Granularity in Reverse Engineering

Reverse Engineering is the process of reconstructing high-level design information from program code 3]. Reverse engineering in traditional engineering disciplines is an extraneous activity but in the eld of software engineering it is an integral part of software maintenance. A maintainer needs to understand the code in terms of which part of the code is implementing which of the domain functions the system is performing. This is the rst step for any kind of maintenance activity ranging from simple bug-xes to large scale system enhancements. In addition, the reverse engineering process is used to extract reusable software components, to recover business rules out of a software system, and to generate documentation from the code. Any reverse engineering eeort typically consists of understanding an existing software system. It starts with existing information such as original design documents, user manuals, and the code. Although many sources of information are available, the actual code is the ultimate description of the current state of the system. Hence, at the crux of the reverse engineering process is the problem of program understanding. Why is reverse engineering hard? A program is intimately tied to the cognitive conceptualisation of the programmer. If we remove the programmer from the system, the static code does not communicate the intent of the programmer well to other human beings. But in many situations the program has to be understood in the absence of the person who created it. The code can communicate the computational intent to some extent but it cannot communicate the conceptual intent and how that conceptual intent is related to the system's objectives in a domain. This is one of the fundamental reasons why understanding a program is so diicult. Other reasons why reverse engineering is diicult include the large size and enormous complexity of real-world systems, and inadequate, non-existing or out-of-date documentation. 2 Our Approach There are many tools and techniques developed to date for doing reverse engineering activities. They involve techniques developed in many elds such as Programming Languages, Artiicial Intelligence, Intelligent Tutoring Systems (ITS), Graph Theory, and Graphical Visualisation. Most of these tools are syntactic in nature and extract information like call graphs, interfaces, and dependency graphs. Some tools like Rigi 10, 11] provide a graphical environment in which an engineer can view/organise/group diierent parts of the system to understand them and record her/his understanding of them. But none of them takes the perspective that …