It looks like the output from clang. You can achieve the same using clang using the approach outlined here: http://clang.llvm.org/docs/UsersManual.html#controlling-diagnostics-via-pragmas:
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-variable"
#include "subfolder/ClassTwo.h"
#pragma clang diagnostic pop
If that's your source file, then just fix the warning.
For GCC, you can use this: Selectively disable GCC warnings for only part of a translation unit?
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-variable"
#include "subfolder/ClassTwo.h"
#pragma GCC diagnostic pop
Of course, that will leave you with a good amount of pragma noise -- debatable if that is a bad thing =)