KeYPl

KeY for Proof Plans

VaMoS 2022 Paper | VaMoS 2022 Presentation

This is a frontend to the KeY verification system [1] for efficiently evaluating the correctness of feature-oriented software product lines.

Software product lines (SPLs) are large families of programs that share a common set of features. The correctness of all method variants in an SPL can be verified with the KeY verification system for individual products of an SPL. However, to check an entire SPL, this approach checks all its product individually, which is inefficient for large SPLs (product-based analysis).

With our approach as implemented in KeYPl, we can avoid checking each product of an SPL in isolation. To do this, we use proof plans, which cache proofs systematically so that we can reuse them for several configurations of an SPL [2, 3]. This implementation of proof plans allows for several concrete verification strategies, including feature-(product-/family-)based approaches.

How to Use

• We provide our case study and evaluation results in the caseStudy directory. To reproduce our results, unzip caseStudy.zip and run the evaluate script (requires JRE 1.8 and possibly dos2unix evaluate under Linux systems).
• Our implementation is based on KeY 2.8.0 (vanilla version). We do not rely on abstract contracts or uninterpreted predicates, but implement partial proofs with abstract model methods [1].
• The KeYBridge class implements the interface to KeY. Our programming model, proof graphs/plans, and partial proof system are all implemented in the Core class. The Shell class addresses code parsing and evaluation concerns.
• A pre-built and self-contained JAR file is available in the evaluation/caseStudy.zip archive. Run java -jar KeYPl.jar to see its usage.
• For a manual build, the only dependency required is JDK 1.8. You can build the JAR by running ./gradlew build, which stores the JAR file into build/libs. Alternatively, you can directly run the JAR with ./gradlew run.
• You can use the project with IntelliJ IDEA. Create an Application run configuration to run the JAR.

License

This project is a research effort of the DBSE working group. It is released under the LGPL v3 license. Feel free to contact me (the main developer) if you have any questions.

References

1. Wolfgang Ahrendt, Bernhard Beckert; Richard Bubel; Reiner Hähnle; Peter H. Schmitt, and Mattias Ulbrich. 2016. Deductive Software Verification - The KeY Book - From Theory to Practice. Springer.
2. Elias Kuiter. 2020. Proof Repositories for Correct-by-Construction Software Product Lines. Otto-von-Guericke-University Magdeburg.
3. Elias Kuiter, Alexander Knüppel, Tabea Bordis, Tobias Runge, and Ina Schaefer. Verification Strategies for Feature-Oriented Software Product Lines. In Proceedings of the International Working Conference on Variability Modelling of Software-Intensive Systems (VaMoS), February 2022.