Index: include/clang/Sema/Sema.h
===================================================================
--- include/clang/Sema/Sema.h	(revision 187706)
+++ include/clang/Sema/Sema.h	(working copy)
@@ -394,0 +395,4 @@
+  typedef llvm::DenseMap<const FunctionDecl *, LateParsedTemplate *>
+  LateParsedTemplateMapT;
+  LateParsedTemplateMapT LateParsedTemplateMap;
+
@@ -396 +400 @@
-  typedef void LateTemplateParserCB(void *P, const FunctionDecl *FD);
+  typedef void LateTemplateParserCB(void *P, LateParsedTemplate &LPT);
@@ -4672 +4676,3 @@
-  void MarkAsLateParsedTemplate(FunctionDecl *FD, bool Flag = true);
+  void MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
+                                CachedTokens &Toks);
+  void UnmarkAsLateParsedTemplate(FunctionDecl *FD);
@@ -7766 +7772,9 @@
-}  // end namespace clang
+/// \brief Contains a late templated function.
+/// Will be parsed at the end of the translation unit, used by Sema & Parser.
+struct LateParsedTemplate {
+  CachedTokens Toks;
+  /// \brief The template function declaration to be late parsed.
+  Decl *D;
+};
+
+} // end namespace clang
Index: include/clang/Sema/ExternalSemaSource.h
===================================================================
--- include/clang/Sema/ExternalSemaSource.h	(revision 187706)
+++ include/clang/Sema/ExternalSemaSource.h	(working copy)
@@ -33 +33,2 @@
-  
+struct LateParsedTemplate;
+
@@ -179,0 +181,9 @@
+  /// \brief Read the set of late parsed template functions for this source.
+  ///
+  /// The external source should insert its own late parsed template functions
+  /// into the map. Note that this routine may be invoked multiple times; the
+  /// external source should take care not to introduce the same map entries
+  /// repeatedly.
+  virtual void ReadLateParsedTemplates(
+      llvm::DenseMap<const FunctionDecl *, LateParsedTemplate *> &LPTMap) {}
+
Index: include/clang/Sema/MultiplexExternalSemaSource.h
===================================================================
--- include/clang/Sema/MultiplexExternalSemaSource.h	(revision 187706)
+++ include/clang/Sema/MultiplexExternalSemaSource.h	(working copy)
@@ -324,0 +325,9 @@
+  /// \brief Read the set of late parsed template functions for this source.
+  ///
+  /// The external source should insert its own late parsed template functions
+  /// into the map. Note that this routine may be invoked multiple times; the
+  /// external source should take care not to introduce the same map entries
+  /// repeatedly.
+  virtual void ReadLateParsedTemplates(
+      llvm::DenseMap<const FunctionDecl *, LateParsedTemplate *> &LPTMap);
+
Index: include/clang/Parse/Parser.h
===================================================================
--- include/clang/Parse/Parser.h	(revision 187706)
+++ include/clang/Parse/Parser.h	(working copy)
@@ -1054,12 +1053,0 @@
-  /// \brief Contains a late templated function.
-  /// Will be parsed at the end of the translation unit.
-  struct LateParsedTemplatedFunction {
-    explicit LateParsedTemplatedFunction(Decl *MD)
-      : D(MD) {}
-
-    CachedTokens Toks;
-
-    /// \brief The template function declaration to be late parsed.
