src/test/ui/builtin-clone-unwind.rs

   1 // run-pass
   2 // needs-unwind
   3
   4 #![allow(unused_variables)]
   5 #![allow(unused_imports)]
   6 // ignore-wasm32-bare compiled with panic=abort by default
   7
   8 // Test that builtin implementations of `Clone` cleanup everything
   9 // in case of unwinding.
  10
  11 use std::thread;
  12 use std::rc::Rc;
  13
  14 struct S(Rc<()>);
  15
  16 impl Clone for S {
  17     fn clone(&self) -> Self {
  18         if Rc::strong_count(&self.0) == 7 {
  19             panic!("oops");
  20         }
  21
  22         S(self.0.clone())
  23     }
  24 }
  25
  26 fn main() {
  27     let counter = Rc::new(());
  28
  29     // Unwinding with tuples...
  30     let ccounter = counter.clone();
  31     let result = std::panic::catch_unwind(move || {
  32         let _ = (
  33             S(ccounter.clone()),
  34             S(ccounter.clone()),
  35             S(ccounter.clone()),
  36             S(ccounter)
  37         ).clone();
  38     });
  39
  40     assert!(result.is_err());
  41     assert_eq!(
  42         1,
  43         Rc::strong_count(&counter)
  44     );
  45
  46     // ... and with arrays.
  47     let ccounter = counter.clone();
  48     let child = std::panic::catch_unwind(move || {
  49         let _ = [
  50             S(ccounter.clone()),
  51             S(ccounter.clone()),
  52             S(ccounter.clone()),
  53             S(ccounter)
  54         ].clone();
  55     });
  56
  57     assert!(child.is_err());
  58     assert_eq!(
  59         1,
  60         Rc::strong_count(&counter)
  61     );
  62 }