1 files changed, 25 insertions, 0 deletions
diff --git a/lib/ubsan/lit_tests/Misc/deduplication.cpp b/lib/ubsan/lit_tests/Misc/deduplication.cpp
new file mode 100644
index 000000000000..d9c909f9af4f
--- /dev/null
+++ b/lib/ubsan/lit_tests/Misc/deduplication.cpp
@@ -0,0 +1,25 @@
+// RUN: %clang -fsanitize=undefined %s -o %t && %t 2>&1 | FileCheck %s
+// Verify deduplication works by ensuring only one diag is emitted.
+#include <limits.h>
+#include <stdio.h>
+
+void overflow() {
+  int i = INT_MIN;
+  --i;
+}
+
+int main() {
+  // CHECK: Start
+  fprintf(stderr, "Start\n");
+
+  // CHECK: runtime error
+  // CHECK-NOT: runtime error
+  // CHECK-NOT: runtime error
+  overflow();
+  overflow();
+  overflow();
+
+  // CHECK: End
+  fprintf(stderr, "End\n");
+  return 0;
+}