vendor/llvm/llvm-trunk-r302069

19 files changed, 327 insertions, 105 deletions

diff --git a/include/llvm/DebugInfo/CodeView/CVRecord.h b/include/llvm/DebugInfo/CodeView/CVRecord.h
index 086d6dff11c53..ac8aaafeadc1b 100644
--- a/include/llvm/DebugInfo/CodeView/CVRecord.h
+++ b/include/llvm/DebugInfo/CodeView/CVRecord.h
@@ -53,7 +53,7 @@ struct VarStreamArrayExtractor<codeview::CVRecord<Kind>> {
   typedef void ContextType;
 
   static Error extract(BinaryStreamRef Stream, uint32_t &Len,
-                       codeview::CVRecord<Kind> &Item, void *Ctx) {
+                       codeview::CVRecord<Kind> &Item) {
     using namespace codeview;
     const RecordPrefix *Prefix = nullptr;
     BinaryStreamReader Reader(Stream);
diff --git a/include/llvm/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.h b/include/llvm/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.h
index a5a3b851b8415..6c08c9aa21370 100644
--- a/include/llvm/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.h
+++ b/include/llvm/DebugInfo/CodeView/ModuleDebugFileChecksumFragment.h
@@ -21,6 +21,8 @@
 namespace llvm {
 namespace codeview {
 
+class StringTable;
+
 struct FileChecksumEntry {
   uint32_t FileNameOffset;    // Byte offset of filename in global stringtable.
   FileChecksumKind Kind;      // The type of checksum.
@@ -35,7 +37,7 @@ public:
   typedef void ContextType;
 
   static Error extract(BinaryStreamRef Stream, uint32_t &Len,
-                       codeview::FileChecksumEntry &Item, void *Ctx);
+                       codeview::FileChecksumEntry &Item);
 };
 }
 
@@ -55,8 +57,8 @@ public:
 
   Error initialize(BinaryStreamReader Reader);
 
-  Iterator begin() const { return Checksums.begin(); }
-  Iterator end() const { return Checksums.end(); }
+  Iterator begin() { return Checksums.begin(); }
+  Iterator end() { return Checksums.end(); }
 
   const FileChecksumArray &getArray() const { return Checksums; }
 
@@ -66,20 +68,22 @@ private:
 
 class ModuleDebugFileChecksumFragment final : public ModuleDebugFragment {
 public:
-  ModuleDebugFileChecksumFragment();
+  explicit ModuleDebugFileChecksumFragment(StringTable &Strings);
 
   static bool classof(const ModuleDebugFragment *S) {
     return S->kind() == ModuleDebugFragmentKind::FileChecksums;
   }
 
-  void addChecksum(uint32_t StringTableOffset, FileChecksumKind Kind,
+  void addChecksum(StringRef FileName, FileChecksumKind Kind,
                    ArrayRef<uint8_t> Bytes);
 
   uint32_t calculateSerializedLength() override;
   Error commit(BinaryStreamWriter &Writer) override;
-  uint32_t mapChecksumOffset(uint32_t StringTableOffset) const;
+  uint32_t mapChecksumOffset(StringRef FileName) const;
 
 private:
+  StringTable &Strings;
+
   DenseMap<uint32_t, uint32_t> OffsetMap;
   uint32_t SerializedSize = 0;
   llvm::BumpPtrAllocator Storage;
diff --git a/include/llvm/DebugInfo/CodeView/ModuleDebugFragmentRecord.h b/include/llvm/DebugInfo/CodeView/ModuleDebugFragmentRecord.h
index b98c8605592c7..f68f21b224f19 100644
--- a/include/llvm/DebugInfo/CodeView/ModuleDebugFragmentRecord.h
+++ b/include/llvm/DebugInfo/CodeView/ModuleDebugFragmentRecord.h
@@ -57,8 +57,6 @@ private:
   ModuleDebugFragment &Frag;
 };
 
