vendor/clang/clang-trunk-r300422

6 files changed, 232 insertions, 107 deletions

diff --git a/include/clang/Serialization/ASTBitCodes.h b/include/clang/Serialization/ASTBitCodes.h
index acbd6d1deb5b3..823440b197137 100644
--- a/include/clang/Serialization/ASTBitCodes.h
+++ b/include/clang/Serialization/ASTBitCodes.h
@@ -226,7 +226,7 @@ namespace clang {
 
       /// \brief The block containing the detailed preprocessing record.
       PREPROCESSOR_DETAIL_BLOCK_ID,
-      
+
       /// \brief The block containing the submodule structure.
       SUBMODULE_BLOCK_ID,
 
@@ -253,6 +253,12 @@ namespace clang {
 
       /// \brief A block containing a module file extension.
       EXTENSION_BLOCK_ID,
+
+      /// A block with unhashed content.
+      ///
+      /// These records should not change the \a ASTFileSignature.  See \a
+      /// UnhashedControlBlockRecordTypes for the list of records.
+      UNHASHED_CONTROL_BLOCK_ID,
     };
 
     /// \brief Record types that occur within the control block.
@@ -288,9 +294,6 @@ namespace clang {
       /// AST file.
       MODULE_MAP_FILE,
 
-      /// \brief Record code for the signature that identifiers this AST file.
-      SIGNATURE,
-
       /// \brief Record code for the module build directory.
       MODULE_DIRECTORY,
     };
@@ -309,9 +312,6 @@ namespace clang {
       /// \brief Record code for the target options table.
       TARGET_OPTIONS,
 
-      /// \brief Record code for the diagnostic options table.
-      DIAGNOSTIC_OPTIONS,
-
       /// \brief Record code for the filesystem options table.
       FILE_SYSTEM_OPTIONS,
 
@@ -322,6 +322,18 @@ namespace clang {
       PREPROCESSOR_OPTIONS,
     };
 
+    /// Record codes for the unhashed control block.
+    enum UnhashedControlBlockRecordTypes {
+      /// Record code for the signature that identifiers this AST file.
+      SIGNATURE = 1,
+
+      /// Record code for the diagnostic options table.
+      DIAGNOSTIC_OPTIONS,
+
+      /// Record code for \#pragma diagnostic mappings.
+      DIAG_PRAGMA_MAPPINGS,
+    };
+
     /// \brief Record code for extension blocks.
     enum ExtensionBlockRecordTypes {
       /// Metadata describing this particular extension.
@@ -493,8 +505,7 @@ namespace clang {
 
       // ID 31 used to be a list of offsets to DECL_CXX_BASE_SPECIFIERS records.
 
-      /// \brief Record code for \#pragma diagnostic mappings.
-      DIAG_PRAGMA_MAPPINGS = 32,
+      // ID 32 used to be the code for \#pragma diagnostic mappings.
 
       /// \brief Record code for special CUDA declarations.
       CUDA_SPECIAL_DECL_REFS = 33,
@@ -591,6 +602,11 @@ namespace clang {
 
       /// \brief Record code for declarations associated with OpenCL extensions.
       OPENCL_EXTENSION_DECLS = 59,
+
+      MODULAR_CODEGEN_DECLS = 60,
+
+      /// \brief Record code for \#pragma pack options.
+      PACK_PRAGMA_OPTIONS = 61,
     };
 
     /// \brief Record types used within a source manager block.
@@ -801,14 +817,12 @@ namespace clang {
       PREDEF_TYPE_SAMPLER_ID    = 39,
       /// \brief OpenCL queue type.
       PREDEF_TYPE_QUEUE_ID      = 40,
-      /// \brief OpenCL ndrange type.
-      PREDEF_TYPE_NDRANGE_ID    = 41,
       /// \brief OpenCL reserve_id type.
-      PREDEF_TYPE_RESERVE_ID_ID = 42,
+      PREDEF_TYPE_RESERVE_ID_ID = 41,
       /// \brief The placeholder type for OpenMP array section.
-      PREDEF_TYPE_OMP_ARRAY_SECTION = 43,
+      PREDEF_TYPE_OMP_ARRAY_SECTION = 42,
       /// \brief The '__float128' type
-      PREDEF_TYPE_FLOAT128_ID = 44,
+      PREDEF_TYPE_FLOAT128_ID = 43,
       /// \brief OpenCL image types with auto numeration
 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
       PREDEF_TYPE_##Id##_ID,
@@ -914,7 +928,11 @@ namespace clang {
       /// \brief A PipeType record.
       TYPE_PIPE                  = 43,
       /// \brief An ObjCTypeParamType record.
-      TYPE_OBJC_TYPE_PARAM       = 44
+      TYPE_OBJC_TYPE_PARAM       = 44,
+      /// \brief A DeducedTemplateSpecializationType record.
+      TYPE_DEDUCED_TEMPLATE_SPECIALIZATION = 45,
+      /// \brief A DependentSizedExtVectorType record.
+      TYPE_DEPENDENT_SIZED_EXT_VECTOR = 46
     };
 
