Use llvm/Object/MachO.h in macho-dumper. Drop the old macho parser.

For Mach-O there were 2 implementations for parsing object files. A
standalone llvm/Object/MachOObject.h and llvm/Object/MachO.h which
implements the generic interface in llvm/Object/ObjectFile.h.

This patch adds the missing features to MachO.h, moves macho-dump to
use MachO.h and removes ObjectFile.h.

In addition to making sure that check-all is clean, I checked that the
new version produces exactly the same output in all Mach-O files in a
llvm+clang build directory (including executables and shared
libraries).

To test the performance, I ran macho-dump over all the files in a
llvm+clang build directory again, but this time redirecting the output
to /dev/null. Both the old and new versions take about 4.6 seconds
(2.5 user) to finish.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180624 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 132 insertions, 452 deletions

diff --git a/lib/Object/CMakeLists.txt b/lib/Object/CMakeLists.txt
index c20fc0cc39..4ed129f467 100644
--- a/lib/Object/CMakeLists.txt
+++ b/lib/Object/CMakeLists.txt
@@ -4,7 +4,6 @@ add_llvm_library(LLVMObject
   COFFObjectFile.cpp
   ELFObjectFile.cpp
   Error.cpp
-  MachOObject.cpp
   MachOObjectFile.cpp
   Object.cpp
   ObjectFile.cpp
diff --git a/lib/Object/MachOObject.cpp b/lib/Object/MachOObject.cpp
deleted file mode 100644
index d88f96f298..0000000000
--- a/lib/Object/MachOObject.cpp
+++ /dev/null
@@ -1,422 +0,0 @@
-//===- MachOObject.cpp - Mach-O Object File Wrapper -----------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Object/MachOObject.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/StringRef.h"
-#include "llvm/Support/DataExtractor.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/Host.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/SwapByteOrder.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace llvm;
-using namespace llvm::object;
-
-/* Translation Utilities */
-
-template<typename T>
-static void SwapValue(T &Value) {
-  Value = sys::SwapByteOrder(Value);
-}
-
-template<typename T>
-static void SwapStruct(T &Value);
-
-template<typename T>
-static void ReadInMemoryStruct(const MachOObject &MOO,
-                               StringRef Buffer, uint64_t Base,
-                               InMemoryStruct<T> &Res) {
-  typedef T struct_type;
-  uint64_t Size = sizeof(struct_type);
-
-  // Check that the buffer contains the expected data.
-  if (Base + Size >  Buffer.size()) {
-    Res = 0;
-    return;
-  }
-
-  // Check whether we can return a direct pointer.
-  struct_type *Ptr = reinterpret_cast<struct_type *>(
-                       const_cast<char *>(Buffer.data() + Base));
-  if (!MOO.isSwappedEndian()) {
-    Res = Ptr;
-    return;
-  }
-
-  // Otherwise, copy the struct and translate the values.
-  Res = *Ptr;
-  SwapStruct(*Res);
-}
-
-/* *** */
-
-MachOObject::MachOObject(MemoryBuffer *Buffer_, bool IsLittleEndian_,
-                         bool Is64Bit_)
-  : Buffer(Buffer_), IsLittleEndian(IsLittleEndian_), Is64Bit(Is64Bit_),
-    IsSwappedEndian(IsLittleEndian != sys::IsLittleEndianHost),
-    HasStringTable(false), LoadCommands(0), NumLoadedCommands(0) {
-  // Load the common header.
-  memcpy(&Header, Buffer->getBuffer().data(), sizeof(Header));
-  if (IsSwappedEndian) {
-    SwapValue(Header.Magic);
-    SwapValue(Header.CPUType);
-    SwapValue(Header.CPUSubtype);
-    SwapValue(Header.FileType);
-    SwapValue(Header.NumLoadCommands);
-    SwapValue(Header.SizeOfLoadCommands);
-    SwapValue(Header.Flags);
-  }
-
-  if (is64Bit()) {
-    memcpy(&Header64Ext, Buffer->getBuffer().data() + sizeof(Header),
-           sizeof(Header64Ext));
-    if (IsSwappedEndian) {
-      SwapValue(Header64Ext.Reserved);
-    }
-  }
-
-  // Create the load command array if sane.
-  if (getHeader().NumLoadCommands < (1 << 20))
-    LoadCommands = new LoadCommandInfo[getHeader().NumLoadCommands];
