Reversible execution and visualization of programs with LEONARDO

In this paper we present LEONARDO, an integrated environment for software visualization that allows the user to edit, compile, execute, and animate general-purpose C programs. LEONARDO relies on a logic-based approach to visualization: a mapping between concrete and abstract data structures can be declared through a logic visualization language and animations are conceived as reflecting formal properties of algorithms. LEONARDO is able to automatically detect visual events during the execution of programs and simplifies the creation of visualizations according to an incremental approach. Moreover, it guarantees the complete reversibility of computations, bounded only by the potentiality of the working machine, and appears simple to be used. The latest version of LEONARDO is currently available over the Internet at the URL http://www.dis.uniroma1.it/similar to demetres/Leonardo/. (C) 2000 Academic Press.