diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs index 10ac7e0d39a..e272c90e0cd 100644 --- a/compiler/rustc_middle/src/mir/mod.rs +++ b/compiler/rustc_middle/src/mir/mod.rs @@ -1640,6 +1640,14 @@ impl<'tcx> PlaceRef<'tcx> { } } + /// Returns `true` if this `Place` contains a `Deref` projection. + /// + /// If `Place::is_indirect` returns false, the caller knows that the `Place` refers to the + /// same region of memory as its base. + pub fn is_indirect(&self) -> bool { + self.projection.iter().any(|elem| elem.is_indirect()) + } + /// If MirPhase >= Derefered and if projection contains Deref, /// It's guaranteed to be in the first place pub fn has_deref(&self) -> bool { diff --git a/compiler/rustc_mir_dataflow/src/value_analysis.rs b/compiler/rustc_mir_dataflow/src/value_analysis.rs index 353b8d801d5..f24280e2187 100644 --- a/compiler/rustc_mir_dataflow/src/value_analysis.rs +++ b/compiler/rustc_mir_dataflow/src/value_analysis.rs @@ -780,6 +780,10 @@ impl Map { tail_elem: Option, f: &mut impl FnMut(PlaceIndex), ) { + if place.is_indirect() { + // We do not track indirect places. + return; + } let Some(&Some(mut index)) = self.locals.get(place.local) else { // The local is not tracked at all, so it does not alias anything. return; @@ -790,6 +794,9 @@ impl Map { .map(|&elem| elem.try_into()) .chain(tail_elem.map(Ok).into_iter()); for elem in elems { + // A field aliases the parent place. + f(index); + let Ok(elem) = elem else { return }; let sub = self.apply(index, elem); if let TrackElem::Variant(..) | TrackElem::Discriminant = elem {