%0 Journal Article
%T Combining Slicing and Constraint Solving for Better Debugging: The CONBAS Approach
%A Birgit Hofer
%A Franz Wotawa
%J Advances in Software Engineering
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/628571
%X Although slices provide a good basis for analyzing programs during debugging, they lack in their capabilities providing precise information regarding the most likely root causes of faults. Hence, a lot of work is left to the programmer during fault localization. In this paper, we present an approach that combines an advanced dynamic slicing method with constraint solving in order to reduce the number of delivered fault candidates. The approach is called Constraints Based Slicing (CONBAS). The idea behind CONBAS is to convert an execution trace of a failing test case into its constraint representation and to check if it is possible to find values for all variables in the execution trace so that there is no contradiction with the test case. For doing so, we make use of the correctness and incorrectness assumptions behind a diagnosis, the given failing test case. Beside the theoretical foundations and the algorithm, we present empirical results and discuss future research. The obtained empirical results indicate an improvement of about 28% for the single fault and 50% for the double-fault case compared to dynamic slicing approaches. 1. Introduction Debugging, that is, locating a fault in a program and correcting it, is a tedious and very time-consuming task that is mainly performed manually. There have been several approaches published that aid the debugging process. However, these approaches are hardly used by programmers except for tools allowing to set breakpoints and to observe the computation of variable values during execution. There are many reasons that justify this observation. In particular, most of the debugging tools do not smoothly integrate with the software development tools. In addition, debuggers fail to identify unique root causes and still leave a lot of work for the programmer. Moreover, the approaches can also be computationally demanding, which prevents them from being used in an interactive manner. In this paper, we do not claim to solve all of the mentioned problems. We discuss a method that improves debugging results when using dependence-based approaches like dynamic slicing. Our method makes use of execution traces and the dependencies between the executed statements. In contrast to slicing, we also use symbolic execution to further reduce the number of potential root causes. In order to introduce our method, we make use of the program numfun that implements a numeric function. The program and a test case are given in Figure 1. When executing the program using the test case, numfun returns a value of 10 for variable f, which
%U http://www.hindawi.com/journals/ase/2012/628571/