Index: include/llvm/DebugInfo/PDB/Raw/ModInfo.h
===================================================================
--- /dev/null
+++ include/llvm/DebugInfo/PDB/Raw/ModInfo.h
@@ -0,0 +1,62 @@
+//===- ModInfo.h - PDB module information -----------------------*- 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_PDB_RAW_MODINFO_H
+#define LLVM_DEBUGINFO_PDB_RAW_MODINFO_H
+
+#include "llvm/ADT/StringRef.h"
+
+#include <stdint.h>
+
+namespace llvm {
+class PDBFile;
+
+class ModInfo {
+private:
+  struct FileLayout;
+
+public:
+  ModInfo(const uint8_t *Bytes);
+  ~ModInfo();
+
+  bool hasECInfo() const;
+  uint16_t getTypeServerIndex() const;
+  uint16_t getModuleStreamIndex() const;
+  uint32_t getSymbolDebugInfoByteSize() const;
+  uint32_t getLineInfoByteSize() const;
+  uint32_t getC13LineInfoByteSize() const;
+  uint32_t getNumberOfFiles() const;
+  uint32_t getSourceFileNameIndex() const;
+  uint32_t getPdbFilePathNameIndex() const;
+
+  llvm::StringRef getModuleName() const;
+  llvm::StringRef getObjFileName() const;
+
+private:
+  const FileLayout *Layout;
+};
+
+class ModInfoIterator {
+public:
+  ModInfoIterator(const uint8_t *Stream);
+  ModInfoIterator(const ModInfoIterator &Other);
+
+  ModInfo operator*();
+  ModInfoIterator &operator++();
+  ModInfoIterator operator++(int);
+  bool operator==(const ModInfoIterator &Other);
+  bool operator!=(const ModInfoIterator &Other);
+  ModInfoIterator &operator=(const ModInfoIterator &Other);
+
+private:
+  const uint8_t *Bytes;
+};
+}
+
+#endif
Index: include/llvm/DebugInfo/PDB/Raw/PDBDbiStream.h
===================================================================
--- include/llvm/DebugInfo/PDB/Raw/PDBDbiStream.h
+++ include/llvm/DebugInfo/PDB/Raw/PDBDbiStream.h
@@ -11,6 +11,7 @@
 #define LLVM_DEBUGINFO_PDB_RAW_PDBDBISTREAM_H
 
 #include "llvm/DebugInfo/PDB/PDBTypes.h"
+#include "llvm/DebugInfo/PDB/Raw/ModInfo.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBRawConstants.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBStream.h"
 #include "llvm/Support/Endian.h"
@@ -42,9 +43,13 @@
 
   PDB_Machine getMachineType() const;
 
+  llvm::iterator_range<ModInfoIterator> modules() const;
+
 private:
   PDBFile &Pdb;
   PDBStream Stream;
+
+  std::vector<uint8_t> ModInfoSubstream;
   std::unique_ptr<HeaderInfo> Header;
 };
 }
Index: lib/DebugInfo/PDB/CMakeLists.txt
===================================================================
--- lib/DebugInfo/PDB/CMakeLists.txt
+++ lib/DebugInfo/PDB/CMakeLists.txt
@@ -27,6 +27,7 @@
 endif()
 
