ptr_offset_unsigned_overflow: extend test

This commit is contained in:
Ralf Jung 2024-09-17 19:22:47 +02:00
parent ba86cf8686
commit 4854ca7411
2 changed files with 6 additions and 5 deletions

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@ -1,7 +1,8 @@
fn main() {
let x = &[0i32; 2];
let x = x.as_ptr().wrapping_add(1);
// If the `!0` is interpreted as `isize`, it is just `-1` and hence harmless.
// However, this is unsigned arithmetic, so really this is `usize::MAX` and hence UB.
unsafe { x.byte_add(!0).read() }; //~ERROR: does not fit in an `isize`
// If `usize::MAX` is interpreted as `isize`, it is just `-1` and hence harmless.
let _ = unsafe { x.byte_offset(usize::MAX as isize) };
// However, `byte_add` uses unsigned arithmetic, so really this is `usize::MAX` and hence UB.
let _ = unsafe { x.byte_add(usize::MAX) }; //~ERROR: does not fit in an `isize`
}

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@ -1,8 +1,8 @@
error: Undefined Behavior: overflowing pointer arithmetic: the total offset in bytes does not fit in an `isize`
--> tests/fail/intrinsics/ptr_offset_unsigned_overflow.rs:LL:CC
|
LL | unsafe { x.byte_add(!0).read() };
| ^^^^^^^^^^^^^^ overflowing pointer arithmetic: the total offset in bytes does not fit in an `isize`
LL | let _ = unsafe { x.byte_add(usize::MAX) };
| ^^^^^^^^^^^^^^^^^^^^^^ overflowing pointer arithmetic: the total offset in bytes does not fit in an `isize`
|
= help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
= help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information