Program slicing using a path dependence flow graph

A method that formally represents various program slices with a unified framework is presented; it uses a previously proposed directed graph called a path dependence flow graph (PDFG). Program slicing is a technique of extracting a set of statements (called slices) with certain desired features from an imperative program. The method proposed here has the following properties. (1) Since slices are represented by operations on dependence relationships defined on a PDFG, properties of slices such as an inclusion relationship among slices can be discussed independently of slicing procedures. (2) Since various slices are represented with the same framework, appropriate slices can be selected for specific purposes using one representation. (3) Since slices are generalized using orthogonal primitive attributes, slices can be represented comprehensively; this includes the ones for which there have been no known construction methods. It is also proven herein that major known slices and the slices represented by this method are identical as a set of statements, thereby demonstrating the appropriateness of this proposed method.