E-SPARK: Automated Generation of Provably Correct Code from Formally Verified Designs

An approach to generating provably correct sequential code from formally developed algorithmic designs is presented. Given an algorithm modelled in the Event-B formalism, we automatically translate the design into the SPARK programming language. Our translation builds upon Abrial’s approach to the development of sequential programs from Event-B models. However, as well as generating code, our approach also automatically generates code level specifications, i.e. SPARK preand post-conditions, along with loop invariants. In terms of the SPARK proof tools, having the loop invariants increases verification automation. A prototype, known as E-SPARK, has been implemented as a plugin for the Rodin Platform (Event-B toolkit), and tested on a range of examples, i.e. searching, sorting and numeric calculations.