- doing an include #include "/dev/random" will block the thread. - including "/etc/passwd" is also possible although I don't see a direct way to turn this into password disclosure.
Seriously; even if it's a weekend project, letting people run all kinds of potentially bad code on your machine is never a good idea. Even though you don't run the binaries yourself there's so many ways to mess around with a compiler. You just don't know what's going to happen.