From c6d69e852edfd2e25d96e8e3f453e2fe9a8896d4 Mon Sep 17 00:00:00 2001
From: Dylan MacKenzie <ecstaticmorse@gmail.com>
Date: Fri, 22 Oct 2021 15:47:36 -0700
Subject: [PATCH] Ignore errors re: unreachable blocks in dataflow cursor unit
 tests

---
 compiler/rustc_mir_dataflow/src/framework/cursor.rs | 7 +++++++
 compiler/rustc_mir_dataflow/src/framework/tests.rs  | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/compiler/rustc_mir_dataflow/src/framework/cursor.rs b/compiler/rustc_mir_dataflow/src/framework/cursor.rs
index c000e49c14bc1..ba6b566a304a5 100644
--- a/compiler/rustc_mir_dataflow/src/framework/cursor.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/cursor.rs
@@ -64,6 +64,13 @@ where
         }
     }
 
+    /// Allows inspection of unreachable basic blocks even with `debug_assertions` enabled.
+    #[cfg(test)]
+    pub(crate) fn allow_unreachable(&mut self) {
+        #[cfg(debug_assertions)]
+        self.reachable_blocks.insert_all()
+    }
+
     /// Returns the underlying `Results`.
     pub fn results(&self) -> &Results<'tcx, A> {
         &self.results.borrow()
diff --git a/compiler/rustc_mir_dataflow/src/framework/tests.rs b/compiler/rustc_mir_dataflow/src/framework/tests.rs
index a5989121679c4..6efa8daec489a 100644
--- a/compiler/rustc_mir_dataflow/src/framework/tests.rs
+++ b/compiler/rustc_mir_dataflow/src/framework/tests.rs
@@ -268,6 +268,8 @@ fn test_cursor<D: Direction>(analysis: MockAnalysis<'tcx, D>) {
     let mut cursor =
         Results { entry_sets: analysis.mock_entry_sets(), analysis }.into_results_cursor(body);
 
+    cursor.allow_unreachable();
+
     let every_target = || {
         body.basic_blocks()
             .iter_enumerated()