Open-source software product line extraction processes: the ArgoUML-SPL and Phaser cases

Abstract

Software Product Lines (SPLs) are rarely developed from scratch. Commonly, they emerge from one product when there is a need to create tailored variants, or from existing variants created in an ad-hoc way once their separated maintenance and evolution become challenging. Despite the vast literature about re-engineering systems into SPLs and related technical approaches, there is a lack of detailed analysis of the process itself and the effort involved. In this paper, we provide and analyze empirical data of the extraction processes of two open-source case studies, namely ArgoUML and Phaser. Both cases emerged from the transition of a monolithic system into an SPL. The analysis relies on information mined from the version control history of their respective source-code repositories and the discussion with developers that took part in the process. Unlike previous works that focused mostly on the structural results of the final SPL, the contribution of this study is an in-depth characterization of the processes. With this work, we aimed at providing a deeper understanding of the strategies for SPL extraction and their implications. Our results indicate that the source code changes can range from almost a fourth to over half of the total lines of code. Developers may or may not use branching strategies for feature extraction. Additionally, the problems faced during the extraction process may be due to lack of tool support, complexity on managing feature dependencies and issues with feature constraints. We made publicly available the datasets and the analysis scripts of both case studies to be used as a baseline for extractive SPL adoption research and practice.

Feature-oriented Test Case Selection during Evolution of Highly-Configurable Systems

“…Despite this being a limitation, the use of pre-processor directives is a very common practice, adopted by most HCSs [7]. However, using other variability mechanisms such as component technologies [59], frameworks [60], or feature-oriented programming with some form of feature modules [61] (i.e., a compositional approach) should be the focus of future work [62].…”

Product Model Derivation from Feature Model and Formal Specification

“…The techniques are code-based export methods that assign features to code [6]. They are usually featureto-artifact mappings [7], e.g., AspectJ for Java or preprocessor annotations [8,9] for text files. The build result of the final product depends on the choice of configuration options provided by the variability model [10].…”