src/test/compile-fail/macro-shadowing.rs

   1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // aux-build:two_macros.rs
  12
  13 #![allow(unused_macros)]
  14
  15 macro_rules! foo { () => {} }
  16 macro_rules! macro_one { () => {} }
  17 #[macro_use(macro_two)] extern crate two_macros;
  18
  19 macro_rules! m1 { () => {
  20     macro_rules! foo { () => {} } //~ ERROR `foo` is already in scope
  21     //~^ NOTE macro-expanded `macro_rules!`s may not shadow existing macros
  22
  23     #[macro_use] //~ ERROR `macro_two` is already in scope
  24     //~^ NOTE macro-expanded `#[macro_use]`s may not shadow existing macros
  25     extern crate two_macros as __;
  26 }}
  27 m1!(); //~ NOTE in this expansion
  28        //~| NOTE in this expansion
  29        //~| NOTE in this expansion
  30        //~| NOTE in this expansion
  31
  32 foo!();
  33
  34 macro_rules! m2 { () => {
  35     macro_rules! foo { () => {} }
  36     foo!();
  37 }}
  38 m2!();
  39 //^ Since `foo` is not used outside this expansion, it is not a shadowing error.
  40
  41 fn main() {}