Employing Dynamic Symbolic Execution for Equivalent Mutant Detection

Equivalent mutants (EM) issue is a key challenge in mutation testing. Many methods were applied for detecting and reducing the equivalent mutants. These methods are classified into four classes: equivalent mutant detection, avoiding the generation of equivalent mutants, higher-order equivalent mutants, and suggesting equivalent mutants. Higher-order mutation testing (HOMT) is considered the strongest employed technique in avoiding the generation of equivalent mutants and reduction of their number. In this paper, a combination of HOMT especially second-order mutation testing (SOMT) and dynamic symbolic execution (DSE) techniques are applied for the automatic detection and reduction of the equivalent second-order mutants. First, SOMT is used to reduce the number of equivalent mutants. Second, DSE technique is applied to classify the SOMs and detect EM. To assess the efficiency of the proposed technique, it is applied to some subject programs and the results of this technique are compared to the manual results and those of related works. The results showed that the proposed algorithm is more effective in detecting and reducing the number of EM. It detects 94% from the equivalent mutants that have manually analyzed. This percentage is a high percentage comparing with previous studies. Besides, the DEM-DSE technique detects 100% of equivalent mutants for 9 of the 14 subject programs.