-typedef VarStreamArray<ModuleDebugFragmentRecord> ModuleDebugFragmentArray;
-
 } // namespace codeview
 
 template <>
@@ -66,13 +64,17 @@ struct VarStreamArrayExtractor<codeview::ModuleDebugFragmentRecord> {
   typedef void ContextType;
 
   static Error extract(BinaryStreamRef Stream, uint32_t &Length,
-                       codeview::ModuleDebugFragmentRecord &Info, void *Ctx) {
+                       codeview::ModuleDebugFragmentRecord &Info) {
     if (auto EC = codeview::ModuleDebugFragmentRecord::initialize(Stream, Info))
       return EC;
     Length = Info.getRecordLength();
     return Error::success();
   }
 };
+
+namespace codeview {
+typedef VarStreamArray<ModuleDebugFragmentRecord> ModuleDebugFragmentArray;
+}
 } // namespace llvm
 
 #endif // LLVM_DEBUGINFO_CODEVIEW_MODULEDEBUGFRAGMENTRECORD_H
diff --git a/include/llvm/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.h b/include/llvm/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.h
index 177367c111c30..348497cbf7f2a 100644
--- a/include/llvm/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.h
+++ b/include/llvm/DebugInfo/CodeView/ModuleDebugInlineeLinesFragment.h
@@ -20,6 +20,8 @@ namespace llvm {
 namespace codeview {
 
 class ModuleDebugInlineeLineFragmentRef;
+class ModuleDebugFileChecksumFragment;
+class StringTable;
 
 enum class InlineeLinesSignature : uint32_t {
   Normal,    // CV_INLINEE_SOURCE_LINE_SIGNATURE
@@ -42,11 +44,10 @@ struct InlineeSourceLine {
 }
 
 template <> struct VarStreamArrayExtractor<codeview::InlineeSourceLine> {
-  typedef codeview::ModuleDebugInlineeLineFragmentRef ContextType;
+  typedef bool ContextType;
 
   static Error extract(BinaryStreamRef Stream, uint32_t &Len,
-                       codeview::InlineeSourceLine &Item,
-                       ContextType *Fragment);
+                       codeview::InlineeSourceLine &Item, bool HasExtraFiles);
 };
 
 namespace codeview {
@@ -74,7 +75,8 @@ private:
 
 class ModuleDebugInlineeLineFragment final : public ModuleDebugFragment {
 public:
-  explicit ModuleDebugInlineeLineFragment(bool HasExtraFiles);
+  ModuleDebugInlineeLineFragment(ModuleDebugFileChecksumFragment &Checksums,
+                                 bool HasExtraFiles);
 
   static bool classof(const ModuleDebugFragment *S) {
     return S->kind() == ModuleDebugFragmentKind::InlineeLines;
@@ -83,11 +85,12 @@ public:
   Error commit(BinaryStreamWriter &Writer) override;
   uint32_t calculateSerializedLength() override;
 
-  void addInlineSite(TypeIndex FuncId, uint32_t FileOffset,
-                     uint32_t SourceLine);
-  void addExtraFile(uint32_t FileOffset);
+  void addInlineSite(TypeIndex FuncId, StringRef FileName, uint32_t SourceLine);
+  void addExtraFile(StringRef FileName);
 
 private:
+  ModuleDebugFileChecksumFragment &Checksums;
+
   bool HasExtraFiles = false;
   uint32_t ExtraFileCount = 0;
 
diff --git a/include/llvm/DebugInfo/CodeView/ModuleDebugLineFragment.h b/include/llvm/DebugInfo/CodeView/ModuleDebugLineFragment.h
index dcfe86dd85030..3124236b8fb1b 100644
--- a/include/llvm/DebugInfo/CodeView/ModuleDebugLineFragment.h
+++ b/include/llvm/DebugInfo/CodeView/ModuleDebugLineFragment.h
@@ -19,6 +19,9 @@
 namespace llvm {
 namespace codeview {
 
+class ModuleDebugFileChecksumFragment;
+class StringTable;
+
 // Corresponds to the `CV_DebugSLinesHeader_t` structure.
 struct LineFragmentHeader {
   support::ulittle32_t RelocOffset;  // Code offset of line contribution.
@@ -61,10 +64,10 @@ struct LineColumnEntry {
 
 class LineColumnExtractor {
 public:
-  typedef const LineFragmentHeader ContextType;
+  typedef const LineFragmentHeader *ContextType;
 
   static Error extract(BinaryStreamRef Stream, uint32_t &Len,
-                       LineColumnEntry &Item, const LineFragmentHeader *Header);
+                       LineColumnEntry &Item, const LineFragmentHeader *Ctx);
 };
 
 class ModuleDebugLineFragmentRef final : public ModuleDebugFragmentRef {
@@ -104,13 +107,14 @@ class ModuleDebugLineFragment final : public ModuleDebugFragment {
   };
 
 public:
-  ModuleDebugLineFragment();
+  ModuleDebugLineFragment(ModuleDebugFileChecksumFragment &Checksums,
+                          StringTable &Strings);
 
   static bool classof(const ModuleDebugFragment *S) {
     return S->kind() == ModuleDebugFragmentKind::Lines;
   }
 
