| // 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. |
| |
| // compile-pass |
| #![allow(unused_macros)] |
| #![allow(dead_code)] |
| #![feature(asm)] |
| |
| type History = Vec<&'static str>; |
| |
| fn wrap<A>(x:A, which: &'static str, history: &mut History) -> A { |
| history.push(which); |
| x |
| } |
| |
| macro_rules! demo { |
| ( $output_constraint:tt ) => { |
| { |
| let mut x: isize = 0; |
| let y: isize = 1; |
| |
| let mut history: History = vec![]; |
| unsafe { |
| asm!("mov ($1), $0" |
| : $output_constraint (*wrap(&mut x, "out", &mut history)) |
| : "r"(&wrap(y, "in", &mut history)) |
| :: "volatile"); |
| } |
| assert_eq!((x,y), (1,1)); |
| let b: &[_] = &["out", "in"]; |
| assert_eq!(history, b); |
| } |
| } |
| } |
| |
| #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] |
| fn main() { |
| fn out_write_only_expr_then_in_expr() { |
| demo!("=r") |
| } |
| |
| fn out_read_write_expr_then_in_expr() { |
| demo!("+r") |
| } |
| |
| out_write_only_expr_then_in_expr(); |
| out_read_write_expr_then_in_expr(); |
| } |
| |
| #[cfg(all(not(target_arch = "x86"), not(target_arch = "x86_64")))] |
| pub fn main() {} |