1 // Some optimizations remove ZST accesses, thus masking this UB.
2 //@compile-flags: -Zmir-opt-level=0
5 // Not using the () type here, as writes of that type do not even have MIR generated.
6 // Also not assigning directly as that's array initialization, not assignment.
7 let zst_val = [1u8; 0];
9 // make sure ZST accesses are checked against being "truly" dangling pointers
10 // (that are out-of-bounds).
11 let mut x_box = Box::new(1u8);
12 let x = (&mut *x_box as *mut u8).wrapping_offset(1);
13 // This one is just "at the edge", but still okay
14 unsafe { *(x as *mut [u8; 0]) = zst_val };
15 // One byte further is OOB.
16 let x = x.wrapping_offset(1);
17 unsafe { *(x as *mut [u8; 0]) = zst_val }; //~ ERROR: out-of-bounds