-    Decl *D;
-  };
-
@@ -1067,4 +1055 @@
-  void ParseLateTemplatedFuncDef(LateParsedTemplatedFunction &LMT);
-  typedef llvm::DenseMap<const FunctionDecl*, LateParsedTemplatedFunction*>
-    LateParsedTemplateMapT;
-  LateParsedTemplateMapT LateParsedTemplateMap;
+  void ParseLateTemplatedFuncDef(LateParsedTemplate &LPT);
@@ -1072,2 +1057 @@
-  static void LateTemplateParserCallback(void *P, const FunctionDecl *FD);
-  void LateTemplateParser(const FunctionDecl *FD);
+  static void LateTemplateParserCallback(void *P, LateParsedTemplate &LPT);
Index: include/clang/Serialization/ASTReader.h
===================================================================
--- include/clang/Serialization/ASTReader.h	(revision 187706)
+++ include/clang/Serialization/ASTReader.h	(working copy)
@@ -242,0 +243 @@
+  typedef SmallVectorImpl<uint64_t> RecordDataImpl;
@@ -712,0 +714,3 @@
+  // \brief A list of late parsed template function data.
+  SmallVector<uint64_t, 1> LateParsedTemplates;
+
@@ -1609,0 +1614,3 @@
+  virtual void ReadLateParsedTemplates(
+      llvm::DenseMap<const FunctionDecl *, LateParsedTemplate *> &LPTMap);
+
@@ -1760 +1767,2 @@
-                                    const RecordData &Record, unsigned &Idx) {
+                                    const RecordDataImpl &Record,
+                                    unsigned &Idx) {
@@ -1811 +1819 @@
-  Token ReadToken(ModuleFile &M, const RecordData &Record, unsigned &Idx);
+  Token ReadToken(ModuleFile &M, const RecordDataImpl &Record, unsigned &Idx);
Index: include/clang/Serialization/ASTBitCodes.h
===================================================================
--- include/clang/Serialization/ASTBitCodes.h	(revision 187706)
+++ include/clang/Serialization/ASTBitCodes.h	(working copy)
@@ -538 +538,4 @@
-      UNDEFINED_BUT_USED = 49
+      UNDEFINED_BUT_USED = 49,
+
+      /// \brief Record code for late parsed template functions.
+      LATE_PARSED_TEMPLATE = 50
Index: include/clang/Serialization/ASTWriter.h
===================================================================
--- include/clang/Serialization/ASTWriter.h	(revision 187706)
+++ include/clang/Serialization/ASTWriter.h	(working copy)
@@ -460 +460,2 @@
-                        
+  void WriteLateParsedTemplates(Sema &SemaRef);
+
Index: lib/Parse/Parser.cpp
===================================================================
--- lib/Parse/Parser.cpp	(revision 187706)
+++ lib/Parse/Parser.cpp	(working copy)
@@ -425,5 +424,0 @@
-  // Free LateParsedTemplatedFunction nodes.
-  for (LateParsedTemplateMapT::iterator it = LateParsedTemplateMap.begin();
-      it != LateParsedTemplateMap.end(); ++it)
-    delete it->second;
-
@@ -1011,2 +1006,2 @@
-    if (DP) {
-      LateParsedTemplatedFunction *LPT = new LateParsedTemplatedFunction(DP);
+    CachedTokens Toks;
+    LexTemplateFunctionForLateParsing(Toks);
@@ -1013,0 +1009 @@
+    if (DP) {
@@ -1019 +1014,0 @@
-      Actions.CheckForFunctionRedefinition(FnD);
@@ -1021,6 +1016,2 @@
-      LateParsedTemplateMap[FnD] = LPT;
-      Actions.MarkAsLateParsedTemplate(FnD);
-      LexTemplateFunctionForLateParsing(LPT->Toks);
-    } else {
