Combining Specification-Based Testing, Correctness Proof, and Inspection for Program Verification in Practice

Specification-based testing is limited in detecting program errors; correctness proof based on Hoare logic is difficult to perform in practice; and inspection is heavily dependent on human decisions. Each of these three is difficult to do a satisfactory job alone, but they complement each other when they come together in an appropriate manner. This paper puts forward a new method that makes good use of Hoare logic and inspection to improve the effectiveness of specification-based testing in detecting errors. The underlying principle of the method is first to use specification-based testing to discover traversed program paths and then to use Hoare logic to prove their correctness, but when proof is impossible to conduct, a special inspection is applied. During the proof or inspection process, all faults on the paths are expected to be detected. A case study is conducted to show its feasibility; an example taken from the case study is used to illustrate how the proposed method is applied; and a discussion on the important issues to be addressed in the future is presented.