1 files changed, 191 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
new file mode 100644
index 000000000000..419734771ccd
--- /dev/null
+++ b/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
@@ -0,0 +1,191 @@
+//===- DbiModuleDescriptorBuilder.cpp - PDB Mod Info Creation ---*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.h"
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/BinaryFormat/COFF.h"
+#include "llvm/DebugInfo/CodeView/DebugSubsectionRecord.h"
+#include "llvm/DebugInfo/MSF/MSFBuilder.h"
+#include "llvm/DebugInfo/MSF/MSFCommon.h"
+#include "llvm/DebugInfo/MSF/MappedBlockStream.h"
+#include "llvm/DebugInfo/PDB/Native/DbiModuleDescriptor.h"
+#include "llvm/DebugInfo/PDB/Native/GSIStreamBuilder.h"
+#include "llvm/DebugInfo/PDB/Native/RawConstants.h"
+#include "llvm/DebugInfo/PDB/Native/RawError.h"
+#include "llvm/Support/BinaryStreamWriter.h"
+
+using namespace llvm;
+using namespace llvm::codeview;
+using namespace llvm::msf;
+using namespace llvm::pdb;
+
+static uint32_t calculateDiSymbolStreamSize(uint32_t SymbolByteSize,
+                                            uint32_t C13Size) {
+  uint32_t Size = sizeof(uint32_t);   // Signature
+  Size += alignTo(SymbolByteSize, 4); // Symbol Data
+  Size += 0;                          // TODO: Layout.C11Bytes
+  Size += C13Size;                    // C13 Debug Info Size
+  Size += sizeof(uint32_t);           // GlobalRefs substream size (always 0)
+  Size += 0;                          // GlobalRefs substream bytes
+  return Size;
+}
+
+DbiModuleDescriptorBuilder::DbiModuleDescriptorBuilder(StringRef ModuleName,
+                                                       uint32_t ModIndex,
+                                                       msf::MSFBuilder &Msf)
+    : MSF(Msf), ModuleName(ModuleName) {
+  ::memset(&Layout, 0, sizeof(Layout));
+  Layout.Mod = ModIndex;
+}
+
+DbiModuleDescriptorBuilder::~DbiModuleDescriptorBuilder() {}
+
+uint16_t DbiModuleDescriptorBuilder::getStreamIndex() const {
+  return Layout.ModDiStream;
+}
+
+void DbiModuleDescriptorBuilder::setObjFileName(StringRef Name) {
+  ObjFileName = Name;
+}
+
+void DbiModuleDescriptorBuilder::setPdbFilePathNI(uint32_t NI) {
+  PdbFilePathNI = NI;
+}
+
+void DbiModuleDescriptorBuilder::setFirstSectionContrib(
+    const SectionContrib &SC) {
+  Layout.SC = SC;
+}
+
+void DbiModuleDescriptorBuilder::addSymbol(CVSymbol Symbol) {
+  // Defer to the bulk API. It does the same thing.
+  addSymbolsInBulk(Symbol.data());
+}
+
+void DbiModuleDescriptorBuilder::addSymbolsInBulk(
+    ArrayRef<uint8_t> BulkSymbols) {
+  // Do nothing for empty runs of symbols.
+  if (BulkSymbols.empty())
+    return;
+
+  Symbols.push_back(BulkSymbols);
+  // Symbols written to a PDB file are required to be 4 byte aligned. The same
+  // is not true of object files.
+  assert(BulkSymbols.size() % alignOf(CodeViewContainer::Pdb) == 0 &&
+         "Invalid Symbol alignment!");
+  SymbolByteSize += BulkSymbols.size();
+}
+
+void DbiModuleDescriptorBuilder::addSourceFile(StringRef Path) {
+  SourceFiles.push_back(Path);
+}
+
+uint32_t DbiModuleDescriptorBuilder::calculateC13DebugInfoSize() const {
+  uint32_t Result = 0;
+  for (const auto &Builder : C13Builders) {
+    assert(Builder && "Empty C13 Fragment Builder!");
+    Result += Builder->calculateSerializedLength();
+  }
+  return Result;
+}
+
+uint32_t DbiModuleDescriptorBuilder::calculateSerializedLength() const {
+  uint32_t L = sizeof(Layout);
+  uint32_t M = ModuleName.size() + 1;
+  uint32_t O = ObjFileName.size() + 1;
+  return alignTo(L + M + O, sizeof(uint32_t));
+}
+
+void DbiModuleDescriptorBuilder::finalize() {
+  Layout.FileNameOffs = 0; // TODO: Fix this
+  Layout.Flags = 0;        // TODO: Fix this
+  Layout.C11Bytes = 0;
+  Layout.C13Bytes = calculateC13DebugInfoSize();
+  (void)Layout.Mod;         // Set in constructor
+  (void)Layout.ModDiStream; // Set in finalizeMsfLayout
+  Layout.NumFiles = SourceFiles.size();
+  Layout.PdbFilePathNI = PdbFilePathNI;
+  Layout.SrcFileNameNI = 0;
+
+  // This value includes both the signature field as well as the record bytes
+  // from the symbol stream.
