diff --git a/include/clang/Frontend/ASTUnit.h b/include/clang/Frontend/ASTUnit.h
index 4a8475b..37ae4e2 100644
--- a/include/clang/Frontend/ASTUnit.h
+++ b/include/clang/Frontend/ASTUnit.h
@@ -68,10 +68,6 @@
 /// \brief Utility class for loading a ASTContext from an AST file.
 ///
 class ASTUnit : public ModuleLoader {
-public:
-  typedef std::map<FileID, std::vector<PreprocessedEntity *> > 
-    PreprocessedEntitiesByFileMap;
-  
 private:
   llvm::IntrusiveRefCntPtr<Diagnostic> Diagnostics;
   llvm::IntrusiveRefCntPtr<FileManager>      FileMgr;
@@ -130,14 +126,6 @@
   // source. In the long term we should make the Index library use efficient and
   // more scalable search mechanisms.
   std::vector<Decl*> TopLevelDecls;
-
-  /// \brief The list of preprocessed entities which appeared when the ASTUnit
-  /// was loaded.
-  ///
-  /// FIXME: This is just an optimization hack to avoid deserializing large
-  /// parts of a PCH file while performing a walk or search. In the long term,
-  /// we should provide more scalable search mechanisms.
-  std::vector<PreprocessedEntity *> PreprocessedEntities;
   
   /// The name of the original source file used to generate this ASTUnit.
   std::string OriginalSourceFile;
@@ -162,15 +150,6 @@
   /// \brief Temporary files that should be removed when the ASTUnit is 
   /// destroyed.
   SmallVector<llvm::sys::Path, 4> TemporaryFiles;
-
-  /// \brief A mapping from file IDs to the set of preprocessed entities
-  /// stored in that file. 
-  ///
-  /// FIXME: This is just an optimization hack to avoid searching through
-  /// many preprocessed entities during cursor traversal in the CIndex library.
-  /// Ideally, we would just be able to perform a binary search within the
-  /// list of preprocessed entities.
-  PreprocessedEntitiesByFileMap PreprocessedEntitiesByFile;
   
   /// \brief Simple hack to allow us to assert that ASTUnit is not being
   /// used concurrently, which is not supported.
@@ -270,10 +249,6 @@
   /// \brief A list of the serialization ID numbers for each of the top-level
   /// declarations parsed within the precompiled preamble.
   std::vector<serialization::DeclID> TopLevelDeclsInPreamble;
-
-  /// \brief A list of the offsets into the precompiled preamble which
-  /// correspond to preprocessed entities.
-  std::vector<uint64_t> PreprocessedEntitiesInPreamble;
   
   /// \brief Whether we should be caching code-completion results.
   bool ShouldCacheCodeCompletionResults;
@@ -418,7 +393,6 @@
                                                      bool AllowRebuild = true,
                                                         unsigned MaxLines = 0);
   void RealizeTopLevelDeclsFromPreamble();
-  void RealizePreprocessedEntitiesFromPreamble();
   
 public:
   class ConcurrencyCheck {
@@ -530,23 +504,6 @@
   ///
   /// Note: This is used internally by the top-level tracking action
   unsigned &getCurrentTopLevelHashValue() { return CurrentTopLevelHashValue; }
-  
-  typedef std::vector<PreprocessedEntity *>::iterator pp_entity_iterator;
-  
-  pp_entity_iterator pp_entity_begin();
-  pp_entity_iterator pp_entity_end();
-  
-  /// \brief Add a new preprocessed entity that's stored at the given offset
-  /// in the precompiled preamble.
-  void addPreprocessedEntityFromPreamble(uint64_t Offset) {
-    PreprocessedEntitiesInPreamble.push_back(Offset);
-  }
-  
-  /// \brief Retrieve the mapping from File IDs to the preprocessed entities
-  /// within that file.
-  PreprocessedEntitiesByFileMap &getPreprocessedEntitiesByFile() {
-    return PreprocessedEntitiesByFile;
-  }
 
