Index: tools/llvm-demangle-fuzzer/CMakeLists.txt
===================================================================
--- /dev/null
+++ tools/llvm-demangle-fuzzer/CMakeLists.txt
@@ -0,0 +1,6 @@
+set(LLVM_LINK_COMPONENTS
+  Demangle
+)
+add_llvm_fuzzer(llvm-demangle-fuzzer
+  EXCLUDE_FROM_ALL
+  llvm-demangle-fuzzer.cpp)
Index: tools/llvm-demangle-fuzzer/llvm-demangle-fuzzer.cpp
===================================================================
--- /dev/null
+++ tools/llvm-demangle-fuzzer/llvm-demangle-fuzzer.cpp
@@ -0,0 +1,24 @@
+//===--- llvm-demangle-fuzzer.cpp - Fuzzer for the Itanium Demangler ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Demangle/Demangle.h"
+
+#include <cstdint>
+#include <cstdlib>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  int status = 0;
+  char *demangle =
+      llvm::itaniumDemangle((const char *)Data, nullptr, nullptr, &status);
+
+  if (demangle)
+    free(demangle);
+
+  return 0;
+}