 add_pdb_impl_folder(Raw
+  Raw/ModInfo.cpp
   Raw/PDBFile.cpp
   Raw/PDBDbiStream.cpp
   Raw/PDBInfoStream.cpp
Index: lib/DebugInfo/PDB/Raw/ModInfo.cpp
===================================================================
--- /dev/null
+++ lib/DebugInfo/PDB/Raw/ModInfo.cpp
@@ -0,0 +1,140 @@
+//===- ModInfo.cpp - PDB module information -------------------------------===//
+//
+//                     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/ModInfo.h"
+#include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
+#include "llvm/Support/Endian.h"
+
+using namespace llvm;
+using namespace llvm::support;
+
+namespace {
+struct SCBytes {
+  ulittle16_t Section;
+  little32_t Offset;
+  little32_t Size;
+  ulittle32_t Characteristics;
+  ulittle16_t ModuleIndex;
+  ulittle32_t DataCrc;
+  ulittle32_t RelocCrc;
+};
+
+// struct Flags {
+//  uint16_t fWritten : 1;   // True if ModInfo is dirty
+//  uint16_t fECEnabled : 1; // Is EC symbolic info present?  (What is EC?)
+//  uint16_t unused : 6;     // Reserved
+//  uint16_t iTSM : 8;       // Type Server Index for this module
+//};
+const uint16_t HasECFlagMask = 0x2;
+
+const uint16_t TypeServerIndexMask = 0xFF00;
+const uint16_t TypeServerIndexShift = 8;
+}
+
+struct ModInfo::FileLayout {
+  ulittle32_t Mod;           // Currently opened module.  This field is a
+                             // pointer in the reference implementation, but
+                             // that won't work on 64-bit systems, and anyway
+                             // it doesn't make sense to read a pointer from a
+                             // file.  For now it is unused, so just ignore it.
+  SCBytes SC;                // First section contribution of this module.
+  ulittle16_t Flags;         // See Flags definition.
+  ulittle16_t ModDiStream;   // Stream Number of module debug info
+  ulittle32_t SymBytes;      // Size of local symbol debug info in above stream
+  ulittle32_t LineBytes;     // Size of line number debug info in above stream
+  ulittle32_t C13Bytes;      // Size of C13 line number info in above stream
+  ulittle16_t NumFiles;      // Number of files contributing to this module
+  ulittle16_t Padding;       // Padding so the next field is 4-byte aligned.
+  ulittle32_t FileNameOffs;  // array of [0..NumFiles) DBI name buffer offsets.
+                             // This field is a pointer in the reference
+                             // implementation, but as with `Mod`, we ignore it
+                             // for now since it is unused.
+  ulittle32_t SrcFileNameNI; // Name Index for src file name
+  ulittle32_t PdbFilePathNI; // Name Index for path to compiler PDB
+  char VarInfo[1];           // Module name followed by Obj File Name
+
+  StringRef getModuleName() const { return StringRef(VarInfo); }
+
+  StringRef getObjectFileName() const {
+    return StringRef(getModuleName().end() + 1);
+  }
+};
+
+ModInfo::ModInfo(const uint8_t *Bytes)
+    : Layout(reinterpret_cast<const FileLayout *>(Bytes)) {}
+
+ModInfo::~ModInfo() {}
+
+bool ModInfo::hasECInfo() const { return (Layout->Flags & HasECFlagMask) != 0; }
+
+uint16_t ModInfo::getTypeServerIndex() const {
+  return (Layout->Flags & TypeServerIndexMask) >> TypeServerIndexShift;
+}
+
+uint16_t ModInfo::getModuleStreamIndex() const { return Layout->ModDiStream; }
+
+uint32_t ModInfo::getSymbolDebugInfoByteSize() const {
+  return Layout->SymBytes;
+}
+
+uint32_t ModInfo::getLineInfoByteSize() const { return Layout->LineBytes; }
+
+uint32_t ModInfo::getC13LineInfoByteSize() const { return Layout->C13Bytes; }
+
+uint32_t ModInfo::getNumberOfFiles() const { return Layout->NumFiles; }
+
+uint32_t ModInfo::getSourceFileNameIndex() const {
+  return Layout->SrcFileNameNI;
+}
+
+uint32_t ModInfo::getPdbFilePathNameIndex() const {
+  return Layout->PdbFilePathNI;
+}
+
+llvm::StringRef ModInfo::getModuleName() const {
+  return Layout->getModuleName();
+}
+
+llvm::StringRef ModInfo::getObjFileName() const {
+  return Layout->getObjectFileName();
+}
+
+ModInfoIterator::ModInfoIterator(const uint8_t *Stream) : Bytes(Stream) {}
+
+ModInfoIterator::ModInfoIterator(const ModInfoIterator &Other)
+    : Bytes(Other.Bytes) {}
+
+ModInfo ModInfoIterator::operator*() { return ModInfo(Bytes); }
+
+ModInfoIterator &ModInfoIterator::operator++() {
+  StringRef Obj = ModInfo(Bytes).getObjFileName();
+  Bytes = Obj.bytes_end() + 1;
+  Bytes = reinterpret_cast<const uint8_t *>(llvm::alignAddr(Bytes, 4));
+
+  return *this;
+}
+
+ModInfoIterator ModInfoIterator::operator++(int) {
+  ModInfoIterator Copy(*this);
+  ++(*this);
+  return Copy;
+}
+
+bool ModInfoIterator::operator==(const ModInfoIterator &Other) {
+  return Bytes == Other.Bytes;
+}
+
+bool ModInfoIterator::operator!=(const ModInfoIterator &Other) {
+  return !(*this == Other);
+}
+
+ModInfoIterator &ModInfoIterator::operator=(const ModInfoIterator &Other) {
+  Bytes = Other.Bytes;
+  return *this;
+}
Index: lib/DebugInfo/PDB/Raw/PDBDbiStream.cpp
===================================================================
--- lib/DebugInfo/PDB/Raw/PDBDbiStream.cpp
+++ lib/DebugInfo/PDB/Raw/PDBDbiStream.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/DebugInfo/PDB/Raw/PDBDbiStream.h"
+#include "llvm/DebugInfo/PDB/Raw/ModInfo.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBInfoStream.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBRawConstants.h"
@@ -84,8 +85,10 @@
   if (Header->VersionSignature != -1)
     return std::make_error_code(std::errc::illegal_byte_sequence);
 
-  // Prior to VC50 an old style header was used.  We don't support this.
-  if (Header->VersionHeader < PdbDbiV50)
+  // Require at least version 7, which should be present in all PDBs
+  // produced in the last decade and allows us to avoid having to
+  // special case all kinds of complicated arcane formats.
+  if (Header->VersionHeader < PdbDbiV70)
     return std::make_error_code(std::errc::not_supported);
 
   if (Header->Age != Pdb.getPDBInfoStream().getAge())
@@ -98,6 +101,14 @@
           Header->OptionalDbgHdrSize + Header->ECSubstreamSize)
     return std::make_error_code(std::errc::illegal_byte_sequence);
 
