally in extension modules"

This reverts commit 9024079.

Author: xuantengh

Modules/_collectionsmodule.c

@@ -1532,7 +1532,9 @@ deque_dealloc(PyObject *self)
     Py_ssize_t i;
 
     PyObject_GC_UnTrack(deque);
-    PyObject_ClearWeakRefs(self);
+    if (deque->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(self);
+    }
     if (deque->leftblock != NULL) {
         (void)deque_clear(self);
         assert(deque->leftblock != NULL);

Modules/_elementtree.c

@@ -690,7 +690,8 @@ element_dealloc(PyObject *op)
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(self);
 
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
 
     /* element_gc_clear clears all references and deallocates extra
     */

Modules/_functoolsmodule.c

@@ -351,7 +351,9 @@ partial_dealloc(PyObject *self)
     PyTypeObject *tp = Py_TYPE(self);
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(self);
-    PyObject_ClearWeakRefs(self);
+    if (partialobject_CAST(self)->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(self);
+    }
     (void)partial_clear(self);
     tp->tp_free(self);
     Py_DECREF(tp);
@@ -1619,7 +1621,9 @@ lru_cache_dealloc(PyObject *op)
     PyTypeObject *tp = Py_TYPE(obj);
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(obj);
-    PyObject_ClearWeakRefs(op);
+    if (obj->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
 
     (void)lru_cache_tp_clear(op);
     tp->tp_free(obj);

Modules/_io/bufferedio.c

@@ -421,7 +421,8 @@ buffered_dealloc(PyObject *op)
         return;
     _PyObject_GC_UNTRACK(self);
     self->ok = 0;
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     if (self->buffer) {
         PyMem_Free(self->buffer);
         self->buffer = NULL;

Modules/_io/fileio.c

@@ -570,7 +570,9 @@ fileio_dealloc(PyObject *op)
         PyMem_Free(self->stat_atopen);
         self->stat_atopen = NULL;
     }
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     (void)fileio_clear(op);
 
     PyTypeObject *tp = Py_TYPE(op);

Modules/_io/iobase.c

@@ -383,7 +383,8 @@ iobase_dealloc(PyObject *op)
     }
     PyTypeObject *tp = Py_TYPE(self);
     _PyObject_GC_UNTRACK(self);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     Py_CLEAR(self->dict);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_io/textio.c

@@ -1469,7 +1469,8 @@ textiowrapper_dealloc(PyObject *op)
         return;
     self->ok = 0;
     _PyObject_GC_UNTRACK(self);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     (void)textiowrapper_clear(op);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_io/winconsoleio.c

@@ -518,7 +518,8 @@ winconsoleio_dealloc(PyObject *op)
     if (_PyIOBase_finalize(op) < 0)
         return;
     _PyObject_GC_UNTRACK(self);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     Py_CLEAR(self->dict);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_queuemodule.c

@@ -221,7 +221,9 @@ simplequeue_dealloc(PyObject *op)
 
     PyObject_GC_UnTrack(self);
     (void)simplequeue_clear(op);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     tp->tp_free(self);
     Py_DECREF(tp);
 }

Modules/_sqlite/blob.c

@@ -56,7 +56,9 @@ blob_dealloc(PyObject *op)
 
     close_blob(self);
 
-    PyObject_ClearWeakRefs(op);
+    if (self->in_weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     (void)tp->tp_clear(op);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_sqlite/cursor.c

@@ -185,7 +185,9 @@ cursor_dealloc(PyObject *op)
     pysqlite_Cursor *self = _pysqlite_Cursor_CAST(op);
     PyTypeObject *tp = Py_TYPE(self);
     PyObject_GC_UnTrack(self);
-    PyObject_ClearWeakRefs(op);
+    if (self->in_weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     (void)tp->tp_clear(op);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_sre/sre.c

@@ -736,7 +736,10 @@ pattern_dealloc(PyObject *self)
 {
     PyTypeObject *tp = Py_TYPE(self);
     PyObject_GC_UnTrack(self);
-    PyObject_ClearWeakRefs(self);
+    PatternObject *obj = _PatternObject_CAST(self);
+    if (obj->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(self);
+    }
     (void)pattern_clear(self);
     tp->tp_free(self);
     Py_DECREF(tp);

