This paper focuses on the version models underlying both commercial systems and research prototypes. It provides an overview and classification of different versioning paradigms. Furthermore, it defines and relates fundamental concepts such as revisions, variants, configurations, and changes. In particular, we focus on intensional versioning, i.e., construction of versions based on configuration rules. Finally,we provide an overview of systems whichhave had significant impact on the development of the SCM discipline, and classify them according to a detailed taxonomy

The reengineering and reverse engineering of software systems is gaining importance in software industry, because the accelerated turnover in software companies creates legacy systems in a shorter period of time. Especially understanding classes is a key activity in object-oriented programming, since classes represent the primary abstractions from which applications are built. The main problem of this task is to quickly grasp the purpose of a class and its inner structure. To help the reverse engineers in their first contact with a foreign system, we propose a categorization of classes based on the visualization of their internal structure. The contributions of this paper are a novel categorization of classes and a visualization of the classes which we call the class blueprint. We have validated the categorization on several case studies, two of which we present here. Keywords Reverse Engineering, Program Understanding, Software Visualization, Visual Patterns, Smalltalk 1.

Reverse engineering software systems has become a major concern in software industry because of their sheer size and complexity. This problem needs to be tackled, since the systems in question are of considerable worth to their owners and maintainers. In this article we present the concept of a polymetric view, a lightweight software visualization technique enriched with software metrics information. Polymetric views help to understand the structure and detect problems of a software system in the initial phases of a reverse engineering process. We discuss the benefits and limits of several predefined polymetric views we have implemented in our tool CodeCrawler. Moreover, based on clusters of different polymetric views we have developed a methodology which supports and guides a software engineer in the first phases of a reverse engineering of a large software system. We have refined this methodology by repeatedly applying it on industrial systems, and illustrate it by applying a selection of polymetric views to a case study.

In this paper, we explain how inheritance and dynamic binding make object-oriented programs difficult to maintain, and we give a concrete example of the problems that arise. We show that the difficulty lies in the fact that conventional tools are poorly suited for work with object-oriented languages, and we argue that semantics-based tools are essential for effective maintenance of object-oriented programs. We then describe a system we have developed for working with C++ programs. This system comprises a relational database system for information about programs, and an interactive database interface integrated with a text editor. We describe our system architecture, detail the database relations, provide informal evidence on the system's effectiveness, and compare it to other research with similar goals. Keywords: software maintenance, object-oriented languages and environments, programming environments, semantic analysis of code, software representation in relational databases, C++. ...

Abstract—Understanding source code is an important task in the maintenance of software systems. Legacy systems are not only limited to procedural languages, but are also written in object-oriented languages. In such a context, understanding classes is a key activity as they are the cornerstone of the object-oriented paradigm and the primary abstraction from which applications are built. Such an understanding is however difficult to obtain because of reasons such as the presence of late binding and inheritance. A first level of class understanding consists of the understanding of its overall structure, the control flow among its methods, and the accesses on its attributes. We propose a novel visualization of classes called class blueprint that is based on a semantically enriched visualization of the internal structure of classes. This visualization allows a software engineer to build a first mental model of a class that he validates via opportunistic code-reading. Furthermore, we have identified visual patterns that represent recurrent situations and as such convey additional information to the viewer. The contributions of this article are the class blueprint, a novel visualization of the internal structure of classes, the identification of visual patterns, and the definition of a vocabulary based on these visual patterns. We have performed several case studies of which one is presented in depth, and validated the usefulness of the approach in a controlled experiment. Index Terms—Object-oriented programming, software visualization, reverse engineering, visual patterns, smalltalk. 1

Software development and maintenance tasks rely on and can benefit from an increased level of program understanding. Object-oriented programming languages provide features which facilitate software maintenance, yet the same features often make object-oriented programs more difficult to understand. We support the use of program visualization techniques to foster object-oriented program comprehension. This paper identifies ways that visualization can increase program understanding, and presents a means for characterizing both static and dynamic aspects of an object-oriented program. We then describe the implementation of a prototypical tool for visualizing the execution of C++ programs. Based on this work, we define a framework for the visualization of object-oriented software which requires little or no programmer intervention and provides a mechanism which allows users to focus quickly on particular aspects of the program. Keywords: program visualization, program comprehension. 1 In...

Modern software systems for application areas like software engineering, CAD, or office automation are usually highly interactive and deal with rather complex object structures. For the realization of these systems a nonstandard database system is needed which is able to efficiently handle different types of coarse- and fine-grained objects (like documents and paragraphs), hierarchical and non-hierarchical relations between objects (like composition-links and cross-references), and finally attributes of rather different size (like chapter numbers and bitmaps). Furthermore, this database system should support incremental computation of derived data, undo/redo of data modifications, error recovery from system crashes, and version control mechanisms. In this paper, we describe the underlying data model and the functionality of GRAS, a database system which has been designed according to the requirements mentioned above. Furthermore, we motivate our central design decisions concerning its ...

this paper, we define the characteristics of some integrated software development environments designed to take advantage of modern UNIX workstations. We describe the DEC FUSE product as an example of one of these environments and present two methods used to create theDEC FUSE product. With the first method, we show how tools are built as graphical user interfaces (GUIs) on top of existing

This paper describes a Bull US Applied Research Laboratory project to build a collaborative inspection and review system called Scrutiny using ConversationBuilder from the University of Illinois at UrbanaChampaign.

Software is multidimensional but the tools that support it are not. The lack of tool support causes the software artifacts representing different dimensions to evolve independently and inconsistently. In order to support the evolution of multidimensional software, an environment must ensure that the different dimensions evolve concurrently. This can be accomplished through an integration framework that maintains consistency of the different dimensions as they evolve. We have build a prototype of such a mechanism by setting up and maintaining constraints among artifacts representing the different software dimensions. This paper describes that prototype and our experiences with it to date. 1