-      CachedTokens Toks;
-      LexTemplateFunctionForLateParsing(Toks);
+      Actions.CheckForFunctionRedefinition(FnD);
+      Actions.MarkAsLateParsedTemplate(FnD, DP, Toks);
Index: lib/Parse/ParseTemplate.cpp
===================================================================
--- lib/Parse/ParseTemplate.cpp	(revision 187706)
+++ lib/Parse/ParseTemplate.cpp	(working copy)
@@ -1245,13 +1245,2 @@
-void Parser::LateTemplateParserCallback(void *P, const FunctionDecl *FD) {
-  ((Parser*)P)->LateTemplateParser(FD);
-}
-
-
-void Parser::LateTemplateParser(const FunctionDecl *FD) {
-  LateParsedTemplatedFunction *LPT = LateParsedTemplateMap[FD];
-  if (LPT) {
-    ParseLateTemplatedFuncDef(*LPT);
-    return;
-  }
-
-  llvm_unreachable("Late templated function without associated lexed tokens");
+void Parser::LateTemplateParserCallback(void *P, LateParsedTemplate &LPT) {
+  ((Parser *)P)->ParseLateTemplatedFuncDef(LPT);
@@ -1261,2 +1250,2 @@
-void Parser::ParseLateTemplatedFuncDef(LateParsedTemplatedFunction &LMT) {
-  if(!LMT.D)
+void Parser::ParseLateTemplatedFuncDef(LateParsedTemplate &LPT) {
+  if(!LPT.D)
@@ -1266 +1255 @@
-  FunctionTemplateDecl *FunTmplD = dyn_cast<FunctionTemplateDecl>(LMT.D);
+  FunctionTemplateDecl *FunTmplD = dyn_cast<FunctionTemplateDecl>(LPT.D);
@@ -1268 +1257 @@
-      FunTmplD ? FunTmplD->getTemplatedDecl() : cast<FunctionDecl>(LMT.D);
+      FunTmplD ? FunTmplD->getTemplatedDecl() : cast<FunctionDecl>(LPT.D);
@@ -1316 +1305 @@
-  Actions.ActOnReenterTemplateScope(getCurScope(), LMT.D);
+  Actions.ActOnReenterTemplateScope(getCurScope(), LPT.D);
@@ -1319 +1308 @@
-  assert(!LMT.Toks.empty() && "Empty body!");
+  assert(!LPT.Toks.empty() && "Empty body!");
@@ -1323,2 +1312,2 @@
-  LMT.Toks.push_back(Tok);
-  PP.EnterTokenStream(LMT.Toks.data(), LMT.Toks.size(), true, false);
+  LPT.Toks.push_back(Tok);
+  PP.EnterTokenStream(LPT.Toks.data(), LPT.Toks.size(), true, false);
@@ -1341 +1330 @@
-    ParseFunctionTryBlock(LMT.D, FnScope);
+    ParseFunctionTryBlock(LPT.D, FnScope);
@@ -1344 +1333 @@
-      ParseConstructorInitializer(LMT.D);
+      ParseConstructorInitializer(LPT.D);
@@ -1346 +1335 @@
-      Actions.ActOnDefaultCtorInitializers(LMT.D);
+      Actions.ActOnDefaultCtorInitializers(LPT.D);
@@ -1353,2 +1342,2 @@
-      ParseFunctionStatementBody(LMT.D, FnScope);
-      Actions.MarkAsLateParsedTemplate(FunD, false);
+      ParseFunctionStatementBody(LPT.D, FnScope);
+      Actions.UnmarkAsLateParsedTemplate(FunD);
@@ -1356 +1345 @@
-      Actions.ActOnFinishFunctionBody(LMT.D, 0);
+      Actions.ActOnFinishFunctionBody(LPT.D, 0);
@@ -1366 +1355 @@
-  DeclGroupPtrTy grp = Actions.ConvertDeclToDeclGroup(LMT.D);
+  DeclGroupPtrTy grp = Actions.ConvertDeclToDeclGroup(LPT.D);
Index: lib/Parse/ParseCXXInlineMethods.cpp
===================================================================
--- lib/Parse/ParseCXXInlineMethods.cpp	(revision 187706)
+++ lib/Parse/ParseCXXInlineMethods.cpp	(working copy)
@@ -123,2 +123,2 @@
-    if (FnD) {
-      LateParsedTemplatedFunction *LPT = new LateParsedTemplatedFunction(FnD);
+    CachedTokens Toks;
+    LexTemplateFunctionForLateParsing(Toks);
