src/test/run-fail/mir_dynamic_drops_3.rs

   1 // Copyright 2016 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 // error-pattern:unwind happens
  12 // error-pattern:drop 3
  13 // error-pattern:drop 2
  14 // error-pattern:drop 1
  15 use std::io::{self, Write};
  16
  17
  18 /// Structure which will not allow to be dropped twice.
  19 struct Droppable<'a>(&'a mut bool, u32);
  20 impl<'a> Drop for Droppable<'a> {
  21     fn drop(&mut self) {
  22         if *self.0 {
  23             writeln!(io::stderr(), "{} dropped twice", self.1);
  24             ::std::process::exit(1);
  25         }
  26         writeln!(io::stderr(), "drop {}", self.1);
  27         *self.0 = true;
  28     }
  29 }
  30
  31 fn may_panic<'a>() -> Droppable<'a> {
  32     panic!("unwind happens");
  33 }
  34
  35 fn mir<'a>(d: Droppable<'a>) {
  36     let (mut a, mut b) = (false, false);
  37     let y = Droppable(&mut a, 2);
  38     let x = [Droppable(&mut b, 1), y, d, may_panic()];
  39 }
  40
  41 fn main() {
  42     let mut c = false;
  43     mir(Droppable(&mut c, 3));
  44 }