From dff1f9f6bbb4a6a9c86da8d81695fec37054b0fb Mon Sep 17 00:00:00 2001
From: DrMeepster <19316085+DrMeepster@users.noreply.github.com>
Date: Thu, 19 May 2022 17:33:12 -0700
Subject: [PATCH] make sure miri ices when dereferencing a box

---
 compiler/rustc_const_eval/src/interpret/place.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs
index ae7180b674f..3dbcba72baf 100644
--- a/compiler/rustc_const_eval/src/interpret/place.rs
+++ b/compiler/rustc_const_eval/src/interpret/place.rs
@@ -313,6 +313,11 @@ where
     ) -> InterpResult<'tcx, MPlaceTy<'tcx, M::PointerTag>> {
         let val = self.read_immediate(src)?;
         trace!("deref to {} on {:?}", val.layout.ty, *val);
+
+        if val.layout.ty.is_box() {
+            bug!("dereferencing {:?}", val.layout.ty);
+        }
+
         let mplace = self.ref_to_mplace(&val)?;
         self.check_mplace_access(mplace, CheckInAllocMsg::DerefTest)?;
         Ok(mplace)