diff --git a/tools/libclang/CIndexDiagnostic.cpp b/tools/libclang/CIndexDiagnostic.cpp
index 26f69b0..1beb993 100644
--- a/tools/libclang/CIndexDiagnostic.cpp
+++ b/tools/libclang/CIndexDiagnostic.cpp
@@ -48,8 +48,7 @@
 }
 
 void clang_disposeDiagnostic(CXDiagnostic Diagnostic) {
-  CXStoredDiagnostic *Stored = static_cast<CXStoredDiagnostic *>(Diagnostic);
-  delete Stored;
+  delete static_cast<CXDiagnosticImpl *>(Diagnostic);
 }
 
 CXString clang_formatDiagnostic(CXDiagnostic Diagnostic, unsigned Options) {
@@ -177,76 +176,37 @@
 }
 
 enum CXDiagnosticSeverity clang_getDiagnosticSeverity(CXDiagnostic Diag) {
-  CXStoredDiagnostic *StoredDiag = static_cast<CXStoredDiagnostic *>(Diag);
-  if (!StoredDiag)
-    return CXDiagnostic_Ignored;
-
-  switch (StoredDiag->Diag.getLevel()) {
-  case DiagnosticsEngine::Ignored: return CXDiagnostic_Ignored;
-  case DiagnosticsEngine::Note:    return CXDiagnostic_Note;
-  case DiagnosticsEngine::Warning: return CXDiagnostic_Warning;
-  case DiagnosticsEngine::Error:   return CXDiagnostic_Error;
-  case DiagnosticsEngine::Fatal:   return CXDiagnostic_Fatal;
-  }
-
-  llvm_unreachable("Invalid diagnostic level");
+  if (CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl*>(Diag))
+    return D->getSeverity();
   return CXDiagnostic_Ignored;
 }
 
 CXSourceLocation clang_getDiagnosticLocation(CXDiagnostic Diag) {
-  CXStoredDiagnostic *StoredDiag = static_cast<CXStoredDiagnostic *>(Diag);
-  if (!StoredDiag || StoredDiag->Diag.getLocation().isInvalid())
-    return clang_getNullLocation();
-
-  return translateSourceLocation(StoredDiag->Diag.getLocation().getManager(),
-                                 StoredDiag->LangOpts,
-                                 StoredDiag->Diag.getLocation());
+  if (CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl*>(Diag))
+    return D->getLocation();
+  return clang_getNullLocation();
 }
 
 CXString clang_getDiagnosticSpelling(CXDiagnostic Diag) {
-  CXStoredDiagnostic *StoredDiag = static_cast<CXStoredDiagnostic *>(Diag);
-  if (!StoredDiag)
-    return createCXString("");
-
-  return createCXString(StoredDiag->Diag.getMessage(), false);
+  if (CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl *>(Diag))
+    return D->getSpelling();
+  return createCXString("");
 }
 
 CXString clang_getDiagnosticOption(CXDiagnostic Diag, CXString *Disable) {
   if (Disable)
     *Disable = createCXString("");
-  
-  CXStoredDiagnostic *StoredDiag = static_cast<CXStoredDiagnostic *>(Diag);
-  if (!StoredDiag)
-    return createCXString("");
-  
-  unsigned ID = StoredDiag->Diag.getID();
-  StringRef Option = DiagnosticIDs::getWarningOptionForDiag(ID);
-  if (!Option.empty()) {
-    if (Disable)
-      *Disable = createCXString((Twine("-Wno-") + Option).str());
-    return createCXString((Twine("-W") + Option).str());
-  }
-  
-  if (ID == diag::fatal_too_many_errors) {
-    if (Disable)
-      *Disable = createCXString("-ferror-limit=0");
-    return createCXString("-ferror-limit=");
-  }
-  
-  bool EnabledByDefault;
-  if (DiagnosticIDs::isBuiltinExtensionDiag(ID, EnabledByDefault) &&
-      !EnabledByDefault)
-    return createCXString("-pedantic");
+
+  if (CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl *>(Diag))
+    return D->getDiagnosticOption(Disable);
 
   return createCXString("");
 }
 
 unsigned clang_getDiagnosticCategory(CXDiagnostic Diag) {
-  CXStoredDiagnostic *StoredDiag = static_cast<CXStoredDiagnostic *>(Diag);
-  if (!StoredDiag)
-    return 0;
-
-  return DiagnosticIDs::getCategoryNumberForDiag(StoredDiag->Diag.getID());
+  if (CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl *>(Diag))
+    return D->getCategory();
+  return 0;
 }
   
