Semi-formal Verification with Supporting Tool by Automatic Application of Hoare Logic

Abstract

Software development is costly endeavors. In general, the cost can be reduced by checking whether the program meets the specification. Usually, software is composed of several modules so that by checking the correctness of each module, developers can find the causes of errors efficiently. Formal verification and specification-based testing are effective techniques to verify programs. Formal verification based on Hoare logic can establish the correctness of programs from the theoretical point of view. However, it is regarded as an impractical technique for realistic programs, due to some challenges, On the other hand, specification-based testing is able to detect errors, and it is easy to perform. Therefore, it is frequently used for realistic developments. However, in most cases, the testing cannot guarantee the correctness of programs. As we described above, both of these techniques cannot do satisfactory job alone. To solve this problem, a novel verification approach was suggested, which is called testing-based formal verification (TBFV). In this paper, we aim to automate application of Hoare logic to Java programs based on the previously proposed TBFV. At the same time, we try to reveal the feasibility of TBFV through developing a supporting tool for Java programs and conducting a case study. At the same time, to achieve an effective automatic verification, we add the function of automatic boundary testing in the result evaluation step in the supporting tool. As a result, our supporting tool has achieved a semi-formal automation of Hoare logic application, which can help reduce the cost of verification process.