diff --git a/clang/lib/Basic/ConvertUTFWrapper.cpp b/clang/lib/Basic/ConvertUTFWrapper.cpp
new file mode 100644
index 0000000..42b4f58
--- /dev/null
+++ b/clang/lib/Basic/ConvertUTFWrapper.cpp
@@ -0,0 +1,54 @@
+//===-- ConvertUTFWrapper.cpp - Wrap ConvertUTF.h with clang data types -----===
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/ConvertUTF.h"
+#include "clang/Basic/LLVM.h"
+
+namespace clang {
+
+bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source,
+                       char *&ResultPtr) {
+  assert(WideCharWidth == 1 || WideCharWidth == 2 || WideCharWidth == 4);
+  ConversionResult result = conversionOK;
+  // Copy the character span over.
+  if (WideCharWidth == 1) {
+    if (!isLegalUTF8String(reinterpret_cast<const UTF8*>(Source.begin()),
+                           reinterpret_cast<const UTF8*>(Source.end())))
+      result = sourceIllegal;
+    memcpy(ResultPtr, Source.data(), Source.size());
+    ResultPtr += Source.size();
+  } else if (WideCharWidth == 2) {
+    const UTF8 *sourceStart = (const UTF8*)Source.data();
+    // FIXME: Make the type of the result buffer correct instead of
+    // using reinterpret_cast.
+    UTF16 *targetStart = reinterpret_cast<UTF16*>(ResultPtr);
+    ConversionFlags flags = strictConversion;
+    result = ConvertUTF8toUTF16(
+        &sourceStart, sourceStart + Source.size(),
+        &targetStart, targetStart + 2*Source.size(), flags);
+    if (result == conversionOK)
+      ResultPtr = reinterpret_cast<char*>(targetStart);
+  } else if (WideCharWidth == 4) {
+    const UTF8 *sourceStart = (const UTF8*)Source.data();
+    // FIXME: Make the type of the result buffer correct instead of
+    // using reinterpret_cast.
+    UTF32 *targetStart = reinterpret_cast<UTF32*>(ResultPtr);
+    ConversionFlags flags = strictConversion;
+    result = ConvertUTF8toUTF32(
+        &sourceStart, sourceStart + Source.size(),
+        &targetStart, targetStart + 4*Source.size(), flags);
+    if (result == conversionOK)
+      ResultPtr = reinterpret_cast<char*>(targetStart);
+  }
+  assert((result != targetExhausted)
+         && "ConvertUTF8toUTFXX exhausted target buffer");
+  return result == conversionOK;
+}
+
+}