rust/tests/ui/consts/const-eval/ptr_fragments_in_final.rs
2025-09-08 13:22:52 +02:00

27 lines
851 B
Rust

//! Test that we properly error when there is a pointer fragment in the final value.
//@ ignore-test: disabled due to <https://github.com/rust-lang/rust/issues/146291>
use std::{mem::{self, MaybeUninit}, ptr};
type Byte = MaybeUninit<u8>;
const unsafe fn memcpy(dst: *mut Byte, src: *const Byte, n: usize) {
let mut i = 0;
while i < n {
dst.add(i).write(src.add(i).read());
i += 1;
}
}
const MEMCPY_RET: MaybeUninit<*const i32> = unsafe { //~ERROR: partial pointer in final value
let ptr = &42;
let mut ptr2 = MaybeUninit::new(ptr::null::<i32>());
memcpy(&mut ptr2 as *mut _ as *mut _, &ptr as *const _ as *const _, mem::size_of::<&i32>() / 2);
// Return in a MaybeUninit so it does not get treated as a scalar.
ptr2
};
fn main() {
assert_eq!(unsafe { MEMCPY_RET.assume_init().read() }, 42);
}