src/test/compile-fail/macro-backtrace-println.rs

   1 // Copyright 2015 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 // The `format_args!` syntax extension issues errors before code expansion
  12 // has completed, but we still need a backtrace.
  13
  14 // This test includes stripped-down versions of `print!` and `println!`,
  15 // because we can't otherwise verify the lines of the backtrace.
  16
  17 fn print(_args: std::fmt::Arguments) {}
  18
  19 macro_rules! myprint {
  20     ($($arg:tt)*) => (print(format_args!($($arg)*)));   //~ NOTE in this expansion of
  21 }
  22
  23 macro_rules! myprintln {
  24     ($fmt:expr) => (myprint!(concat!($fmt, "\n"))); //~ ERROR invalid reference to argument `0`
  25                                                     //~^ NOTE in this expansion of myprint!
  26                                                     //~^^ NOTE in this expansion of concat!
  27 }
  28
  29 fn main() {
  30     myprintln!("{}"); //~ NOTE in this expansion of
  31 }