Visualization of Code Flow

Abstract: Visual representation of Control Flow Graphs (CFG) is a feature available in many tools, such as decompilers. These tools often rely on graph drawing frameworks which implement the Sugiyama hierarchical style graph drawing method, a well known method for drawing directed graphs. The main disadvantage of the Sugiyama framework, is the fact that it does not take into account the nature of the graph to be visualized, specically loops are treated as second class citizens. The question this paper attempts to answer is; how can we improve the visual representation of loops in the graph? A method based on the Sugiyama framework was developed and implemented in Qt. It was evaluated by informally interviewing test subjects, who were allowed to test the implementation and compare it to the normal Sugiyama. The results show that all test subjects concluded that loops, as well as the overall representation of the graph was improved, although with reservations. The method presented in this paper has problems which need to be adressed, before it can be seen as an optimal solution for drawing Control Flow Graphs.