Section: Software

STG

Participant : Thierry Jéron.

Stg (Symbolic Test Generation) is a prototype tool for the generation and execution of test cases using symbolic techniques. It takes as input a specification and a test purpose described as IOSTS, and generates a test case program also in the form of IOSTS. Test generation in STG is based on a syntactic product of the specification and test purpose IOSTS, an extraction of the subgraph corresponding to the test purpose, elimination of internal actions, determinisation, and simplification. The simplification phase now relies on NBAC , which approximates reachable and coreachable states using abstract interpretation. It is used to eliminate unreachable states, and to strengthen the guards of system inputs in order to eliminate some Inconclusive verdicts. After a translation into C++ or Java, test cases can be executed on an implementation in the corresponding language. Constraints on system input parameters are solved on-the-fly (i.e. during execution) using a constraint solver. The first version of STG was developed in C++, using Omega as constraint solver during execution. This version has been deposited at APP under number IDDN.FR.001.510006.000.S.P.2004.000.10600.

A new version in OCaml has been developed in the last years. This version is more generic and will serve as a library for symbolic operations on IOSTS. Most functionalities of the C++ version have been re-implemented. Also a new translation of abstract test cases into Java executable tests has been developed, in which the constraint solver is LuckyDraw (VERIMAG ). This version has also been deposit at APP and is available for download on the web as well as its documentation and some examples.

Finally, in collaboration with ULB, we implemented a prototype SMACS , derived from STG , that is devoted to the control of infinite system modeled by STS.