1. In a computer system including a memory, a method of compiling source programs, the method comprising the steps of: compiling a first program to produce a first compiled program and a first set of post-code generation information characterizing the first compiled program; compiling a second program to produce a second compiled program using the first set of postcode generation information to minimize differences between the first and second compiled program; determining differences between the first and second compiled programs; and compiling a third program dependent upon the differences between the first and second compiled programs.