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

1 files changed, 30 insertions, 26 deletions

diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 77b8cf93ec..801615280f 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -775,6 +775,7 @@ void ASTWriter::WriteBlockInfoBlock() {
   RECORD(TARGET_OPTIONS);
   RECORD(ORIGINAL_FILE);
   RECORD(ORIGINAL_PCH_DIR);
+  RECORD(INPUT_FILE_OFFSETS);
 
   BLOCK(INPUT_FILES_BLOCK);
   RECORD(INPUT_FILE);
@@ -1119,8 +1120,10 @@ void ASTWriter::WriteInputFiles(SourceManager &SourceMgr, StringRef isysroot) {
   // Create input-file abbreviation.
   BitCodeAbbrev *IFAbbrev = new BitCodeAbbrev();
   IFAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE));
+  IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
+  IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Overridden
   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
   unsigned IFAbbrevCode = Stream.EmitAbbrev(IFAbbrev);
 
@@ -1135,16 +1138,24 @@ void ASTWriter::WriteInputFiles(SourceManager &SourceMgr, StringRef isysroot) {
     if (!SLoc->isFile())
       continue;
     const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
-    if (!Cache->OrigEntry || Cache->BufferOverridden)
+    if (!Cache->OrigEntry)
       continue;
 
+    // Record this entry's offset.
+    InputFileOffsets.push_back(Stream.GetCurrentBitNo());
+    InputFileIDs[Cache->OrigEntry] = InputFileOffsets.size();
+
     Record.clear();
     Record.push_back(INPUT_FILE);
+    Record.push_back(InputFileOffsets.size());
 
     // Emit size/modification time for this file.
     Record.push_back(Cache->OrigEntry->getSize());
     Record.push_back(Cache->OrigEntry->getModificationTime());
 
+    // Whether this file was overridden.
+    Record.push_back(Cache->BufferOverridden);
+
     // Turn the file name into an absolute path, if it isn't already.
     const char *Filename = Cache->OrigEntry->getName();
     SmallString<128> FilePath(Filename);
@@ -1164,6 +1175,19 @@ void ASTWriter::WriteInputFiles(SourceManager &SourceMgr, StringRef isysroot) {
   }  
   
   Stream.ExitBlock();
+
+  // Create input file offsets abbreviation.
+  BitCodeAbbrev *OffsetsAbbrev = new BitCodeAbbrev();
+  OffsetsAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_OFFSETS));
+  OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # input files
+  OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));   // Array
+  unsigned OffsetsAbbrevCode = Stream.EmitAbbrev(OffsetsAbbrev);
+
+  // Write input file offsets.
+  Record.clear();
+  Record.push_back(INPUT_FILE_OFFSETS);
+  Record.push_back(InputFileOffsets.size());
+  Stream.EmitRecordWithBlob(OffsetsAbbrevCode, Record, data(InputFileOffsets));
 }
 
 //===----------------------------------------------------------------------===//
@@ -1269,13 +1293,10 @@ static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
   // FileEntry fields.
-  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
-  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
-  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // BufferOverridden
+  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Input File ID
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
-  Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
   return Stream.EmitAbbrev(Abbrev);
 }
 
@@ -1538,13 +1559,10 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
         assert(Content->OrigEntry == Content->ContentsEntry &&
                "Writing to AST an overridden file is not supported");
 
-        // The source location entry is a file. The blob associated
-        // with this entry is the file name.
+        // The source location entry is a file. Emit input file ID.
+        assert(InputFileIDs[Content->OrigEntry] != 0 && "Missed file entry");
+        Record.push_back(InputFileIDs[Content->OrigEntry]);
 
-        // Emit size/modification time for this file.
-        Record.push_back(Content->OrigEntry->getSize());
-        Record.push_back(Content->OrigEntry->getModificationTime());
-        Record.push_back(Content->BufferOverridden);
         Record.push_back(File.NumCreatedFIDs);
         
         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(FID);
@@ -1556,21 +1574,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
           Record.push_back(0);
         }
         
-        // Turn the file name into an absolute path, if it isn't already.
-        const char *Filename = Content->OrigEntry->getName();
-        SmallString<128> FilePath(Filename);
-
-        // Ask the file manager to fixup the relative path for us. This will 
-        // honor the working directory.
-        SourceMgr.getFileManager().FixupRelativePath(FilePath);
-
-        // FIXME: This call to make_absolute shouldn't be necessary, the
-        // call to FixupRelativePath should always return an absolute path.
-        llvm::sys::fs::make_absolute(FilePath);
-        Filename = FilePath.c_str();
-
-        Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
-        Stream.EmitRecordWithBlob(SLocFileAbbrv, Record, Filename);
+        Stream.EmitRecordWithAbbrev(SLocFileAbbrv, Record);
         
         if (Content->BufferOverridden) {
           Record.clear();