https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82702
--- Comment #8 from Martin Liška <marxin at gcc dot gnu.org> --- > We are not using directly lcov, but a replacement we rewrote in Rust. > We can easily support reading from multiple gcov files instead of one > (actually, we already support it when llvm is used, since it doesn't support > the intermediate format). > The only problem is that it slows down parsing for large projects, which is > unfortunate since I guess the intermediate format was introduced to speed-up > parsing. We have a lot of included files (e.g. I just run it with one of our > gcno files and it generated 160 > gcov files), so clearly opening and reading thousands of files is faster > than opening and reading hundreds of thousands. Agree, so let's print it to a single file. I'll work on that.