-}
-
-MachOObject::~MachOObject() {
-  delete [] LoadCommands;
-}
-
-MachOObject *MachOObject::LoadFromBuffer(MemoryBuffer *Buffer,
-                                         std::string *ErrorStr) {
-  // First, check the magic value and initialize the basic object info.
-  bool IsLittleEndian = false, Is64Bit = false;
-  StringRef Magic = Buffer->getBuffer().slice(0, 4);
-  if (Magic == "\xFE\xED\xFA\xCE") {
-  }  else if (Magic == "\xCE\xFA\xED\xFE") {
-    IsLittleEndian = true;
-  } else if (Magic == "\xFE\xED\xFA\xCF") {
-    Is64Bit = true;
-  } else if (Magic == "\xCF\xFA\xED\xFE") {
-    IsLittleEndian = true;
-    Is64Bit = true;
-  } else {
-    if (ErrorStr) *ErrorStr = "not a Mach object file (invalid magic)";
-    return 0;
-  }
-
-  // Ensure that the at least the full header is present.
-  unsigned HeaderSize = Is64Bit ? macho::Header64Size : macho::Header32Size;
-  if (Buffer->getBufferSize() < HeaderSize) {
-    if (ErrorStr) *ErrorStr = "not a Mach object file (invalid header)";
-    return 0;
-  }
-
-  OwningPtr<MachOObject> Object(new MachOObject(Buffer, IsLittleEndian,
-                                                Is64Bit));
-
-  // Check for bogus number of load commands.
-  if (Object->getHeader().NumLoadCommands >= (1 << 20)) {
-    if (ErrorStr) *ErrorStr = "not a Mach object file (unreasonable header)";
-    return 0;
-  }
-
-  if (ErrorStr) *ErrorStr = "";
-  return Object.take();
-}
-
-StringRef MachOObject::getData(size_t Offset, size_t Size) const {
-  return Buffer->getBuffer().substr(Offset,Size);
-}
-
-void MachOObject::RegisterStringTable(macho::SymtabLoadCommand &SLC) {
-  HasStringTable = true;
-  StringTable = Buffer->getBuffer().substr(SLC.StringTableOffset,
-                                           SLC.StringTableSize);
-}
-
-const MachOObject::LoadCommandInfo &
-MachOObject::getLoadCommandInfo(unsigned Index) const {
-  assert(Index < getHeader().NumLoadCommands && "Invalid index!");
-
-  // Load the command, if necessary.
-  if (Index >= NumLoadedCommands) {
-    uint64_t Offset;
-    if (Index == 0) {
-      Offset = getHeaderSize();
-    } else {
-      const LoadCommandInfo &Prev = getLoadCommandInfo(Index - 1);
-      Offset = Prev.Offset + Prev.Command.Size;
-    }
-
-    LoadCommandInfo &Info = LoadCommands[Index];
-    memcpy(&Info.Command, Buffer->getBuffer().data() + Offset,
-           sizeof(macho::LoadCommand));
-    if (IsSwappedEndian) {
-      SwapValue(Info.Command.Type);
-      SwapValue(Info.Command.Size);
-    }
-    Info.Offset = Offset;
-    NumLoadedCommands = Index + 1;
-  }
-
-  return LoadCommands[Index];
-}
-
-template<>
-void SwapStruct(macho::SegmentLoadCommand &Value) {
-  SwapValue(Value.Type);
-  SwapValue(Value.Size);
-  SwapValue(Value.VMAddress);
-  SwapValue(Value.VMSize);
-  SwapValue(Value.FileOffset);
-  SwapValue(Value.FileSize);
-  SwapValue(Value.MaxVMProtection);
-  SwapValue(Value.InitialVMProtection);
-  SwapValue(Value.NumSections);
-  SwapValue(Value.Flags);
-}
-void MachOObject::ReadSegmentLoadCommand(const LoadCommandInfo &LCI,
-                         InMemoryStruct<macho::SegmentLoadCommand> &Res) const {
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), LCI.Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::Segment64LoadCommand &Value) {
-  SwapValue(Value.Type);
-  SwapValue(Value.Size);
-  SwapValue(Value.VMAddress);
-  SwapValue(Value.VMSize);
-  SwapValue(Value.FileOffset);
-  SwapValue(Value.FileSize);
-  SwapValue(Value.MaxVMProtection);
-  SwapValue(Value.InitialVMProtection);
-  SwapValue(Value.NumSections);
-  SwapValue(Value.Flags);
-}
-void MachOObject::ReadSegment64LoadCommand(const LoadCommandInfo &LCI,
-                       InMemoryStruct<macho::Segment64LoadCommand> &Res) const {
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), LCI.Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::SymtabLoadCommand &Value) {
-  SwapValue(Value.Type);