 CXString clang_getDiagnosticCategoryName(unsigned Category) {
@@ -254,56 +214,33 @@
 }
   
 unsigned clang_getDiagnosticNumRanges(CXDiagnostic Diag) {
-  CXStoredDiagnostic *StoredDiag = static_cast<CXStoredDiagnostic *>(Diag);
-  if (!StoredDiag || StoredDiag->Diag.getLocation().isInvalid())
-    return 0;
-
-  return StoredDiag->Diag.range_size();
+  if (CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl *>(Diag))
+    return D->getNumRanges();
+  return 0;
 }
 
 CXSourceRange clang_getDiagnosticRange(CXDiagnostic Diag, unsigned Range) {
-  CXStoredDiagnostic *StoredDiag = static_cast<CXStoredDiagnostic *>(Diag);
-  if (!StoredDiag || Range >= StoredDiag->Diag.range_size() ||
-      StoredDiag->Diag.getLocation().isInvalid())
+  CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl *>(Diag);  
+  if (!D || Range >= D->getNumRanges())
     return clang_getNullRange();
-
-  return translateSourceRange(StoredDiag->Diag.getLocation().getManager(),
-                              StoredDiag->LangOpts,
-                              StoredDiag->Diag.range_begin()[Range]);
+  return D->getRange(Range);
 }
 
 unsigned clang_getDiagnosticNumFixIts(CXDiagnostic Diag) {
-  CXStoredDiagnostic *StoredDiag = static_cast<CXStoredDiagnostic *>(Diag);
-  if (!StoredDiag)
-    return 0;
-
-  return StoredDiag->Diag.fixit_size();
+  if (CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl *>(Diag))
+    return D->getNumFixIts();
+  return 0;
 }
 
-CXString clang_getDiagnosticFixIt(CXDiagnostic Diagnostic, unsigned FixIt,
+CXString clang_getDiagnosticFixIt(CXDiagnostic Diag, unsigned FixIt,
                                   CXSourceRange *ReplacementRange) {
-  CXStoredDiagnostic *StoredDiag
-    = static_cast<CXStoredDiagnostic *>(Diagnostic);
-  if (!StoredDiag || FixIt >= StoredDiag->Diag.fixit_size() ||
-      StoredDiag->Diag.getLocation().isInvalid()) {
+  CXDiagnosticImpl *D = static_cast<CXDiagnosticImpl *>(Diag);
+  if (!D || FixIt >= D->getNumFixIts()) {
     if (ReplacementRange)
       *ReplacementRange = clang_getNullRange();
-
     return createCXString("");
   }
-
-  const FixItHint &Hint = StoredDiag->Diag.fixit_begin()[FixIt];
-  if (ReplacementRange) {
-    // Create a range that covers the entire replacement (or
-    // removal) range, adjusting the end of the range to point to
-    // the end of the token.
-    *ReplacementRange
-        = translateSourceRange(StoredDiag->Diag.getLocation().getManager(),
-                                StoredDiag->LangOpts,
-                                Hint.RemoveRange);
-  }
-
-  return createCXString(Hint.CodeToInsert);
+  return D->getFixIt(FixIt, ReplacementRange);
 }
 
 } // end extern "C"
diff --git a/tools/libclang/CIndexDiagnostic.h b/tools/libclang/CIndexDiagnostic.h
index 0d935fa..07b6b15 100644
--- a/tools/libclang/CIndexDiagnostic.h
+++ b/tools/libclang/CIndexDiagnostic.h
@@ -13,19 +13,99 @@
 #ifndef LLVM_CLANG_CINDEX_DIAGNOSTIC_H
 #define LLVM_CLANG_CINDEX_DIAGNOSTIC_H
 
+#include "clang-c/Index.h"
+
 namespace clang {
 
 class LangOptions;
 class StoredDiagnostic;
 
