Section: New Results

Verified compilation of Lustre

Participants : Timothy Bourke, Lélio Brun, Marc Pouzet.

Synchronous dataflow languages and their compilers are increasingly used to develop safety-critical applications, like fly-by-wire controllers in aircraft and monitoring software for power plants. A striking example is the SCADE Suite tool of ANSYS/Esterel Technologies which is DO-178B/C qualified for the aerospace and defense industries. This tool allows engineers to develop and validate systems at the level of abstract block diagrams that are automatically compiled into executable code.

Formal modeling and verification in an interactive theorem prover can potentially complement the industrial certification of such tools to give very precise definitions of language features and increased confidence in their correct compilation; ideally, right down to the binary code that actually executes.

This year we continued work on our verified Lustre compiler. We developed a new semantic model for the modular reset feature provided by the Scade language and required for the compilation of hierarchical state machines. This work was presented at the SCOPES workshop in Germany in May [17]. Work continues on connecting this semantic model to the intermediate compilation target.

We completed work on generalizing the compiler to treat clocked arguments. This involved changes to our intermediate Obc language and the addition of a pass to add some (necessary) variable initializations in an efficient way. This work was accepted for presentation at the Journées Francophones des Langages Applicatifs in 2019.