-  SwapValue(Value.Size);
-  SwapValue(Value.SymbolTableOffset);
-  SwapValue(Value.NumSymbolTableEntries);
-  SwapValue(Value.StringTableOffset);
-  SwapValue(Value.StringTableSize);
-}
-void MachOObject::ReadSymtabLoadCommand(const LoadCommandInfo &LCI,
-                          InMemoryStruct<macho::SymtabLoadCommand> &Res) const {
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), LCI.Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::DysymtabLoadCommand &Value) {
-  SwapValue(Value.Type);
-  SwapValue(Value.Size);
-  SwapValue(Value.LocalSymbolsIndex);
-  SwapValue(Value.NumLocalSymbols);
-  SwapValue(Value.ExternalSymbolsIndex);
-  SwapValue(Value.NumExternalSymbols);
-  SwapValue(Value.UndefinedSymbolsIndex);
-  SwapValue(Value.NumUndefinedSymbols);
-  SwapValue(Value.TOCOffset);
-  SwapValue(Value.NumTOCEntries);
-  SwapValue(Value.ModuleTableOffset);
-  SwapValue(Value.NumModuleTableEntries);
-  SwapValue(Value.ReferenceSymbolTableOffset);
-  SwapValue(Value.NumReferencedSymbolTableEntries);
-  SwapValue(Value.IndirectSymbolTableOffset);
-  SwapValue(Value.NumIndirectSymbolTableEntries);
-  SwapValue(Value.ExternalRelocationTableOffset);
-  SwapValue(Value.NumExternalRelocationTableEntries);
-  SwapValue(Value.LocalRelocationTableOffset);
-  SwapValue(Value.NumLocalRelocationTableEntries);
-}
-void MachOObject::ReadDysymtabLoadCommand(const LoadCommandInfo &LCI,
-                        InMemoryStruct<macho::DysymtabLoadCommand> &Res) const {
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), LCI.Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::LinkeditDataLoadCommand &Value) {
-  SwapValue(Value.Type);
-  SwapValue(Value.Size);
-  SwapValue(Value.DataOffset);
-  SwapValue(Value.DataSize);
-}
-void MachOObject::ReadLinkeditDataLoadCommand(const LoadCommandInfo &LCI,
-                    InMemoryStruct<macho::LinkeditDataLoadCommand> &Res) const {
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), LCI.Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::LinkerOptionsLoadCommand &Value) {
-  SwapValue(Value.Type);
-  SwapValue(Value.Size);
-  SwapValue(Value.Count);
-}
-void MachOObject::ReadLinkerOptionsLoadCommand(const LoadCommandInfo &LCI,
-                   InMemoryStruct<macho::LinkerOptionsLoadCommand> &Res) const {
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), LCI.Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::IndirectSymbolTableEntry &Value) {
-  SwapValue(Value.Index);
-}
-void
-MachOObject::ReadIndirectSymbolTableEntry(const macho::DysymtabLoadCommand &DLC,
-                                          unsigned Index,
-                   InMemoryStruct<macho::IndirectSymbolTableEntry> &Res) const {
-  uint64_t Offset = (DLC.IndirectSymbolTableOffset +
-                     Index * sizeof(macho::IndirectSymbolTableEntry));
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), Offset, Res);
-}
-
-
-template<>
-void SwapStruct(macho::Section &Value) {
-  SwapValue(Value.Address);
-  SwapValue(Value.Size);
-  SwapValue(Value.Offset);
-  SwapValue(Value.Align);
-  SwapValue(Value.RelocationTableOffset);
-  SwapValue(Value.NumRelocationTableEntries);
-  SwapValue(Value.Flags);
-  SwapValue(Value.Reserved1);
-  SwapValue(Value.Reserved2);
-}
-void MachOObject::ReadSection(const LoadCommandInfo &LCI,
-                              unsigned Index,
-                              InMemoryStruct<macho::Section> &Res) const {
-  assert(LCI.Command.Type == macho::LCT_Segment &&
-         "Unexpected load command info!");
-  uint64_t Offset = (LCI.Offset + sizeof(macho::SegmentLoadCommand) +
-                     Index * sizeof(macho::Section));
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::Section64 &Value) {
-  SwapValue(Value.Address);
-  SwapValue(Value.Size);
-  SwapValue(Value.Offset);
-  SwapValue(Value.Align);
-  SwapValue(Value.RelocationTableOffset);
-  SwapValue(Value.NumRelocationTableEntries);
-  SwapValue(Value.Flags);
