| // Stacked Borrows catches this (correctly) as UB. |
| //@compile-flags: -Zmiri-disable-stacked-borrows |
| |
| // This test is intended to guard against the problem described in commit |
| // 39bb1254d1eaf74f45a4e741097e33fc942168d5. |
| // |
| // As written, it might be considered UB in compiled Rust, but of course Miri gives it a safe, |
| // deterministic behaviour (one that might not correspond with how an eventual Rust spec would |
| // defined this). |
| // |
| // An alternative way to write the test without `unsafe` would be to use `Cell<i32>`, but it would |
| // only surface the bug described by the above commit if `Cell<i32>` on the stack got represented |
| // as a primitive `PrimVal::I32` which is not yet the case. |
| |
| fn main() { |
| let mut x = 0; |
| let y: *const i32 = &x; |
| x = 1; |
| |
| // When the described bug is in place, this results in `0`, not observing the `x = 1` line. |
| assert_eq!(unsafe { *y }, 1); |
| |
| assert_eq!(x, 1); |
| } |
