A Declarative Foundation for Comprehensive History Querying

Researchers in the field of Mining Software Repositories perform studies about the evolution of software projects. To this end, they use the version control system storing the changes made to a single software project. Such studies are concerned with the source code characteristics in one particular revision, the commit data for that revision, how the code evolves over time and what concrete, fine-grained changes were applied to the source code between two revisions. Although tools exist to analyse an individual concern, scripts and manual work is required to combine these tools to perform a single experiment. We present a general-purpose history querying tool named QwalKeko that enables expressing these concerns in a single uniform language, and having them detected in a git repository. We have validated our work by means of replication studies as well as through MSR studies of our own.