-  SwapValue(Value.Reserved1);
-  SwapValue(Value.Reserved2);
-  SwapValue(Value.Reserved3);
-}
-void MachOObject::ReadSection64(const LoadCommandInfo &LCI,
-                                unsigned Index,
-                                InMemoryStruct<macho::Section64> &Res) const {
-  assert(LCI.Command.Type == macho::LCT_Segment64 &&
-         "Unexpected load command info!");
-  uint64_t Offset = (LCI.Offset + sizeof(macho::Segment64LoadCommand) +
-                     Index * sizeof(macho::Section64));
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::RelocationEntry &Value) {
-  SwapValue(Value.Word0);
-  SwapValue(Value.Word1);
-}
-void MachOObject::ReadRelocationEntry(uint64_t RelocationTableOffset,
-                                      unsigned Index,
-                            InMemoryStruct<macho::RelocationEntry> &Res) const {
-  uint64_t Offset = (RelocationTableOffset +
-                     Index * sizeof(macho::RelocationEntry));
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::SymbolTableEntry &Value) {
-  SwapValue(Value.StringIndex);
-  SwapValue(Value.Flags);
-  SwapValue(Value.Value);
-}
-void MachOObject::ReadSymbolTableEntry(uint64_t SymbolTableOffset,
-                                       unsigned Index,
-                           InMemoryStruct<macho::SymbolTableEntry> &Res) const {
-  uint64_t Offset = (SymbolTableOffset +
-                     Index * sizeof(macho::SymbolTableEntry));
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::Symbol64TableEntry &Value) {
-  SwapValue(Value.StringIndex);
-  SwapValue(Value.Flags);
-  SwapValue(Value.Value);
-}
-void MachOObject::ReadSymbol64TableEntry(uint64_t SymbolTableOffset,
-                                       unsigned Index,
-                         InMemoryStruct<macho::Symbol64TableEntry> &Res) const {
-  uint64_t Offset = (SymbolTableOffset +
-                     Index * sizeof(macho::Symbol64TableEntry));
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), Offset, Res);
-}
-
-template<>
-void SwapStruct(macho::DataInCodeTableEntry &Value) {
-  SwapValue(Value.Offset);
-  SwapValue(Value.Length);
-  SwapValue(Value.Kind);
-}
-void MachOObject::ReadDataInCodeTableEntry(uint64_t TableOffset,
-                                           unsigned Index,
-                       InMemoryStruct<macho::DataInCodeTableEntry> &Res) const {
-  uint64_t Offset = (TableOffset +
-                     Index * sizeof(macho::DataInCodeTableEntry));
-  ReadInMemoryStruct(*this, Buffer->getBuffer(), Offset, Res);
-}
-
-void MachOObject::ReadULEB128s(uint64_t Index,
-                               SmallVectorImpl<uint64_t> &Out) const {
-  DataExtractor extractor(Buffer->getBuffer(), true, 0);
-
-  uint32_t offset = Index;
-  uint64_t data = 0;
-  while (uint64_t delta = extractor.getULEB128(&offset)) {
-    data += delta;
-    Out.push_back(data);
-  }
-}
-
-/* ** */
-// Object Dumping Facilities
-void MachOObject::dump() const { print(dbgs()); dbgs() << '\n'; }
-void MachOObject::dumpHeader() const { printHeader(dbgs()); dbgs() << '\n'; }
-
-void MachOObject::printHeader(raw_ostream &O) const {
-  O << "('cputype', " << Header.CPUType << ")\n";
-  O << "('cpusubtype', " << Header.CPUSubtype << ")\n";
-  O << "('filetype', " << Header.FileType << ")\n";
-  O << "('num_load_commands', " << Header.NumLoadCommands << ")\n";
-  O << "('load_commands_size', " << Header.SizeOfLoadCommands << ")\n";
-  O << "('flag', " << Header.Flags << ")\n";
-
-  // Print extended header if 64-bit.
-  if (is64Bit())
-    O << "('reserved', " << Header64Ext.Reserved << ")\n";
-}
-
-void MachOObject::print(raw_ostream &O) const {
-  O << "Header:\n";
-  printHeader(O);
-  O << "Load Commands:\n";
-
-  O << "Buffer:\n";
-}
diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 38198b1793..bb6ca93176 100644
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -120,6 +120,11 @@ void SwapStruct(macho::Header &H) {
 }
 
