From 090b8341bcd1eb7de3d0cbaa71eb2d77924fc4bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20K=C3=A5re=20Alsaker?= <john.kare.alsaker@gmail.com>
Date: Sun, 27 May 2018 07:47:44 +0200
Subject: [PATCH] Add and use OnDrop::disable

---
 src/librustc/ty/maps/job.rs         | 2 +-
 src/librustc_data_structures/lib.rs | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/librustc/ty/maps/job.rs b/src/librustc/ty/maps/job.rs
index 3fe22dba6e15..6b7170f2c476 100644
--- a/src/librustc/ty/maps/job.rs
+++ b/src/librustc/ty/maps/job.rs
@@ -456,5 +456,5 @@ fn deadlock(tcx: TyCtxt<'_, '_, '_>, registry: &rayon_core::Registry) {
         waiter.notify(tcx, registry);
     }
 
-    mem::forget(on_panic);
+    on_panic.disable();
 }
diff --git a/src/librustc_data_structures/lib.rs b/src/librustc_data_structures/lib.rs
index 7046a2a2a493..5844edf000a8 100644
--- a/src/librustc_data_structures/lib.rs
+++ b/src/librustc_data_structures/lib.rs
@@ -80,6 +80,14 @@ pub mod sorted_map;
 
 pub struct OnDrop<F: Fn()>(pub F);
 
+impl<F: Fn()> OnDrop<F> {
+      /// Forgets the function which prevents it from running.
+      /// Ensure that the function owns no memory, otherwise it will be leaked.
+      pub fn disable(self) {
+            std::mem::forget(self);
+      }
+}
+
 impl<F: Fn()> Drop for OnDrop<F> {
       fn drop(&mut self) {
             (self.0)();