Implement (de-)serialization of the buffer contents for an overridden

file in the source manager. This allows us to properly create and use
modules described by module map files without umbrella headers (or
with incompletely umbrella headers). More generally, we can actually
build a PCH file that makes use of  file -> buffer remappings, which
could be useful in libclang in the future.

llvm-svn: 144830

1 files changed, 16 insertions, 4 deletions

diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 6893dbd9f57..51aadb35e5c 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1174,6 +1174,7 @@ static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
   // 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, 8)); // NumCreatedFIDs
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
@@ -1421,7 +1422,8 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
     // Figure out which record code to use.
     unsigned Code;
     if (SLoc->isFile()) {
-      if (SLoc->getFile().getContentCache()->OrigEntry) {
+      const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
+      if (Cache->OrigEntry) {
         Code = SM_SLOC_FILE_ENTRY;
         SLocFileEntryOffsets.push_back(Stream.GetCurrentBitNo());
       } else
@@ -1442,7 +1444,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
       const SrcMgr::ContentCache *Content = File.getContentCache();
       if (Content->OrigEntry) {
         assert(Content->OrigEntry == Content->ContentsEntry &&
-               "Writing to AST an overriden file is not supported");
+               "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.
@@ -1450,7 +1452,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
         // 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(SLoc);
@@ -1461,7 +1463,7 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
           Record.push_back(0);
           Record.push_back(0);
         }
-
+        
         // Turn the file name into an absolute path, if it isn't already.
         const char *Filename = Content->OrigEntry->getName();
         llvm::SmallString<128> FilePath(Filename);
@@ -1477,6 +1479,16 @@ void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
 
         Filename = adjustFilenameForRelocatablePCH(Filename, isysroot);
         Stream.EmitRecordWithBlob(SLocFileAbbrv, Record, Filename);
+        
+        if (Content->BufferOverridden) {
+          Record.clear();
+          Record.push_back(SM_SLOC_BUFFER_BLOB);
+          const llvm::MemoryBuffer *Buffer
+            = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
+          Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record,
+                                    StringRef(Buffer->getBufferStart(),
+                                              Buffer->getBufferSize() + 1));          
+        }
       } else {
         // The source location entry is a buffer. The blob associated
         // with this entry contains the contents of the buffer.