   /// \brief Get the source location for the given file:line:col triplet.
   ///
diff --git a/include/clang/Lex/PreprocessingRecord.h b/include/clang/Lex/PreprocessingRecord.h
index 00b93c0..bf1bb53 100644
--- a/include/clang/Lex/PreprocessingRecord.h
+++ b/include/clang/Lex/PreprocessingRecord.h
@@ -275,10 +275,6 @@
     /// preprocessed entities that \arg Range encompasses.
     virtual std::pair<unsigned, unsigned>
         findPreprocessedEntitiesInRange(SourceRange Range) = 0;
-
-    /// \brief Read the preprocessed entity at the given offset.
-    virtual PreprocessedEntity *
-    ReadPreprocessedEntityAtOffset(uint64_t Offset) = 0;
   };
   
   /// \brief A record of the steps taken while preprocessing a source file,
diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index 96b5e58..48f8053 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -801,9 +801,6 @@
   virtual std::pair<unsigned, unsigned>
       findPreprocessedEntitiesInRange(SourceRange Range);
 
-  /// \brief Read the preprocessed entity at the given offset.
-  virtual PreprocessedEntity *ReadPreprocessedEntityAtOffset(uint64_t Offset);
-
   /// \brief Read the header file information for the given file entry.
   virtual HeaderFileInfo GetHeaderFileInfo(const FileEntry *FE);
 
diff --git a/include/clang/Serialization/ASTSerializationListener.h b/include/clang/Serialization/ASTSerializationListener.h
deleted file mode 100644
index 0c62e0b..0000000
--- a/include/clang/Serialization/ASTSerializationListener.h
+++ /dev/null
@@ -1,44 +0,0 @@
-//===- ASTSerializationListener.h - Decl/Type PCH Write Events -*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-//  This file defines the ASTSerializationListener class, which is notified
-//  by the ASTWriter when an entity is serialized.
-//
-//===----------------------------------------------------------------------===//
-#ifndef LLVM_CLANG_FRONTEND_AST_SERIALIZATION_LISTENER_H
-#define LLVM_CLANG_FRONTEND_AST_SERIALIZATION_LISTENER_H
-
-#include "llvm/Support/DataTypes.h"
-
-namespace clang {
-
-class PreprocessedEntity;
-  
-/// \brief Listener object that receives callbacks when certain kinds of 
-/// entities are serialized.
-class ASTSerializationListener {
-public:
-  virtual ~ASTSerializationListener();
-  
-  /// \brief Callback invoked whenever a preprocessed entity is serialized.
-  ///
-  /// This callback will only occur when the translation unit was created with
-  /// a detailed preprocessing record.
-  ///
-  /// \param Entity The entity that has been serialized.
-  ///
-  /// \param Offset The offset (in bits) of this entity in the resulting
-  /// AST file.
-  virtual void SerializedPreprocessedEntity(PreprocessedEntity *Entity,
-                                            uint64_t Offset) = 0;
-};
-
-}
-
-#endif
diff --git a/include/clang/Serialization/ASTWriter.h b/include/clang/Serialization/ASTWriter.h
index 13220f4..b8ac8fa 100644
--- a/include/clang/Serialization/ASTWriter.h
+++ b/include/clang/Serialization/ASTWriter.h
@@ -38,7 +38,6 @@
 namespace clang {
 
 class ASTContext;
-class ASTSerializationListener;
 class NestedNameSpecifier;
 class CXXBaseSpecifier;
 class CXXCtorInitializer;
@@ -93,10 +92,6 @@
                     
   /// \brief The reader of existing AST files, if we're chaining.
   ASTReader *Chain;
-
-  /// \brief A listener object that receives notifications when certain 
-  /// entities are serialized.                    
-  ASTSerializationListener *SerializationListener;
                    
   /// \brief Indicates when the AST writing is actively performing 
   /// serialization, rather than just queueing updates.
@@ -393,12 +388,6 @@
   /// \brief Create a new precompiled header writer that outputs to
   /// the given bitstream.
   ASTWriter(llvm::BitstreamWriter &Stream);
-
-  /// \brief Set the listener that will receive notification of serialization
-  /// events.
-  void SetSerializationListener(ASTSerializationListener *Listener) {
-    SerializationListener = Listener;
-  }
                     
   /// \brief Write a precompiled header for the given semantic analysis.
   ///
@@ -665,7 +654,6 @@
   virtual void InitializeSema(Sema &S) { SemaPtr = &S; }
   virtual void HandleTranslationUnit(ASTContext &Ctx);
   virtual ASTMutationListener *GetASTMutationListener();
-  virtual ASTSerializationListener *GetASTSerializationListener();
   virtual ASTDeserializationListener *GetASTDeserializationListener();
 };
 
