Exception specifications can aid in the tasks of writing correct exception
handlers and understanding exceptional control flow, but current exception
specification systems are impractical in a number of ways. In particular, they
are too low-level, too heavyweight, and do not provide adequate support for
describing exception policies.

We have identified the essential properties of a practical exception
specification system and we present a methodology and tool that provides
integrated support for specifying, understanding, and evolving exception
policies.  The annotations required of the programmer are lightweight and easier
to maintain than those of current systems; in our studies we observed a 50% to
93% reduction in annotations. By leveraging these annotations, our system
provides scalable support for understanding exception flow and for modifying
exception annotations.