Section: Software

Constraint-Based Testing of critical C programs

Participant : Arnaud Gotlieb [ contact point ] .

Euclide is software testing tool that features three main applications: structural test data generation, counter-example generation and partial program proving for critical C programs. The core algorithm of the tool takes as input a C program and a point to reach somewhere in the code. As a result, it outcomes either a test datum that reaches the selected point, or an “unreachable” indication showing that the selected point is unreachable. Optionally, the tool takes as input additional safety properties that can be given under the form of pre/post conditions or assertions directly written in the code. In this case, Euclide can either prove that these properties or assertions are verified according to an error-free semantics of the language or find a counter-example when there is one. As these problems are undecidable in the general case, Euclide only provides a semi-correct procedure (when it terminates, it provides the right answer) for them. Hopefully, by restricting the subset of C that the tool can handle (no dynamic memory allocation, no recursion) these non-termination problems remain infrequent in practice. In addition, Euclide implements several procedures that combine atomic calls to the core algorithm. For example, by selecting appropriate points to reach in the source code, the tool can generate a complete test suite able to cover the all_statements or the all_decisions criteria.