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index 60e1c3b..19b8ccb 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -29,7 +29,6 @@
 #include "clang/Frontend/FrontendOptions.h"
 #include "clang/Frontend/Utils.h"
 #include "clang/Serialization/ASTReader.h"
-#include "clang/Serialization/ASTSerializationListener.h"
 #include "clang/Serialization/ASTWriter.h"
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/Preprocessor.h"
@@ -775,8 +774,7 @@
   }
 };
 
-class PrecompilePreambleConsumer : public PCHGenerator, 
-                                   public ASTSerializationListener {
+class PrecompilePreambleConsumer : public PCHGenerator {
   ASTUnit &Unit;
   unsigned &Hash;                                   
   std::vector<Decl *> TopLevelDecls;
@@ -815,15 +813,6 @@
                                       getWriter().getDeclID(TopLevelDecls[I]));
     }
   }
-                                     
-  virtual void SerializedPreprocessedEntity(PreprocessedEntity *Entity,
-                                            uint64_t Offset) {
-    Unit.addPreprocessedEntityFromPreamble(Offset);
-  }
-                                     
-  virtual ASTSerializationListener *GetASTSerializationListener() {
-    return this;
-  }
 };
 
 class PrecompilePreambleAction : public ASTFrontendAction {
@@ -922,16 +911,13 @@
   
   // Clear out old caches and data.
   TopLevelDecls.clear();
-  PreprocessedEntities.clear();
   CleanTemporaryFiles();
-  PreprocessedEntitiesByFile.clear();
 
   if (!OverrideMainBuffer) {
     StoredDiagnostics.erase(
                     StoredDiagnostics.begin() + NumStoredDiagnosticsFromDriver,
                             StoredDiagnostics.end());
     TopLevelDeclsInPreamble.clear();
-    PreprocessedEntitiesInPreamble.clear();
   }
 
   // Create a file manager object to provide access to and cache the filesystem.
@@ -1407,8 +1393,6 @@
                           StoredDiagnostics.end());
   TopLevelDecls.clear();
   TopLevelDeclsInPreamble.clear();
-  PreprocessedEntities.clear();
-  PreprocessedEntitiesInPreamble.clear();
   
   // Create a file manager object to provide access to and cache the filesystem.
   Clang->setFileManager(new FileManager(Clang->getFileSystemOpts()));
@@ -1439,8 +1423,6 @@
     llvm::sys::Path(FrontendOpts.OutputFile).eraseFromDisk();
     Preamble.clear();
     TopLevelDeclsInPreamble.clear();
-    PreprocessedEntities.clear();
-    PreprocessedEntitiesInPreamble.clear();
     PreambleRebuildCounter = DefaultPreambleRebuildInterval;
     PreprocessorOpts.eraseRemappedFile(
                                PreprocessorOpts.remapped_file_buffer_end() - 1);
@@ -1511,48 +1493,6 @@
   TopLevelDecls.insert(TopLevelDecls.begin(), Resolved.begin(), Resolved.end());
 }
 
-void ASTUnit::RealizePreprocessedEntitiesFromPreamble() {
-  if (!PP)
-    return;
-  
-  PreprocessingRecord *PPRec = PP->getPreprocessingRecord();
-  if (!PPRec)
-    return;
-  
-  ExternalPreprocessingRecordSource *External = PPRec->getExternalSource();
-  if (!External)
-    return;
-
-  for (unsigned I = 0, N = PreprocessedEntitiesInPreamble.size(); I != N; ++I) {
-    if (PreprocessedEntity *PE
-          = External->ReadPreprocessedEntityAtOffset(
-                                            PreprocessedEntitiesInPreamble[I]))
-      PreprocessedEntities.push_back(PE);
-  }
-  
-  if (PreprocessedEntities.empty())
-    return;
-  
-  PreprocessedEntities.insert(PreprocessedEntities.end(), 
-                              PPRec->local_begin(), PPRec->local_end());
-}
-
-ASTUnit::pp_entity_iterator ASTUnit::pp_entity_begin() {
-  if (!PreprocessedEntitiesInPreamble.empty() &&
-      PreprocessedEntities.empty())
-    RealizePreprocessedEntitiesFromPreamble();
-  
-  return PreprocessedEntities.begin();
-}
-
-ASTUnit::pp_entity_iterator ASTUnit::pp_entity_end() {
-  if (!PreprocessedEntitiesInPreamble.empty() &&
-      PreprocessedEntities.empty())
-    RealizePreprocessedEntitiesFromPreamble();
-    
-  return PreprocessedEntities.end();
-}
-
 StringRef ASTUnit::getMainFileName() const {
   return Invocation->getFrontendOpts().Inputs[0].second;
 }
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 02d7eea..25b8687 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -2999,16 +2999,6 @@
   return std::make_pair(BeginID, EndID);
 }
 
