| Reliability is critical for system software, such as OS kernels, mobile browsers, embedded systems and cloud systems. The correctness of these programs, especially for security, is highly desirable, as they should provide a trustworthy platform for higher-level applications and the end-users. Unfortunately, due to its inherent complexity, the verification process of these programs is typically manual/semi-automatic, tedious, and painful. Automating the reasoning behind these verification tasks and decreasing the dependence on manual help is one of the greatest challenges in software verification. This dissertation presents two logic-based automatic software verification systems, namely Strand and Dryad, that help in the task of verification of heap-manipulating programs, which is one of the most complex aspects of modern software that eludes automatic verification. Strand is a logic that combines an expressive heap-logic with an arbitrary data-logic and admits several powerful decidable fragments. The general decision procedures can be used in not only proving programs correct but also in software analysis and testing. Dryad is a family of logics, including Dryad-tree as a first-order logic for trees and Dryad-sep as a dialect of separation logic. Both the two logics are amenable to automated reasoning using the natural proof strategy, a radically new approach to software verification. Dryad and the natural proof techniques are so far the most efficient logic-based approach that can verify the full correctness of a wide variety of challenging programs, including a large number of programs from various open-source libraries. They hold promise of hatching the next-generation automatic verification techniques. |
