diff options
| -rw-r--r-- | compiler/rustc_lint/src/reference_casting.rs | 7 | ||||
| -rw-r--r-- | tests/ui/lint/reference_casting.rs | 8 |
2 files changed, 15 insertions, 0 deletions
diff --git a/compiler/rustc_lint/src/reference_casting.rs b/compiler/rustc_lint/src/reference_casting.rs index 9fed91f7262..63d55a73a98 100644 --- a/compiler/rustc_lint/src/reference_casting.rs +++ b/compiler/rustc_lint/src/reference_casting.rs @@ -199,6 +199,13 @@ fn is_cast_to_bigger_memory_layout<'tcx>( let e_alloc = cx.expr_or_init(e); let e_alloc = if let ExprKind::AddrOf(_, _, inner_expr) = e_alloc.kind { inner_expr } else { e_alloc }; + + // if the current expr looks like this `&mut expr[index]` then just looking + // at `expr[index]` won't give us the underlying allocation, so we just skip it + if let ExprKind::Index(..) = e_alloc.kind { + return None; + } + let alloc_ty = cx.typeck_results().node_type(e_alloc.hir_id); // if we do not find it we bail out, as this may not be UB diff --git a/tests/ui/lint/reference_casting.rs b/tests/ui/lint/reference_casting.rs index d6897ab7b14..3d0c36ca118 100644 --- a/tests/ui/lint/reference_casting.rs +++ b/tests/ui/lint/reference_casting.rs @@ -247,6 +247,14 @@ unsafe fn bigger_layout() { unsafe fn from_ref(this: &i32) -> &i64 { &*(this as *const i32 as *const i64) } + + // https://github.com/rust-lang/rust/issues/124685 + unsafe fn slice_index(array: &mut [u8], offset: usize) { + let a1 = &mut array[offset]; + let a2 = a1 as *mut u8; + let a3 = a2 as *mut u64; + unsafe { *a3 = 3 }; + } } const RAW_PTR: *mut u8 = 1 as *mut u8; |