src/test/run-pass-fulldeps/auxiliary/hello_macro.rs

   1 // Copyright 2017 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 #![feature(plugin)]
  12 #![feature(plugin_registrar)]
  13 #![feature(rustc_private)]
  14 #![plugin(proc_macro_plugin)]
  15
  16 extern crate rustc_plugin;
  17 extern crate syntax;
  18
  19 use rustc_plugin::Registry;
  20 use syntax::ext::base::SyntaxExtension;
  21 use syntax::symbol::Symbol;
  22 use syntax::tokenstream::TokenStream;
  23
  24 #[plugin_registrar]
  25 pub fn plugin_registrar(reg: &mut Registry) {
  26     reg.register_syntax_extension(Symbol::intern("hello"),
  27                                   SyntaxExtension::ProcMacro(Box::new(hello)));
  28 }
  29
  30 // This macro is not very interesting, but it does contain delimited tokens with
  31 // no content - `()` and `{}` - which has caused problems in the past.
  32 // Also, it tests that we can escape `$` via `$$`.
  33 fn hello(_: TokenStream) -> TokenStream {
  34     quote!({
  35         fn hello() {}
  36         macro_rules! m { ($$($$t:tt)*) => { $$($$t)* } }
  37         m!(hello());
  38     })
  39 }