From 09ae438eb095e6e2a94e1516cb962e66bfc6d747 Mon Sep 17 00:00:00 2001
From: Nadrieril <nadrieril+git@gmail.com>
Date: Thu, 8 Aug 2024 10:20:26 +0200
Subject: [PATCH 1/2] Add `Steal::is_stolen()`

---
 compiler/rustc_data_structures/src/steal.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/compiler/rustc_data_structures/src/steal.rs b/compiler/rustc_data_structures/src/steal.rs
index 9a0fd52677d13..f305a8ad12000 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> {

From c966370b1959707be06dd2cbfb1436233fa595a3 Mon Sep 17 00:00:00 2001
From: Nadrieril <Nadrieril@users.noreply.github.com>
Date: Thu, 8 Aug 2024 21:51:50 +0200
Subject: [PATCH 2/2] Tweak wording

Co-authored-by: lcnr <rust@lcnr.de>
---
 compiler/rustc_data_structures/src/steal.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/compiler/rustc_data_structures/src/steal.rs b/compiler/rustc_data_structures/src/steal.rs
index f305a8ad12000..0f2c0eee27d2f 100644
--- a/compiler/rustc_data_structures/src/steal.rs
+++ b/compiler/rustc_data_structures/src/steal.rs
@@ -53,7 +53,10 @@ impl<T> Steal<T> {
     }
 
     /// 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.
+    /// handle these errors gracefully.
+    ///
+    /// This should not be used within rustc as it leaks information not tracked
+    /// by the query system, breaking incremental compilation.
     pub fn is_stolen(&self) -> bool {
         self.value.borrow().is_none()
     }