-PreprocessedEntity *ASTReader::ReadPreprocessedEntityAtOffset(uint64_t Offset) {
-  RecordLocation Loc = getLocalBitOffset(Offset);
-
-  // Keep track of where we are in the stream, then jump back there
-  // after reading this entity.
-  SavedStreamPosition SavedPosition(Loc.F->PreprocessorDetailCursor);  
-  Loc.F->PreprocessorDetailCursor.JumpToBit(Loc.Offset);
-  return LoadPreprocessedEntity(*Loc.F);
-}
-
 namespace {
   /// \brief Visitor used to search for information about a header file.
   class HeaderFileInfoVisitor {
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index ac961c7..2aa1e6c 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Serialization/ASTWriter.h"
-#include "clang/Serialization/ASTSerializationListener.h"
 #include "ASTCommon.h"
 #include "clang/Sema/Sema.h"
 #include "clang/Sema/IdentifierResolver.h"
@@ -1743,7 +1742,6 @@
     + NUM_PREDEF_PP_ENTITY_IDS;
   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
   RecordData Record;
-  uint64_t BitsInChain = Chain? Chain->TotalModulesSizeInBits : 0;
   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
                                   EEnd = PPRec.local_end();
        E != EEnd; 
@@ -1757,11 +1755,6 @@
       // Record this macro definition's ID.
       MacroDefinitions[MD] = NextPreprocessorEntityID;
       
-      // Notify the serialization listener that we're serializing this entity.
-      if (SerializationListener)
-        SerializationListener->SerializedPreprocessedEntity(*E, 
-          BitsInChain + Stream.GetCurrentBitNo());
-      
       Record.push_back(NextPreprocessorEntityID);
       AddSourceLocation(MD->getSourceRange().getBegin(), Record);
       AddSourceLocation(MD->getSourceRange().getEnd(), Record);
@@ -1771,11 +1764,6 @@
       continue;
     }
 
-    // Notify the serialization listener that we're serializing this entity.
-    if (SerializationListener)
-      SerializationListener->SerializedPreprocessedEntity(*E, 
-        BitsInChain + Stream.GetCurrentBitNo());
-
     if (MacroExpansion *ME = dyn_cast<MacroExpansion>(*E)) {
       Record.push_back(NextPreprocessorEntityID);
       AddSourceLocation(ME->getSourceRange().getBegin(), Record);
@@ -2719,8 +2707,7 @@
 }
 
 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream)
-  : Stream(Stream), Context(0), Chain(0), SerializationListener(0), 
-    WritingAST(false),
+  : Stream(Stream), Context(0), Chain(0), WritingAST(false),
     FirstDeclID(NUM_PREDEF_DECL_IDS), NextDeclID(FirstDeclID),
     FirstTypeID(NUM_PREDEF_TYPE_IDS), NextTypeID(FirstTypeID),
     FirstIdentID(NUM_PREDEF_IDENT_IDS), NextIdentID(FirstIdentID), 
@@ -4045,5 +4032,3 @@
   ChainedObjCCategoriesData Data =  { IFD, CatD, 0, 0 };
   LocalChainedObjCCategories.push_back(Data);
 }
-
-ASTSerializationListener::~ASTSerializationListener() { }
diff --git a/lib/Serialization/GeneratePCH.cpp b/lib/Serialization/GeneratePCH.cpp
index 25fac8b..a2534db 100644
--- a/lib/Serialization/GeneratePCH.cpp
+++ b/lib/Serialization/GeneratePCH.cpp
@@ -46,9 +46,6 @@
 void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
   if (PP.getDiagnostics().hasErrorOccurred())
     return;
-
-  // Set up the serialization listener.
-  Writer.SetSerializationListener(GetASTSerializationListener());
   
