TODO.rst

TODO list for new Python C API

• Write a tool to automate migration from the old C API to the new C API
• capi_tests: check for reference leaks
• Modify PyObject_INIT(op, type) macro to return op again? use an inlined function?
• Do we need PySequence_Fast_GetItemRef()?
• Enhance documentation to document reference counting

Replace Py_TYPE() =================o

Dealloc:

Py_TYPE(self)->tp_free((PyObject *)self);

becomes:

PyTypeObject *type = Py_GetType(self);
type->tp_free((PyObject *)self);
Py_DECREF(type);

Size:

res = _PyObject_SIZE(Py_TYPE(self)) + self->allocated * self->ob_descr->itemsize;

becomes:

PyTypeObject *type = Py_GetType(self);
res = _PyObject_SIZE(type) + self->allocated * self->ob_descr->itemsize;
Py_DECREF(type);

Error:

PyErr_Format(PyExc_TypeError,
    "first argument must be a type object, not %.200s",
    Py_TYPE(arraytype)->tp_name);

becomes:

PyErr_Format(PyExc_TypeError,
             "first argument must be a type object, not %T",
             arraytype);

Py_BuildValue:

result = Py_BuildValue(
    "N(CO)O", Py_GetType(self), typecode, list, dict);

becomes:

result = Py_BuildValue(
    "N(CO)O", Py_GetType(self), typecode, list, dict);

Remove Py_TYPE()?

Error:

PyErr_Format(PyExc_TypeError,
             "Struct() argument 1 must be a str or bytes object, "
             "not %.200s",
             Py_TYPE(format)->tp_name);

Dealloc:

static void
s_dealloc(PyStructObject *s)
{
    ...
    Py_TYPE(s)->tp_free((PyObject *)s);
}

Object size:

Py_ssize_t size = _PyObject_SIZE(Py_TYPE(self)) + sizeof(formatcode);

Check type:

#define PyStruct_CheckExact(op) (Py_TYPE(op) == &PyStructType)

Issues

Following code becomes invalid:

(void)PyObject_INIT(im, &PyMethod_Type);
Py_SIZE(obj) = size;   /* must use _Py_SET_SIZE(obj, size); */
Py_TYPE(obj) = type;   /* must use _Py_SET_TYPE(obj, type); */