     /// \brief The type IDs for special types constructed by semantic
@@ -1121,6 +1139,8 @@ namespace clang {
       DECL_EXPORT,
       /// \brief A CXXRecordDecl record.
       DECL_CXX_RECORD,
+      /// \brief A CXXDeductionGuideDecl record.
+      DECL_CXX_DEDUCTION_GUIDE,
       /// \brief A CXXMethodDecl record.
       DECL_CXX_METHOD,
       /// \brief A CXXConstructorDecl record.
@@ -1624,7 +1644,8 @@ namespace clang {
 
       IdentifierInfo *getIdentifier() const {
         assert(Kind == DeclarationName::Identifier ||
-               Kind == DeclarationName::CXXLiteralOperatorName);
+               Kind == DeclarationName::CXXLiteralOperatorName ||
+               Kind == DeclarationName::CXXDeductionGuideName);
         return (IdentifierInfo *)Data;
       }
       Selector getSelector() const {
diff --git a/include/clang/Serialization/ASTDeserializationListener.h b/include/clang/Serialization/ASTDeserializationListener.h
index 4b10c39d8fb22..c26f3e0b425e4 100644
--- a/include/clang/Serialization/ASTDeserializationListener.h
+++ b/include/clang/Serialization/ASTDeserializationListener.h
@@ -26,6 +26,7 @@ class QualType;
 class MacroDefinitionRecord;
 class MacroInfo;
 class Module;
+class SourceLocation;
 
 class ASTDeserializationListener {
 public:
@@ -52,6 +53,9 @@ public:
                                    MacroDefinitionRecord *MD) {}
   /// \brief A module definition was read from the AST file.
   virtual void ModuleRead(serialization::SubmoduleID ID, Module *Mod) {}
+  /// \brief A module import was read from the AST file.
+  virtual void ModuleImportRead(serialization::SubmoduleID ID,
+                                SourceLocation ImportLoc) {}
 };
 }
 
diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index 93994e2c519c7..63ccb24616165 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -408,6 +408,9 @@ private:
   /// \brief The module manager which manages modules and their dependencies
   ModuleManager ModuleMgr;
 
+  /// The cache that manages memory buffers for PCM files.
+  MemoryBufferCache &PCMCache;
+
   /// \brief A dummy identifier resolver used to merge TU-scope declarations in
   /// C, for the cases where we don't have a Sema object to provide a real
   /// identifier resolver.
@@ -700,7 +703,7 @@ private:
 
   /// \brief Mapping from global preprocessing entity IDs to the module in
   /// which the preprocessed entity resides along with the offset that should be
-  /// added to the global preprocessing entitiy ID to produce a local ID.
+  /// added to the global preprocessing entity ID to produce a local ID.
   GlobalPreprocessedEntityMapType GlobalPreprocessedEntityMap;
 
   /// \name CodeGen-relevant special data
@@ -808,6 +811,17 @@ private:
   int PragmaMSPointersToMembersState = -1;
   SourceLocation PointersToMembersPragmaLocation;
 
+  /// \brief The pragma pack state.
+  Optional<unsigned> PragmaPackCurrentValue;
+  SourceLocation PragmaPackCurrentLocation;
+  struct PragmaPackStackEntry {
+    unsigned Value;
+    SourceLocation Location;
+    StringRef SlotLabel;
+  };
+  llvm::SmallVector<PragmaPackStackEntry, 2> PragmaPackStack;
+  llvm::SmallVector<std::string, 2> PragmaPackStrings;
+
   /// \brief The OpenCL extension settings.
   OpenCLOptions OpenCLExtensions;
 
@@ -970,14 +984,26 @@ private:
   /// \brief The generation number of each identifier, which keeps track of
   /// the last time we loaded information about this identifier.
   llvm::DenseMap<IdentifierInfo *, unsigned> IdentifierGeneration;
-  
-  /// \brief Contains declarations and definitions that will be
+
+  class InterestingDecl {
+    Decl *D;
+    bool DeclHasPendingBody;
+
+  public:
+    InterestingDecl(Decl *D, bool HasBody)
+        : D(D), DeclHasPendingBody(HasBody) {}
+    Decl *getDecl() { return D; }
+    /// Whether the declaration has a pending body.
+    bool hasPendingBody() { return DeclHasPendingBody; }
+  };
+
+  /// \brief Contains declarations and definitions that could be
   /// "interesting" to the ASTConsumer, when we get that AST consumer.
   ///
   /// "Interesting" declarations are those that have data that may
   /// need to be emitted, such as inline function definitions or
   /// Objective-C protocols.
-  std::deque<Decl *> InterestingDecls;
+  std::deque<InterestingDecl> PotentiallyInterestingDecls;
 
   /// \brief The list of redeclaration chains that still need to be 
   /// reconstructed, and the local offset to the corresponding list
@@ -1101,6 +1127,8 @@ private:
   /// predefines buffer may contain additional definitions.
   std::string SuggestedPredefines;
 
+  llvm::DenseMap<const Decl *, bool> BodySource;
+
   /// \brief Reads a statement from the specified cursor.
   Stmt *ReadStmtFromStream(ModuleFile &F);
 
