diff options
Diffstat (limited to 'compiler/rustc_mir_transform')
| -rw-r--r-- | compiler/rustc_mir_transform/src/add_retag.rs | 26 |
1 files changed, 5 insertions, 21 deletions
diff --git a/compiler/rustc_mir_transform/src/add_retag.rs b/compiler/rustc_mir_transform/src/add_retag.rs index b91ae083cf5..9c5896c4e4a 100644 --- a/compiler/rustc_mir_transform/src/add_retag.rs +++ b/compiler/rustc_mir_transform/src/add_retag.rs @@ -15,22 +15,9 @@ pub struct AddRetag; /// (Concurrent accesses by other threads are no problem as these are anyway non-atomic /// copies. Data races are UB.) fn is_stable(place: PlaceRef<'_>) -> bool { - place.projection.iter().all(|elem| { - match elem { - // Which place this evaluates to can change with any memory write, - // so cannot assume this to be stable. - ProjectionElem::Deref => false, - // Array indices are interesting, but MIR building generates a *fresh* - // temporary for every array access, so the index cannot be changed as - // a side-effect. - ProjectionElem::Index { .. } | - // The rest is completely boring, they just offset by a constant. - ProjectionElem::Field { .. } | - ProjectionElem::ConstantIndex { .. } | - ProjectionElem::Subslice { .. } | - ProjectionElem::Downcast { .. } => true, - } - }) + // Which place this evaluates to can change with any memory write, + // so cannot assume deref to be stable. + !place.has_deref() } /// Determine whether this type may contain a reference (or box), and thus needs retagging. @@ -91,11 +78,8 @@ impl<'tcx> MirPass<'tcx> for AddRetag { }; let place_base_raw = |place: &Place<'tcx>| { // If this is a `Deref`, get the type of what we are deref'ing. - let deref_base = - place.projection.iter().rposition(|p| matches!(p, ProjectionElem::Deref)); - if let Some(deref_base) = deref_base { - let base_proj = &place.projection[..deref_base]; - let ty = Place::ty_from(place.local, base_proj, &*local_decls, tcx).ty; + if place.has_deref() { + let ty = &local_decls[place.local].ty; ty.is_unsafe_ptr() } else { // Not a deref, and thus not raw. |