A strategy to verify the code generation from concurrent and state-rich circus specifications to executable code

Abstract

The use of Automatic Code Generators for Formal Methods not only minimizes efforts on the implementation of Software Systems, but also reduces the chance of existing errors on the execution of such Systems. These tools, however, can themselves have faults on their source codes that may cause errors on the generation of Software Systems, and thus verification of such tools is encouraged. This PhD thesis aims at creating and developing a strategy to verify the code generation from the Circus formal method to Java Code. The interest in Circus comes from the fact that it allows the specification of concurrent and state-rich aspects of a System in a straightforward manner. The code generation envisaged to be verified is performed by JCircus, a tool that translates a large subset of Circus to Java code that implements the JCSP API. The strategy of verification consists on the following steps: (1) extension of Woodcock’s Operational Semantics to Circus processes and proof that it is sound with respect to the Denotational Semantics of Circus in the Unifying Theories of Programming (UTP), that is a framework that allows proof and unification of different theories; (2) development and implementation of a strategy that refinement-checks the code generated by JCircus, through a toolchain that encompasses (2.1) a Labelled Predicate Transition System (LPTS) Generator for Circus and (2.2) a Model Generator that inputs (I) a LPTS and (II) the code generated by JCircus, and generates a model (that uses the Java Pathfinder code model-checker) that refinement-checks the code generated by JCircus. Combined with coverage-based techniques on the source code of JCircus, we envisage improving the reliability of the Code Generation from Circus to Java.