src/test/run-pass/mir_trans_call_converging.rs

// Copyright 2015 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(rustc_attrs)]

fn converging_fn() -> u64 {
    43
}

#[rustc_mir]
fn mir() -> u64 {
    let x;
    loop {
        x = converging_fn();
        break;
    }
    x
}

fn main() {
    assert_eq!(mir(), 43);
}