rust/src/test/ui/cleanup-rvalue-temp-during-incomplete-alloc.rs
David Koloski ea68758299 Add needs-unwind to tests that depend on panicking
This directive isn't automatically set by compiletest or x.py, but can
be turned on manually for targets that require it.
2021-12-09 22:03:52 +00:00

48 lines
1.1 KiB
Rust

// run-pass
// needs-unwind
#![allow(unused_must_use)]
#![allow(dead_code)]
#![allow(unused_variables)]
// Test cleanup of rvalue temporary that occurs while `box` construction
// is in progress. This scenario revealed a rather terrible bug. The
// ingredients are:
//
// 1. Partial cleanup of `box` is in scope,
// 2. cleanup of return value from `get_bar()` is in scope,
// 3. do_it() panics.
//
// This led to a bug because `the top-most frame that was to be
// cleaned (which happens to be the partial cleanup of `box`) required
// multiple basic blocks, which led to us dropping part of the cleanup
// from the top-most frame.
//
// It's unclear how likely such a bug is to recur, but it seems like a
// scenario worth testing.
// ignore-emscripten no threads support
use std::thread;
enum Conzabble {
Bickwick(Foo)
}
struct Foo { field: Box<usize> }
fn do_it(x: &[usize]) -> Foo {
panic!()
}
fn get_bar(x: usize) -> Vec<usize> { vec![x * 2] }
pub fn fails() {
let x = 2;
let mut y: Vec<Box<_>> = Vec::new();
y.push(Box::new(Conzabble::Bickwick(do_it(&get_bar(x)))));
}
pub fn main() {
thread::spawn(fails).join();
}