Variable Data-Flow Graph for Lightweight Program Slicing and Visualization

Abstract

SUMMARYTo understand the behavior of a program, developers often need to read source code fragments in various modules. Systemdependence-graph-based (SDG) program slicing is a good candidate for supporting the investigation of data-flow paths among modules, as SDG is capable of showing the data-dependence of focused program elements. However, this technique has two problems. First, constructing SDG requires heavyweight analysis, so SDG is not suitable for daily uses. Second, the results of SDG-based program slicing are difficult to visualize, as they contain many vertices. In this research, we proposed variable dataflow graphs (VDFG) for use in program slicing techniques. In contrast to SDG, VDFG is created by lightweight analysis because several approximations are used. Furthermore, we propose using the fractal value to visualize VDFG-based program slice in order to reduce the graph complexity for visualization purposes. We performed three experiments that demonstrate the accuracy of VDFG program slicing with fractal value, the size of a visualized program slice, and effectiveness of our tool for source code reading.

Ways To Write Algorithms And Their Execution Traces For Teaching Programming

“…A step-by-step log of commands executed by a program is called a program trace (or just a trace or tracing). The importance of the traces has been frequently mentioned earlier to both developing program code (Abualese et al, 2017;Fittkau et al, 2015;Feng et al, 2018;Kashima et al, 2015;Kadar et al, 2016;Khoury et al, 2017;Khoury et al, 2019;Perez & Abreu, 2016) and programming education (Aggarwal et al, 2018;Paaßen et al, 2016;Srinivasan et al, 2016;Terada, 2005).…”

“…Reading source code is an important part of a programmer's work which takes up to half of their working time (Kashima et al, 2015). Plenty of various tools assisting code understanding is developed, see (Kadar et al, 2016;Perez & Abreu, 2016), but they address the needs of experienced developers while learning to read and understand program code is one of the important stages of computer science education.…”