--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/lib/Driver/InputInfo.h	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,107 @@
+//===--- InputInfo.h - Input Source & Type Information ----------*- 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_CLANG_LIB_DRIVER_INPUTINFO_H
+#define LLVM_CLANG_LIB_DRIVER_INPUTINFO_H
+
+#include "clang/Driver/Action.h"
+#include "clang/Driver/Types.h"
+#include "llvm/Option/Arg.h"
+#include <cassert>
+#include <string>
+
+namespace clang {
+namespace driver {
+
+/// InputInfo - Wrapper for information about an input source.
+class InputInfo {
+  // FIXME: The distinction between filenames and inputarg here is
+  // gross; we should probably drop the idea of a "linker
+  // input". Doing so means tweaking pipelining to still create link
+  // steps when it sees linker inputs (but not treat them as
+  // arguments), and making sure that arguments get rendered
+  // correctly.
+  enum Class {
+    Nothing,
+    Filename,
+    InputArg,
+    Pipe
+  };
+
+  union {
+    const char *Filename;
+    const llvm::opt::Arg *InputArg;
+  } Data;
+  Class Kind;
+  const Action* Act;
+  types::ID Type;
+  const char *BaseInput;
+
+  static types::ID GetActionType(const Action *A) {
+    return A != nullptr ? A->getType() : types::TY_Nothing;
+  }
+
+public:
+  InputInfo() : InputInfo(nullptr, nullptr) {}
+  InputInfo(const Action *A, const char *_BaseInput)
+      : Kind(Nothing), Act(A), Type(GetActionType(A)), BaseInput(_BaseInput) {}
+
+  InputInfo(types::ID _Type, const char *_Filename, const char *_BaseInput)
+      : Kind(Filename), Act(nullptr), Type(_Type), BaseInput(_BaseInput) {
+    Data.Filename = _Filename;
+  }
+  InputInfo(const Action *A, const char *_Filename, const char *_BaseInput)
+      : Kind(Filename), Act(A), Type(GetActionType(A)), BaseInput(_BaseInput) {
+    Data.Filename = _Filename;
+  }
+
+  InputInfo(types::ID _Type, const llvm::opt::Arg *_InputArg,
+            const char *_BaseInput)
+      : Kind(InputArg), Act(nullptr), Type(_Type), BaseInput(_BaseInput) {
+    Data.InputArg = _InputArg;
+  }
+  InputInfo(const Action *A, const llvm::opt::Arg *_InputArg,
+            const char *_BaseInput)
+      : Kind(InputArg), Act(A), Type(GetActionType(A)), BaseInput(_BaseInput) {
+    Data.InputArg = _InputArg;
+  }
+
+  bool isNothing() const { return Kind == Nothing; }
+  bool isFilename() const { return Kind == Filename; }
+  bool isInputArg() const { return Kind == InputArg; }
+  types::ID getType() const { return Type; }
+  const char *getBaseInput() const { return BaseInput; }
+  /// The action for which this InputInfo was created.  May be null.
+  const Action *getAction() const { return Act; }
+  void setAction(const Action *A) { Act = A; }
+
+  const char *getFilename() const {
+    assert(isFilename() && "Invalid accessor.");
+    return Data.Filename;
+  }
+  const llvm::opt::Arg &getInputArg() const {
+    assert(isInputArg() && "Invalid accessor.");
+    return *Data.InputArg;
+  }
+
+  /// getAsString - Return a string name for this input, for
+  /// debugging.
+  std::string getAsString() const {
+    if (isFilename())
+      return std::string("\"") + getFilename() + '"';
+    else if (isInputArg())
+      return "(input arg)";
+    else
+      return "(nothing)";
+  }
+};
+
+} // end namespace driver
+} // end namespace clang
+
+#endif