+class CXDiagnosticImpl {
+public:
+  enum Kind { StoredDiagnosticKind, SerializedDiagnosticKind };
+  
+  virtual ~CXDiagnosticImpl();
+  
+  /// \brief Return the severity of the diagnostic.
+  virtual CXDiagnosticSeverity getSeverity() const = 0;
+  
+  /// \brief Return the location of the diagnostic.
+  virtual CXSourceLocation getLocation() const = 0;
+
+  /// \brief Return the spelling of the diagnostic.
+  virtual CXString getSpelling() const = 0;
+
+  /// \brief Return the text for the diagnostic option.
+  virtual CXString getDiagnosticOption(CXString *Disable) const = 0;
+  
+  /// \brief Return the category of the diagnostic.
+  virtual unsigned getCategory() const = 0;
+  
+  /// \brief Return the number of source ranges for the diagnostic.
+  virtual unsigned getNumRanges() const = 0;
+  
+  /// \brief Return the source ranges for the diagnostic.
+  virtual CXSourceRange getRange(unsigned Range) const = 0;
+
+  /// \brief Return the number of FixIts.
+  virtual unsigned getNumFixIts() const = 0;
+
+  /// \brief Return the FixIt information (source range and inserted text).
+  virtual CXString getFixIt(unsigned FixIt,
+                            CXSourceRange *ReplacementRange) const = 0;
+
+  Kind getKind() const { return K; }
+
+protected:
+  CXDiagnosticImpl(Kind k) : K(k) {}
+  
+private:
+  Kind K;
+};
+  
 /// \brief The storage behind a CXDiagnostic
-struct CXStoredDiagnostic {
+struct CXStoredDiagnostic : public CXDiagnosticImpl {
   const StoredDiagnostic &Diag;
   const LangOptions &LangOpts;
   
   CXStoredDiagnostic(const StoredDiagnostic &Diag,
                      const LangOptions &LangOpts)
-    : Diag(Diag), LangOpts(LangOpts) { }
+    : CXDiagnosticImpl(StoredDiagnosticKind),
+      Diag(Diag), LangOpts(LangOpts) { }
+  
+  virtual ~CXStoredDiagnostic() {}
+  
+  /// \brief Return the severity of the diagnostic.
+  virtual CXDiagnosticSeverity getSeverity() const;
+  
+  /// \brief Return the location of the diagnostic.
+  virtual CXSourceLocation getLocation() const;
+
+  /// \brief Return the spelling of the diagnostic.
+  virtual CXString getSpelling() const;
+
+  /// \brief Return the text for the diagnostic option.
+  virtual CXString getDiagnosticOption(CXString *Disable) const;
+  
+  /// \brief Return the category of the diagnostic.
+  virtual unsigned getCategory() const;
+  
+  /// \brief Return the number of source ranges for the diagnostic.
+  virtual unsigned getNumRanges() const;
+  
+  /// \brief Return the source ranges for the diagnostic.
+  virtual CXSourceRange getRange(unsigned Range) const;
+
+  /// \brief Return the number of FixIts.
+  virtual unsigned getNumFixIts() const;
+
+  /// \brief Return the FixIt information (source range and inserted text).
+  virtual CXString getFixIt(unsigned FixIt,
+                            CXSourceRange *ReplacementRange) const;
+
+  static bool classof(const CXDiagnosticImpl *D) {
+    return D->getKind() == StoredDiagnosticKind;
+  }
 };
 
 } // end namespace clang
diff --git a/tools/libclang/CMakeLists.txt b/tools/libclang/CMakeLists.txt
index 00b4692..6f62d23 100644
--- a/tools/libclang/CMakeLists.txt
+++ b/tools/libclang/CMakeLists.txt
@@ -21,18 +21,28 @@
   CIndexCXX.cpp
   CIndexCodeCompletion.cpp
   CIndexDiagnostic.cpp
+  CIndexDiagnostic.h
   CIndexHigh.cpp
   CIndexInclusionStack.cpp
   CIndexUSRs.cpp
   CIndexer.cpp
+  CIndexer.h
   CXCursor.cpp
+  CXCursor.h
+  CXSourceLocation.h
+  CXStoredDiagnostic.cpp
   CXString.cpp
+  CXString.h
+  CXTranslationUnit.h
   CXType.cpp
+  CXType.h
   IndexBody.cpp
   IndexDecl.cpp
   IndexTypeSourceInfo.cpp
+  Index_Internal.h
   Indexing.cpp
   IndexingContext.cpp
+  IndexingContext.h
   ../../include/clang-c/Index.h
   )
 
