4 files changed, 151 insertions, 0 deletions
diff --git a/llvm/lib/DebugInfo/PDB/CMakeLists.txt b/llvm/lib/DebugInfo/PDB/CMakeLists.txt
index d6a3d2bf71c..2fa74b96246 100644
--- a/llvm/lib/DebugInfo/PDB/CMakeLists.txt
+++ b/llvm/lib/DebugInfo/PDB/CMakeLists.txt
@@ -33,6 +33,7 @@ add_pdb_impl_folder(Raw
   Raw/PDBFile.cpp
   Raw/DbiStream.cpp
   Raw/InfoStream.cpp
+  Raw/NameHashTable.cpp
   Raw/NameMap.cpp
   Raw/RawSession.cpp
   Raw/StreamReader.cpp)
diff --git a/llvm/lib/DebugInfo/PDB/Raw/ByteStream.cpp b/llvm/lib/DebugInfo/PDB/Raw/ByteStream.cpp
index d8b78ec2248..89477ead223 100644
--- a/llvm/lib/DebugInfo/PDB/Raw/ByteStream.cpp
+++ b/llvm/lib/DebugInfo/PDB/Raw/ByteStream.cpp
@@ -59,3 +59,8 @@ std::error_code ByteStream::readBytes(uint32_t Offset,
 }
 
 uint32_t ByteStream::getLength() const { return Data.size(); }
+
+StringRef ByteStream::str() const {
+  const char *CharData = reinterpret_cast<const char *>(Data.data());
+  return StringRef(CharData, Data.size());
+}
diff --git a/llvm/lib/DebugInfo/PDB/Raw/DbiStream.cpp b/llvm/lib/DebugInfo/PDB/Raw/DbiStream.cpp
index 7762fa34ceb..57f7644d034 100644
--- a/llvm/lib/DebugInfo/PDB/Raw/DbiStream.cpp
+++ b/llvm/lib/DebugInfo/PDB/Raw/DbiStream.cpp
@@ -10,6 +10,7 @@
 #include "llvm/DebugInfo/PDB/Raw/DbiStream.h"
 #include "llvm/DebugInfo/PDB/Raw/InfoStream.h"
 #include "llvm/DebugInfo/PDB/Raw/ModInfo.h"
+#include "llvm/DebugInfo/PDB/Raw/NameHashTable.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
 #include "llvm/DebugInfo/PDB/Raw/RawConstants.h"
 #include "llvm/DebugInfo/PDB/Raw/StreamReader.h"
@@ -148,6 +149,9 @@ std::error_code DbiStream::reload() {
   if (Reader.bytesRemaining() > 0)
     return std::make_error_code(std::errc::illegal_byte_sequence);
 
+  StreamReader ECReader(ECSubstream);
+  ECNames.load(ECReader);
+
   return std::error_code();
 }
 
