After config/parsing, it runs the search at the end of cmd_grep in https://github.com/git/git/blob/master/builtin/grep.c?source=c https://github.com/git/git/blo

After config/parsing, it runs the search at the end of cmd_grep in https://github.com/git/git/blob/master/builtin/grep.c?source=c https://github.com/git/git/blob/master/builtin/grep.c?source... I don't know the answer to your question, but the git source is simple and rewards reading.