--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/llvm-objcopy/llvm-objcopy.h	Mon May 25 11:07:02 2020 +0900
@@ -0,0 +1,42 @@
+//===- llvm-objcopy.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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_OBJCOPY_OBJCOPY_H
+#define LLVM_TOOLS_OBJCOPY_OBJCOPY_H
+
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+
+namespace llvm {
+namespace objcopy {
+
+LLVM_ATTRIBUTE_NORETURN extern void error(Twine Message);
+LLVM_ATTRIBUTE_NORETURN extern void error(Error E);
+LLVM_ATTRIBUTE_NORETURN extern void reportError(StringRef File, Error E);
+LLVM_ATTRIBUTE_NORETURN extern void reportError(StringRef File,
+                                                std::error_code EC);
+
+// This is taken from llvm-readobj.
+// [see here](llvm/tools/llvm-readobj/llvm-readobj.h:38)
+template <class T> T unwrapOrError(Expected<T> EO) {
+  if (EO)
+    return *EO;
+  std::string Buf;
+  raw_string_ostream OS(Buf);
+  logAllUnhandledErrors(EO.takeError(), OS);
+  OS.flush();
+  error(Buf);
+}
+
+} // end namespace objcopy
+} // end namespace llvm
+
+#endif // LLVM_TOOLS_OBJCOPY_OBJCOPY_H