rust/src/test/compile-fail/hygienic-label-4.rs
Edward Wang 386db05df8 Make break and continue hygienic
Makes labelled loops hygiene by performing renaming of the labels
defined in e.g. `'x: loop { ... }` and then used in break and continue
statements within loop body so that they act hygienically when used with
macros.

Closes #12262.
2014-02-23 21:20:37 +08:00

20 lines
649 B
Rust

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#[feature(macro_rules)];
macro_rules! foo {
($e: expr) => { 'x: for _ in range(0,1) { $e } }
}
pub fn main() {
foo!(break 'x); //~ ERROR use of undeclared label `x`
}