From e37d0e312596c06659b881c240a5afdd58395665 Mon Sep 17 00:00:00 2001
From: David Cook <divergentdave@gmail.com>
Date: Tue, 21 Apr 2020 21:28:22 -0500
Subject: [PATCH] Print hex dump of alloc on reading undef bytes

---
 src/diagnostics.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/diagnostics.rs b/src/diagnostics.rs
index 5189982b136..77aaacea024 100644
--- a/src/diagnostics.rs
+++ b/src/diagnostics.rs
@@ -114,6 +114,9 @@ pub fn report_error<'tcx, 'mir>(
     };
 
     e.print_backtrace();
+    if let UndefinedBehavior(UndefinedBehaviorInfo::InvalidUndefBytes(Some(ptr))) = e.kind {
+        ecx.memory.dump_alloc(ptr.alloc_id);
+    }
     let msg = e.to_string();
     report_msg(ecx, &format!("{}: {}", title, msg), msg, helps, true)
 }