bpo-42332: Add weakref slot to types.GenericAlias (GH-23250)

Automerge-Triggered-By: GH:gvanrossum

1 files changed, 6 insertions, 0 deletions

diff --git a/Objects/genericaliasobject.c b/Objects/genericaliasobject.c
index 28ea487..6102e05 100644
--- a/Objects/genericaliasobject.c
+++ b/Objects/genericaliasobject.c
@@ -10,6 +10,7 @@ typedef struct {
     PyObject *origin;
     PyObject *args;
     PyObject *parameters;
+    PyObject* weakreflist;
 } gaobject;
 
 static void
@@ -18,6 +19,9 @@ ga_dealloc(PyObject *self)
     gaobject *alias = (gaobject *)self;
 
     _PyObject_GC_UNTRACK(self);
+    if (alias->weakreflist != NULL) {
+        PyObject_ClearWeakRefs((PyObject *)alias);
+    }
     Py_XDECREF(alias->origin);
     Py_XDECREF(alias->args);
     Py_XDECREF(alias->parameters);
@@ -599,6 +603,7 @@ PyTypeObject Py_GenericAliasType = {
     .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
     .tp_traverse = ga_traverse,
     .tp_richcompare = ga_richcompare,
+    .tp_weaklistoffset = offsetof(gaobject, weakreflist),
     .tp_methods = ga_methods,
     .tp_members = ga_members,
     .tp_alloc = PyType_GenericAlloc,
@@ -630,6 +635,7 @@ Py_GenericAlias(PyObject *origin, PyObject *args)
     alias->origin = origin;
     alias->args = args;
     alias->parameters = NULL;
+    alias->weakreflist = NULL;
     _PyObject_GC_TRACK(alias);
     return (PyObject *)alias;
 }