--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler-rt/test/fuzzer/Reject.cpp	Wed Nov 09 17:45:10 2022 +0900
@@ -0,0 +1,23 @@
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+// Tests how the fuzzer rejects inputs if the target returns -1.
+#include <cstddef>
+#include <cstdint>
+
+static volatile int Sink;
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  if (Size != 3)
+    return -1; // Reject anyting that's not 3 bytes long.
+  // Reject 'rej'.
+  if (Data[0] == 'r' && Data[1] == 'e' && Data[2] == 'j')
+    return -1;
+  // Accept 'acc'.
+  if (Data[0] == 'a' && Data[1] == 'c' && Data[2] == 'c') {
+    Sink = 1;
+    return 0;
+  }
+  return 0;
+}