-  void createBlock(uint32_t ChecksumBufferOffset);
+  void createBlock(StringRef FileName);
   void addLineInfo(uint32_t Offset, const LineInfo &Line);
   void addLineAndColumnInfo(uint32_t Offset, const LineInfo &Line,
                             uint32_t ColStart, uint32_t ColEnd);
@@ -125,6 +129,8 @@ public:
   bool hasColumnInfo() const;
 
 private:
+  ModuleDebugFileChecksumFragment &Checksums;
+
   uint16_t RelocOffset = 0;
   uint16_t RelocSegment = 0;
   uint32_t CodeSize = 0;
diff --git a/include/llvm/DebugInfo/CodeView/StringTable.h b/include/llvm/DebugInfo/CodeView/StringTable.h
new file mode 100644
index 0000000000000..05dc02ee849f3
--- /dev/null
+++ b/include/llvm/DebugInfo/CodeView/StringTable.h
@@ -0,0 +1,75 @@
+//===- StringTable.h - CodeView String Table Reader/Writer ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_CODEVIEW_STRINGTABLE_H
+#define LLVM_DEBUGINFO_CODEVIEW_STRINGTABLE_H
+
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringRef.h"
+
+#include "llvm/Support/BinaryStreamRef.h"
+#include "llvm/Support/Error.h"
+
+#include <stdint.h>
+
+namespace llvm {
+
+class BinaryStreamReader;
+class BinaryStreamRef;
+class BinaryStreamWriter;
+
+namespace codeview {
+
+/// Represents a read-only view of a CodeView string table.  This is a very
+/// simple flat buffer consisting of null-terminated strings, where strings
+/// are retrieved by their offset in the buffer.  StringTableRef does not own
+/// the underlying storage for the buffer.
+class StringTableRef {
+public:
+  StringTableRef();
+
+  Error initialize(BinaryStreamRef Contents);
+
+  Expected<StringRef> getString(uint32_t Offset) const;
+
+  bool valid() const { return Stream.valid(); }
+
+private:
+  BinaryStreamRef Stream;
+};
+
+/// Represents a read-write view of a CodeView string table.  StringTable owns
+/// the underlying storage for the table, and is capable of serializing the
+/// string table into a format understood by StringTableRef.
+class StringTable {
+public:
+  // If string S does not exist in the string table, insert it.
+  // Returns the ID for S.
+  uint32_t insert(StringRef S);
+
+  // Return the ID for string S.  Assumes S exists in the table.
+  uint32_t getStringId(StringRef S) const;
+
+  uint32_t calculateSerializedSize() const;
+  Error commit(BinaryStreamWriter &Writer) const;
+
+  uint32_t size() const;
+
+  StringMap<uint32_t>::const_iterator begin() const { return Strings.begin(); }
+
+  StringMap<uint32_t>::const_iterator end() const { return Strings.end(); }
+
+private:
+  StringMap<uint32_t> Strings;
+  uint32_t StringSize = 1;
+};
+}
+}
+
+#endif
diff --git a/include/llvm/DebugInfo/CodeView/SymbolVisitorDelegate.h b/include/llvm/DebugInfo/CodeView/SymbolVisitorDelegate.h
index 2bef3f61adfcc..96c8a47a36690 100644
--- a/include/llvm/DebugInfo/CodeView/SymbolVisitorDelegate.h
+++ b/include/llvm/DebugInfo/CodeView/SymbolVisitorDelegate.h
@@ -19,13 +19,15 @@ class BinaryStreamReader;
 
 namespace codeview {
 
+class StringTableRef;
+
 class SymbolVisitorDelegate {
 public:
   virtual ~SymbolVisitorDelegate() = default;
 
   virtual uint32_t getRecordOffset(BinaryStreamReader Reader) = 0;
   virtual StringRef getFileNameForFileOffset(uint32_t FileOffset) = 0;
-  virtual StringRef getStringTable() = 0;
+  virtual StringTableRef getStringTable() = 0;
 };
 
