Analyzing dynamic call graphs enhanced with program state information for feature location and understanding

ABSTRACT

In this paper we present a prototype tool for locating and understanding features in unfamiliar source code of complex C/C++ software systems. The key concepts of the analysis tool are (1) combining dynamic function call graphs with information on the functions' containment within hierarchically structured modules and (2) providing means of gathering program state information on user-defined locations within the call graph. Starting from a typically huge dynamic call graph logged during feature execution, developers narrow their search for functions implementing the feature's core functionality by successively pruning the graph from feature-irrelevant functions. The assessment whether a function contributes to a feature is performed on various levels of abstraction, namely on (1) module containment, (2) on the function's call relations, and (3) on the way it modifies data. Having sorted out feature-irrelevant functions this way, users are able to analyze the remaining, probably highly feature-relevant functions with other heavy-weight analysis techniques, such as debugging techniques, to get a deep understanding of the feature implementation.

REFERENCES

• 1: Johannes Bohnet , Jürgen Döllner, Visual exploration of function call graphs for feature location in complex software systems, Proceedings of the 2006 ACM symposium on Software visualization, September 04-05, 2006, Brighton, United Kingdom [doi>10.1145/1148493.1148508]
• 2: Bohnet, J. and Döllner, J. 2007. Visually Exploring Control Flow Graphs to Support Legacy Software Migration. In Proceedings of the GI Conference on Software Engineering SE07, pp. 245--246.
• 3: Bohnet, J. and Döllner, J. 2007. Facilitating Exploration of Unfamiliar Source Code by Providing 2-1/2-D Visualizations of Dynamic Call Graphs. In Proceedings of the IEEE Int''l Workshop on Visualizing Software for Understanding and Analysis VISSOFT, pp. 63--66.
• 4: Bohnet, J. and Döllner, J. 2007. CGA Call Graph Analyzer - Locating and Understanding Functionality within the Gnu Compiler Collection''s Million Lines of Code. In Proceedings of the IEEE Int''l Workshop on Visualizing Software for Understanding and Analysis VISSOFT, pp. 161--162.

INDEX TERMS

Primary Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING
      D.2.7 Distribution, Maintenance, and Enhancement

General Terms:
Design, Human Factors

Keywords:
concept assignment, dynamic analysis, feature location, maintenance, reverse engineering, software visualization