tests/ui/builtin-clone-unwind.rs

   1 // run-pass
   2 // needs-unwind
   3
   4 #![allow(unused_variables)]
   5 #![allow(unused_imports)]
   6
   7 // Test that builtin implementations of `Clone` cleanup everything
   8 // in case of unwinding.
   9
  10 use std::thread;
  11 use std::rc::Rc;
  12
  13 struct S(Rc<()>);
  14
  15 impl Clone for S {
  16     fn clone(&self) -> Self {
  17         if Rc::strong_count(&self.0) == 7 {
  18             panic!("oops");
  19         }
  20
  21         S(self.0.clone())
  22     }
  23 }
  24
  25 fn main() {
  26     let counter = Rc::new(());
  27
  28     // Unwinding with tuples...
  29     let ccounter = counter.clone();
  30     let result = std::panic::catch_unwind(move || {
  31         let _ = (
  32             S(ccounter.clone()),
  33             S(ccounter.clone()),
  34             S(ccounter.clone()),
  35             S(ccounter)
  36         ).clone();
  37     });
  38
  39     assert!(result.is_err());
  40     assert_eq!(
  41         1,
  42         Rc::strong_count(&counter)
  43     );
  44
  45     // ... and with arrays.
  46     let ccounter = counter.clone();
  47     let child = std::panic::catch_unwind(move || {
  48         let _ = [
  49             S(ccounter.clone()),
  50             S(ccounter.clone()),
  51             S(ccounter.clone()),
  52             S(ccounter)
  53         ].clone();
  54     });
  55
  56     assert!(child.is_err());
  57     assert_eq!(
  58         1,
  59         Rc::strong_count(&counter)
  60     );
  61 }