Recovering Multi-Dimensionality From Legacy Software

Even in the most well-designed systems, some modules are difficult to maintain due to tangling of multiple concerns within a single monolithic codebase. Software plans have been proposed as an alternative multi-dimensional representation of software in which the programmer can implement independent concerns in separate views of the code. This reduces the difficulty of maintenance by allowing the programmer to view, reason about, and edit the software in a multidimensional manner, where each dimension corresponds to a concern of interest. As promising as this approach may be, there remains a large amount of legacy code that was developed using the traditional monolithic representation. We present an approach for reverse engineering software plans from existing monolithic code using static and dynamic feature location techniques. To evaluate our approach, we applied it to GNU gcc, extracting software plans that separate previously tangled code into multiple concern dimensions.