@@ -1174,7 +1202,7 @@ private:
                             SourceLocation ImportLoc, ModuleFile *ImportedBy,
                             SmallVectorImpl<ImportedModule> &Loaded,
                             off_t ExpectedSize, time_t ExpectedModTime,
-                            serialization::ASTFileSignature ExpectedSignature,
+                            ASTFileSignature ExpectedSignature,
                             unsigned ClientLoadCapabilities);
   ASTReadResult ReadControlBlock(ModuleFile &F,
                                  SmallVectorImpl<ImportedModule> &Loaded,
@@ -1183,9 +1211,25 @@ private:
   static ASTReadResult ReadOptionsBlock(
       llvm::BitstreamCursor &Stream, unsigned ClientLoadCapabilities,
       bool AllowCompatibleConfigurationMismatch, ASTReaderListener &Listener,
-      std::string &SuggestedPredefines, bool ValidateDiagnosticOptions);
+      std::string &SuggestedPredefines);
+
+  /// Read the unhashed control block.
+  ///
+  /// This has no effect on \c F.Stream, instead creating a fresh cursor from
+  /// \c F.Data and reading ahead.
+  ASTReadResult readUnhashedControlBlock(ModuleFile &F, bool WasImportedBy,
+                                         unsigned ClientLoadCapabilities);
+
+  static ASTReadResult
+  readUnhashedControlBlockImpl(ModuleFile *F, llvm::StringRef StreamData,
+                               unsigned ClientLoadCapabilities,
+                               bool AllowCompatibleConfigurationMismatch,
+                               ASTReaderListener *Listener,
+                               bool ValidateDiagnosticOptions);
+
   ASTReadResult ReadASTBlock(ModuleFile &F, unsigned ClientLoadCapabilities);
   ASTReadResult ReadExtensionBlock(ModuleFile &F);
+  void ReadModuleOffsetMap(ModuleFile &F) const;
   bool ParseLineTable(ModuleFile &F, const RecordData &Record);
   bool ReadSourceManagerBlock(ModuleFile &F);
   llvm::BitstreamCursor &SLocCursorForID(int ID);
@@ -1268,6 +1312,7 @@ private:
   llvm::iterator_range<PreprocessingRecord::iterator>
   getModulePreprocessedEntities(ModuleFile &Mod) const;
 
+public:
   class ModuleDeclIterator
       : public llvm::iterator_adaptor_base<
             ModuleDeclIterator, const serialization::LocalDeclID *,
@@ -1298,6 +1343,7 @@ private:
   llvm::iterator_range<ModuleDeclIterator>
   getModuleFileLevelDecls(ModuleFile &Mod);
 
+private:
   void PassInterestingDeclsToConsumer();
   void PassInterestingDeclToConsumer(Decl *D);
 
@@ -1318,9 +1364,9 @@ private:
   ///
   /// This routine should only be used for fatal errors that have to
   /// do with non-routine failures (e.g., corrupted AST file).
-  void Error(StringRef Msg);
+  void Error(StringRef Msg) const;
   void Error(unsigned DiagID, StringRef Arg1 = StringRef(),
-             StringRef Arg2 = StringRef());
+             StringRef Arg2 = StringRef()) const;
 
   ASTReader(const ASTReader &) = delete;
   void operator=(const ASTReader &) = delete;
@@ -1564,7 +1610,7 @@ public:
                                   const LangOptions &LangOpts,
                                   const TargetOptions &TargetOpts,
                                   const PreprocessorOptions &PPOpts,
-                                  std::string ExistingModuleCachePath);
+                                  StringRef ExistingModuleCachePath);
 
   /// \brief Returns the suggested contents of the predefines buffer,
   /// which contains a (typically-empty) subset of the predefines
@@ -1631,11 +1677,8 @@ public:
   /// reader.
   unsigned getTotalNumPreprocessedEntities() const {
     unsigned Result = 0;
-    for (ModuleConstIterator I = ModuleMgr.begin(),
-        E = ModuleMgr.end(); I != E; ++I) {
-      Result += (*I)->NumPreprocessedEntities;
-    }
-
+    for (const auto &M : ModuleMgr)
+      Result += M.NumPreprocessedEntities;
     return Result;
   }
 
@@ -1904,10 +1947,10 @@ public:
                                SmallVectorImpl<Decl *> *Decls = nullptr);
 
   /// \brief Report a diagnostic.
-  DiagnosticBuilder Diag(unsigned DiagID);
+  DiagnosticBuilder Diag(unsigned DiagID) const;
 
   /// \brief Report a diagnostic.
-  DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID);
+  DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) const;
 
   IdentifierInfo *DecodeIdentifierInfo(serialization::IdentifierID ID);
 
@@ -1968,6 +2011,8 @@ public:
   /// \brief Return a descriptor for the corresponding module.
   llvm::Optional<ASTSourceDescriptor> getSourceDescriptor(unsigned ID) override;
 
