How can i compare gnu and clang in 1 file or project
I think you will need to be more specific about what aspect you want to compare.
oh i read freebsd. have before freebsd 12 use gnu build and now using clang
FreeBSD has used Clang since FreeBSD 10 in 2014. But the answer is simple: pick a representative bit of code you care about, compile it with both compilers using equivalent sets of flags and gather metrics on the result that you care about, normally code size or performance, but sometimes also compile time itself.
Thank you bro