A demand-driven approach to slicing legacy COBOL systems
Article first published online: 17 MAR 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Journal of Software: Evolution and Process
Volume 24, Issue 1, pages 67–82, January 2012
How to Cite
Hajnal, Á. and Forgács, I. (2012), A demand-driven approach to slicing legacy COBOL systems. J. Softw. Evol. and Proc., 24: 67–82. doi: 10.1002/smr.533
- Issue published online: 24 JAN 2012
- Article first published online: 17 MAR 2011
- Manuscript Accepted: 23 DEC 2010
- Manuscript Revised: 10 NOV 2010
- Manuscript Received: 23 JUN 2010
- program slicing;
- data flow analysis;
- software maintenance
Maintenance of aging legacy COBOL systems is labor-intensive and is becoming a more and more difficult problem. Program slicing is a potentially useful analysis for aiding different maintenance activities, including program comprehension, reverse engineering, debugging, and testing. Numerous techniques have been proposed in the past decades; however, in interactive contexts, we found none of them suitable for slicing industrial-scale COBOL systems due to their large space or preprocessing requirements. This paper proposes a novel static program slicing approach, which is based on context-sensitive token propagation over control flow graphs (CFGs). CFGs require less space compared with program dependence graphs (PDGs) used by other techniques, and the token propagation method computes the necessary information only, on demand. Algorithms are presented for data flow and full slicing to calculate precise program slices. Preliminary application experiences on industrial-scale COBOL systems are also summarized. Copyright © 2011 John Wiley & Sons, Ltd.