+  ExtKind hasExternalDefinitions(const Decl *D) override;
+
   /// \brief Retrieve a selector from the given module with its local ID
   /// number.
   Selector getLocalSelector(ModuleFile &M, unsigned LocalID);
@@ -2057,6 +2102,8 @@ public:
   /// location space into ours.
   SourceLocation TranslateSourceLocation(ModuleFile &ModuleFile,
                                          SourceLocation Loc) const {
+    if (!ModuleFile.ModuleOffsetMap.empty())
+      ReadModuleOffsetMap(ModuleFile);
     assert(ModuleFile.SLocRemap.find(Loc.getOffset()) !=
                ModuleFile.SLocRemap.end() &&
            "Cannot find offset to remap.");
@@ -2098,8 +2145,7 @@ public:
                                  unsigned &Idx);
 
   /// \brief Reads attributes from the current stream position.
-  void ReadAttributes(ModuleFile &F, AttrVec &Attrs,
-                      const RecordData &Record, unsigned &Idx);
+  void ReadAttributes(ASTRecordReader &Record, AttrVec &Attrs);
 
   /// \brief Reads a statement.
   Stmt *ReadStmt(ModuleFile &F);
@@ -2189,6 +2235,12 @@ public:
   /// \brief Loads comments ranges.
   void ReadComments() override;
 
+  /// Visit all the input files of the given module file.
+  void visitInputFiles(serialization::ModuleFile &MF,
+                       bool IncludeSystem, bool Complain,
+          llvm::function_ref<void(const serialization::InputFile &IF,
+                                  bool isSystem)> Visitor);
+
   bool isProcessingUpdateRecords() { return ProcessingUpdateRecords; }
 };
 
@@ -2284,6 +2336,14 @@ public:
   /// \brief Reads a sub-expression operand during statement reading.
   Expr *readSubExpr() { return Reader->ReadSubExpr(); }
 
+  /// \brief Reads a declaration with the given local ID in the given module.
+  ///
+  /// \returns The requested declaration, casted to the given return type.
+  template<typename T>
+  T *GetLocalDeclAs(uint32_t LocalID) {
+    return cast_or_null<T>(Reader->GetLocalDecl(*F, LocalID));
+  }
+
   /// \brief Reads a TemplateArgumentLocInfo appropriate for the
   /// given TemplateArgument kind, advancing Idx.
   TemplateArgumentLocInfo
@@ -2455,7 +2515,7 @@ public:
 
   /// \brief Reads attributes from the current stream position, advancing Idx.
   void readAttributes(AttrVec &Attrs) {
-    return Reader->ReadAttributes(*F, Attrs, Record, Idx);
+    return Reader->ReadAttributes(*this, Attrs);
   }
 
   /// \brief Reads a token out of a record, advancing Idx.
diff --git a/include/clang/Serialization/ASTWriter.h b/include/clang/Serialization/ASTWriter.h
index 0d6b0268109dc..17cf726e4d6bb 100644
--- a/include/clang/Serialization/ASTWriter.h
+++ b/include/clang/Serialization/ASTWriter.h
@@ -54,6 +54,7 @@ class MacroInfo;
 class OpaqueValueExpr;
 class OpenCLOptions;
 class ASTReader;
+class MemoryBufferCache;
 class Module;
 class ModuleFileExtension;
 class ModuleFileExtensionWriter;
@@ -106,6 +107,12 @@ private:
   /// \brief The bitstream writer used to emit this precompiled header.
   llvm::BitstreamWriter &Stream;
 
+  /// The buffer associated with the bitstream.
+  const SmallVectorImpl<char> &Buffer;
+
+  /// \brief The PCM manager which manages memory buffers for pcm files.
+  MemoryBufferCache &PCMCache;
+
   /// \brief The ASTContext we're writing.
   ASTContext *Context = nullptr;
 
@@ -365,6 +372,7 @@ private:
   /// IDs, since they will be written out to an EAGERLY_DESERIALIZED_DECLS
   /// record.
   SmallVector<uint64_t, 16> EagerlyDeserializedDecls;
+  SmallVector<uint64_t, 16> ModularCodegenDecls;
 
   /// \brief DeclContexts that have received extensions since their serialized
   /// form.
@@ -424,8 +432,16 @@ private:
   void WriteSubStmt(Stmt *S);
 
   void WriteBlockInfoBlock();
-  uint64_t WriteControlBlock(Preprocessor &PP, ASTContext &Context,
-                             StringRef isysroot, const std::string &OutputFile);
+  void WriteControlBlock(Preprocessor &PP, ASTContext &Context,
+                         StringRef isysroot, const std::string &OutputFile);
+
+  /// Write out the signature and diagnostic options, and return the signature.
+  ASTFileSignature writeUnhashedControlBlock(Preprocessor &PP,
+                                             ASTContext &Context);
+
+  /// Calculate hash of the pcm content.
+  static ASTFileSignature createSignature(StringRef Bytes);
+
   void WriteInputFiles(SourceManager &SourceMgr, HeaderSearchOptions &HSOpts,
                        bool Modules);
   void WriteSourceManagerBlock(SourceManager &SourceMgr,
@@ -469,6 +485,7 @@ private:
   void WriteOptimizePragmaOptions(Sema &SemaRef);
   void WriteMSStructPragmaOptions(Sema &SemaRef);
   void WriteMSPointersToMembersPragmaOptions(Sema &SemaRef);
+  void WritePackPragmaOptions(Sema &SemaRef);
   void WriteModuleFileExtension(Sema &SemaRef,
                                 ModuleFileExtensionWriter &Writer);
 
