I am happy to announce that the prime path coverage support has been merged into GCC mainline. This was a continuation of my MC/DC project with NASA. I did most of the programming in the spring through autumn of 2024, followed by a long period of mostly testing and paper writing. NASA have been using GCC builds with this feature for about six months now, and they are quite happy with what they can learn from it. Process wise, it is an opportunity for simplification too – because prime path coverage subsumes most other coverage metrics we can now focus on a single metric.

I gave a talk today at the Johnson Space Center in Houston, on the GCC coverage features I have done with them. The talk covered what prime paths and the motivation for prime path coverage, why they are an important development in dynamic analysis and how leveraging it will improve the quality of the testing we do of our systems. This marks the end of my two projects with them, MC/DC and prime path coverage, and it has truly been an incredible journey. The team at Orion have been absolutely brilliant to work with; they put trust in me when we scoped out the features and requirements, were great sparring parterns in development, and helped me test the features and gathered a lot of useful user feedback.

My paper on Modified Condition/Decision Coverage in GCC is published (in preprint)! You can get a copy from here or from arxiv. It covers the reasning, inner workings, and algorithms behind the -fcondition-coverage flag in GCC.