use macros

diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index d78e2a3d155c804671a3fec1a7bfd1d0e26624c9..6d933a10fb71d360723422f46a04195d9a9e9f57 100644 (file)
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -3948,7 +3948,7 @@ static PyObject *
 string_sizeof(PyStringObject *v)
 {
        Py_ssize_t res;
-       res = PyStringObject_SIZE + v->ob_size * v->ob_type->tp_itemsize;
+       res = PyStringObject_SIZE + PyString_GET_SIZE(v) * Py_TYPE(v)->tp_itemsize;
        return PyInt_FromSsize_t(res);
 }