Modules/_struct.c

@@ -1794,7 +1794,9 @@ s_dealloc(PyObject *op)
     PyStructObject *s = PyStructObject_CAST(op);
     PyTypeObject *tp = Py_TYPE(s);
     PyObject_GC_UnTrack(s);
-    PyObject_ClearWeakRefs(op);
+    if (s->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     if (s->s_codes != NULL) {
         PyMem_Free(s->s_codes);
     }

Modules/_testcapi/heaptype.c

@@ -1034,7 +1034,8 @@ heapctypewithweakref_dealloc(PyObject *op)
 {
     HeapCTypeWithWeakrefObject *self = (HeapCTypeWithWeakrefObject*)op;
     PyTypeObject *tp = Py_TYPE(self);
-    PyObject_ClearWeakRefs((PyObject *) self);
+    if (self->weakreflist != NULL)
+        PyObject_ClearWeakRefs((PyObject *) self);
     Py_XDECREF(self->weakreflist);
     PyObject_Free(self);
     Py_DECREF(tp);

Modules/_testlimitedcapi/heaptype_relative.c

@@ -297,7 +297,9 @@ heapctypewithrelativeweakref_dealloc(PyObject* self)
 {
     PyTypeObject *tp = Py_TYPE(self);
     HeapCTypeWithWeakrefStruct *data = PyObject_GetTypeData(self, tp);
-    PyObject_ClearWeakRefs(self);
+    if (data->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(self);
+    }
     Py_XDECREF(data->weakreflist);
     PyObject_Free(self);
     Py_DECREF(tp);

Modules/_threadmodule.c

@@ -1365,7 +1365,9 @@ static void
 localdummy_dealloc(PyObject *op)
 {
     localdummyobject *self = localdummyobject_CAST(op);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     PyTypeObject *tp = Py_TYPE(self);
     tp->tp_free(self);
     Py_DECREF(tp);
@@ -1535,7 +1537,9 @@ local_dealloc(PyObject *op)
     localobject *self = localobject_CAST(op);
     /* Weakrefs must be invalidated right now, otherwise they can be used
        from code called below, which is very dangerous since Py_REFCNT(self) == 0 */
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     PyObject_GC_UnTrack(self);
     (void)local_clear(op);
     PyTypeObject *tp = Py_TYPE(self);

Modules/_zoneinfo.c

@@ -375,7 +375,9 @@ zoneinfo_dealloc(PyObject *obj_self)
     PyTypeObject *tp = Py_TYPE(self);
     PyObject_GC_UnTrack(self);
 
-    PyObject_ClearWeakRefs(obj_self);
+    if (self->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(obj_self);
+    }
 
     if (self->trans_list_utc != NULL) {
         PyMem_Free(self->trans_list_utc);

Modules/arraymodule.c

@@ -728,7 +728,9 @@ array_dealloc(PyObject *op)
     PyObject_GC_UnTrack(op);
 
     arrayobject *self = arrayobject_CAST(op);
-    PyObject_ClearWeakRefs(op);
+    if (self->weakreflist != NULL) {
+        PyObject_ClearWeakRefs(op);
+    }
     if (self->ob_item != NULL) {
         PyMem_Free(self->ob_item);
     }

Modules/itertoolsmodule.c

@@ -1018,7 +1018,8 @@ static int
 tee_clear(PyObject *op)
 {
     teeobject *to = teeobject_CAST(op);
-    PyObject_ClearWeakRefs(op);
+    if (to->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
     Py_CLEAR(to->dataobj);
     return 0;
 }

Modules/mmapmodule.c

@@ -163,7 +163,8 @@ mmap_object_dealloc(PyObject *op)
     Py_END_ALLOW_THREADS
 #endif /* UNIX */
 
-    PyObject_ClearWeakRefs(op);
+    if (m_obj->weakreflist != NULL)
+        PyObject_ClearWeakRefs(op);
 
     tp->tp_free(m_obj);
     Py_DECREF(tp);