   // Emit the PCH file
   assert(SemaPtr && "No Sema?");
@@ -68,10 +65,6 @@
   return &Writer;
 }
 
-ASTSerializationListener *PCHGenerator::GetASTSerializationListener() {
-  return 0;
-}
-
 ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
   return &Writer;
 }
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index 8390a7c..5916d5c 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -263,10 +263,6 @@
   bool visitPreprocessedEntitiesInRegion();
 
   template<typename InputIterator>
-  bool visitPreprocessedEntitiesInRegion(InputIterator First, 
-                                         InputIterator Last);
-
-  template<typename InputIterator>
   bool visitPreprocessedEntities(InputIterator First, InputIterator Last);
 
   bool VisitChildren(CXCursor Parent);
@@ -399,62 +395,19 @@
   PreprocessingRecord &PPRec
     = *AU->getPreprocessor().getPreprocessingRecord();
   
+  if (RegionOfInterest.isValid()) {
+    std::pair<PreprocessingRecord::iterator, PreprocessingRecord::iterator>
+      Entities = PPRec.getPreprocessedEntitiesInRange(RegionOfInterest);
+    return visitPreprocessedEntities(Entities.first, Entities.second);
+  }
+
   bool OnlyLocalDecls
     = !AU->isMainFileAST() && AU->getOnlyLocalDecls(); 
   
-  if (OnlyLocalDecls && RegionOfInterest.isValid()) {
-    // If we would only look at local declarations but we have a region of 
-    // interest, check whether that region of interest is in the main file.
-    // If not, we should traverse all declarations.
-    // FIXME: My kingdom for a proper binary search approach to finding
-    // cursors!
-    std::pair<FileID, unsigned> Location
-      = AU->getSourceManager().getDecomposedExpansionLoc(
-                                                   RegionOfInterest.getBegin());
-    if (Location.first != AU->getSourceManager().getMainFileID())
-      OnlyLocalDecls = false;
-  }
-  
-  PreprocessingRecord::iterator StartEntity, EndEntity;
-  if (OnlyLocalDecls && AU->pp_entity_begin() != AU->pp_entity_end())
-    return visitPreprocessedEntitiesInRegion(AU->pp_entity_begin(), 
-                                      AU->pp_entity_end());
-  else
-    return visitPreprocessedEntitiesInRegion(PPRec.begin(), PPRec.end());  
-}
+  if (OnlyLocalDecls)
+    return visitPreprocessedEntities(PPRec.local_begin(), PPRec.local_end());
 
-template<typename InputIterator>
-bool CursorVisitor::visitPreprocessedEntitiesInRegion(InputIterator First,
-                                                      InputIterator Last) {
-  // There is no region of interest; we have to walk everything.
-  if (RegionOfInterest.isInvalid())
-    return visitPreprocessedEntities(First, Last);
-  
-  // Find the file in which the region of interest lands.
-  SourceManager &SM = AU->getSourceManager();
-  std::pair<FileID, unsigned> Begin
-    = SM.getDecomposedExpansionLoc(RegionOfInterest.getBegin());
-  std::pair<FileID, unsigned> End
-    = SM.getDecomposedExpansionLoc(RegionOfInterest.getEnd());
-  
-  // The region of interest spans files; we have to walk everything.
-  if (Begin.first != End.first)
-    return visitPreprocessedEntities(First, Last);
-  
-  ASTUnit::PreprocessedEntitiesByFileMap &ByFileMap
-  = AU->getPreprocessedEntitiesByFile();
-  if (ByFileMap.empty()) {
-    // Build the mapping from files to sets of preprocessed entities.
-    for (; First != Last; ++First) {
-      std::pair<FileID, unsigned> P
-        = SM.getDecomposedExpansionLoc((*First)->getSourceRange().getBegin());
-      
-      ByFileMap[P.first].push_back(*First);
-    }
-  }
-  
-  return visitPreprocessedEntities(ByFileMap[Begin.first].begin(), 
-                                   ByFileMap[Begin.first].end());
+  return visitPreprocessedEntities(PPRec.begin(), PPRec.end());
 }
 
 template<typename InputIterator>