@@ -125,0 +126 @@
+    if (FnD) {
@@ -128,7 +129 @@
-
-      LateParsedTemplateMap[FD] = LPT;
-      Actions.MarkAsLateParsedTemplate(FD);
-      LexTemplateFunctionForLateParsing(LPT->Toks);
-    } else {
-      CachedTokens Toks;
-      LexTemplateFunctionForLateParsing(Toks);
+      Actions.MarkAsLateParsedTemplate(FD, FnD, Toks);
Index: lib/Serialization/ASTWriter.cpp
===================================================================
--- lib/Serialization/ASTWriter.cpp	(revision 187706)
+++ lib/Serialization/ASTWriter.cpp	(working copy)
@@ -850,0 +851 @@
+  RECORD(LATE_PARSED_TEMPLATE);
@@ -3672,0 +3674,24 @@
+void ASTWriter::WriteLateParsedTemplates(Sema &SemaRef) {
+  Sema::LateParsedTemplateMapT &LPTMap = SemaRef.LateParsedTemplateMap;
+
+  if (LPTMap.empty())
+    return;
+
+  RecordData Record;
+  for (Sema::LateParsedTemplateMapT::iterator It = LPTMap.begin(),
+                                              ItEnd = LPTMap.end();
+       It != ItEnd; ++It) {
+    LateParsedTemplate *LPT = It->second;
+    AddDeclRef(It->first, Record);
+    AddDeclRef(LPT->D, Record);
+    Record.push_back(LPT->Toks.size());
+
+    for (CachedTokens::iterator TokIt = LPT->Toks.begin(),
+                                TokEnd = LPT->Toks.end();
+         TokIt != TokEnd; ++TokIt) {
+      AddToken(*TokIt, Record);
+    }
+  }
+  Stream.EmitRecord(LATE_PARSED_TEMPLATE, Record);
+}
+
@@ -4240 +4265,2 @@
-  
+  WriteLateParsedTemplates(SemaRef);
+
Index: lib/Serialization/ASTReaderDecl.cpp
===================================================================
--- lib/Serialization/ASTReaderDecl.cpp	(revision 187706)
+++ lib/Serialization/ASTReaderDecl.cpp	(working copy)
@@ -537,0 +538 @@
+  FD->IsLateTemplateParsed = Record[Idx++];
Index: lib/Serialization/ASTReader.cpp
===================================================================
--- lib/Serialization/ASTReader.cpp	(revision 187706)
+++ lib/Serialization/ASTReader.cpp	(working copy)
@@ -1106 +1106 @@
-Token ASTReader::ReadToken(ModuleFile &F, const RecordData &Record,
+Token ASTReader::ReadToken(ModuleFile &F, const RecordDataImpl &Record,
@@ -2753,0 +2754,5 @@
+
+    case LATE_PARSED_TEMPLATE: {
+      LateParsedTemplates.append(Record.begin(), Record.end());
+      break;
+    }
@@ -6477,0 +6483,23 @@
+void ASTReader::ReadLateParsedTemplates(
+    llvm::DenseMap<const FunctionDecl *, LateParsedTemplate *> &LPTMap) {
+  for (unsigned Idx = 0, N = LateParsedTemplates.size(); Idx < N;
+       /* In loop */) {
+    FunctionDecl *FD = cast<FunctionDecl>(GetDecl(LateParsedTemplates[Idx++]));
+
+    LateParsedTemplate *LT = new LateParsedTemplate;
+    LT->D = GetDecl(LateParsedTemplates[Idx++]);
+
+    ModuleFile *F = getOwningModuleFile(LT->D);
+    assert(F && "No module");
+
+    unsigned TokN = LateParsedTemplates[Idx++];
+    LT->Toks.reserve(TokN);
+    for (unsigned T = 0; T < TokN; ++T)
+      LT->Toks.push_back(ReadToken(*F, LateParsedTemplates, Idx));
+
+    LPTMap[FD] = LT;
+  }
+
+  LateParsedTemplates.clear();
+}
+
Index: lib/Serialization/ASTWriterDecl.cpp
===================================================================