+  if (Header->ModiSubstreamSize % sizeof(uint32_t) != 0)
+    return std::make_error_code(std::errc::illegal_byte_sequence);
+
+  ModInfoSubstream.resize(Header->ModiSubstreamSize);
+  if (auto EC =
+          Stream.readBytes(&ModInfoSubstream[0], Header->ModiSubstreamSize))
+    return EC;
+
   return std::error_code();
 }
 
@@ -138,3 +149,8 @@
   uint16_t Machine = Header->MachineType;
   return static_cast<PDB_Machine>(Machine);
 }
+
+llvm::iterator_range<ModInfoIterator> PDBDbiStream::modules() const {
+  return llvm::make_range(ModInfoIterator(&ModInfoSubstream.front()),
+                          ModInfoIterator(&ModInfoSubstream.back() + 1));
+}
Index: test/DebugInfo/PDB/pdbdump-headers.test
===================================================================
--- test/DebugInfo/PDB/pdbdump-headers.test
+++ test/DebugInfo/PDB/pdbdump-headers.test
@@ -28,3 +28,27 @@
 ; CHECK-NEXT: Number of Symbols: 8
 ; CHECK-NEXT: Toolchain Version: 12.0
 ; CHECK-NEXT: mspdb120.dll version: 12.0.31101
+
+; CHECK:      Modules:
+; CHECK-NEXT: d:\src\llvm\test\DebugInfo\PDB\Inputs\empty.obj
+; CHECK-NEXT:     Debug Stream Index: 12
+; CHECK-NEXT:     Object File: d:\src\llvm\test\DebugInfo\PDB\Inputs\empty.obj
+; CHECK-NEXT:     Num Files: 1
+; CHECK-NEXT:     Source File Name Idx: 0
+; CHECK-NEXT:     Pdb File Name Idx: 0
+; CHECK-NEXT:     Line Info Byte Size: 0
+; CHECK-NEXT:     C13 Line Info Byte Size: 88
+; CHECK-NEXT:     Symbol Byte Size: 208
+; CHECK-NEXT:     Type Server Index: 0
+; CHECK-NEXT:     Has EC Info: 0
+; CHECK-NEXT: * Linker *
+; CHECK-NEXT:     Debug Stream Index: 14
+; CHECK-NEXT:     Object File:
+; CHECK-NEXT:     Num Files: 0
+; CHECK-NEXT:     Source File Name Idx: 0
+; CHECK-NEXT:     Pdb File Name Idx: 1
+; CHECK-NEXT:     Line Info Byte Size: 0
+; CHECK-NEXT:     C13 Line Info Byte Size: 0
+; CHECK-NEXT:     Symbol Byte Size: 516
+; CHECK-NEXT:     Type Server Index: 0
+; CHECK-NEXT:     Has EC Info: 0
Index: tools/llvm-pdbdump/llvm-pdbdump.cpp
===================================================================
--- tools/llvm-pdbdump/llvm-pdbdump.cpp
+++ tools/llvm-pdbdump/llvm-pdbdump.cpp
@@ -35,6 +35,7 @@
 #include "llvm/DebugInfo/PDB/PDBSymbolExe.h"
 #include "llvm/DebugInfo/PDB/PDBSymbolFunc.h"
 #include "llvm/DebugInfo/PDB/PDBSymbolThunk.h"
+#include "llvm/DebugInfo/PDB/Raw/ModInfo.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBDbiStream.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBInfoStream.h"
@@ -278,6 +279,28 @@
   outs() << "Toolchain Version: " << Major << "." << Minor << '\n';
   outs() << "mspdb" << Major << Minor << ".dll version: " << Major << "."
          << Minor << "." << DbiStream.getPdbDllVersion() << '\n';
+
+  outs() << "Modules: \n";
+  for (auto Modi : DbiStream.modules()) {
+    outs() << Modi.getModuleName() << '\n';
+    outs().indent(4) << "Debug Stream Index: " << Modi.getModuleStreamIndex()
+                     << '\n';
+    outs().indent(4) << "Object File: " << Modi.getObjFileName() << '\n';
+    outs().indent(4) << "Num Files: " << Modi.getNumberOfFiles() << '\n';
+    outs().indent(4) << "Source File Name Idx: "
+                     << Modi.getSourceFileNameIndex() << '\n';
+    outs().indent(4) << "Pdb File Name Idx: " << Modi.getPdbFilePathNameIndex()
+                     << '\n';
+    outs().indent(4) << "Line Info Byte Size: " << Modi.getLineInfoByteSize()
+                     << '\n';
+    outs().indent(4) << "C13 Line Info Byte Size: "
+                     << Modi.getC13LineInfoByteSize() << '\n';
+    outs().indent(4) << "Symbol Byte Size: "
+                     << Modi.getSymbolDebugInfoByteSize() << '\n';
+    outs().indent(4) << "Type Server Index: " << Modi.getTypeServerIndex()
+                     << '\n';
+    outs().indent(4) << "Has EC Info: " << Modi.hasECInfo() << '\n';
+  }
 }
 
 static void dumpInput(StringRef Path) {