--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/Support/Twine.cpp	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,171 @@
+//===-- Twine.cpp - Fast Temporary String Concatenation -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/Twine.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+std::string Twine::str() const {
+  // If we're storing only a std::string, just return it.
+  if (LHSKind == StdStringKind && RHSKind == EmptyKind)
+    return *LHS.stdString;
+
+  // Otherwise, flatten and copy the contents first.
+  SmallString<256> Vec;
+  return toStringRef(Vec).str();
+}
+
+void Twine::toVector(SmallVectorImpl<char> &Out) const {
+  raw_svector_ostream OS(Out);
+  print(OS);
+}
+
+StringRef Twine::toStringRef(SmallVectorImpl<char> &Out) const {
+  if (isSingleStringRef())
+    return getSingleStringRef();
+  toVector(Out);
+  return StringRef(Out.data(), Out.size());
+}
+
+StringRef Twine::toNullTerminatedStringRef(SmallVectorImpl<char> &Out) const {
+  if (isUnary()) {
+    switch (getLHSKind()) {
+    case CStringKind:
+      // Already null terminated, yay!
+      return StringRef(LHS.cString);
+    case StdStringKind: {
+      const std::string *str = LHS.stdString;
+      return StringRef(str->c_str(), str->size());
+    }
+    default:
+      break;
+    }
+  }
+  toVector(Out);
+  Out.push_back(0);
+  Out.pop_back();
+  return StringRef(Out.data(), Out.size());
+}
+
+void Twine::printOneChild(raw_ostream &OS, Child Ptr,
+                          NodeKind Kind) const {
+  switch (Kind) {
+  case Twine::NullKind: break;
+  case Twine::EmptyKind: break;
+  case Twine::TwineKind:
+    Ptr.twine->print(OS);
+    break;
+  case Twine::CStringKind:
+    OS << Ptr.cString;
+    break;
+  case Twine::StdStringKind:
+    OS << *Ptr.stdString;
+    break;
+  case Twine::StringRefKind:
+    OS << *Ptr.stringRef;
+    break;
+  case Twine::CharKind:
+    OS << Ptr.character;
+    break;
+  case Twine::DecUIKind:
+    OS << Ptr.decUI;
+    break;
+  case Twine::DecIKind:
+    OS << Ptr.decI;
+    break;
+  case Twine::DecULKind:
+    OS << *Ptr.decUL;
+    break;
+  case Twine::DecLKind:
+    OS << *Ptr.decL;
+    break;
+  case Twine::DecULLKind:
+    OS << *Ptr.decULL;
+    break;
+  case Twine::DecLLKind:
+    OS << *Ptr.decLL;
+    break;
+  case Twine::UHexKind:
+    OS.write_hex(*Ptr.uHex);
+    break;
+  }
+}
+
+void Twine::printOneChildRepr(raw_ostream &OS, Child Ptr,
+                              NodeKind Kind) const {
+  switch (Kind) {
+  case Twine::NullKind:
+    OS << "null"; break;
+  case Twine::EmptyKind:
+    OS << "empty"; break;
+  case Twine::TwineKind:
+    OS << "rope:";
+    Ptr.twine->printRepr(OS);
+    break;
+  case Twine::CStringKind:
+    OS << "cstring:\""
+       << Ptr.cString << "\"";
+    break;
+  case Twine::StdStringKind:
+    OS << "std::string:\""
+       << Ptr.stdString << "\"";
+    break;
+  case Twine::StringRefKind:
+    OS << "stringref:\""
+       << Ptr.stringRef << "\"";
+    break;
+  case Twine::CharKind:
+    OS << "char:\"" << Ptr.character << "\"";
+    break;
+  case Twine::DecUIKind:
+    OS << "decUI:\"" << Ptr.decUI << "\"";
+    break;
+  case Twine::DecIKind:
+    OS << "decI:\"" << Ptr.decI << "\"";
+    break;
+  case Twine::DecULKind:
+    OS << "decUL:\"" << *Ptr.decUL << "\"";
+    break;
+  case Twine::DecLKind:
+    OS << "decL:\"" << *Ptr.decL << "\"";
+    break;
+  case Twine::DecULLKind:
+    OS << "decULL:\"" << *Ptr.decULL << "\"";
+    break;
+  case Twine::DecLLKind:
+    OS << "decLL:\"" << *Ptr.decLL << "\"";
+    break;
+  case Twine::UHexKind:
+    OS << "uhex:\"" << Ptr.uHex << "\"";
+    break;
+  }
+}
+
+void Twine::print(raw_ostream &OS) const {
+  printOneChild(OS, LHS, getLHSKind());
+  printOneChild(OS, RHS, getRHSKind());
+}
+
+void Twine::printRepr(raw_ostream &OS) const {
+  OS << "(Twine ";
+  printOneChildRepr(OS, LHS, getLHSKind());
+  OS << " ";
+  printOneChildRepr(OS, RHS, getRHSKind());
+  OS << ")";
+}
+
+void Twine::dump() const {
+  print(llvm::dbgs());
+}
+
+void Twine::dumpRepr() const {
+  printRepr(llvm::dbgs());
+}