X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Flibrustc_mir%2Finterpret%2Fplace.rs;h=fff9c740f7e493ab944b1e607380b0dae6d933d5;hb=49c82d117084ad0362fee6fb9a524400c1140ce7;hp=4f96cb698915d25146c45e2bff6d9528bf49e772;hpb=2a201336ed2f253cd22561477764989050acb889;p=rust.git

diff --git a/src/librustc_mir/interpret/place.rs b/src/librustc_mir/interpret/place.rs
index 4f96cb69891..fff9c740f7e 100644
--- a/src/librustc_mir/interpret/place.rs
+++ b/src/librustc_mir/interpret/place.rs
@@ -410,6 +410,14 @@ pub fn mplace_field(
                 stride * field
             }
             layout::FieldPlacement::Union(count) => {
+                // This is a narrow bug-fix for rust-lang/rust#69191: if we are
+                // trying to access absent field of uninhabited variant, then
+                // signal UB (but don't ICE the compiler).
+                // FIXME temporary hack to work around incoherence between
+                // layout computation and MIR building
+                if field >= count as u64 && base.layout.abi == layout::Abi::Uninhabited {
+                    throw_ub!(Unreachable);
+                }
                 assert!(
                     field < count as u64,
                     "Tried to access field {} of union {:#?} with {} fields",
@@ -647,7 +655,7 @@ pub fn eval_place(
             }
             local => PlaceTy {
                 // This works even for dead/uninitialized locals; we check further when writing
-                place: Place::Local { frame: self.cur_frame(), local: local },
+                place: Place::Local { frame: self.cur_frame(), local },
                 layout: self.layout_of_local(self.frame(), local, None)?,
             },
         };