From 946fb894a667bf256936e356a80d36fe50341005 Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Wed, 27 Feb 2019 17:21:31 -0700
Subject: [PATCH] Permit unwinding through FFI by default

See #58794 for context.
---
 src/librustc_mir/build/mod.rs | 2 +-
 src/test/ui/abort-on-c-abi.rs | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/librustc_mir/build/mod.rs b/src/librustc_mir/build/mod.rs
index 4e970aee42cf4..6a3bb8b8b86a2 100644
--- a/src/librustc_mir/build/mod.rs
+++ b/src/librustc_mir/build/mod.rs
@@ -502,7 +502,7 @@ fn should_abort_on_panic(tcx: TyCtxt<'_>, fn_def_id: DefId, abi: Abi) -> bool {
     // This is a special case: some functions have a C abi but are meant to
     // unwind anyway. Don't stop them.
     match unwind_attr {
-        None => true,
+        None => false, // FIXME(#58794)
         Some(UnwindAttr::Allowed) => false,
         Some(UnwindAttr::Aborts) => true,
     }
diff --git a/src/test/ui/abort-on-c-abi.rs b/src/test/ui/abort-on-c-abi.rs
index cd7dd1b6a452f..2f08730ec6132 100644
--- a/src/test/ui/abort-on-c-abi.rs
+++ b/src/test/ui/abort-on-c-abi.rs
@@ -1,6 +1,7 @@
 // run-pass
 
 #![allow(unused_must_use)]
+#![feature(unwind_attributes)]
 // Since we mark some ABIs as "nounwind" to LLVM, we must make sure that
 // we never unwind through them.
 
@@ -13,6 +14,7 @@ use std::io::prelude::*;
 use std::io;
 use std::process::{Command, Stdio};
 
+#[unwind(aborts)] // FIXME(#58794)
 extern "C" fn panic_in_ffi() {
     panic!("Test");
 }