diff --git a/tools/libclang/CXStoredDiagnostic.cpp b/tools/libclang/CXStoredDiagnostic.cpp
new file mode 100644
index 0000000..117e539
--- /dev/null
+++ b/tools/libclang/CXStoredDiagnostic.cpp
@@ -0,0 +1,118 @@
+/*===-- CXStoreDiagnostic.cpp - Diagnostics C Interface ----------*- C++ -*-===*\
+|*                                                                            *|
+|*                     The LLVM Compiler Infrastructure                       *|
+|*                                                                            *|
+|* This file is distributed under the University of Illinois Open Source      *|
+|* License. See LICENSE.TXT for details.                                      *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*|
+|*                                                                            *|
+|* Implements part of the diagnostic functions of the Clang C interface.      *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+#include "CIndexDiagnostic.h"
+#include "CIndexer.h"
+#include "CXTranslationUnit.h"
+#include "CXSourceLocation.h"
+#include "CXString.h"
+
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Frontend/FrontendDiagnostic.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+using namespace clang::cxloc;
+using namespace clang::cxstring;
+
+// Needed for vtable of CXPersisetntDiagnostic.
+CXDiagnosticImpl::~CXDiagnosticImpl() {}
+
+CXDiagnosticSeverity CXStoredDiagnostic::getSeverity() const {
+  switch (Diag.getLevel()) {
+    case DiagnosticsEngine::Ignored: return CXDiagnostic_Ignored;
+    case DiagnosticsEngine::Note:    return CXDiagnostic_Note;
+    case DiagnosticsEngine::Warning: return CXDiagnostic_Warning;
+    case DiagnosticsEngine::Error:   return CXDiagnostic_Error;
+    case DiagnosticsEngine::Fatal:   return CXDiagnostic_Fatal;
+  }
+  
+  llvm_unreachable("Invalid diagnostic level");
+  return CXDiagnostic_Ignored;
+}
+
+CXSourceLocation CXStoredDiagnostic::getLocation() const {
+  if (Diag.getLocation().isInvalid())
+    return clang_getNullLocation();
+  
+  return translateSourceLocation(Diag.getLocation().getManager(),
+                                 LangOpts, Diag.getLocation());
+}
+
+CXString CXStoredDiagnostic::getSpelling() const {
+  return createCXString(Diag.getMessage(), false);
+}
+
+CXString CXStoredDiagnostic::getDiagnosticOption(CXString *Disable) const {
+  unsigned ID = Diag.getID();
+  StringRef Option = DiagnosticIDs::getWarningOptionForDiag(ID);
+  if (!Option.empty()) {
+    if (Disable)
+      *Disable = createCXString((Twine("-Wno-") + Option).str());
+    return createCXString((Twine("-W") + Option).str());
+  }
+  
+  if (ID == diag::fatal_too_many_errors) {
+    if (Disable)
+      *Disable = createCXString("-ferror-limit=0");
+    return createCXString("-ferror-limit=");
+  }
+  
+  bool EnabledByDefault;
+  if (DiagnosticIDs::isBuiltinExtensionDiag(ID, EnabledByDefault) &&
+      !EnabledByDefault)
+    return createCXString("-pedantic");
+
+  return createCXString("");  
+}
+
+unsigned CXStoredDiagnostic::getCategory() const {
+  return DiagnosticIDs::getCategoryNumberForDiag(Diag.getID());
+}
+
+unsigned CXStoredDiagnostic::getNumRanges() const {
+  if (Diag.getLocation().isInvalid())
+    return 0;
+  
+  return Diag.range_size();
+}
+
+CXSourceRange CXStoredDiagnostic::getRange(unsigned int Range) const {
+  assert(Diag.getLocation().isValid());
+  return translateSourceRange(Diag.getLocation().getManager(),
+                              LangOpts,
+                              Diag.range_begin()[Range]);
+}
+
+unsigned CXStoredDiagnostic::getNumFixIts() const {
+  if (Diag.getLocation().isInvalid())
+    return 0;    
+  return Diag.fixit_size();
+}
+
+CXString CXStoredDiagnostic::getFixIt(unsigned FixIt,
+                                      CXSourceRange *ReplacementRange) const {  
+  const FixItHint &Hint = Diag.fixit_begin()[FixIt];
+  if (ReplacementRange) {
+    // Create a range that covers the entire replacement (or
+    // removal) range, adjusting the end of the range to point to
+    // the end of the token.
+    *ReplacementRange = translateSourceRange(Diag.getLocation().getManager(),
+                                             LangOpts, Hint.RemoveRange);
+  }
+  return createCXString(Hint.CodeToInsert);
+}
+