 } // end namespace codeview
diff --git a/include/llvm/DebugInfo/DWARF/DWARFContext.h b/include/llvm/DebugInfo/DWARF/DWARFContext.h
index 3c04c6716ea39..b9f3425d5deb3 100644
--- a/include/llvm/DebugInfo/DWARF/DWARFContext.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFContext.h
@@ -172,6 +172,9 @@ public:
     return DWOCUs[index].get();
   }
 
+  /// Get a DIE given an exact offset.
+  DWARFDie getDIEForOffset(uint32_t Offset);
+
   const DWARFUnitIndex &getCUIndex();
   DWARFGdbIndex &getGdbIndex();
   const DWARFUnitIndex &getTUIndex();
diff --git a/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h b/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h
index dd0e2648bf309..e21245b97b730 100644
--- a/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h
@@ -30,7 +30,7 @@ public:
   struct FileNameEntry {
     FileNameEntry() = default;
 
-    const char *Name = nullptr;
+    StringRef Name = StringRef();
     uint64_t DirIdx = 0;
     uint64_t ModTime = 0;
     uint64_t Length = 0;
@@ -44,6 +44,10 @@ public:
     uint64_t TotalLength;
     /// Version identifier for the statement information format.
     uint16_t Version;
+    /// In v5, size in bytes of an address (or segment offset).
+    uint8_t AddressSize;
+    /// In v5, size in bytes of a segment selector.
+    uint8_t SegSelectorSize;
     /// The number of bytes following the prologue_length field to the beginning
     /// of the first byte of the statement program itself.
     uint64_t PrologueLength;
@@ -63,7 +67,7 @@ public:
     /// The number assigned to the first special opcode.
     uint8_t OpcodeBase;
     std::vector<uint8_t> StandardOpcodeLengths;
-    std::vector<const char *> IncludeDirectories;
+    std::vector<StringRef> IncludeDirectories;
     std::vector<FileNameEntry> FileNames;
 
     bool IsDWARF64;
@@ -100,7 +104,7 @@ public:
     void postAppend();
     void reset(bool DefaultIsStmt);
     void dump(raw_ostream &OS) const;
-
+    static void dumpTableHeader(raw_ostream &OS);
     static bool orderByAddress(const Row &LHS, const Row &RHS) {
       return LHS.Address < RHS.Address;
     }
diff --git a/include/llvm/DebugInfo/DWARF/DWARFUnit.h b/include/llvm/DebugInfo/DWARF/DWARFUnit.h
index e29ba523238c1..68e541bac73c6 100644
--- a/include/llvm/DebugInfo/DWARF/DWARFUnit.h
+++ b/include/llvm/DebugInfo/DWARF/DWARFUnit.h
@@ -312,9 +312,9 @@ public:
         [](const DWARFDebugInfoEntry &LHS, uint32_t Offset) {
           return LHS.getOffset() < Offset;
         });
-    if (it == DieArray.end())
-      return DWARFDie();
-    return DWARFDie(this, &*it);
+    if (it != DieArray.end() && it->getOffset() == Offset)
+      return DWARFDie(this, &*it);
+    return DWARFDie();
   }
 
