From 4fd7ed60859c86508b8e7e11c6a063e5e1a47862 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Tue, 5 Dec 2023 10:37:57 +0100
Subject: [PATCH] gh-111506: Implement Py_REFCNT() as opaque function call

In the limited C API version 3.13, the Py_REFCNT() function is now
implemented as an opaque function call.
---
 Include/object.h                                          | 8 +++++++-
 .../C API/2023-12-05-10-39-06.gh-issue-111506.gz90Ft.rst  | 2 ++
 Objects/object.c                                          | 8 ++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/C API/2023-12-05-10-39-06.gh-issue-111506.gz90Ft.rst

diff --git a/Include/object.h b/Include/object.h
index dfeb43bda7d841..dd73da54ea73de 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -290,8 +290,14 @@ _Py_IsOwnedByCurrentThread(PyObject *ob)
 }
 #endif
 
+PyAPI_FUNC(Py_ssize_t) _Py_GetRefcnt(PyObject *ob);
+
 static inline Py_ssize_t Py_REFCNT(PyObject *ob) {
-#if !defined(Py_GIL_DISABLED)
+#if defined(Py_LIMITED_API) && Py_LIMITED_API+0 >= 0x030d0000
+    // Stable ABI implements Py_SET_REFCNT() as a function call
+    // on limited C API version 3.13 and newer.
+    return _Py_GetRefcnt(ob);
+#elif !defined(Py_GIL_DISABLED)
     return ob->ob_refcnt;
 #else
     uint32_t local = _Py_atomic_load_uint32_relaxed(&ob->ob_ref_local);
diff --git a/Misc/NEWS.d/next/C API/2023-12-05-10-39-06.gh-issue-111506.gz90Ft.rst b/Misc/NEWS.d/next/C API/2023-12-05-10-39-06.gh-issue-111506.gz90Ft.rst
new file mode 100644
index 00000000000000..9a9706c2b339f1
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2023-12-05-10-39-06.gh-issue-111506.gz90Ft.rst	
@@ -0,0 +1,2 @@
+In the limited C API version 3.13, the :c:func:`Py_REFCNT` function is now
+implemented as an opaque function call. Patch by Victor Stinner.
diff --git a/Objects/object.c b/Objects/object.c
index d145674cb3ba34..2d9eb92f092ac3 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -2932,6 +2932,14 @@ int Py_IsFalse(PyObject *x)
 }
 
 
+// Py_REFCNT() implementation for stable ABI
+Py_ssize_t
+_Py_GetRefcnt(PyObject *ob)
+{
+    return Py_REFCNT(ob);
+}
+
+
 // Py_SET_REFCNT() implementation for stable ABI
 void
 _Py_SetRefcnt(PyObject *ob, Py_ssize_t refcnt)