Java Program Verification via a Hoare Logic with Abrupt Termination

Abstract

Abstract. This paper formalises a semantics for statements and expressions (in sequential imperative languages) which includes non-termination, normal termination and abrupt termination (e.g. because of an exception, break, return or continue). This extends the traditional semantics underlying e.g. Hoare logic, which only distinguishes termination and non-termination. An extension of Hoare logic is elaborated that includes means for reasoning about abrupt termination (and side-effects). It prominently involves rules for reasoning about while loops, which may contain exceptions, breaks, continues and returns. This extension applies in particular to Java. As an example, a standard pattern search algorithm in Java (involving a while loop with returns) is proven correct using the proof-tool PVS.

A Sound and Complete Program Logic for Eiffel

“…Huisman and Jacobs [4] have developed a Hoare-style logic with abrupt termination. It includes not only exception handling but also while loops which may contain exceptions, breaks, continues, returns and side-effects.…”

“…However, exception handling is not treated in their work. Huisman and Jacobs [4] developed a Hoare-stype logic which handles abrupt termination. It includes not only exception handling but also break, continue, and return statements.…”

A Relational Model for Object-Oriented Designs

“…There are a number of recent articles on Hoare Logics for object-oriented programming (see, e.g. [30,35,20,31,23,9]). The normal form of a program in our paper is similarly to that of [9,30].…”

Specification of the Javacard API in JML

“…A compiler has been built, the LOOP tool, which translates a Java program into logical theories describing its semantics [9,2,6,14]. These logical theories are in a format that can serve as input for theorem provers, which can then be used to prove properties of the original Java program, thus achieving a high level of reliability for this program.…”

“…Both normal_ behavior and exceptional_ behavior are just special cases of behavior, and can be regarded as useful syntactic sugar. All these behaviors can be translated into an extended Hoare logic dealing with abrupt termination, see [6].…”