   uint32_t getLineTableOffset() const {
diff --git a/include/llvm/DebugInfo/DWARF/DWARFVerifier.h b/include/llvm/DebugInfo/DWARF/DWARFVerifier.h
new file mode 100644
index 0000000000000..8e12bcd2c8e27
--- /dev/null
+++ b/include/llvm/DebugInfo/DWARF/DWARFVerifier.h
@@ -0,0 +1,98 @@
+//===- DWARFVerifier.h ----------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_DWARF_DWARFVERIFIER_H
+#define LLVM_DEBUGINFO_DWARF_DWARFVERIFIER_H
+
+#include <cstdint>
+#include <map>
+#include <set>
+
+namespace llvm {
+class raw_ostream;
+struct DWARFAttribute;
+class DWARFContext;
+class DWARFDie;
+class DWARFUnit;
+
+/// A class that verifies DWARF debug information given a DWARF Context.
+class DWARFVerifier {
+  raw_ostream &OS;
+  DWARFContext &DCtx;
+  /// A map that tracks all references (converted absolute references) so we
+  /// can verify each reference points to a valid DIE and not an offset that
+  /// lies between to valid DIEs.
+  std::map<uint64_t, std::set<uint32_t>> ReferenceToDIEOffsets;
+  uint32_t NumDebugInfoErrors;
+  uint32_t NumDebugLineErrors;
+
+  /// Verifies the attribute's DWARF attribute and its value.
+  ///
+  /// This function currently checks for:
+  /// - DW_AT_ranges values is a valid .debug_ranges offset
+  /// - DW_AT_stmt_list is a valid .debug_line offset
+  ///
+  /// @param Die          The DWARF DIE that owns the attribute value
+  /// @param AttrValue    The DWARF attribute value to check
+  void verifyDebugInfoAttribute(DWARFDie &Die, DWARFAttribute &AttrValue);
+
+  /// Verifies the attribute's DWARF form.
+  ///
+  /// This function currently checks for:
+  /// - All DW_FORM_ref values that are CU relative have valid CU offsets
+  /// - All DW_FORM_ref_addr values have valid .debug_info offsets
+  /// - All DW_FORM_strp values have valid .debug_str offsets
+  ///
+  /// @param Die          The DWARF DIE that owns the attribute value
+  /// @param AttrValue    The DWARF attribute value to check
+  void verifyDebugInfoForm(DWARFDie &Die, DWARFAttribute &AttrValue);
+
+  /// Verifies the all valid references that were found when iterating through
+  /// all of the DIE attributes.
+  ///
+  /// This function will verify that all references point to DIEs whose DIE
+  /// offset matches. This helps to ensure if a DWARF link phase moved things
+  /// around, that it doesn't create invalid references by failing to relocate
+  /// CU relative and absolute references.
+  void veifyDebugInfoReferences();
+
+  /// Verify the the DW_AT_stmt_list encoding and value and ensure that no
+  /// compile units that have the same DW_AT_stmt_list value.
+  void verifyDebugLineStmtOffsets();
+
+  /// Verify that all of the rows in the line table are valid.
+  ///
+  /// This function currently checks for:
+  /// - addresses within a sequence that decrease in value
+  /// - invalid file indexes
+  void verifyDebugLineRows();
+
+public:
+  DWARFVerifier(raw_ostream &S, DWARFContext &D)
+      : OS(S), DCtx(D), NumDebugInfoErrors(0), NumDebugLineErrors(0) {}
+  /// Verify the information in the .debug_info section.
+  ///
+  /// Any errors are reported to the stream that was this object was
+  /// constructed with.
+  ///
+  /// @return True if the .debug_info verifies successfully, false otherwise.
+  bool handleDebugInfo();
+
+  /// Verify the information in the .debug_line section.
+  ///
+  /// Any errors are reported to the stream that was this object was
+  /// constructed with.
+  ///
+  /// @return True if the .debug_line verifies successfully, false otherwise.
+  bool handleDebugLine();
+};
+
+} // end namespace llvm
+
+#endif // LLVM_DEBUGINFO_DWARF_DWARFCONTEXT_H
diff --git a/include/llvm/DebugInfo/PDB/Native/DbiModuleDescriptor.h b/include/llvm/DebugInfo/PDB/Native/DbiModuleDescriptor.h
index 879cb4285cd7a..d1f791b9daede 100644
--- a/include/llvm/DebugInfo/PDB/Native/DbiModuleDescriptor.h
+++ b/include/llvm/DebugInfo/PDB/Native/DbiModuleDescriptor.h
@@ -66,7 +66,7 @@ struct ModuleInfoEx {
 template <> struct VarStreamArrayExtractor<pdb::DbiModuleDescriptor> {
   typedef void ContextType;
   static Error extract(BinaryStreamRef Stream, uint32_t &Length,
-                       pdb::DbiModuleDescriptor &Info, void *Ctx) {
+                       pdb::DbiModuleDescriptor &Info) {
     if (auto EC = pdb::DbiModuleDescriptor::initialize(Stream, Info))
       return EC;
     Length = Info.getRecordLength();
diff --git a/include/llvm/DebugInfo/PDB/Native/DbiStream.h b/include/llvm/DebugInfo/PDB/Native/DbiStream.h
index 84ae57f2e23ac..08262e47f77f5 100644
--- a/include/llvm/DebugInfo/PDB/Native/DbiStream.h
+++ b/include/llvm/DebugInfo/PDB/Native/DbiStream.h
@@ -13,9 +13,9 @@
 #include "llvm/DebugInfo/CodeView/ModuleDebugFragment.h"
 #include "llvm/DebugInfo/MSF/MappedBlockStream.h"
 #include "llvm/DebugInfo/PDB/Native/DbiModuleDescriptor.h"
+#include "llvm/DebugInfo/PDB/Native/PDBStringTable.h"
 #include "llvm/DebugInfo/PDB/Native/RawConstants.h"
 #include "llvm/DebugInfo/PDB/Native/RawTypes.h"
-#include "llvm/DebugInfo/PDB/Native/StringTable.h"
 #include "llvm/DebugInfo/PDB/PDBTypes.h"
 #include "llvm/Support/BinaryStreamArray.h"
 #include "llvm/Support/BinaryStreamArray.h"
@@ -91,7 +91,7 @@ private:
   std::unique_ptr<msf::MappedBlockStream> Stream;
 
