From 823837922bfc55c715a170fda3aa5823ead2e235 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 25 Aug 2018 11:07:21 +0200
Subject: [PATCH] update for enum discriminant changes

---
 src/intrinsic.rs                                 |  2 +-
 tests/compile-fail/invalid_enum_discriminant.rs  |  5 ++---
 tests/compile-fail/invalid_enum_discriminant2.rs | 16 ++++++++++++++++
 3 files changed, 19 insertions(+), 4 deletions(-)
 create mode 100644 tests/compile-fail/invalid_enum_discriminant2.rs

diff --git a/src/intrinsic.rs b/src/intrinsic.rs
index 62a1938d0fc1..ed8514863c19 100644
--- a/src/intrinsic.rs
+++ b/src/intrinsic.rs
@@ -198,7 +198,7 @@ impl<'a, 'mir, 'tcx> EvalContextExt<'tcx> for EvalContext<'a, 'mir, 'tcx, super:
 
             "discriminant_value" => {
                 let place = self.ref_to_mplace(self.read_value(args[0])?)?;
-                let discr_val = self.read_discriminant_value(place.into())?;
+                let discr_val = self.read_discriminant(place.into())?.0;
                 self.write_scalar(Scalar::from_uint(discr_val, dest.layout.size), dest)?;
             }
 
diff --git a/tests/compile-fail/invalid_enum_discriminant.rs b/tests/compile-fail/invalid_enum_discriminant.rs
index 760b6563d27c..a188623a1e0e 100644
--- a/tests/compile-fail/invalid_enum_discriminant.rs
+++ b/tests/compile-fail/invalid_enum_discriminant.rs
@@ -8,11 +8,10 @@ pub enum Foo {
 
 fn main() {
     let f = unsafe { std::mem::transmute::<i32, Foo>(42) };
-    match f {
+    match f { //~ ERROR invalid enum discriminant
         Foo::A => {},
         Foo::B => {},
         Foo::C => {},
         Foo::D => {},
     }
-} //~ ERROR constant evaluation error
-//~^ NOTE entered unreachable code
+}
diff --git a/tests/compile-fail/invalid_enum_discriminant2.rs b/tests/compile-fail/invalid_enum_discriminant2.rs
new file mode 100644
index 000000000000..5a5a20c48695
--- /dev/null
+++ b/tests/compile-fail/invalid_enum_discriminant2.rs
@@ -0,0 +1,16 @@
+// Validation makes this fail in the wrong place
+// compile-flags: -Zmir-emit-validate=0
+
+// error-pattern: invalid enum discriminant
+
+use std::mem;
+
+#[repr(C)]
+pub enum Foo {
+    A, B, C, D
+}
+
+fn main() {
+    let f = unsafe { std::mem::transmute::<i32, Foo>(42) };
+    let _ = mem::discriminant(&f);
+}