Reverse Engineering Techniques for Lisp Systems

Reverse engineering software systems, especially large legacy systems, is a difficult task, because of the sheer size and complexity of the systems. Many approaches have been developed to analyze software systems written in different languages. These approaches employ vary techniques like metrics or visualizations, and typically rely on parsing the system and on extracting a model that conforms to a meta-model. However, no existent meta-model could fulfill the requirements for analyzing Lisp systems, so we developed the FAMIX-Lisp meta-model, as an extension of an existing meta-model. Our FAMIX-Lisp meta-model extends the initial meta-model with capabilities to model Lisp systems by adding new entities that are unique to Lisp, like Macros and CLOS entities. Software visualization has been widely used by the reverse engineering research community during the past two decades, becoming one of the major approaches in reverse engineering. In our thesis we also propose a set of new visualizations for Lisp systems, developed to underline the differences of the language and to help understand and browse complex Lisp systems, namely: • The Class-Method Relation View is a visual way of supporting the understanding of the relation between classes and methods in a object-oriented Lisp program; • The Class Types View is a visual way of identifying different types of classes, based on their structure (the attributes to methods ratio); • The Programming Style Distribution View is a visual way of identifying the programming paradigm used in a program and their distribution over the system’s packages; • TheGeneric ConcernsView is a visual way of identifying different cross-cutting concerns in a system by visualizing the spread of generic functions in the system. The target of our views is to visualize very large Lisp systems, for which we want to obtain an initial understanding of their structure and their properties, which helps to guide software developers in the first steps of the reverse engineering process of an unknown system.