__attribute__((cleanup(function)) versus try/finally

[Richard Kenner]

    > In any case, there are some semantics to be defined; if a cleanup throws
    > an exception, what happens?

    At present, the old exception doesn't get destroyed, and the new
    exception propagates.  I'm not really sure *what* should be said
    except that it's undefined behaviour.

Just FYI, in Ada this is defined and the action depends on how the
cleanup was invoked.