diff --git a/llvm/lib/DebugInfo/PDB/Raw/NameHashTable.cpp b/llvm/lib/DebugInfo/PDB/Raw/NameHashTable.cpp
new file mode 100644
index 00000000000..3e8de73609f
--- /dev/null
+++ b/llvm/lib/DebugInfo/PDB/Raw/NameHashTable.cpp
@@ -0,0 +1,141 @@
+//===- NameHashTable.cpp - PDB Name Hash Table ------------------*- 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/Raw/NameHashTable.h"
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/DebugInfo/PDB/Raw/ByteStream.h"
+#include "llvm/DebugInfo/PDB/Raw/StreamReader.h"
+#include "llvm/Support/Endian.h"
+
+using namespace llvm;
+using namespace llvm::support;
+using namespace llvm::pdb;
+
+typedef uint32_t *PUL;
+typedef uint16_t *PUS;
+
+static inline uint32_t HashStringV1(StringRef Str) {
+  uint32_t Result = 0;
+  uint32_t Size = Str.size();
+
+  ArrayRef<ulittle32_t> Longs(reinterpret_cast<const ulittle32_t *>(Str.data()),
+                              Size / 4);
+
+  for (auto Value : Longs)
+    Result ^= Value;
+
+  const uint8_t *Remainder = reinterpret_cast<const uint8_t *>(Longs.end());
+  uint32_t RemainderSize = Size - Longs.size() * 4;
+
+  // Maximum of 3 bytes left.  Hash a 2 byte word if possible, then hash the
+  // possibly remaining 1 byte.
+  if (RemainderSize >= 2) {
+    Result ^= *reinterpret_cast<const ulittle16_t *>(Remainder);
+    Remainder += 2;
+    RemainderSize -= 2;
+  }
+
+  // hash possible odd byte
+  if (RemainderSize == 1) {
+    Result ^= *(Remainder++);
+  }
+
+  const uint32_t toLowerMask = 0x20202020;
+  Result |= toLowerMask;
+  Result ^= (Result >> 11);
+
+  return Result ^ (Result >> 16);
+}
+
+static inline uint32_t HashStringV2(StringRef Str) {
+  uint32_t Hash = 0xb170a1bf;
+
+  ArrayRef<char> Buffer(Str.begin(), Str.end());
+
+  ArrayRef<ulittle32_t> Items(
+      reinterpret_cast<const ulittle32_t *>(Buffer.data()),
+      Buffer.size() / sizeof(ulittle32_t));
+  for (ulittle32_t Item : Items) {
+    Hash += Item;
+    Hash += (Hash << 10);
+    Hash ^= (Hash >> 6);
+  }
+  Buffer = Buffer.slice(Items.size() * sizeof(ulittle32_t));
+  for (uint8_t Item : Buffer) {
+    Hash += Item;
+    Hash += (Hash << 10);
+    Hash ^= (Hash >> 6);
+  }
+
+  return Hash * 1664525L + 1013904223L;
+}
+
+NameHashTable::NameHashTable() : Signature(0), HashVersion(0), NameCount(0) {}
+
+std::error_code NameHashTable::load(StreamReader &Stream) {
+  struct Header {
+    support::ulittle32_t Signature;
+    support::ulittle32_t HashVersion;
+    support::ulittle32_t ByteSize;
+  };
+
+  Header H;
+  Stream.readObject(&H);
+  if (H.Signature != 0xEFFEEFFE)
+    return std::make_error_code(std::errc::illegal_byte_sequence);
+  if (H.HashVersion != 1 && H.HashVersion != 2)
+    return std::make_error_code(std::errc::not_supported);
+
+  Signature = H.Signature;
+  HashVersion = H.HashVersion;
+  NamesBuffer.initialize(Stream, H.ByteSize);
+
+  support::ulittle32_t HashCount;
+  Stream.readObject(&HashCount);
+  std::vector<support::ulittle32_t> BucketArray(HashCount);
+  Stream.readArray<support::ulittle32_t>(BucketArray);
+  IDs.assign(BucketArray.begin(), BucketArray.end());
+
+  if (Stream.bytesRemaining() < sizeof(support::ulittle32_t))
+    return std::make_error_code(std::errc::illegal_byte_sequence);
+
+  Stream.readInteger(NameCount);
+  return std::error_code();
+}
+
+StringRef NameHashTable::getStringForID(uint32_t ID) const {
+  if (ID == IDs[0])
+    return StringRef();
+
+  return StringRef(NamesBuffer.str().begin() + ID);
+}
+
+uint32_t NameHashTable::getIDForString(StringRef Str) const {
+  uint32_t Hash = (HashVersion == 1) ? HashStringV1(Str) : HashStringV2(Str);
+  size_t Count = IDs.size();
+  uint32_t Start = Hash % Count;
+  for (size_t I = 0; I < Count; ++I) {
+    // The hash is just a starting point for the search, but if it
+    // doesn't work we should find the string no matter what, because
+    // we iterate the entire array.
+    uint32_t Index = (Start + I) % Count;
+
+    uint32_t ID = IDs[Index];
+    StringRef S = getStringForID(ID);
+    if (S == Str)
+      return ID;
+  }
+  // IDs[0] contains the ID of the "invalid" entry.
+  return IDs[0];
+}
+
+ArrayRef<uint32_t> NameHashTable::name_ids() const {
+  return ArrayRef<uint32_t>(IDs).slice(1, NameCount);
+}