   std::vector<ModuleInfoEx> ModuleInfos;
-  StringTable ECNames;
+  PDBStringTable ECNames;
 
   BinaryStreamRef ModInfoSubstream;
   BinaryStreamRef SecContrSubstream;
diff --git a/include/llvm/DebugInfo/PDB/Native/PDBFile.h b/include/llvm/DebugInfo/PDB/Native/PDBFile.h
index fbca62d6e9d93..3bed67141c56a 100644
--- a/include/llvm/DebugInfo/PDB/Native/PDBFile.h
+++ b/include/llvm/DebugInfo/PDB/Native/PDBFile.h
@@ -33,7 +33,7 @@ namespace pdb {
 class DbiStream;
 class GlobalsStream;
 class InfoStream;
-class StringTable;
+class PDBStringTable;
 class PDBFileBuilder;
 class PublicsStream;
 class SymbolStream;
@@ -95,7 +95,7 @@ public:
   Expected<TpiStream &> getPDBIpiStream();
   Expected<PublicsStream &> getPDBPublicsStream();
   Expected<SymbolStream &> getPDBSymbolStream();
-  Expected<StringTable &> getStringTable();
+  Expected<PDBStringTable &> getStringTable();
 
   BumpPtrAllocator &getAllocator() { return Allocator; }
 
@@ -106,7 +106,7 @@ public:
   bool hasPDBPublicsStream();
   bool hasPDBSymbolStream();
   bool hasPDBTpiStream() const;
-  bool hasStringTable();
+  bool hasPDBStringTable();
 
 private:
   Expected<std::unique_ptr<msf::MappedBlockStream>>
@@ -131,7 +131,7 @@ private:
   std::unique_ptr<SymbolStream> Symbols;
   std::unique_ptr<msf::MappedBlockStream> DirectoryStream;
   std::unique_ptr<msf::MappedBlockStream> StringTableStream;
-  std::unique_ptr<StringTable> Strings;
+  std::unique_ptr<PDBStringTable> Strings;
 };
 }
 }
diff --git a/include/llvm/DebugInfo/PDB/Native/PDBFileBuilder.h b/include/llvm/DebugInfo/PDB/Native/PDBFileBuilder.h
index 3898af5afc9e4..cd7d3b0637933 100644
--- a/include/llvm/DebugInfo/PDB/Native/PDBFileBuilder.h
+++ b/include/llvm/DebugInfo/PDB/Native/PDBFileBuilder.h
@@ -15,8 +15,8 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/DebugInfo/PDB/Native/NamedStreamMap.h"
 #include "llvm/DebugInfo/PDB/Native/PDBFile.h"
+#include "llvm/DebugInfo/PDB/Native/PDBStringTableBuilder.h"
 #include "llvm/DebugInfo/PDB/Native/RawConstants.h"
-#include "llvm/DebugInfo/PDB/Native/StringTableBuilder.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/Error.h"
@@ -46,12 +46,14 @@ public:
   DbiStreamBuilder &getDbiBuilder();
   TpiStreamBuilder &getTpiBuilder();
   TpiStreamBuilder &getIpiBuilder();
-  StringTableBuilder &getStringTableBuilder();
+  PDBStringTableBuilder &getStringTableBuilder();
 