 template<>
+void SwapStruct(macho::Header64Ext &E) {
+  SwapValue(E.Reserved);
+}
+
+template<>
 void SwapStruct(macho::SymtabLoadCommand &C) {
   SwapValue(C.Type);
   SwapValue(C.Size);
@@ -130,6 +135,30 @@ void SwapStruct(macho::SymtabLoadCommand &C) {
 }
 
 template<>
+void SwapStruct(macho::DysymtabLoadCommand &C) {
+  SwapValue(C.Type);
+  SwapValue(C.Size);
+  SwapValue(C.LocalSymbolsIndex);
+  SwapValue(C.NumLocalSymbols);
+  SwapValue(C.ExternalSymbolsIndex);
+  SwapValue(C.NumExternalSymbols);
+  SwapValue(C.UndefinedSymbolsIndex);
+  SwapValue(C.NumUndefinedSymbols);
+  SwapValue(C.TOCOffset);
+  SwapValue(C.NumTOCEntries);
+  SwapValue(C.ModuleTableOffset);
+  SwapValue(C.NumModuleTableEntries);
+  SwapValue(C.ReferenceSymbolTableOffset);
+  SwapValue(C.NumReferencedSymbolTableEntries);
+  SwapValue(C.IndirectSymbolTableOffset);
+  SwapValue(C.NumIndirectSymbolTableEntries);
+  SwapValue(C.ExternalRelocationTableOffset);
+  SwapValue(C.NumExternalRelocationTableEntries);
+  SwapValue(C.LocalRelocationTableOffset);
+  SwapValue(C.NumLocalRelocationTableEntries);
+}
+
+template<>
 void SwapStruct(macho::LinkeditDataLoadCommand &C) {
   SwapValue(C.Type);
   SwapValue(C.Size);
@@ -165,6 +194,25 @@ void SwapStruct(macho::Segment64LoadCommand &C) {
   SwapValue(C.Flags);
 }
 
