Segfault in safe code that spawns a thread with an infinite loop when optimized #39753
Description
Summary
Complete original report
Originally reported on Stack Overflow.
use std::thread;
fn main() {
thread::spawn(|| {
let a = 2;
loop {
a*a;
}
}).join();
}$ rustc -O inf.rs
warning: unused result which must be used, #[warn(unused_must_use)] on by default
--> inf.rs:4:5
|
4 | thread::spawn(|| {
| _____^ starting here...
5 | | let a = 2;
6 | | loop {
7 | | a*a;
8 | | }
9 | | }).join();
| |______________^ ...ending here
$ ./inf
Segmentation fault: 11
$ rustc --version --verbose
rustc 1.15.1 (021bd294c 2017-02-08)
binary: rustc
commit-hash: 021bd294c039bd54aa5c4aa85bcdffb0d24bc892
commit-date: 2017-02-08
host: x86_64-apple-darwin
release: 1.15.1
LLVM version: 3.9
Adding an unwrap() does not change the behavior.