   Error commit(StringRef Filename);
 
-private:
+  Expected<uint32_t> getNamedStreamIndex(StringRef Name) const;
   Error addNamedStream(StringRef Name, uint32_t Size);
+
+private:
   Expected<msf::MSFLayout> finalizeMsfLayout();
 
   BumpPtrAllocator &Allocator;
@@ -62,7 +64,7 @@ private:
   std::unique_ptr<TpiStreamBuilder> Tpi;
   std::unique_ptr<TpiStreamBuilder> Ipi;
 
-  StringTableBuilder Strings;
+  PDBStringTableBuilder Strings;
   NamedStreamMap NamedStreams;
 };
 }
diff --git a/include/llvm/DebugInfo/PDB/Native/StringTable.h b/include/llvm/DebugInfo/PDB/Native/PDBStringTable.h
index dd5e30e618270..7c7f16bd1c732 100644
--- a/include/llvm/DebugInfo/PDB/Native/StringTable.h
+++ b/include/llvm/DebugInfo/PDB/Native/PDBStringTable.h
@@ -1,4 +1,4 @@
-//===- StringTable.h - PDB String Table -------------------------*- C++ -*-===//
+//===- PDBStringTable.h - PDB String Table -----------------------*- C++-*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,11 +7,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_DEBUGINFO_PDB_RAW_STRINGTABLE_H
-#define LLVM_DEBUGINFO_PDB_RAW_STRINGTABLE_H
+#ifndef LLVM_DEBUGINFO_PDB_RAW_PDBSTRINGTABLE_H
+#define LLVM_DEBUGINFO_PDB_RAW_PDBSTRINGTABLE_H
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/DebugInfo/CodeView/StringTable.h"
 #include "llvm/Support/BinaryStreamArray.h"
 #include "llvm/Support/BinaryStreamRef.h"
 #include "llvm/Support/Endian.h"
@@ -22,31 +23,38 @@
 namespace llvm {
 class BinaryStreamReader;
 
+namespace msf {
+class MappedBlockStream;
+}
+
 namespace pdb {
 
-class StringTable {
-public:
-  StringTable();
+struct PDBStringTableHeader;
 
-  Error load(BinaryStreamReader &Stream);
+class PDBStringTable {
+public:
+  Error reload(BinaryStreamReader &Reader);
 
   uint32_t getByteSize() const;
+  uint32_t getNameCount() const;
+  uint32_t getHashVersion() const;
+  uint32_t getSignature() const;
 
-  uint32_t getNameCount() const { return NameCount; }
-  uint32_t getHashVersion() const { return HashVersion; }
-  uint32_t getSignature() const { return Signature; }
-
-  StringRef getStringForID(uint32_t ID) const;
-  uint32_t getIDForString(StringRef Str) const;
+  Expected<StringRef> getStringForID(uint32_t ID) const;
+  Expected<uint32_t> getIDForString(StringRef Str) const;
 
   FixedStreamArray<support::ulittle32_t> name_ids() const;
 
 private:
-  BinaryStreamRef NamesBuffer;
+  Error readHeader(BinaryStreamReader &Reader);
+  Error readStrings(BinaryStreamReader &Reader);
+  Error readHashTable(BinaryStreamReader &Reader);
+  Error readEpilogue(BinaryStreamReader &Reader);
+
+  const PDBStringTableHeader *Header = nullptr;
+  codeview::StringTableRef Strings;
   FixedStreamArray<support::ulittle32_t> IDs;
   uint32_t ByteSize = 0;
-  uint32_t Signature = 0;
-  uint32_t HashVersion = 0;
   uint32_t NameCount = 0;
 };
 
