Program Normalization for Removing Code Variations

Code variations are widely believed to impede program analysis. This paper introduces a program normalization approach to remove code variations. Semantic-preserving transformations are performed on the system dependence graphs of programs. As a result, various syntactically different but semantically equivalent constructs are transformed to the same system dependence graph representation, so that code variations are removed. This approach establishes a good framework for testing the semantic equivalence of source codes and it can facilitate program analysis.