You seem quite paranoid. Open source was thought to sweep away for hidden code, I really doubt GCC or other compilers has that special code that is reproduced

You seem quite paranoid. Open source was thought to sweep away for hidden code, I really doubt GCC or other compilers has that special code that is reproduced each time you recompile a compiler with it. If there was such self-reproducing code in a compiled GCC, it would be quite easy to find. There are many eyes looking at a program like GCC. And even with such a conspiracy theory, which is still possible, open source has better margin than proprietary. It's not perfect, but it's much more transparent if you get what I mean.