tests/ui/macros/missing-semi.rs - rust-lang/rust - Git at Google

 #[allow(unused_macros)]
 macro_rules! foo {
     () => {

     }
     () => {
         //~^ ERROR expected `;`, found `(`
     }
 }

 fn main() {}
	#[allow(unused_macros)]
	macro_rules! foo {
	() => {

	}
	() => {
	//~^ ERROR expected `;`, found `(`
	}
	}

	fn main() {}