1 // The `format_args!` syntax extension issues errors before code expansion 2 // has completed, but we still need a backtrace. 3 4 // This test includes stripped-down versions of `print!` and `println!`, 5 // because we can't otherwise verify the lines of the backtrace. 6 print(_args: std::fmt::Arguments)7fn print(_args: std::fmt::Arguments) {} 8 9 macro_rules! myprint { 10 ($($arg:tt)*) => (print(format_args!($($arg)*))); 11 } 12 13 macro_rules! myprintln { 14 ($fmt:expr) => (myprint!(concat!($fmt, "\n"))); //~ ERROR no arguments were given 15 } 16 main()17fn main() { 18 myprintln!("{}"); 19 } 20