@@ -492,14 +509,15 @@ private:
   void WriteDeclAbbrevs();
   void WriteDecl(ASTContext &Context, Decl *D);
 
-  uint64_t WriteASTCore(Sema &SemaRef,
-                        StringRef isysroot, const std::string &OutputFile,
-                        Module *WritingModule);
+  ASTFileSignature WriteASTCore(Sema &SemaRef, StringRef isysroot,
+                                const std::string &OutputFile,
+                                Module *WritingModule);
 
 public:
   /// \brief Create a new precompiled header writer that outputs to
   /// the given bitstream.
-  ASTWriter(llvm::BitstreamWriter &Stream,
+  ASTWriter(llvm::BitstreamWriter &Stream, SmallVectorImpl<char> &Buffer,
+            MemoryBufferCache &PCMCache,
             ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
             bool IncludeTimestamps = true);
   ~ASTWriter() override;
@@ -525,9 +543,9 @@ public:
   ///
   /// \return the module signature, which eventually will be a hash of
   /// the module but currently is merely a random 32-bit number.
-  uint64_t WriteAST(Sema &SemaRef, const std::string &OutputFile,
-                    Module *WritingModule, StringRef isysroot,
-                    bool hasErrors = false);
+  ASTFileSignature WriteAST(Sema &SemaRef, const std::string &OutputFile,
+                            Module *WritingModule, StringRef isysroot,
+                            bool hasErrors = false);
 
   /// \brief Emit a token.
   void AddToken(const Token &Tok, RecordDataImpl &Record);
diff --git a/include/clang/Serialization/Module.h b/include/clang/Serialization/Module.h
index 58b3149d407e7..4e4bf44f34920 100644
--- a/include/clang/Serialization/Module.h
+++ b/include/clang/Serialization/Module.h
@@ -16,6 +16,7 @@
 #define LLVM_CLANG_SERIALIZATION_MODULE_H
 
 #include "clang/Basic/FileManager.h"
+#include "clang/Basic/Module.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Serialization/ASTBitCodes.h"
 #include "clang/Serialization/ContinuousRangeMap.h"
@@ -89,8 +90,6 @@ public:
   bool isNotFound() const { return Val.getInt() == NotFound; }
 };
 
-typedef unsigned ASTFileSignature;
-
 /// \brief Information about a module that has been loaded by the ASTReader.
 ///
 /// Each instance of the Module class corresponds to a single AST file, which
@@ -100,13 +99,14 @@ typedef unsigned ASTFileSignature;
 /// other modules.
 class ModuleFile {
 public:
-  ModuleFile(ModuleKind Kind, unsigned Generation);
+  ModuleFile(ModuleKind Kind, unsigned Generation)
+      : Kind(Kind), Generation(Generation) {}
   ~ModuleFile();
 
   // === General information ===
 
   /// \brief The index of this module in the list of modules.
-  unsigned Index;
+  unsigned Index = 0;
 
   /// \brief The type of this module.
   ModuleKind Kind;
@@ -144,34 +144,34 @@ public:
   std::string ModuleMapPath;
 
   /// \brief Whether this precompiled header is a relocatable PCH file.
-  bool RelocatablePCH;
+  bool RelocatablePCH = false;
 
   /// \brief Whether timestamps are included in this module file.
-  bool HasTimestamps;
+  bool HasTimestamps = false;
 
   /// \brief The file entry for the module file.
-  const FileEntry *File;
+  const FileEntry *File = nullptr;
 
-  /// \brief The signature of the module file, which may be used along with size
+  /// The signature of the module file, which may be used instead of the size
   /// and modification time to identify this particular file.
   ASTFileSignature Signature;
 
   /// \brief Whether this module has been directly imported by the
   /// user.
-  bool DirectlyImported;
+  bool DirectlyImported = false;
 
   /// \brief The generation of which this module file is a part.
   unsigned Generation;
   
-  /// \brief The memory buffer that stores the data associated with
-  /// this AST file.
-  std::unique_ptr<llvm::MemoryBuffer> Buffer;
+  /// The memory buffer that stores the data associated with
+  /// this AST file, owned by the PCMCache in the ModuleManager.
+  llvm::MemoryBuffer *Buffer;
 
   /// \brief The size of this file, in bits.
-  uint64_t SizeInBits;
+  uint64_t SizeInBits = 0;
 
   /// \brief The global bit offset (or base) of this module
-  uint64_t GlobalBitOffset;
+  uint64_t GlobalBitOffset = 0;
 
   /// \brief The serialized bitstream data for this file.
   StringRef Data;
@@ -200,21 +200,29 @@ public:
   /// file.
   std::vector<std::unique_ptr<ModuleFileExtensionReader>> ExtensionReaders;
 
