Software salvaging based on conditions

Abstract

This paper presents algorithms for isolating reusable functions in large monolithic programs. The functions to be isolated are specified in terms of either pre-conditions or binding conditions, and these are mapped onto predicates on program's variables. Code components whose execution is triggered and/or bound by these predicates are then isolated. Each component is a candidate to implement a reusable function. The algorithms exploit a representation of the subject program in the form of a program dependence graph. This work forms part of RE/sup 2/, a research project that addresses the wider issue of software reuse. RE/sup 2/ project aims to promote the reuse of software through the exploration of reverse engineering and re-engineering techniques to identify and extract reusable software components from existing systems.