4 files changed, 29 insertions, 3 deletions
diff --git a/include/clang/Serialization/ASTBitCodes.h b/include/clang/Serialization/ASTBitCodes.h
index 988cac20b3..1cf118638c 100644
--- a/include/clang/Serialization/ASTBitCodes.h
+++ b/include/clang/Serialization/ASTBitCodes.h
@@ -257,7 +257,11 @@ namespace clang {
       ORIGINAL_FILE = 5,
       
       /// \brief The directory that the PCH was originally created in.
-      ORIGINAL_PCH_DIR = 6
+      ORIGINAL_PCH_DIR = 6,
+
+      /// \brief Offsets into the input-files block where input files
+      /// reside.
+      INPUT_FILE_OFFSETS = 7
     };
 
     /// \brief Record types that occur within the input-files block
diff --git a/include/clang/Serialization/ASTReader.h b/include/clang/Serialization/ASTReader.h
index 03ec200035..6be01d47e7 100644
--- a/include/clang/Serialization/ASTReader.h
+++ b/include/clang/Serialization/ASTReader.h
@@ -860,18 +860,23 @@ private:
   /// \brief Reads a statement from the specified cursor.
   Stmt *ReadStmtFromStream(ModuleFile &F);
 
+  typedef llvm::PointerIntPair<const FileEntry *, 1, bool> InputFile;
+
+  /// \brief Retrieve the file entry and 'overridden' bit for an input
+  /// file in the given module file.
+  InputFile getInputFile(ModuleFile &F, unsigned ID);
+
   /// \brief Get a FileEntry out of stored-in-PCH filename, making sure we take
   /// into account all the necessary relocations.
   const FileEntry *getFileEntry(StringRef filename);
 
-  void MaybeAddSystemRootToFilename(ModuleFile &M, std::string &Filename);
+  StringRef MaybeAddSystemRootToFilename(ModuleFile &M, std::string &Filename);
 
   ASTReadResult ReadASTCore(StringRef FileName, ModuleKind Type,
                             ModuleFile *ImportedBy,
                             llvm::SmallVectorImpl<ModuleFile *> &Loaded);
   ASTReadResult ReadControlBlock(ModuleFile &F,
                                  llvm::SmallVectorImpl<ModuleFile *> &Loaded);
-  ASTReadResult ReadInputFilesBlock(ModuleFile &F);
   ASTReadResult ReadASTBlock(ModuleFile &F);
   bool CheckPredefinesBuffers();
   bool ParseLineTable(ModuleFile &F, SmallVectorImpl<uint64_t> &Record);
diff --git a/include/clang/Serialization/ASTWriter.h b/include/clang/Serialization/ASTWriter.h
index 37cf1b3c36..be8e78e7b3 100644
--- a/include/clang/Serialization/ASTWriter.h
+++ b/include/clang/Serialization/ASTWriter.h
@@ -45,6 +45,7 @@ class ASTContext;
 class NestedNameSpecifier;
 class CXXBaseSpecifier;
 class CXXCtorInitializer;
+class FileEntry;
 class FPOptions;
 class HeaderSearch;
 class IdentifierResolver;
@@ -121,6 +122,10 @@ private:
   /// \brief Indicates that the AST contained compiler errors.
   bool ASTHasCompilerErrors;
 
+  /// \brief Mapping from input file entries to the index into the
+  /// offset table where information about that input file is stored.
+  llvm::DenseMap<const FileEntry *, uint32_t> InputFileIDs;
+
   /// \brief Stores a declaration or a type to be written to the AST file.
   class DeclOrType {
   public:
diff --git a/include/clang/Serialization/Module.h b/include/clang/Serialization/Module.h
index a1a47d8b04..2915cfc01c 100644
--- a/include/clang/Serialization/Module.h
+++ b/include/clang/Serialization/Module.h
@@ -128,6 +128,18 @@ public:
   /// \brief The first source location in this module.
   SourceLocation FirstLoc;
 
+  // === 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 uint32_t *InputFileOffsets;
+
+  /// \brief The input files that have been loaded from this AST file, along
+  /// with a bool indicating whether this was an overridden buffer.
+  std::vector<llvm::PointerIntPair<const FileEntry *, 1, bool> > 
+    InputFilesLoaded;
+
   // === Source Locations ===
 
   /// \brief Cursor used to read source location entries.