Program understanding and maintenance with the CANTO environment

During maintenance activities, the availability of integrated conceptual views that present software at different levels of abstraction, from software architecture to control and data flow relations at code level, is fundamental to understand and modify legacy systems. This paper presents CANTO, a comprehensive program understanding and maintenance environment which integrates fine grained information with architectural views extracted from source code, giving the user control on what is being computed by analyses. The capabilities and usefulness of CANTO are illustrated with reference to a real understanding and maintenance task.