Very nice finding, ollydbg.
Instead of "-", I would use
/dev/null or
nul depending on operating system, since otherwise gcc will hang (at least does here). Also, if you already call
g++, the
-x c++ is not needed.
Now, the question is whether to call
gcc or
g++, actually it would be nice to always call the "correct" compiler depending on whether you compile C or C++ so include paths would be different for C (which they are in real, too) ... but projects may be mixed, and you don't want to call an external program for every single source file parsed...