Eliminate the redundancy between source-file information in the source

manager block and input-file information in the control block. The
source manager entries now point back into the control block. Input
files are now lazily deserialized (if validation is disabled). Reduces
Cocoa's PCH by the ~70k I added when I introduced the redundancy in
r166251.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166429 91177308-0d34-0410-b5e6-96231b3b80d8

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.