3 files changed, 44 insertions, 8 deletions

diff --git a/llvm/lib/DebugInfo/PDB/Raw/DbiStream.cpp b/llvm/lib/DebugInfo/PDB/Raw/DbiStream.cpp
index 8c46957706e..e79d6572be1 100644
--- a/llvm/lib/DebugInfo/PDB/Raw/DbiStream.cpp
+++ b/llvm/lib/DebugInfo/PDB/Raw/DbiStream.cpp
@@ -345,7 +345,6 @@ Error DbiStream::initializeFileInfo() {
 
   FixedStreamArray<ulittle16_t> ModIndexArray;
   FixedStreamArray<ulittle16_t> ModFileCountArray;
-  FixedStreamArray<little32_t> FileNameOffsets;
 
   // First is an array of `NumModules` module indices.  This is not used for the
   // same reason that `NumSourceFiles` is not used.  It's an array of uint16's,
@@ -373,10 +372,8 @@ Error DbiStream::initializeFileInfo() {
   if (auto EC = FISR.readArray(FileNameOffsets, NumSourceFiles))
     return EC;
 
-  StreamRef NamesBufferRef;
-  if (auto EC = FISR.readStreamRef(NamesBufferRef))
+  if (auto EC = FISR.readStreamRef(NamesBuffer))
     return EC;
-  StreamReader Names(NamesBufferRef);
 
   // We go through each ModuleInfo, determine the number N of source files for
   // that module, and then get the next N offsets from the Offsets array, using
@@ -387,10 +384,10 @@ Error DbiStream::initializeFileInfo() {
     uint32_t NumFiles = ModFileCountArray[I];
     ModuleInfos[I].SourceFiles.resize(NumFiles);
     for (size_t J = 0; J < NumFiles; ++J, ++NextFileIndex) {
-      uint32_t FileOffset = FileNameOffsets[NextFileIndex];
-      Names.setOffset(FileOffset);
-      if (auto EC = Names.readZeroString(ModuleInfos[I].SourceFiles[J]))
-        return EC;
+      if (auto Name = getFileNameForIndex(NextFileIndex))
+        ModuleInfos[I].SourceFiles[J] = Name.get();
+      else
+        return Name.takeError();
     }
   }
 
@@ -400,3 +397,16 @@ Error DbiStream::initializeFileInfo() {
 uint32_t DbiStream::getDebugStreamIndex(DbgHeaderType Type) const {
   return DbgStreams[static_cast<uint16_t>(Type)];
 }
+
+Expected<StringRef> DbiStream::getFileNameForIndex(uint32_t Index) const {
+  StreamReader Names(NamesBuffer);
+  if (Index >= FileNameOffsets.size())
+    return make_error<RawError>(raw_error_code::index_out_of_bounds);
+
+  uint32_t FileOffset = FileNameOffsets[Index];
+  Names.setOffset(FileOffset);
+  StringRef Name;
+  if (auto EC = Names.readZeroString(Name))
+    return std::move(EC);
+  return Name;
+}
diff --git a/llvm/lib/DebugInfo/PDB/Raw/PDBFile.cpp b/llvm/lib/DebugInfo/PDB/Raw/PDBFile.cpp
index d0fbb142ec3..73d8eef570f 100644
--- a/llvm/lib/DebugInfo/PDB/Raw/PDBFile.cpp
+++ b/llvm/lib/DebugInfo/PDB/Raw/PDBFile.cpp
@@ -11,6 +11,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/DebugInfo/PDB/Raw/DbiStream.h"
 #include "llvm/DebugInfo/PDB/Raw/InfoStream.h"
+#include "llvm/DebugInfo/PDB/Raw/NameHashTable.h"
 #include "llvm/DebugInfo/PDB/Raw/PublicsStream.h"
 #include "llvm/DebugInfo/PDB/Raw/RawError.h"
 #include "llvm/DebugInfo/PDB/Raw/SymbolStream.h"
@@ -359,3 +360,24 @@ Expected<SymbolStream &> PDBFile::getPDBSymbolStream() {
   }
   return *Symbols;
 }
+
+Expected<NameHashTable &> PDBFile::getStringTable() {
+  if (!StringTable || !StringTableStream) {
+    auto InfoS = getPDBInfoStream();
+    if (auto EC = InfoS.takeError())
+      return std::move(EC);
+    auto &IS = InfoS.get();
+    uint32_t NameStreamIndex = IS.getNamedStreamIndex("/names");
+
+    if (NameStreamIndex == 0)
+      return make_error<RawError>(raw_error_code::no_stream);
+    auto S = llvm::make_unique<MappedBlockStream>(NameStreamIndex, *this);
+    codeview::StreamReader Reader(*S);
+    auto N = llvm::make_unique<NameHashTable>();
+    if (auto EC = N->load(Reader))
+      return std::move(EC);
+    StringTable = std::move(N);
+    StringTableStream = std::move(S);
+  }
+  return *StringTable;
+}
diff --git a/llvm/lib/DebugInfo/PDB/Raw/RawError.cpp b/llvm/lib/DebugInfo/PDB/Raw/RawError.cpp
index 037a1aab4b1..bcfa55a8b01 100644
--- a/llvm/lib/DebugInfo/PDB/Raw/RawError.cpp
+++ b/llvm/lib/DebugInfo/PDB/Raw/RawError.cpp
@@ -24,6 +24,10 @@ public:
     case raw_error_code::insufficient_buffer:
       return "The buffer is not large enough to read the requested number of "
              "bytes.";
+    case raw_error_code::no_stream:
+      return "The specified stream could not be loaded.";
+    case raw_error_code::index_out_of_bounds:
+      return "The specified item does not exist in the array.";
     }
     llvm_unreachable("Unrecognized raw_error_code");
   }