The gcno files contain valuable information that can be used together with other tools, for example to augment basic block coverage gathered during fuzzing. For this purpose, it would be quite useful to have an output format that just reads the gcno files and summarizes them in one json blob.

My current use case is that I have basic block coverage and want to merge this data with regular source coverage. For this purpose I need the information contained in gcno files about which lines belong to the same basic block, so I can appropriately convert the data.