https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82476 --- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #4) > Note GCC knows main can only be called once (calling main more than once in > C/C++ is undefined IIRC) It's undefined in C++, I don't think it is in C.