To hide all implementation details, I propose to stop using macros and use function calls instead. For example, replace:
#define PyTuple_GET_ITEM(op, i) \ (((PyTupleObject *)(op))->ob_item[i]) with: # define PyTuple_GET_ITEM(op, i) PyTuple_GetItem(op, i) With this change, C extensions using PyTuple_GET_ITEM() does no longer dereference PyObject* nor access PyTupleObject.ob_item. For example, PyPy doesn't have to convert all tuple items to PyObject, but only create one PyObject for the requested item. Another example is that it becomes possible to use a "CPython debug runtime" which checks at runtime that the first argument is a tuple and that the index is valid. For a longer explanation, see the idea of different "Python runtimes": https://pythoncapi.readthedocs.io/runtimes.html Replacing macros with function calls is only a first step. It doesn't solve the problem of borrowed references for example. Obviously, such change has a cost on performances. Sadly, I didn't run a benchmark yet. At this point, I mostly care about correctness and the feasibility of the whole project. I also hope that the new C API will allow to implement new optimizations which cannot even be imagined today, because of the backward compatibility. The question is if the performance balance is positive or not at the all :-) Hopefully, there is no urgency to take any decision at this point. The whole project is experimental and can be cancelled anytime. Victor _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
