Feature-Context Interfaces: Tailored Programming Interfaces for Software Product Lines

Despite the wide use of software product lines, their imple-mentation and evolution is a challenging task. When im-plementing a feature, a developer has to know which code fragments of other (already implemented) features are ac-cessible in each program variant in which the feature is in-cluded. Especially for composition-based implementation techniques, in which the code is implemented in separated modules, it is an exhausting and error-prone task to find safely accessible code fragments of other modules. State-of-the-art tool support, such as product-line type checkers, de-tect errors a posteriori (i.e., during compilation), but fails to prevent errors during the implementation. To overcome this problem, we propose feature-context interfaces, which pro-vide a modular and non-variable programming interface to the variable source code of a product line. These interfaces ease changes, extensions, and the maintainability of product lines. To demonstrate applicability, we implemented a con-tent assist and an outline view in Eclipse based on feature-context interfaces. We evaluate the potential of our method by analyzing the number of potential type errors we prevent compared to state-of-the-art techniques