tests/ui/invalid/invalid-macro-matcher.rs - rust-lang/rust - Git at Google

 #![allow(unused_macros)]

 macro_rules! invalid {
     _ => (); //~ ERROR invalid macro matcher
 }

 fn main() {
 }
	#![allow(unused_macros)]

	macro_rules! invalid {
	_ => (); //~ ERROR invalid macro matcher
	}

	fn main() {
	}