pythongh-138342: Use a common utility for visiting an object's type (pythonGH-138343)

Add `_PyObject_VisitType` in place of `tp_traverse` functions that only visit the object's type.

Author: ZeroIntensity

Include/cpython/object.h

@@ -491,3 +491,7 @@ PyAPI_FUNC(int) PyUnstable_TryIncRef(PyObject *);
 PyAPI_FUNC(void) PyUnstable_EnableTryIncRef(PyObject *);
 
 PyAPI_FUNC(int) PyUnstable_Object_IsUniquelyReferenced(PyObject *);
+
+/* Utility for the tp_traverse slot of mutable heap types that have no other
+ * references. */
+PyAPI_FUNC(int) _PyObject_VisitType(PyObject *op, visitproc visit, void *arg);

Modules/_dbmmodule.c

@@ -96,12 +96,6 @@ newdbmobject(_dbm_state *state, const char *file, int flags, int mode)
 }
 
 /* Methods */
-static int
-dbm_traverse(PyObject *dp, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(dp));
-    return 0;
-}
 
 static void
 dbm_dealloc(PyObject *self)
@@ -540,7 +534,7 @@ static PyMethodDef dbm_methods[] = {
 
 static PyType_Slot dbmtype_spec_slots[] = {
     {Py_tp_dealloc, dbm_dealloc},
-    {Py_tp_traverse, dbm_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {Py_tp_methods, dbm_methods},
     {Py_sq_contains, dbm_contains},
     {Py_mp_length, dbm_length},

Modules/_decimal/_decimal.c

@@ -746,13 +746,6 @@ signaldict_setitem(PyObject *self, PyObject *key, PyObject *value)
     return 0;
 }
 
-static int
-signaldict_traverse(PyObject *self, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(self));
-    return 0;
-}
-
 static void
 signaldict_dealloc(PyObject *self)
 {
@@ -845,7 +838,7 @@ static PyMethodDef signaldict_methods[] = {
 
 static PyType_Slot signaldict_slots[] = {
     {Py_tp_dealloc, signaldict_dealloc},
-    {Py_tp_traverse, signaldict_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {Py_tp_repr, signaldict_repr},
     {Py_tp_hash, PyObject_HashNotImplemented},
     {Py_tp_getattro, PyObject_GenericGetAttr},
@@ -2194,13 +2187,6 @@ PyDecType_New(decimal_state *state, PyTypeObject *type)
 }
 #define dec_alloc(st) PyDecType_New(st, (st)->PyDec_Type)
 
-static int
-dec_traverse(PyObject *dec, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(dec));
-    return 0;
-}
-
 static void
 dec_dealloc(PyObject *dec)
 {
@@ -6032,7 +6018,7 @@ static PyType_Slot dec_slots[] = {
     {Py_tp_token, Py_TP_USE_SPEC},
     {Py_tp_dealloc, dec_dealloc},
     {Py_tp_getattro, PyObject_GenericGetAttr},
-    {Py_tp_traverse, dec_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {Py_tp_repr, dec_repr},
     {Py_tp_hash, dec_hash},
     {Py_tp_str, dec_str},

Modules/_functoolsmodule.c

@@ -108,20 +108,13 @@ placeholder_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
     return placeholder;
 }
 
-static int
-placeholder_traverse(PyObject *self, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(self));
-    return 0;
-}
-
 static PyType_Slot placeholder_type_slots[] = {
     {Py_tp_dealloc, placeholder_dealloc},
     {Py_tp_repr, placeholder_repr},
     {Py_tp_doc, (void *)placeholder_doc},
     {Py_tp_methods, placeholder_methods},
     {Py_tp_new, placeholder_new},
-    {Py_tp_traverse, placeholder_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {0, 0}
 };
 

Modules/_gdbmmodule.c

@@ -122,13 +122,6 @@ newgdbmobject(_gdbm_state *state, const char *file, int flags, int mode)
 }
 
