Add `Steal::is_stolen()`

1 files changed, 6 insertions, 0 deletions

diff --git a/compiler/rustc_data_structures/src/steal.rs b/compiler/rustc_data_structures/src/steal.rs
index 9a0fd52677d..f305a8ad120 100644
--- a/compiler/rustc_data_structures/src/steal.rs
+++ b/compiler/rustc_data_structures/src/steal.rs
@@ -51,6 +51,12 @@ impl<T> Steal<T> {
         let value = value_ref.take();
         value.expect("attempt to steal from stolen value")
     }
+
+    /// Writers of rustc drivers often encounter stealing issues. This function makes it possible to
+    /// handle these errors gracefully. This is not used within rustc as the time of writing.
+    pub fn is_stolen(&self) -> bool {
+        self.value.borrow().is_none()
+    }
 }
 
 impl<CTX, T: HashStable<CTX>> HashStable<CTX> for Steal<T> {