diff --git a/include/llvm/DebugInfo/PDB/Native/PDBStringTableBuilder.h b/include/llvm/DebugInfo/PDB/Native/PDBStringTableBuilder.h
new file mode 100644
index 0000000000000..6f85e7a4a0741
--- /dev/null
+++ b/include/llvm/DebugInfo/PDB/Native/PDBStringTableBuilder.h
@@ -0,0 +1,60 @@
+//===- PDBStringTableBuilder.h - PDB String Table Builder -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file creates the "/names" stream.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_PDB_RAW_PDBSTRINGTABLEBUILDER_H
+#define LLVM_DEBUGINFO_PDB_RAW_PDBSTRINGTABLEBUILDER_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/DebugInfo/CodeView/StringTable.h"
+#include "llvm/Support/Error.h"
+#include <vector>
+
+namespace llvm {
+class BinaryStreamWriter;
+class WritableBinaryStreamRef;
+
+namespace msf {
+struct MSFLayout;
+}
+
+namespace pdb {
+
+class PDBFileBuilder;
+
+class PDBStringTableBuilder {
+public:
+  // If string S does not exist in the string table, insert it.
+  // Returns the ID for S.
+  uint32_t insert(StringRef S);
+
+  uint32_t calculateSerializedSize() const;
+  Error commit(BinaryStreamWriter &Writer) const;
+
+  codeview::StringTable &getStrings() { return Strings; }
+  const codeview::StringTable &getStrings() const { return Strings; }
+
+private:
+  uint32_t calculateHashTableSize() const;
+  Error writeHeader(BinaryStreamWriter &Writer) const;
+  Error writeStrings(BinaryStreamWriter &Writer) const;
+  Error writeHashTable(BinaryStreamWriter &Writer) const;
+  Error writeEpilogue(BinaryStreamWriter &Writer) const;
+
+  codeview::StringTable Strings;
+};
+
+} // end namespace pdb
+} // end namespace llvm
+
+#endif // LLVM_DEBUGINFO_PDB_RAW_PDBSTRINGTABLEBUILDER_H
diff --git a/include/llvm/DebugInfo/PDB/Native/RawTypes.h b/include/llvm/DebugInfo/PDB/Native/RawTypes.h
index e1c6cf0021d5e..93622d0a43949 100644
--- a/include/llvm/DebugInfo/PDB/Native/RawTypes.h
+++ b/include/llvm/DebugInfo/PDB/Native/RawTypes.h
@@ -307,13 +307,13 @@ struct InfoStreamHeader {
 };
 
 /// The header preceeding the /names stream.
-struct StringTableHeader {
-  support::ulittle32_t Signature;
-  support::ulittle32_t HashVersion;
-  support::ulittle32_t ByteSize;
+struct PDBStringTableHeader {
+  support::ulittle32_t Signature;   // PDBStringTableSignature
+  support::ulittle32_t HashVersion; // 1 or 2
+  support::ulittle32_t ByteSize;    // Number of bytes of names buffer.
 };
 
-const uint32_t StringTableSignature = 0xEFFEEFFE;
+const uint32_t PDBStringTableSignature = 0xEFFEEFFE;
 
 } // namespace pdb
 } // namespace llvm
diff --git a/include/llvm/DebugInfo/PDB/Native/StringTableBuilder.h b/include/llvm/DebugInfo/PDB/Native/StringTableBuilder.h
deleted file mode 100644
index 9c4b12e33ba05..0000000000000
--- a/include/llvm/DebugInfo/PDB/Native/StringTableBuilder.h
+++ /dev/null
@@ -1,45 +0,0 @@
-//===- StringTableBuilder.h - PDB String Table Builder ----------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file creates the "/names" stream.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_DEBUGINFO_PDB_RAW_STRINGTABLEBUILDER_H
-#define LLVM_DEBUGINFO_PDB_RAW_STRINGTABLEBUILDER_H
-
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/StringRef.h"
-#include "llvm/Support/Error.h"
-#include <vector>
-
-namespace llvm {
-class BinaryStreamWriter;
-
-namespace pdb {
-
-class StringTableBuilder {
-public:
-  // If string S does not exist in the string table, insert it.
-  // Returns the ID for S.
-  uint32_t insert(StringRef S);
-  uint32_t getStringIndex(StringRef S);
-
-  uint32_t finalize();
-  Error commit(BinaryStreamWriter &Writer) const;
-
-private:
-  DenseMap<StringRef, uint32_t> Strings;
-  uint32_t StringSize = 1;
-};
-
-} // end namespace pdb
-} // end namespace llvm
-
-#endif // LLVM_DEBUGINFO_PDB_RAW_STRINGTABLEBUILDER_H