From b4d045719d77e40f294eb85d8e5cf8143d661718 Mon Sep 17 00:00:00 2001
From: Wesley Wiser <wwiser@gmail.com>
Date: Wed, 24 Jun 2020 08:49:09 -0400
Subject: [PATCH] Use exhaustive match in const_prop.rs

---
 src/librustc_mir/transform/const_prop.rs | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs
index 2c1565b54261c..e4c1ca4e851b0 100644
--- a/src/librustc_mir/transform/const_prop.rs
+++ b/src/librustc_mir/transform/const_prop.rs
@@ -638,8 +638,20 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
 
                 return None;
             }
+            Rvalue::ThreadLocalRef(def_id) => {
+                trace!("skipping ThreadLocalRef({:?})", def_id);
 
-            _ => {}
+                return None;
+            }
+
+            // There's no other checking to do at this time.
+            Rvalue::Aggregate(..)
+            | Rvalue::Use(..)
+            | Rvalue::Repeat(..)
+            | Rvalue::Len(..)
+            | Rvalue::Cast(..)
+            | Rvalue::Discriminant(..)
+            | Rvalue::NullaryOp(..) => {}
         }
 
         // FIXME we need to revisit this for #67176