--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libsanitizer/sanitizer_common/sanitizer_getauxval.h	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,59 @@
+//===-- sanitizer_getauxval.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
+//
+//===----------------------------------------------------------------------===//
+//
+// Common getauxval() guards and definitions.
+// getauxval() is not defined until glibc version 2.16, or until API level 21
+// for Android.
+// Implement the getauxval() compat function for NetBSD.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_GETAUXVAL_H
+#define SANITIZER_GETAUXVAL_H
+
+#include "sanitizer_platform.h"
+#include "sanitizer_glibc_version.h"
+
+#if SANITIZER_LINUX || SANITIZER_FUCHSIA
+
+# if __GLIBC_PREREQ(2, 16) || (SANITIZER_ANDROID && __ANDROID_API__ >= 21) || \
+     SANITIZER_FUCHSIA
+#  define SANITIZER_USE_GETAUXVAL 1
+# else
+#  define SANITIZER_USE_GETAUXVAL 0
+# endif
+
+# if SANITIZER_USE_GETAUXVAL
+#  include <sys/auxv.h>
+# else
+// The weak getauxval definition allows to check for the function at runtime.
+// This is useful for Android, when compiled at a lower API level yet running
+// on a more recent platform that offers the function.
+extern "C" SANITIZER_WEAK_ATTRIBUTE unsigned long getauxval(unsigned long type);
+# endif
+
+#elif SANITIZER_NETBSD
+
+#define SANITIZER_USE_GETAUXVAL 1
+
+#include <dlfcn.h>
+#include <elf.h>
+
+static inline decltype(AuxInfo::a_v) getauxval(decltype(AuxInfo::a_type) type) {
+  for (const AuxInfo *aux = (const AuxInfo *)_dlauxinfo();
+       aux->a_type != AT_NULL; ++aux) {
+    if (type == aux->a_type)
+      return aux->a_v;
+  }
+
+  return 0;
+}
+
+#endif
+
+#endif // SANITIZER_GETAUXVAL_H