1 files changed, 79 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/PDB/Native/GlobalsStreamBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/GlobalsStreamBuilder.cpp
new file mode 100644
index 00000000000..004691e78e7
--- /dev/null
+++ b/llvm/lib/DebugInfo/PDB/Native/GlobalsStreamBuilder.cpp
@@ -0,0 +1,79 @@
+//===- GlobalsStreamBuilder.cpp - PDB Globals Stream Creation ---*- C++ -*-===//
+//
+//                     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/Native/GlobalsStreamBuilder.h"
+
+#include "llvm/DebugInfo/MSF/MSFBuilder.h"
+#include "llvm/DebugInfo/MSF/MSFCommon.h"
+#include "llvm/DebugInfo/MSF/MappedBlockStream.h"
+#include "llvm/DebugInfo/PDB/Native/GlobalsStream.h"
+
+using namespace llvm;
+using namespace llvm::msf;
+using namespace llvm::pdb;
+
+GlobalsStreamBuilder::GlobalsStreamBuilder(msf::MSFBuilder &Msf) : Msf(Msf) {}
+
+GlobalsStreamBuilder::~GlobalsStreamBuilder() {}
+
+uint32_t GlobalsStreamBuilder::calculateSerializedLength() const {
+  uint32_t Size = 0;
+  // First is the header
+  Size += sizeof(GSIHashHeader);
+
+  // Next is the records.  For now we don't write any records, just an empty
+  // stream.
+  // FIXME: Write records and account for their size here.
+  Size += 0;
+
+  // Next is a bitmap indicating which hash buckets are valid.  The bitmap
+  // is alway present, but we only write buckets for bitmap entries which are
+  // non-zero, which now is noting.
+  size_t BitmapSizeInBits = alignTo(IPHR_HASH + 1, 32);
+  uint32_t NumBitmapEntries = BitmapSizeInBits / 8;
+  Size += NumBitmapEntries;
+
+  // FIXME: Account for hash buckets.  For now since we we write a zero-bitmap
+  // indicating that no hash buckets are valid, we also write zero byets of hash
+  // bucket data.
+  Size += 0;
+  return Size;
+}
+
+Error GlobalsStreamBuilder::finalizeMsfLayout() {
+  Expected<uint32_t> Idx = Msf.addStream(calculateSerializedLength());
+  if (!Idx)
+    return Idx.takeError();
+  StreamIdx = *Idx;
+  return Error::success();
+}
+
+Error GlobalsStreamBuilder::commit(BinaryStreamWriter &PublicsWriter) {
+  GSIHashHeader GSH;
+
+  GSH.VerSignature = GSIHashHeader::HdrSignature;
+  GSH.VerHdr = GSIHashHeader::HdrVersion;
+  GSH.HrSize = 0;
+  GSH.NumBuckets = 0;
+
+  if (auto EC = PublicsWriter.writeObject(GSH))
+    return EC;
+
+  // FIXME: Once we start writing a value other than 0 for GSH.HrSize, we need
+  // to write the hash records here.
+  size_t BitmapSizeInBits = alignTo(IPHR_HASH + 1, 32);
+  uint32_t NumBitmapEntries = BitmapSizeInBits / 8;
+  std::vector<uint8_t> BitmapData(NumBitmapEntries);
+  // FIXME: Build an actual bitmap
+  if (auto EC = PublicsWriter.writeBytes(makeArrayRef(BitmapData)))
+    return EC;
+
+  // FIXME: Write actual hash buckets.
+  return Error::success();
+}