+  /// The module offset map data for this file. If non-empty, the various
+  /// ContinuousRangeMaps described below have not yet been populated.
+  StringRef ModuleOffsetMap;
+
   // === Input Files ===
   /// \brief The cursor to the start of the input-files block.
   llvm::BitstreamCursor InputFilesCursor;
 
   /// \brief Offsets for all of the input file entries in the AST file.
-  const llvm::support::unaligned_uint64_t *InputFileOffsets;
+  const llvm::support::unaligned_uint64_t *InputFileOffsets = nullptr;
 
   /// \brief The input files that have been loaded from this AST file.
   std::vector<InputFile> InputFilesLoaded;
 
+  // All user input files reside at the index range [0, NumUserInputFiles), and
+  // system input files reside at [NumUserInputFiles, InputFilesLoaded.size()).
+  unsigned NumUserInputFiles = 0;
+
   /// \brief If non-zero, specifies the time when we last validated input
   /// files.  Zero means we never validated them.
   ///
   /// The time is specified in seconds since the start of the Epoch.
-  uint64_t InputFilesValidationTimestamp;
+  uint64_t InputFilesValidationTimestamp = 0;
 
   // === Source Locations ===
 
@@ -222,17 +230,17 @@ public:
   llvm::BitstreamCursor SLocEntryCursor;
 
   /// \brief The number of source location entries in this AST file.
-  unsigned LocalNumSLocEntries;
+  unsigned LocalNumSLocEntries = 0;
 
   /// \brief The base ID in the source manager's view of this module.
-  int SLocEntryBaseID;
+  int SLocEntryBaseID = 0;
 
   /// \brief The base offset in the source manager's view of this module.
-  unsigned SLocEntryBaseOffset;
+  unsigned SLocEntryBaseOffset = 0;
 
   /// \brief Offsets for all of the source location entries in the
   /// AST file.
-  const uint32_t *SLocEntryOffsets;
+  const uint32_t *SLocEntryOffsets = nullptr;
 
   /// \brief SLocEntries that we're going to preload.
   SmallVector<uint64_t, 4> PreloadSLocEntries;
@@ -243,17 +251,17 @@ public:
   // === Identifiers ===
 
   /// \brief The number of identifiers in this AST file.
-  unsigned LocalNumIdentifiers;
+  unsigned LocalNumIdentifiers = 0;
 
   /// \brief Offsets into the identifier table data.
   ///
   /// This array is indexed by the identifier ID (-1), and provides
   /// the offset into IdentifierTableData where the string data is
   /// stored.
-  const uint32_t *IdentifierOffsets;
+  const uint32_t *IdentifierOffsets = nullptr;
 
   /// \brief Base identifier ID for identifiers local to this module.
-  serialization::IdentID BaseIdentifierID;
+  serialization::IdentID BaseIdentifierID = 0;
 
   /// \brief Remapping table for identifier IDs in this module.
   ContinuousRangeMap<uint32_t, int, 2> IdentifierRemap;
@@ -262,11 +270,11 @@ public:
   ///
   /// This pointer points into a memory buffer, where the on-disk hash
   /// table for identifiers actually lives.
-  const char *IdentifierTableData;
+  const char *IdentifierTableData = nullptr;
 
   /// \brief A pointer to an on-disk hash table of opaque type
   /// IdentifierHashTable.
-  void *IdentifierLookupTable;
+  void *IdentifierLookupTable = nullptr;
 
   /// \brief Offsets of identifiers that we're going to preload within
   /// IdentifierTableData.
@@ -279,23 +287,23 @@ public:
   llvm::BitstreamCursor MacroCursor;
 
   /// \brief The number of macros in this AST file.
-  unsigned LocalNumMacros;
+  unsigned LocalNumMacros = 0;
 
   /// \brief Offsets of macros in the preprocessor block.
   ///
   /// This array is indexed by the macro ID (-1), and provides
   /// the offset into the preprocessor block where macro definitions are
   /// stored.
-  const uint32_t *MacroOffsets;
+  const uint32_t *MacroOffsets = nullptr;
 
   /// \brief Base macro ID for macros local to this module.
-  serialization::MacroID BaseMacroID;
+  serialization::MacroID BaseMacroID = 0;
 
   /// \brief Remapping table for macro IDs in this module.
   ContinuousRangeMap<uint32_t, int, 2> MacroRemap;
 
   /// \brief The offset of the start of the set of defined macros.
-  uint64_t MacroStartOffset;
+  uint64_t MacroStartOffset = 0;
 
   // === Detailed PreprocessingRecord ===
 
@@ -304,40 +312,40 @@ public:
   llvm::BitstreamCursor PreprocessorDetailCursor;
 
   /// \brief The offset of the start of the preprocessor detail cursor.
-  uint64_t PreprocessorDetailStartOffset;
+  uint64_t PreprocessorDetailStartOffset = 0;
 