--- lib/Serialization/ASTWriterDecl.cpp	(revision 187706)
+++ lib/Serialization/ASTWriterDecl.cpp	(working copy)
@@ -340,0 +341 @@
+  Record.push_back(D->isLateTemplateParsed());
Index: lib/Sema/SemaTemplate.cpp
===================================================================
--- lib/Sema/SemaTemplate.cpp	(revision 187706)
+++ lib/Sema/SemaTemplate.cpp	(working copy)
@@ -7382 +7382,2 @@
-void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, bool Flag) {
+void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
+                                    CachedTokens &Toks) {
@@ -7385,2 +7386,16 @@
-  FD->setLateTemplateParsed(Flag);
-} 
+
+  LateParsedTemplate *LPT = new LateParsedTemplate;
+
+  // Take tokens to avoid allocations
+  LPT->Toks.swap(Toks);
+  LPT->D = FnD;
+  LateParsedTemplateMap[FD] = LPT;
+
+  FD->setLateTemplateParsed(true);
+}
+
+void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) {
+  if (!FD)
+    return;
+  FD->setLateTemplateParsed(false);
+}
Index: lib/Sema/SemaTemplateInstantiateDecl.cpp
===================================================================
--- lib/Sema/SemaTemplateInstantiateDecl.cpp	(revision 187706)
+++ lib/Sema/SemaTemplateInstantiateDecl.cpp	(working copy)
@@ -2887 +2887,6 @@
-    LateTemplateParser(OpaqueParser, PatternDecl);
+    if (PatternDecl->isFromASTFile())
+      ExternalSource->ReadLateParsedTemplates(LateParsedTemplateMap);
+
+    LateParsedTemplate *LPT = LateParsedTemplateMap.lookup(PatternDecl);
+    assert(LPT && "missing LateParsedTemplate");
+    LateTemplateParser(OpaqueParser, *LPT);
Index: lib/Sema/MultiplexExternalSemaSource.cpp
===================================================================
--- lib/Sema/MultiplexExternalSemaSource.cpp	(revision 187706)
+++ lib/Sema/MultiplexExternalSemaSource.cpp	(working copy)
@@ -269,0 +270,6 @@
+
+void MultiplexExternalSemaSource::ReadLateParsedTemplates(
+    llvm::DenseMap<const FunctionDecl *, LateParsedTemplate *> &LPTMap) {
+  for (size_t i = 0; i < Sources.size(); ++i)
+    Sources[i]->ReadLateParsedTemplates(LPTMap);
+}
\ No newline at end of file
Index: lib/Sema/Sema.cpp
===================================================================
--- lib/Sema/Sema.cpp	(revision 187706)
+++ lib/Sema/Sema.cpp	(working copy)
@@ -175,0 +176,4 @@
+  for (LateParsedTemplateMapT::iterator I = LateParsedTemplateMap.begin(),
+                                        E = LateParsedTemplateMap.end();
+       I != E; ++I)
+    delete I->second;
Index: test/PCH/cxx-templates.cpp
===================================================================
--- test/PCH/cxx-templates.cpp	(revision 187706)
+++ test/PCH/cxx-templates.cpp	(working copy)
@@ -14,0 +15,5 @@
+// Test with pch and delayed template parsing.
+// RUN: %clang_cc1 -std=c++11 -fcxx-exceptions -fdelayed-template-parsing -fexceptions -x c++-header -emit-pch -o %t %S/cxx-templates.h
+// RUN: %clang_cc1 -std=c++11 -fcxx-exceptions -fdelayed-template-parsing -fexceptions -include-pch %t -verify %s -ast-dump  -o -
+// RUN: %clang_cc1 -std=c++11 -fcxx-exceptions -fdelayed-template-parsing -fexceptions -include-pch %t %s -emit-llvm -o - | FileCheck %s
+