gh-91632: Fix generic_alias_iterator to be finalized at exit. (GH-91727)

Author: corona10

Misc/NEWS.d/next/Core and Builtins/2022-04-20-14-43-37.gh-issue-91632.cvUhsZ.rst

@@ -0,0 +1 @@
+Fix a minor memory leak at exit: release the memory of the :class:`generic_alias_iterator` type. Patch by Dong-hee Na.

Objects/genericaliasobject.c

@@ -683,7 +683,9 @@ ga_iter_clear(PyObject *self) {
     return 0;
 }
 
-static PyTypeObject Py_GenericAliasIterType = {
+// gh-91632: _Py_GenericAliasIterType is exported  to be cleared
+// in _PyTypes_FiniTypes.
+PyTypeObject _Py_GenericAliasIterType = {
     PyVarObject_HEAD_INIT(&PyType_Type, 0)
     .tp_name = "generic_alias_iterator",
     .tp_basicsize = sizeof(gaiterobject),
@@ -697,7 +699,7 @@ static PyTypeObject Py_GenericAliasIterType = {
 
 static PyObject *
 ga_iter(PyObject *self) {
-    gaiterobject *gi = PyObject_GC_New(gaiterobject, &Py_GenericAliasIterType);
+    gaiterobject *gi = PyObject_GC_New(gaiterobject, &_Py_GenericAliasIterType);
     if (gi == NULL) {
         return NULL;
     }

Objects/object.c

@@ -1834,6 +1834,7 @@ _PyTypes_InitState(PyInterpreterState *interp)
 #ifdef MS_WINDOWS
 extern PyTypeObject PyHKEY_Type;
 #endif
+extern PyTypeObject _Py_GenericAliasIterType;
 
 static PyTypeObject* static_types[] = {
     // The two most important base types: must be initialized first and
@@ -1923,6 +1924,7 @@ static PyTypeObject* static_types[] = {
     &_PyAsyncGenWrappedValue_Type,
     &_PyContextTokenMissing_Type,
     &_PyCoroWrapper_Type,
+    &_Py_GenericAliasIterType,
     &_PyHamtItems_Type,
     &_PyHamtKeys_Type,
     &_PyHamtValues_Type,