+  Layout.SymBytes =
+      Layout.ModDiStream == kInvalidStreamIndex ? 0 : getNextSymbolOffset();
+}
+
+Error DbiModuleDescriptorBuilder::finalizeMsfLayout() {
+  this->Layout.ModDiStream = kInvalidStreamIndex;
+  uint32_t C13Size = calculateC13DebugInfoSize();
+  if (!C13Size && !SymbolByteSize)
+    return Error::success();
+  auto ExpectedSN =
+      MSF.addStream(calculateDiSymbolStreamSize(SymbolByteSize, C13Size));
+  if (!ExpectedSN)
+    return ExpectedSN.takeError();
+  Layout.ModDiStream = *ExpectedSN;
+  return Error::success();
+}
+
+Error DbiModuleDescriptorBuilder::commit(BinaryStreamWriter &ModiWriter,
+                                         const msf::MSFLayout &MsfLayout,
+                                         WritableBinaryStreamRef MsfBuffer) {
+  // We write the Modi record to the `ModiWriter`, but we additionally write its
+  // symbol stream to a brand new stream.
+  if (auto EC = ModiWriter.writeObject(Layout))
+    return EC;
+  if (auto EC = ModiWriter.writeCString(ModuleName))
+    return EC;
+  if (auto EC = ModiWriter.writeCString(ObjFileName))
+    return EC;
+  if (auto EC = ModiWriter.padToAlignment(sizeof(uint32_t)))
+    return EC;
+
+  if (Layout.ModDiStream != kInvalidStreamIndex) {
+    auto NS = WritableMappedBlockStream::createIndexedStream(
+        MsfLayout, MsfBuffer, Layout.ModDiStream, MSF.getAllocator());
+    WritableBinaryStreamRef Ref(*NS);
+    BinaryStreamWriter SymbolWriter(Ref);
+    // Write the symbols.
+    if (auto EC =
+            SymbolWriter.writeInteger<uint32_t>(COFF::DEBUG_SECTION_MAGIC))
+      return EC;
+    for (ArrayRef<uint8_t> Syms : Symbols) {
+      if (auto EC = SymbolWriter.writeBytes(Syms))
+        return EC;
+    }
+    assert(SymbolWriter.getOffset() % alignOf(CodeViewContainer::Pdb) == 0 &&
+           "Invalid debug section alignment!");
+    // TODO: Write C11 Line data
+    for (const auto &Builder : C13Builders) {
+      assert(Builder && "Empty C13 Fragment Builder!");
+      if (auto EC = Builder->commit(SymbolWriter))
+        return EC;
+    }
+
+    // TODO: Figure out what GlobalRefs substream actually is and populate it.
+    if (auto EC = SymbolWriter.writeInteger<uint32_t>(0))
+      return EC;
+    if (SymbolWriter.bytesRemaining() > 0)
+      return make_error<RawError>(raw_error_code::stream_too_long);
+  }
+  return Error::success();
+}
+
+void DbiModuleDescriptorBuilder::addDebugSubsection(
+    std::shared_ptr<DebugSubsection> Subsection) {
+  assert(Subsection);
+  C13Builders.push_back(std::make_unique<DebugSubsectionRecordBuilder>(
+      std::move(Subsection), CodeViewContainer::Pdb));
+}
+
+void DbiModuleDescriptorBuilder::addDebugSubsection(
+    const DebugSubsectionRecord &SubsectionContents) {
+  C13Builders.push_back(std::make_unique<DebugSubsectionRecordBuilder>(
+      SubsectionContents, CodeViewContainer::Pdb));
+}