Abstraction mechanisms for pictorial slicing

Big programs tend to have big slices, so reverse engineering tools based on slicing must apply additional abstractions to make slices intelligible. We have built a tool that displays slices as diagrams. By confining the slice to the statements of a single procedure, by eluding all primitive statements, and by merging different calls of the same procedure, we eliminate local information that is easily seen in the code without the help of tools. And by labelling edges with the variables responsible for flows between procedure calls, global information about called procedures is represented locally. The resulting diagram gives a compact but rich summary of the role of called procedures in the slice.>