From a50224804d7bd8c492ecd83c4f2d81d33145ba88 Mon Sep 17 00:00:00 2001
From: varkor <github@varkor.com>
Date: Wed, 15 Aug 2018 16:56:54 +0100
Subject: [PATCH] Make proc_macro Level #[non_exhaustive]

---
 src/libproc_macro/diagnostic.rs | 3 +--
 src/libproc_macro/lib.rs        | 1 +
 src/libproc_macro/rustc.rs      | 1 -
 3 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/libproc_macro/diagnostic.rs b/src/libproc_macro/diagnostic.rs
index 51e7647f36c..af779016418 100644
--- a/src/libproc_macro/diagnostic.rs
+++ b/src/libproc_macro/diagnostic.rs
@@ -16,6 +16,7 @@ use syntax_pos::MultiSpan;
 /// An enum representing a diagnostic level.
 #[unstable(feature = "proc_macro_diagnostic", issue = "38356")]
 #[derive(Copy, Clone, Debug)]
+#[non_exhaustive]
 pub enum Level {
     /// An error.
     Error,
@@ -25,8 +26,6 @@ pub enum Level {
     Note,
     /// A help message.
     Help,
-    #[doc(hidden)]
-    __Nonexhaustive,
 }
 
 /// A structure representing a diagnostic message and associated children
diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs
index fec90008c67..97cf4c14c0c 100644
--- a/src/libproc_macro/lib.rs
+++ b/src/libproc_macro/lib.rs
@@ -36,6 +36,7 @@
 #![feature(staged_api)]
 #![feature(lang_items)]
 #![feature(optin_builtin_traits)]
+#![feature(non_exhaustive)]
 
 #![recursion_limit="256"]
 
diff --git a/src/libproc_macro/rustc.rs b/src/libproc_macro/rustc.rs
index a54c695f637..21229d3299d 100644
--- a/src/libproc_macro/rustc.rs
+++ b/src/libproc_macro/rustc.rs
@@ -278,7 +278,6 @@ impl Level {
             Level::Warning => errors::Level::Warning,
             Level::Note => errors::Level::Note,
             Level::Help => errors::Level::Help,
-            Level::__Nonexhaustive => unreachable!("Level::__Nonexhaustive"),
         }
     }
 }