Index: compiler-rt/trunk/include/CMakeLists.txt
===================================================================
--- compiler-rt/trunk/include/CMakeLists.txt
+++ compiler-rt/trunk/include/CMakeLists.txt
@@ -13,6 +13,7 @@
     sanitizer/scudo_interface.h
     sanitizer/tsan_interface.h
     sanitizer/tsan_interface_atomic.h
+    sanitizer/ubsan_interface.h
     )
   set(FUZZER_HEADERS
     fuzzer/FuzzedDataProvider.h
Index: compiler-rt/trunk/include/sanitizer/ubsan_interface.h
===================================================================
--- compiler-rt/trunk/include/sanitizer/ubsan_interface.h
+++ compiler-rt/trunk/include/sanitizer/ubsan_interface.h
@@ -0,0 +1,32 @@
+//===-- sanitizer/ubsan_interface.h -----------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of UBSanitizer (UBSan).
+//
+// Public interface header.
+//===----------------------------------------------------------------------===//
+#ifndef SANITIZER_UBSAN_INTERFACE_H
+#define SANITIZER_UBSAN_INTERFACE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+/// User-provided default option settings.
+///
+/// You can provide your own implementation of this function to return a string
+/// containing UBSan runtime options (for example,
+/// <c>verbosity=1:halt_on_error=0</c>).
+///
+/// \returns Default options string.
+const char* __ubsan_default_options(void);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // SANITIZER_UBSAN_INTERFACE_H