How do I find out why g++ takes a very long time on a particular file?

Question

I am building a lot of auto-generated code, including one particularly large file (~15K lines), using a mingw32 cross compiler on linux. Most files are extremely quick, but thi

Answer 1

Won't give all the details you want, but try running with the -v (verbose) and -ftime-report flags. The latter produces a summary of what the compiler has been up to.