3 // ignore-emscripten no threads support
5 // rust-lang/rust#64655: with panic=unwind, a panic from a subroutine
6 // should still run destructors as it unwinds the stack. However,
7 // bugs with how the nounwind LLVM attribute was applied led to this
8 // simple case being mishandled *if* you had fat LTO turned on.
10 // Unlike issue-64655-extern-rust-must-allow-unwind.rs, the issue
11 // embodied in this test cropped up regardless of optimization level.
12 // Therefore it seemed worthy of being enshrined as a dedicated unit
15 // LTO settings cannot be combined with -C prefer-dynamic
18 // The revisions just enumerate lto settings (the opt-level appeared irrelevant in practice)
20 // revisions: no thin fat
21 //[no]compile-flags: -C lto=no
22 //[thin]compile-flags: -C lto=thin
23 //[fat]compile-flags: -C lto=fat
25 #![feature(core_panic)]
27 // (For some reason, reproducing the LTO issue requires pulling in std
28 // explicitly this way.)
33 use std::sync::atomic::{AtomicUsize, Ordering};
36 static SHARED: AtomicUsize = AtomicUsize::new(0);
38 assert_eq!(SHARED.fetch_add(0, Ordering::SeqCst), 0);
40 let old_hook = std::panic::take_hook();
42 std::panic::set_hook(Box::new(|_| { } )); // no-op on panic.
44 let handle = std::thread::spawn(|| {
46 impl Drop for Droppable {
48 SHARED.fetch_add(1, Ordering::SeqCst);
52 let _guard = Droppable;
53 core::panicking::panic("???");
56 let wait = handle.join();
58 // Reinstate handler to ease observation of assertion failures.
59 std::panic::set_hook(old_hook);
61 assert!(wait.is_err());
63 assert_eq!(SHARED.fetch_add(0, Ordering::SeqCst), 1);