An object-oriented dependency graph for program slicing

Abstract

Program dependency graphs (PDG's) of a program facilitate program analysis and related applications such as program slicing, a method to identify the relevant entities of the program according to data and control dependencies. In the past, PDG's and program slicing were most developed for (conventional) imperative programs. Recently, the object-oriented (OO) paradigm gained momentum and popularity. The OO paradigm introduces the features of object abstraction, encapsulation, inheritance, and polymorphism to programs, but is not considered in PDG's and program slicing. In this paper, we present an Object-Oriented Dependency Graph (ODG) to represent the structure of OO programs. The ODG is defined based on a property multi-digraph that is extended from a directed graph by augmenting multiple edge types, vertex properties, and property relations. With the extension, the ODG cart avoid the specious dependencies due to object encapsulation. Based on the ODC, a program slicing method for OO software is developed. Besides data and control dependencies, dependencies caused by OO features are taken into consideration in our slicing method. Through the ODG, the slicing method might be applied to facilitate understanding debugging, and maintaining OO software as well as traditional program slicing methods do.