Algorithmic software fault localization

Debugging tools offer a rich set of breakpoint and displaying facilities. Those do not involve, however, a means for automatic identification of potentially faulty parts of the programs being debugged. Although that goal might be unrealistic in general, even partial solution to the problem, for a restricted classes of faults, might be useful. Towards that goal the authors present a novel fault localization algorithm that is capable of identifying a restricted class of programming faults for Pascal-like languages. The algorithm uses the following principle for fault localization: if a program component produces an incorrect result, while its input is correct, then the program component is faulty. The algorithm uses the computation trajectory-based influence relations to formulate hypotheses about the nature of the fault. User input is needed to assess correctness of intermediate situations on the trajectory. The set of potentially faulty statements generated by the algorithm is closely related to the concept of dynamic slice (B. Korel et al., 1988). The algorithm has been implemented in the System for Testing and Debugging (B. Korel et al., 1988). Early experiments indicate that the approach can be quite useful, particularly for inexperienced programmers