+template<>
+void SwapStruct(macho::IndirectSymbolTableEntry &C) {
+  SwapValue(C.Index);
+}
+
+template<>
+void SwapStruct(macho::LinkerOptionsLoadCommand &C) {
+  SwapValue(C.Type);
+  SwapValue(C.Size);
+  SwapValue(C.Count);
+}
+
+template<>
+void SwapStruct(macho::DataInCodeTableEntry &C) {
+  SwapValue(C.Offset);
+  SwapValue(C.Length);
+  SwapValue(C.Kind);
+}
+
 template<typename T>
 T getStruct(const MachOObjectFile *O, const char *P) {
   T Cmd;
@@ -174,32 +222,20 @@ T getStruct(const MachOObjectFile *O, const char *P) {
   return Cmd;
 }
 
-static macho::SegmentLoadCommand
-getSegmentLoadCommand(const MachOObjectFile *O,
-                      const MachOObjectFile::LoadCommandInfo &L) {
-  return getStruct<macho::SegmentLoadCommand>(O, L.Ptr);
-}
-
-static macho::Segment64LoadCommand
-getSegment64LoadCommand(const MachOObjectFile *O,
-                        const MachOObjectFile::LoadCommandInfo &L) {
-  return getStruct<macho::Segment64LoadCommand>(O, L.Ptr);
-}
-
 static uint32_t
 getSegmentLoadCommandNumSections(const MachOObjectFile *O,
                                  const MachOObjectFile::LoadCommandInfo &L) {
   if (O->is64Bit()) {
-    macho::Segment64LoadCommand S = getSegment64LoadCommand(O, L);
+    macho::Segment64LoadCommand S = O->getSegment64LoadCommand(L);
     return S.NumSections;
   }
-  macho::SegmentLoadCommand S = getSegmentLoadCommand(O, L);
+  macho::SegmentLoadCommand S = O->getSegmentLoadCommand(L);
   return S.NumSections;
 }
 
-static const SectionBase *
-getSectionBase(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
-               unsigned Sec) {
+static const char *
+getSectionPtr(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
+              unsigned Sec) {
   uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
 
   bool Is64 = O->is64Bit();
@@ -209,7 +245,7 @@ getSectionBase(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
                                 sizeof(macho::Section);
 
   uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
-  return reinterpret_cast<const SectionBase*>(SectionAddr);
+  return reinterpret_cast<const char*>(SectionAddr);
 }
 
 static const char *getPtr(const MachOObjectFile *O, size_t Offset) {
@@ -377,7 +413,7 @@ MachOObjectFile::MachOObjectFile(MemoryBuffer *Object,
                                  bool IsLittleEndian, bool Is64bits,
                                  error_code &ec)
     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object),
-      SymtabLoadCmd(NULL) {
+      SymtabLoadCmd(NULL), DysymtabLoadCmd(NULL) {
   uint32_t LoadCommandCount = this->getHeader().NumLoadCommands;
   macho::LoadCommandType SegmentLoadType = is64Bit() ?
     macho::LCT_Segment64 : macho::LCT_Segment;
@@ -387,13 +423,14 @@ MachOObjectFile::MachOObjectFile(MemoryBuffer *Object,
     if (Load.C.Type == macho::LCT_Symtab) {
       assert(!SymtabLoadCmd && "Multiple symbol tables");
       SymtabLoadCmd = Load.Ptr;
-    }
-
-    if (Load.C.Type == SegmentLoadType) {
+    } else if (Load.C.Type == macho::LCT_Dysymtab) {
+      assert(!DysymtabLoadCmd && "Multiple dynamic symbol tables");
+      DysymtabLoadCmd = Load.Ptr;
+    } else if (Load.C.Type == SegmentLoadType) {
       uint32_t NumSections = getSegmentLoadCommandNumSections(this, Load);
       for (unsigned J = 0; J < NumSections; ++J) {
-        const SectionBase *Sec = getSectionBase(this, Load, J);
-        Sections.push_back(reinterpret_cast<const char*>(Sec));
+        const char *Sec = getSectionPtr(this, Load, J);
+        Sections.push_back(Sec);
       }
     }
 
@@ -416,10 +453,9 @@ error_code MachOObjectFile::getSymbolNext(DataRefImpl Symb,
 
 error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
                                           StringRef &Res) const {
-  macho::SymtabLoadCommand S = getSymtabLoadCommand();
-  const char *StringTable = getPtr(this, S.StringTableOffset);
+  StringRef StringTable = getStringTableData();
   SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, Symb);
-  const char *Start = &StringTable[Entry.StringIndex];
+  const char *Start = &StringTable.data()[Entry.StringIndex];
   Res = StringRef(Start);
   return object_error::success;
 }
@@ -1271,6 +1307,18 @@ StringRef MachOObjectFile::getLoadName() const {
   report_fatal_error("get_load_name() unimplemented in MachOObjectFile");
 }
 
