1. A computer implemented method for generating an interprocedural exception control flow graph (IECFG) for a computer program comprising the steps of: building for each function within the computer program, an interprocedural exception flow graph that annotates an overapproximated set of signed types of exceptions for each exceptional control edge, and has exceptional exit and exceptional call-return nodes; and performing an interprocedural exception analysis on the interprocedural graphs built thereby generating the IECFG; wherein the overapproximated set signed types may include a positive set of exception types and a negative set of exception types, said negative set of exception types including every exception type other than those in the set.