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// compile-flags: -Z panic-in-drop=abort -O -Z new-llvm-pass-manager=no
// Ensure that unwinding code paths are eliminated from the output after
// optimization.
// This test uses -Z new-llvm-pass-manager=no, because the expected optimization does not happen
// on targets using SEH exceptions (i.e. MSVC) anymore. The core issue is that Rust promises that
// the drop_in_place() function can't unwind, but implements it in a way that *can*, because we
// currently go out of our way to allow longjmps, which also use the unwinding mechanism on MSVC
// targets. We should either forbid longjmps, or not assume nounwind, making this optimization
// incompatible with the current behavior of running cleanuppads on longjmp unwinding.
// CHECK-NOT: {{(call|invoke).*}}should_not_appear_in_output
#![crate_type = "lib"]
use std::any::Any;
use std::mem::forget;
pub struct ExternDrop;
impl Drop for ExternDrop {
#[inline(always)]
fn drop(&mut self) {
// This call may potentially unwind.
extern "Rust" {
fn extern_drop();
}
unsafe {
extern_drop();
}
}
}
struct AssertNeverDrop;
impl Drop for AssertNeverDrop {
#[inline(always)]
fn drop(&mut self) {
// This call should be optimized away as unreachable.
extern "C" {
fn should_not_appear_in_output();
}
unsafe {
should_not_appear_in_output();
}
}
}
#[no_mangle]
pub fn normal_drop(x: ExternDrop) {
let guard = AssertNeverDrop;
drop(x);
forget(guard);
}
#[no_mangle]
pub fn indirect_drop(x: Box<dyn Any>) {
let guard = AssertNeverDrop;
drop(x);
forget(guard);
}
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