From 9797665b286db3f34cc475560a68380012fadde7 Mon Sep 17 00:00:00 2001
From: Evan Simmons <esims89@gmail.com>
Date: Sun, 1 Jul 2018 14:30:16 -0700
Subject: [PATCH] Make Stdio handle UnwindSafe

---
 src/libstd/io/stdio.rs           | 22 ++++++++++++++++++++++
 src/libstd/sys_common/remutex.rs |  4 ++++
 2 files changed, 26 insertions(+)

diff --git a/src/libstd/io/stdio.rs b/src/libstd/io/stdio.rs
index 2472bed5ba435..fce85a200ba2e 100644
--- a/src/libstd/io/stdio.rs
+++ b/src/libstd/io/stdio.rs
@@ -712,9 +712,31 @@ pub fn _eprint(args: fmt::Arguments) {
 
 #[cfg(test)]
 mod tests {
+    use panic::{UnwindSafe, RefUnwindSafe};
     use thread;
     use super::*;
 
+    #[test]
+    fn stdout_unwind_safe() {
+        assert_unwind_safe::<Stdout>();
+    }
+    #[test]
+    fn stdoutlock_unwind_safe() {
+        assert_unwind_safe::<StdoutLock>();
+        assert_unwind_safe::<StdoutLock<'static>>();
+    }
+    #[test]
+    fn stderr_unwind_safe() {
+        assert_unwind_safe::<Stderr>();
+    }
+    #[test]
+    fn stderrlock_unwind_safe() {
+        assert_unwind_safe::<StderrLock>();
+        assert_unwind_safe::<StderrLock<'static>>();
+    }
+
+    fn assert_unwind_safe<T: UnwindSafe + RefUnwindSafe>() {}
+
     #[test]
     #[cfg_attr(target_os = "emscripten", ignore)]
     fn panic_doesnt_poison() {
diff --git a/src/libstd/sys_common/remutex.rs b/src/libstd/sys_common/remutex.rs
index 022056f8a8a70..071a3a25c7acd 100644
--- a/src/libstd/sys_common/remutex.rs
+++ b/src/libstd/sys_common/remutex.rs
@@ -13,6 +13,7 @@ use marker;
 use ops::Deref;
 use sys_common::poison::{self, TryLockError, TryLockResult, LockResult};
 use sys::mutex as sys;
+use panic::{UnwindSafe, RefUnwindSafe};
 
 /// A re-entrant mutual exclusion
 ///
@@ -28,6 +29,9 @@ pub struct ReentrantMutex<T> {
 unsafe impl<T: Send> Send for ReentrantMutex<T> {}
 unsafe impl<T: Send> Sync for ReentrantMutex<T> {}
 
+impl<T> UnwindSafe for ReentrantMutex<T> {}
+impl<T> RefUnwindSafe for ReentrantMutex<T> {}
+
 
 /// An RAII implementation of a "scoped lock" of a mutex. When this structure is
 /// dropped (falls out of scope), the lock will be unlocked.