From 4aa66dbe01758740fe1e716771db9fdfe9a2e07b Mon Sep 17 00:00:00 2001
From: Eduard-Mihai Burtescu <edy.burt@gmail.com>
Date: Thu, 8 Feb 2018 17:15:41 +0200
Subject: [PATCH] rustc: don't ICE when using Rvalue::Discriminant on a
 non-ADT.

---
 src/librustc/mir/tcx.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/librustc/mir/tcx.rs b/src/librustc/mir/tcx.rs
index 53607764b3984..7c6e065d6a31e 100644
--- a/src/librustc/mir/tcx.rs
+++ b/src/librustc/mir/tcx.rs
@@ -182,9 +182,8 @@ impl<'tcx> Rvalue<'tcx> {
                 if let ty::TyAdt(adt_def, _) = ty.sty {
                     adt_def.repr.discr_type().to_ty(tcx)
                 } else {
-                    // Undefined behaviour, bug for now; may want to return something for
-                    // the `discriminant` intrinsic later.
-                    bug!("Rvalue::Discriminant on Place of type {:?}", ty);
+                    // This can only be `0`, for now, so `u8` will suffice.
+                    tcx.types.u8
                 }
             }
             Rvalue::NullaryOp(NullOp::Box, t) => tcx.mk_box(t),