//@ compile-flags:--crate-type lib #![feature(decl_macro)] #![feature(rustc_attrs)] #[rustc_builtin_macro] pub macro test($item:item) { //~^ NOTE previously defined /* compiler built-in */ } mod inner { #[rustc_builtin_macro] pub macro test($item:item) { //~^ ERROR attempted to define built-in macro more than once [E0773] /* compiler built-in */ } }