Software reengineering has been described as being "about as easy as reconstructing a pig from a sausage" [11]. But the development of program transformation theory, as embodied in the FermaT transformation system, has made this miraculous feat into a practical possibility. This paper describes the theory...

The aim of this paper is to provide a unified mathematical framework for program slicing which places all slicing work, for sequential programs, on a sound theoretical foundation. The main advantage to a mathematical approach is that it is not tied to a particular representation. In fact the mathematics provides a sound basis for any particular representation. We use the WSL (Wide Spectrum Language) program transformation theory as our framework. Within this framework we define a new semantic relation, semi-refinement which lies between semantic equivalence and semantic refinement. Combining this semantic relation, a syntactic relation (called reduction) and WSL’s remove statement, we can give mathematical definitions for backwards slicing, conditioned slicing, static and dynamic slicing and semantic slicing as program transformations in the WSL transformation theory. A novel technique of “encoding ” operational semantics within a denotational semantics allows the framework to handle “operational slicing”. The theory also enables the concept of slicing to be applied to nondeterministic programs. These transformations are implemented in the industry-strength FermaT transformation system.

In this paper we describe the legacy assembler problem and describe how the FermaT transformation system is used to reengineer assembler systems and migrate from assembler to C and COBOL.

With the widespread use of the Web, distributed object technologies have been widely adopted to construct network-centric architectures, using XML, Web Services, CORBA, and DCOM. Organizations would like to take advantage of the Web in its various forms of Internet, Intranet and Extranets. This requires organizations to port and integrate their legacy assets to distributed Web-enabled environments, so that the functionality of existing legacy systems can be leveraged without having to rebuild these systems. In this chapter, we provide techniques to re-engineer standalone legacy systems into Web-enabled environments. Specifically, we aim for a framework that allows for the identification of reusable business logic entities in large legacy systems in the form of major legacy components, the migration of these procedural components to an object oriented design, the specification of interfaces of these identified components, the automatic generation of CORBA wrappers to enable remote access, and finally, the seamless interoperation with Web services via HTTP based on the SOAP messaging mechanism. Keywords: Software migration, software integration, software reengineering, legacy systems, multi-tier

A program transformation is an operation which can be applied to any program (satisfying the transformations applicability conditions) and returns a semantically equivalent program. In the FermaT transformation system program transformations are carried out in a wide spectrum language, called WSL, and the transformations themselves are written in an extension of WSL called METAWSL which was specifically designed to be a domain-specific language for writing program transformations. As a result, FermaT is capable of transforming its own source code via metatransformations. This paper introduces METAWSL and describes some applications of meta-transformations in the FermaT system.