diff options
| -rw-r--r-- | clippy_lints/src/transmute.rs | 10 | ||||
| -rw-r--r-- | tests/ui/transmutes_expressible_as_ptr_casts.rs | 11 |
2 files changed, 19 insertions, 2 deletions
diff --git a/clippy_lints/src/transmute.rs b/clippy_lints/src/transmute.rs index ea14f2829ea..231f13b236c 100644 --- a/clippy_lints/src/transmute.rs +++ b/clippy_lints/src/transmute.rs @@ -694,7 +694,10 @@ fn is_layout_incompatible<'tcx>(cx: &LateContext<'tcx>, from: Ty<'tcx>, to: Ty<' } } -/// Check if the the type conversion can be expressed as a pointer cast, instead of a transmute. +/// Check if the the type conversion can be expressed as a pointer cast, instead of +/// a transmute. In certain cases, including some invalid casts from array +/// references to pointers, this may cause additional errors to be emitted and/or +/// ICE error messages. fn can_be_expressed_as_pointer_cast<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) -> bool { use CastKind::*; matches!( @@ -710,7 +713,10 @@ fn can_be_expressed_as_pointer_cast<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr< ) } -/// If a cast from from_ty to to_ty is valid, returns an Ok containing the kind of the cast. +/// If a cast from from_ty to to_ty is valid, returns an Ok containing the kind of +/// the cast. In certain cases, including some invalid casts from array references +/// to pointers, this may cause additional errors to be emitted and/or ICE error +/// messages. fn check_cast<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'_>, from_ty: Ty<'tcx>, to_ty: Ty<'tcx>) -> Option<CastKind> { let hir_id = e.hir_id; let local_def_id = hir_id.owner; diff --git a/tests/ui/transmutes_expressible_as_ptr_casts.rs b/tests/ui/transmutes_expressible_as_ptr_casts.rs index db544b438a2..007526da40d 100644 --- a/tests/ui/transmutes_expressible_as_ptr_casts.rs +++ b/tests/ui/transmutes_expressible_as_ptr_casts.rs @@ -63,3 +63,14 @@ fn main() { }; let usize_from_fn_ptr = foo as *const usize; } + +// If a ref-to-ptr cast of this form where the pointer type points to a type other +// than the referenced type, calling `CastCheck::do_check` has been observed to +// cause an ICE error message. `do_check` is currently called inside the +// `transmutes_expressible_as_ptr_casts` check, but other, more specific lints +// currently prevent it from being called in these cases. This test is meant to +// fail if the ordering of the checks ever changes enough to cause these cases to +// fall through into `do_check`. +fn trigger_do_check_to_emit_error(in_param: &[i32; 1]) -> *const u8 { + unsafe { transmute::<&[i32; 1], *const u8>(in_param) } +} \ No newline at end of file |