src/test/ui/proc-macro/nested-nonterminal-tokens.rs

   1 // check-pass
   2 // edition:2018
   3 // compile-flags: -Z span-debug
   4 // aux-build:test-macros.rs
   5
   6 // Tests that we properly pass tokens to proc-macro when nested
   7 // nonterminals are involved.
   8
   9 #![no_std] // Don't load unnecessary hygiene information from std
  10 extern crate std;
  11
  12 #[macro_use]
  13 extern crate test_macros;
  14
  15
  16 macro_rules! wrap {
  17     (first, $e:expr) => { wrap!(second, $e + 1) };
  18     (second, $e:expr) => { wrap!(third, $e + 2) };
  19     (third, $e:expr) => {
  20         print_bang!($e + 3)
  21     };
  22 }
  23
  24 fn main() {
  25     let _ = wrap!(first, 0);
  26 }