Add Py_IsFinalizing()

docs/api.rst

@@ -67,6 +67,15 @@ Python 3.13
 
    See `PyWeakref_GetRef() documentation <https://docs.python.org/dev/c-api/weakref.html#c.PyWeakref_GetRef>`__.
 
+.. c:function:: int Py_IsFinalizing()
+
+   Return non-zero if the Python interpreter is shutting down, return 0
+   otherwise.
+
+   Availability: Python 3.3 and newer.
+
+   See `Py_IsFinalizing() documentation <https://docs.python.org/dev/c-api/init.html#c.Py_IsFinalizing>`__.
+
 
 Python 3.12
 -----------

docs/changelog.rst

@@ -1,6 +1,7 @@
 Changelog
 =========
 
+* 2023-08-16: Add ``Py_IsFinalizing()`` function.
 * 2023-07-21: Add ``PyDict_GetItemRef()`` function.
 * 2023-07-18: Add ``PyModule_Add()`` function.
 * 2023-07-12: Add ``PyObject_GetOptionalAttr()``,

pythoncapi_compat.h

@@ -846,6 +846,22 @@ PyModule_Add(PyObject *mod, const char *name, PyObject *value)
 #endif
 
 
+// gh-108014 added Py_IsFinalizing() to Python 3.13.0a1
+// bpo-1856 added _Py_Finalizing to Python 3.2.1b1.
+#if PY_VERSION_HEX < 0x030D00A1 && PY_VERSION_HEX >= 0x030201B1
+PYCAPI_COMPAT_STATIC_INLINE(int)
+Py_IsFinalizing(void)
+{
+#if PY_VERSION_HEX >= 0x030700A1
+    // _Py_IsFinalizing() was added to Python 3.7.0a1.
+    return _Py_IsFinalizing();
+#else
+    return (_Py_Finalizing != NULL);
+#endif
+}
+#endif
+
+
 #ifdef __cplusplus
 }
 #endif

tests/test_pythoncapi_compat_cext.c

@@ -328,6 +328,11 @@ test_interpreter(PyObject *Py_UNUSED(module), PyObject* Py_UNUSED(ignored))
     PyInterpreterState *interp2 = PyThreadState_GetInterpreter(tstate);
     assert(interp == interp2);
 
+#if 0x030300A1 <= PY_VERSION_HEX
+    // test Py_IsFinalizing()
+    assert(Py_IsFinalizing() == 0);
+#endif
+
     Py_RETURN_NONE;
 }