1 files changed, 3 insertions, 0 deletions
diff --git a/src/librustc/hir/mod.rs b/src/librustc/hir/mod.rs
index d0b92587b59..df02b91996f 100644
--- a/src/librustc/hir/mod.rs
+++ b/src/librustc/hir/mod.rs
@@ -2518,6 +2518,9 @@ bitflags! {
         /// `#[used]`: indicates that LLVM can't eliminate this function (but the
         /// linker can!).
         const USED                      = 1 << 9;
+        /// #[ffi_returns_twice], indicates that an extern function can return
+        /// multiple times
+        const FFI_RETURNS_TWICE = 1 << 10;
     }
 }