1 files changed, 85 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/PDB/Raw/SymbolStream.cpp b/llvm/lib/DebugInfo/PDB/Raw/SymbolStream.cpp
new file mode 100644
index 00000000000..adf5412e8ca
--- /dev/null
+++ b/llvm/lib/DebugInfo/PDB/Raw/SymbolStream.cpp
@@ -0,0 +1,85 @@
+//===- SymbolStream.cpp - PDB Symbol 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/SymbolStream.h"
+
+#include "llvm/DebugInfo/CodeView/CodeView.h"
+#include "llvm/DebugInfo/CodeView/TypeRecord.h"
+#include "llvm/DebugInfo/PDB/Raw/MappedBlockStream.h"
+#include "llvm/DebugInfo/PDB/Raw/RawConstants.h"
+#include "llvm/DebugInfo/PDB/Raw/RawError.h"
+#include "llvm/DebugInfo/PDB/Raw/StreamReader.h"
+
+#include "llvm/Support/Endian.h"
+
+using namespace llvm;
+using namespace llvm::support;
+using namespace llvm::pdb;
+
+// Symbol stream is an array of symbol records. Each record starts with
+// length and type fields followed by type-specfic fields.
+namespace {
+struct SymbolHeader {
+  ulittle16_t Len; // Record length
+  ulittle16_t Type;
+};
+
+// For S_PUB32 symbol type.
+struct DataSym32 {
+  ulittle32_t TypIndex; // Type index, or Metadata token if a managed symbol
+  ulittle32_t off;
+  ulittle16_t seg;
+  char name[1];
+};
+
+// For S_PROCREF symbol type.
+struct RefSym {
+  ulittle32_t SumName;   // SUC of the name (?)
+  ulittle32_t SymOffset; // Offset of actual symbol in $$Symbols
+  ulittle16_t Mod;       // Module containing the actual symbol
+  char name[1];
+};
+}
+
+SymbolStream::SymbolStream(PDBFile &File, uint32_t StreamNum)
+    : Stream(StreamNum, File) {}
+
+SymbolStream::~SymbolStream() {}
+
+Error SymbolStream::reload() { return Error::success(); }
+
+static StringRef makeStringRef(char *p) { return {p, strlen(p)}; }
+
+Expected<std::string> SymbolStream::getSymbolName(uint32_t Off) const {
+  StreamReader Reader(Stream);
+  Reader.setOffset(Off);
+
+  // Read length field.
+  SymbolHeader Hdr;
+  if (Reader.readObject(&Hdr))
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Corrupted symbol stream.");
+
+  // Read the entire record.
+  std::vector<uint8_t> Buf(Hdr.Len - sizeof(Hdr.Type));
+  if (Reader.readBytes(Buf))
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Corrupted symbol stream.");
+
+  switch (Hdr.Type) {
+  case codeview::S_PUB32:
+    return makeStringRef(reinterpret_cast<DataSym32 *>(Buf.data())->name);
+  case codeview::S_PROCREF:
+    return makeStringRef(reinterpret_cast<RefSym *>(Buf.data())->name);
+  default:
+    return make_error<RawError>(raw_error_code::corrupt_file,
+                                "Unknown symbol type");
+  }
+  return Error::success();
+}