   /// \brief Base preprocessed entity ID for preprocessed entities local to
   /// this module.
-  serialization::PreprocessedEntityID BasePreprocessedEntityID;
+  serialization::PreprocessedEntityID BasePreprocessedEntityID = 0;
 
   /// \brief Remapping table for preprocessed entity IDs in this module.
   ContinuousRangeMap<uint32_t, int, 2> PreprocessedEntityRemap;
 
-  const PPEntityOffset *PreprocessedEntityOffsets;
-  unsigned NumPreprocessedEntities;
+  const PPEntityOffset *PreprocessedEntityOffsets = nullptr;
+  unsigned NumPreprocessedEntities = 0;
 
   // === Header search information ===
 
   /// \brief The number of local HeaderFileInfo structures.
-  unsigned LocalNumHeaderFileInfos;
+  unsigned LocalNumHeaderFileInfos = 0;
 
   /// \brief Actual data for the on-disk hash table of header file
   /// information.
   ///
   /// This pointer points into a memory buffer, where the on-disk hash
   /// table for header file information actually lives.
-  const char *HeaderFileInfoTableData;
+  const char *HeaderFileInfoTableData = nullptr;
 
   /// \brief The on-disk hash table that contains information about each of
   /// the header files.
-  void *HeaderFileInfoTable;
+  void *HeaderFileInfoTable = nullptr;
 
   // === Submodule information ===  
   /// \brief The number of submodules in this module.
-  unsigned LocalNumSubmodules;
+  unsigned LocalNumSubmodules = 0;
   
   /// \brief Base submodule ID for submodules local to this module.
-  serialization::SubmoduleID BaseSubmoduleID;
+  serialization::SubmoduleID BaseSubmoduleID = 0;
   
   /// \brief Remapping table for submodule IDs in this module.
   ContinuousRangeMap<uint32_t, int, 2> SubmoduleRemap;
@@ -347,14 +355,14 @@ public:
   /// \brief The number of selectors new to this file.
   ///
   /// This is the number of entries in SelectorOffsets.
-  unsigned LocalNumSelectors;
+  unsigned LocalNumSelectors = 0;
 
   /// \brief Offsets into the selector lookup table's data array
   /// where each selector resides.
-  const uint32_t *SelectorOffsets;
+  const uint32_t *SelectorOffsets = nullptr;
 
   /// \brief Base selector ID for selectors local to this module.
-  serialization::SelectorID BaseSelectorID;
+  serialization::SelectorID BaseSelectorID = 0;
 
   /// \brief Remapping table for selector IDs in this module.
   ContinuousRangeMap<uint32_t, int, 2> SelectorRemap;
@@ -362,14 +370,14 @@ public:
   /// \brief A pointer to the character data that comprises the selector table
   ///
   /// The SelectorOffsets table refers into this memory.
-  const unsigned char *SelectorLookupTableData;
+  const unsigned char *SelectorLookupTableData = nullptr;
 
   /// \brief A pointer to an on-disk hash table of opaque type
   /// ASTSelectorLookupTable.
   ///
   /// This hash table provides the IDs of all selectors, and the associated
   /// instance and factory methods.
-  void *SelectorLookupTable;
+  void *SelectorLookupTable = nullptr;
 
   // === Declarations ===
 
@@ -379,14 +387,14 @@ public:
   llvm::BitstreamCursor DeclsCursor;
 
   /// \brief The number of declarations in this AST file.
-  unsigned LocalNumDecls;
+  unsigned LocalNumDecls = 0;
 
   /// \brief Offset of each declaration within the bitstream, indexed
   /// by the declaration ID (-1).
-  const DeclOffset *DeclOffsets;
+  const DeclOffset *DeclOffsets = nullptr;
 
   /// \brief Base declaration ID for declarations local to this module.
-  serialization::DeclID BaseDeclID;
+  serialization::DeclID BaseDeclID = 0;
 
   /// \brief Remapping table for declaration IDs in this module.
   ContinuousRangeMap<uint32_t, int, 2> DeclRemap;
@@ -401,15 +409,15 @@ public:
   llvm::DenseMap<ModuleFile *, serialization::DeclID> GlobalToLocalDeclIDs;
 
   /// \brief Array of file-level DeclIDs sorted by file.
-  const serialization::DeclID *FileSortedDecls;
-  unsigned NumFileSortedDecls;
+  const serialization::DeclID *FileSortedDecls = nullptr;
+  unsigned NumFileSortedDecls = 0;
 
   /// \brief Array of category list location information within this 
   /// module file, sorted by the definition ID.
-  const serialization::ObjCCategoriesInfo *ObjCCategoriesMap;
+  const serialization::ObjCCategoriesInfo *ObjCCategoriesMap = nullptr;
   
   /// \brief The number of redeclaration info entries in ObjCCategoriesMap.
-  unsigned LocalNumObjCCategoriesInMap;
+  unsigned LocalNumObjCCategoriesInMap = 0;
   
   /// \brief The Objective-C category lists for categories known to this
   /// module.
@@ -418,15 +426,15 @@ public:
   // === Types ===
 
   /// \brief The number of types in this AST file.
-  unsigned LocalNumTypes;
+  unsigned LocalNumTypes = 0;
 
