Abstract Rust is a modern programming language that guarantees memory safety and the absence of data races with a strong type system. We present RustyDL, a program logic for Rust, as a foundation for an auto-interactive, deductive verification tool for Rust. RustyDL reasons about Rust programs directly on the source code level, in contrast to other tools that are all based on translation to an intermediate language. A source-level program logic for Rust is crucial for a human-in-the-loop (HIL) style of verification that permits proving highly complex functional properties. We discuss specific Rust challenges in designing a program logic and calculus for HIL-style verification and propose a solution in each case. We provide a proof-of-concept of our ideas in the form of a prototype of a Rust instance of the well-known deductive verification tool KeY.

Abstract The KeY tool is a state-of-the-art deductive program verifier for the Java language. Its verification engine is based on a sequent calculus for dynamic logic, realizing forward symbolic execution of the target program, whereby all symbolic paths through a program are explored. Method contracts make verification scalable. KeY combines auto-active and fine-grained proof interaction, which is possible both at the level of the verification target and its specification, as well as at the level of proof rules and program logic. This makes KeY well-suited for teaching program verification, but also permits proof debugging at the source code level. The latter made it possible to verify some of the most complex Java code to date. The article provides a self-contained introduction to the working principles and the practical usage of KeY for anyone with basic knowledge in logic and formal methods.