The Research Of Coarse-Grained Object-Level Slicing Method

An important area of software engineering is the program understanding, with the increasing scale of software, understanding of the source code became a more difficult problem. In the demand for this problem, the program slicing technique came into being. Program slicing is a program decomposition technique, this technique was used to get the program fragments we may be interest in, and it plays a significant role in program understanding. However, for large programs, the traditional program slicing is difficulty to compute, the results are still difficult to understand. Especially for object-oriented programming, the traditional program slicing is difficult to identify the framework of object-oriented programming.The current work of object-oriented program slicing concentrated in statement level program slices which combined the structure of object-oriented program. There are some study in the relationship between the object, seldom study in the object level slicing. and the research in objects is undoubtedly an important aspect in object-oriented programming. Before our research, some scholars have done some study in the coarse-grained slicing in object-oriented program, the granularity of those study is method-level or object-level, but those coarse-grained slicing were based on the system dependence graph, and were difficulty to compute, and the relationship between objects and can only be partially reflected. The research in this paper, slicing is based on syntax and semantics relationship between objects, we study the relationship between objects in object-oriented program thoroughly, and we researched an coarse-grained object-level slice method based on the study of relationship between objects. This method is used in object-oriented programming, for this method the granularity level is the object level, the coarse-grained object-level program slicing we get is useful in understanding the structure of object-oriented program.The job of this paper has the following two points:The first points, based on the syntax relationship between objects, we proposed a syntax-level coarse-grained object slicing method. This method is based on the syntax of inheritance relationship between objects. First we construct inheritance tree, then based on this tree we can get object-level inheritance relationship forward slice and object-level inheritance relationship backward slice. The second points, based on the semantics relationship between objects, we proposed a semantics-level coarse-grained object slicing method. This method is not based on the traditional program dependence graph or system dependence graph, but on two kinds of semantic level relationships between objects, association relationships and composition relationships. Firstly, we construct object graph according the semantic level relationship between objects, then create all kinds of slice we needed on the base of object graph.It is obviously that coarse-grained slice is more efficient and comprehensible than statement-level slicing. Since the basical element of object-oriented program is object, so this kind of object-level granularity slicing method is useful. This concept is based on Java program which the feature of object-oriented is obvious, other object-oriented language is to be studied.