Variability Hiding in Contracts for Dependent Software Product Lines

Software product lines are used to efficiently develop and verify similar software products. While they focus on reuse of artifacts between products, a product line may also be reused itself in other product lines. A challenge with such dependent product lines is evolution; every change in a product line may influence all dependent product lines. With variability hiding, we aim to hide certain features and their artifacts in dependent product lines. In prior work, we focused on feature models and implementation artifacts. We build on this by discussing how variability hiding can be extended to specifications in terms of method contracts. We illustrate variability hiding in contracts by means of a running example and share our insights with preliminary experiments on the benefits for formal verification. In particular, we find that not every change in a certain product line requires a re-verification of other dependent product lines.