   /// \brief Offset of each type within the bitstream, indexed by the
   /// type ID, or the representation of a Type*.
-  const uint32_t *TypeOffsets;
+  const uint32_t *TypeOffsets = nullptr;
 
   /// \brief Base type ID for types local to this module as represented in
   /// the global type ID space.
-  serialization::TypeID BaseTypeIndex;
+  serialization::TypeID BaseTypeIndex = 0;
 
   /// \brief Remapping table for type IDs in this module.
   ContinuousRangeMap<uint32_t, int, 2> TypeRemap;
diff --git a/include/clang/Serialization/ModuleManager.h b/include/clang/Serialization/ModuleManager.h
index 1c4d88e979e3a..fae387cac7e21 100644
--- a/include/clang/Serialization/ModuleManager.h
+++ b/include/clang/Serialization/ModuleManager.h
@@ -19,10 +19,12 @@
 #include "clang/Serialization/Module.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/iterator.h"
 
 namespace clang { 
 
 class GlobalModuleIndex;
+class MemoryBufferCache;
 class ModuleMap;
 class PCHContainerReader;
 
@@ -32,7 +34,7 @@ namespace serialization {
 class ModuleManager {
   /// \brief The chain of AST files, in the order in which we started to load
   /// them (this order isn't really useful for anything).
-  SmallVector<ModuleFile *, 2> Chain;
+  SmallVector<std::unique_ptr<ModuleFile>, 2> Chain;
 
   /// \brief The chain of non-module PCH files. The first entry is the one named
   /// by the user, the last one is the one that doesn't depend on anything
@@ -50,6 +52,9 @@ class ModuleManager {
   /// FileEntry *.
   FileManager &FileMgr;
 
+  /// Cache of PCM files.
+  IntrusiveRefCntPtr<MemoryBufferCache> PCMCache;
+
   /// \brief Knows how to unwrap module containers.
   const PCHContainerReader &PCHContainerRdr;
 
@@ -111,12 +116,18 @@ class ModuleManager {
   void returnVisitState(VisitState *State);
 
 public:
-  typedef SmallVectorImpl<ModuleFile*>::iterator ModuleIterator;
-  typedef SmallVectorImpl<ModuleFile*>::const_iterator ModuleConstIterator;
-  typedef SmallVectorImpl<ModuleFile*>::reverse_iterator ModuleReverseIterator;
+  typedef llvm::pointee_iterator<
+      SmallVectorImpl<std::unique_ptr<ModuleFile>>::iterator>
+      ModuleIterator;
+  typedef llvm::pointee_iterator<
+      SmallVectorImpl<std::unique_ptr<ModuleFile>>::const_iterator>
+      ModuleConstIterator;
+  typedef llvm::pointee_iterator<
+      SmallVectorImpl<std::unique_ptr<ModuleFile>>::reverse_iterator>
+      ModuleReverseIterator;
   typedef std::pair<uint32_t, StringRef> ModuleOffset;
 
-  explicit ModuleManager(FileManager &FileMgr,
+  explicit ModuleManager(FileManager &FileMgr, MemoryBufferCache &PCMCache,
                          const PCHContainerReader &PCHContainerRdr);
   ~ModuleManager();
 
@@ -136,7 +147,8 @@ public:
   ModuleReverseIterator rend() { return Chain.rend(); }
 
   /// \brief A range covering the PCH and preamble module files loaded.
-  llvm::iterator_range<ModuleConstIterator> pch_modules() const {
+  llvm::iterator_range<SmallVectorImpl<ModuleFile *>::const_iterator>
+  pch_modules() const {
     return llvm::make_range(PCHChain.begin(), PCHChain.end());
   }
 
@@ -152,10 +164,10 @@ public:
   ModuleFile &operator[](unsigned Index) const { return *Chain[Index]; }
   
   /// \brief Returns the module associated with the given name
-  ModuleFile *lookup(StringRef Name);
+  ModuleFile *lookup(StringRef Name) const;
 
   /// \brief Returns the module associated with the given module file.
-  ModuleFile *lookup(const FileEntry *File);
+  ModuleFile *lookup(const FileEntry *File) const;
 
   /// \brief Returns the in-memory (virtual file) buffer with the given name
   std::unique_ptr<llvm::MemoryBuffer> lookupBuffer(StringRef Name);
@@ -220,8 +232,8 @@ public:
                             ModuleFile *&Module,
                             std::string &ErrorStr);
 
-  /// \brief Remove the given set of modules.
-  void removeModules(ModuleIterator first, ModuleIterator last,
+  /// \brief Remove the modules starting from First (to the end).
+  void removeModules(ModuleIterator First,
                      llvm::SmallPtrSetImpl<ModuleFile *> &LoadedSuccessfully,
                      ModuleMap *modMap);
 
@@ -282,6 +294,8 @@ public:
 
   /// \brief View the graphviz representation of the module graph.
   void viewGraph();
+
+  MemoryBufferCache &getPCMCache() const { return *PCMCache; }
 };
 
 } } // end namespace clang::serialization