1 files changed, 59 insertions, 0 deletions
diff --git a/test/fuzzer/CustomCrossOverTest.cpp b/test/fuzzer/CustomCrossOverTest.cpp
new file mode 100644
index 0000000000000..bd9afe774d33c
--- /dev/null
+++ b/test/fuzzer/CustomCrossOverTest.cpp
@@ -0,0 +1,59 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Simple test for a cutom crossover.
+#include <assert.h>
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <iostream>
+#include <ostream>
+#include <random>
+#include <string.h>
+#include <functional>
+
+static const char *Separator = "-########-";
+static const char *Target = "A-########-B";
+
+static volatile int sink;
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  assert(Data);
+  std::string Str(reinterpret_cast<const char *>(Data), Size);
+  static const size_t TargetHash = std::hash<std::string>{}(std::string(Target));
+  size_t StrHash = std::hash<std::string>{}(Str);
+
+  // Ensure we have 'A' and 'B' in the corpus.
+  if (Size == 1 && *Data == 'A')
+    sink++;
+  if (Size == 1 && *Data == 'B')
+    sink--;
+
+  if (TargetHash == StrHash) {
+    std::cout << "BINGO; Found the target, exiting\n" << std::flush;
+    exit(1);
+  }
+  return 0;
+}
+
+extern "C" size_t LLVMFuzzerCustomCrossOver(const uint8_t *Data1, size_t Size1,
+                                            const uint8_t *Data2, size_t Size2,
+                                            uint8_t *Out, size_t MaxOutSize,
+                                            unsigned int Seed) {
+  static size_t Printed;
+  static size_t SeparatorLen = strlen(Separator);
+
+  if (Printed++ < 32)
+    std::cerr << "In LLVMFuzzerCustomCrossover " << Size1 << " " << Size2 << "\n";
+
+  size_t Size = Size1 + Size2 + SeparatorLen;
+
+  if (Size > MaxOutSize)
+    return 0;
+
+  memcpy(Out, Data1, Size1);
+  memcpy(Out + Size1, Separator, SeparatorLen);
+  memcpy(Out + Size1 + SeparatorLen, Data2, Size2);
+
+  return Size;
+}