In the limited C API 3.14 and newer, I propose to change Py_TYPE() and Py_SET_TYPE() implementation to opaque function calls to hide implementation details. I made a similar change for Py_REFCNT() and Py_SET_REFCNT() in Python 3.12.

The problem is that with Free Threading (PEP 703), the implementation of these functions become less trivial than just getting/setting an object member:

staticinlinePyTypeObject*Py_TYPE(PyObject*ob) {return (PyTypeObject*)_Py_atomic_load_ptr_relaxed(&ob->ob_type);}staticinlinevoidPy_SET_TYPE(PyObject*ob,PyTypeObject*type) {_Py_atomic_store_ptr(&ob->ob_type,type);}

_Py_atomic_load_ptr_relaxed() and_Py_atomic_store_ptr() must now be called. But I would prefer to not "leak" such implementation detail into the limited C API.

cc@colesbury@Fidget-Spinner

Linked PRs

• gh-120600: Make Py_TYPE() opaque in limited C API 3.14 #120601