tests/ui/parser/unsafe-mod.rs - toolchain/rustc - Git at Google

 unsafe mod m {
     //~^ ERROR module cannot be declared unsafe
 }

 unsafe mod n;
 //~^ ERROR module cannot be declared unsafe
 //~^^ ERROR file not found for module `n`

 fn main() {}
	unsafe mod m {
	//~^ ERROR module cannot be declared unsafe
	}

	unsafe mod n;
	//~^ ERROR module cannot be declared unsafe
	//~^^ ERROR file not found for module `n`

	fn main() {}