2 files changed, 9 insertions, 8 deletions
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index 19d1690051..7b87d3c268 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -479,7 +479,7 @@ ASTUnit *ASTUnit::LoadFromASTFile(const std::string &Filename,
   Reader->setListener(new ASTInfoCollector(LangInfo, HeaderInfo, TargetTriple,
                                            Predefines, Counter));
 
-  switch (Reader->ReadAST(Filename)) {
+  switch (Reader->ReadAST(Filename, ASTReader::MainFile)) {
   case ASTReader::Success:
     break;
 
@@ -1305,10 +1305,7 @@ unsigned ASTUnit::getMaxPCHLevel() const {
   if (!getOnlyLocalDecls())
     return Decl::MaxPCHLevel;
 
-  unsigned Result = 0;
-  if (isMainFileAST() || SavedMainFileBuffer)
-    ++Result;
-  return Result;
+  return 0;
 }
 
 ASTUnit *ASTUnit::LoadFromCompilerInvocation(CompilerInvocation *CI,
diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index 212a1cf9f2..e3eb859153 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/lib/Frontend/CompilerInstance.cpp
@@ -251,10 +251,12 @@ void CompilerInstance::createPCHExternalASTSource(llvm::StringRef Path,
                                                   bool DisablePCHValidation,
                                                  void *DeserializationListener){
   llvm::OwningPtr<ExternalASTSource> Source;
+  bool Preamble = getPreprocessorOpts().PrecompiledPreambleBytes.first != 0;
   Source.reset(createPCHExternalASTSource(Path, getHeaderSearchOpts().Sysroot,
                                           DisablePCHValidation,
                                           getPreprocessor(), getASTContext(),
-                                          DeserializationListener));
+                                          DeserializationListener,
+                                          Preamble));
   getASTContext().setExternalSource(Source);
 }
 
@@ -264,7 +266,8 @@ CompilerInstance::createPCHExternalASTSource(llvm::StringRef Path,
                                              bool DisablePCHValidation,
                                              Preprocessor &PP,
                                              ASTContext &Context,
-                                             void *DeserializationListener) {
+                                             void *DeserializationListener,
+                                             bool Preamble) {
   llvm::OwningPtr<ASTReader> Reader;
   Reader.reset(new ASTReader(PP, &Context,
                              Sysroot.empty() ? 0 : Sysroot.c_str(),
@@ -272,7 +275,8 @@ CompilerInstance::createPCHExternalASTSource(llvm::StringRef Path,
 
   Reader->setDeserializationListener(
             static_cast<ASTDeserializationListener *>(DeserializationListener));
-  switch (Reader->ReadAST(Path)) {
+  switch (Reader->ReadAST(Path,
+                          Preamble ? ASTReader::Preamble : ASTReader::PCH)) {
   case ASTReader::Success:
     // Set the predefines buffer as suggested by the PCH reader. Typically, the
     // predefines buffer will be empty.