 /* Methods */
-static int
-gdbm_traverse(PyObject *op, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(op));
-    return 0;
-}
-
 static void
 gdbm_dealloc(PyObject *op)
 {
@@ -714,7 +707,7 @@ static PyMethodDef gdbm_methods[] = {
 
 static PyType_Slot gdbmtype_spec_slots[] = {
     {Py_tp_dealloc, gdbm_dealloc},
-    {Py_tp_traverse, gdbm_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {Py_tp_methods, gdbm_methods},
     {Py_sq_contains, gdbm_contains},
     {Py_mp_length, gdbm_length},

Modules/_multiprocessing/semaphore.c

@@ -720,13 +720,6 @@ _multiprocessing_SemLock___exit___impl(SemLockObject *self,
     return _multiprocessing_SemLock_release_impl(self);
 }
 
-static int
-semlock_traverse(PyObject *s, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(s));
-    return 0;
-}
-
 /*
  * Semaphore methods
  */
@@ -773,7 +766,7 @@ static PyType_Slot _PyMp_SemLockType_slots[] = {
     {Py_tp_members, semlock_members},
     {Py_tp_alloc, PyType_GenericAlloc},
     {Py_tp_new, _multiprocessing_SemLock},
-    {Py_tp_traverse, semlock_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {Py_tp_free, PyObject_GC_Del},
     {Py_tp_doc, (void *)PyDoc_STR("Semaphore/Mutex type")},
     {0, 0},

Modules/_pickle.c

@@ -413,13 +413,6 @@ typedef struct {
 
 #define Pdata_CAST(op)  ((Pdata *)(op))
 
-static int
-Pdata_traverse(PyObject *self, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(self));
-    return 0;
-}
-
 static void
 Pdata_dealloc(PyObject *op)
 {
@@ -437,7 +430,7 @@ Pdata_dealloc(PyObject *op)
 
 static PyType_Slot pdata_slots[] = {
     {Py_tp_dealloc, Pdata_dealloc},
-    {Py_tp_traverse, Pdata_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {0, NULL},
 };
 

Modules/_sqlite/prepare_protocol.c

@@ -29,13 +29,6 @@ pysqlite_prepare_protocol_init(PyObject *self, PyObject *args, PyObject *kwargs)
     return 0;
 }
 
-static int
-pysqlite_prepare_protocol_traverse(PyObject *self, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(self));
-    return 0;
-}
-
 static void
 pysqlite_prepare_protocol_dealloc(PyObject *self)
 {
@@ -50,7 +43,7 @@ PyDoc_STRVAR(doc, "PEP 246 style object adaption protocol type.");
 static PyType_Slot type_slots[] = {
     {Py_tp_dealloc, pysqlite_prepare_protocol_dealloc},
     {Py_tp_init, pysqlite_prepare_protocol_init},
-    {Py_tp_traverse, pysqlite_prepare_protocol_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {Py_tp_doc, (void *)doc},
     {0, NULL},
 };

Modules/_sqlite/statement.c

@@ -116,13 +116,6 @@ stmt_dealloc(PyObject *op)
     Py_DECREF(tp);
 }
 
-static int
-stmt_traverse(PyObject *self, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(self));
-    return 0;
-}
-
 /*
  * Strip leading whitespace and comments from incoming SQL (null terminated C
  * string) and return a pointer to the first non-whitespace, non-comment
@@ -183,7 +176,7 @@ lstrip_sql(const char *sql)
 
 static PyType_Slot stmt_slots[] = {
     {Py_tp_dealloc, stmt_dealloc},
-    {Py_tp_traverse, stmt_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {0, NULL},
 };
 

Modules/_ssl.c

@@ -5692,13 +5692,6 @@ _ssl_MemoryBIO_impl(PyTypeObject *type)
     return (PyObject *) self;
 }
 
-static int
-memory_bio_traverse(PyObject *self, visitproc visit, void *arg)
-{
-    Py_VISIT(Py_TYPE(self));
-    return 0;
-}
-
 static void
 memory_bio_dealloc(PyObject *op)
 {
@@ -5869,7 +5862,7 @@ static PyType_Slot PySSLMemoryBIO_slots[] = {
     {Py_tp_getset, memory_bio_getsetlist},
     {Py_tp_new, _ssl_MemoryBIO},
     {Py_tp_dealloc, memory_bio_dealloc},
-    {Py_tp_traverse, memory_bio_traverse},
+    {Py_tp_traverse, _PyObject_VisitType},
     {0, 0},
 };