[pdb] Parse the module info stream for each module.

Differential Revision: http://reviews.llvm.org/D20026
Reviewed By: rnk

llvm-svn: 268942
diff --git a/llvm/lib/DebugInfo/PDB/Raw/ModStream.cpp b/llvm/lib/DebugInfo/PDB/Raw/ModStream.cpp
new file mode 100644
index 0000000..8c43507
--- /dev/null
+++ b/llvm/lib/DebugInfo/PDB/Raw/ModStream.cpp
@@ -0,0 +1,55 @@
+//===- ModStream.cpp - PDB Module Info Stream Access ----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/PDB/Raw/ModStream.h"
+#include "llvm/DebugInfo/PDB/Raw/ModInfo.h"
+#include "llvm/DebugInfo/PDB/Raw/RawError.h"
+#include "llvm/DebugInfo/PDB/Raw/StreamReader.h"
+
+using namespace llvm;
+using namespace llvm::pdb;
+
+ModStream::ModStream(PDBFile &File, const ModInfo &Module)
+    : Mod(Module), Stream(Module.getModuleStreamIndex(), File) {}
+
+ModStream::~ModStream() {}
+
+Error ModStream::reload() {
+  StreamReader Reader(Stream);
+
+  uint32_t SymbolSize = Mod.getSymbolDebugInfoByteSize();
+  uint32_t C11Size = Mod.getLineInfoByteSize();
+  uint32_t C13Size = Mod.getC13LineInfoByteSize();
+
+  if (C11Size > 0 && C13Size > 0)
+    return llvm::make_error<RawError>(raw_error_code::corrupt_file,
+                                      "Module has both C11 and C13 line info");
+
+  if (auto EC = SymbolsSubstream.initialize(Reader, SymbolSize))
+    return EC;
+  if (auto EC = LinesSubstream.initialize(Reader, C11Size))
+    return EC;
+  if (auto EC = C13LinesSubstream.initialize(Reader, C13Size))
+    return EC;
+
+  uint32_t GlobalRefsSize;
+  if (auto EC = Reader.readInteger(GlobalRefsSize))
+    return EC;
+  if (auto EC = GlobalRefsSubstream.initialize(Reader, GlobalRefsSize))
+    return EC;
+  if (Reader.bytesRemaining() > 0)
+    return llvm::make_error<RawError>(raw_error_code::corrupt_file,
+                                      "Unexpected bytes in module stream.");
+
+  return Error::success();
+}
+
+iterator_range<codeview::SymbolIterator> ModStream::symbols() const {
+  return codeview::makeSymbolRange(SymbolsSubstream.data().slice(4));
+}