+relocation_iterator MachOObjectFile::getSectionRelBegin(unsigned Index) const {
+  DataRefImpl DRI;
+  DRI.d.a = Index;
+  return getSectionRelBegin(DRI);
+}
+
+relocation_iterator MachOObjectFile::getSectionRelEnd(unsigned Index) const {
+  DataRefImpl DRI;
+  DRI.d.a = Index;
+  return getSectionRelEnd(DRI);
+}
+
 StringRef
 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
@@ -1375,6 +1423,18 @@ macho::Section64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
   return getStruct<macho::Section64>(this, Sections[DRI.d.a]);
 }
 
+macho::Section MachOObjectFile::getSection(const LoadCommandInfo &L,
+                                           unsigned Index) const {
+  const char *Sec = getSectionPtr(this, L, Index);
+  return getStruct<macho::Section>(this, Sec);
+}
+
+macho::Section64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
+                                               unsigned Index) const {
+  const char *Sec = getSectionPtr(this, L, Index);
+  return getStruct<macho::Section64>(this, Sec);
+}
+
 macho::SymbolTableEntry
 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
   const char *P = reinterpret_cast<const char *>(DRI.p);
@@ -1392,6 +1452,21 @@ MachOObjectFile::getLinkeditDataLoadCommand(const MachOObjectFile::LoadCommandIn
   return getStruct<macho::LinkeditDataLoadCommand>(this, L.Ptr);
 }
 
+macho::SegmentLoadCommand
+MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
+  return getStruct<macho::SegmentLoadCommand>(this, L.Ptr);
+}
+
+macho::Segment64LoadCommand
+MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
+  return getStruct<macho::Segment64LoadCommand>(this, L.Ptr);
+}
+
+macho::LinkerOptionsLoadCommand
+MachOObjectFile::getLinkerOptionsLoadCommand(const LoadCommandInfo &L) const {
+  return getStruct<macho::LinkerOptionsLoadCommand>(this, L.Ptr);
+}
+
 macho::RelocationEntry
 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
   const char *P = reinterpret_cast<const char *>(Rel.p);
@@ -1402,11 +1477,39 @@ macho::Header MachOObjectFile::getHeader() const {
   return getStruct<macho::Header>(this, getPtr(this, 0));
 }
 
-macho::SymtabLoadCommand
-MachOObjectFile::getSymtabLoadCommand() const {
+macho::Header64Ext MachOObjectFile::getHeader64Ext() const {
+  return
+    getStruct<macho::Header64Ext>(this, getPtr(this, sizeof(macho::Header)));
+}
+
+macho::IndirectSymbolTableEntry MachOObjectFile::getIndirectSymbolTableEntry(
+                                          const macho::DysymtabLoadCommand &DLC,
+                                          unsigned Index) const {
+  uint64_t Offset = DLC.IndirectSymbolTableOffset +
+    Index * sizeof(macho::IndirectSymbolTableEntry);
+  return getStruct<macho::IndirectSymbolTableEntry>(this, getPtr(this, Offset));
+}
+
+macho::DataInCodeTableEntry
+MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
+                                         unsigned Index) const {
+  uint64_t Offset = DataOffset + Index * sizeof(macho::DataInCodeTableEntry);
+  return getStruct<macho::DataInCodeTableEntry>(this, getPtr(this, Offset));
+}
+
+macho::SymtabLoadCommand MachOObjectFile::getSymtabLoadCommand() const {
   return getStruct<macho::SymtabLoadCommand>(this, SymtabLoadCmd);
 }
 
+macho::DysymtabLoadCommand MachOObjectFile::getDysymtabLoadCommand() const {
+  return getStruct<macho::DysymtabLoadCommand>(this, DysymtabLoadCmd);
+}
+
+StringRef MachOObjectFile::getStringTableData() const {
+  macho::SymtabLoadCommand S = getSymtabLoadCommand();
+  return getData().substr(S.StringTableOffset, S.StringTableSize);
+}
+
 bool MachOObjectFile::is64Bit() const {
   return getType() == getMachOType(false, true) ||
     getType() == getMachOType(true, true);