[Python-Dev] PyErr_NoMemory
Tim Peters
tim_one@email.msn.com
Fri, 18 Aug 2000 01:43:14 -0400
[Vladimir Marangozov]
> The current PyErr_NoMemory() function reads:
>
> PyObject *
> PyErr_NoMemory(void)
> {
> /* raise the pre-allocated instance if it still exists */
> if (PyExc_MemoryErrorInst)
> PyErr_SetObject(PyExc_MemoryError, PyExc_MemoryErrorInst);
> else
> /* this will probably fail since there's no
> memory and hee,
> hee, we have to instantiate this class
> */
> PyErr_SetNone(PyExc_MemoryError);
>
> return NULL;
> }
>
> thus overriding any previous exceptions unconditionally. This is a
> problem when the current exception already *is* PyExc_MemoryError,
> notably when we have a chain (cascade) of memory errors. It is a
> problem because the original memory error and eventually its error
> message is lost.
>
> I suggest to make this code look like:
>
> PyObject *
> PyErr_NoMemory(void)
> {
> if (PyErr_ExceptionMatches(PyExc_MemoryError))
> /* already current */
> return NULL;
>
> /* raise the pre-allocated instance if it still exists */
> if (PyExc_MemoryErrorInst)
> PyErr_SetObject(PyExc_MemoryError, PyExc_MemoryErrorInst);
> ...
>
>
> If nobody sees a problem with this, I'm very tempted to check it in.
> Any objections?
Looks good to me. And if it breaks something, it will be darned hard to
tell <wink>.