Merge alignment of common GlobalValue.
[oota-llvm.git] / lib / Object / MachOObjectFile.cpp
index 1fb0c13407344e6d23325654f0baefe8ffb74a9f..c6815ea27d24cfd02f8289a5a872cfc10c6cf2b5 100644 (file)
 
 #include "llvm/Object/MachO.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/Host.h"
+#include "llvm/Support/LEB128.h"
+#include "llvm/Support/MachO.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cctype>
 using namespace llvm;
 using namespace object;
 
-namespace llvm {
-namespace object {
-
-struct nlist_base {
-  uint32_t n_strx;
-  uint8_t n_type;
-  uint8_t n_sect;
-  uint16_t n_desc;
-};
-
-struct section_base {
-  char sectname[16];
-  char segname[16];
-};
-
-template<typename T>
-static void SwapValue(T &Value) {
-  Value = sys::SwapByteOrder(Value);
-}
-
-template<typename T>
-static void SwapStruct(T &Value);
-
-template<>
-void SwapStruct(MachO::any_relocation_info &H) {
-  SwapValue(H.r_word0);
-  SwapValue(H.r_word1);
-}
-
-template<>
-void SwapStruct(MachO::load_command &L) {
-  SwapValue(L.cmd);
-  SwapValue(L.cmdsize);
-}
-
-template<>
-void SwapStruct(nlist_base &S) {
-  SwapValue(S.n_strx);
-  SwapValue(S.n_desc);
-}
-
-template<>
-void SwapStruct(MachO::section &S) {
-  SwapValue(S.addr);
-  SwapValue(S.size);
-  SwapValue(S.offset);
-  SwapValue(S.align);
-  SwapValue(S.reloff);
-  SwapValue(S.nreloc);
-  SwapValue(S.flags);
-  SwapValue(S.reserved1);
-  SwapValue(S.reserved2);
-}
-
-template<>
-void SwapStruct(MachO::section_64 &S) {
-  SwapValue(S.addr);
-  SwapValue(S.size);
-  SwapValue(S.offset);
-  SwapValue(S.align);
-  SwapValue(S.reloff);
-  SwapValue(S.nreloc);
-  SwapValue(S.flags);
-  SwapValue(S.reserved1);
-  SwapValue(S.reserved2);
-  SwapValue(S.reserved3);
-}
-
-template<>
-void SwapStruct(MachO::nlist &S) {
-  SwapValue(S.n_strx);
-  SwapValue(S.n_desc);
-  SwapValue(S.n_value);
-}
-
-template<>
-void SwapStruct(MachO::nlist_64 &S) {
-  SwapValue(S.n_strx);
-  SwapValue(S.n_desc);
-  SwapValue(S.n_value);
-}
-
-template<>
-void SwapStruct(MachO::mach_header &H) {
-  SwapValue(H.magic);
-  SwapValue(H.cputype);
-  SwapValue(H.cpusubtype);
-  SwapValue(H.filetype);
-  SwapValue(H.ncmds);
-  SwapValue(H.sizeofcmds);
-  SwapValue(H.flags);
-}
-
-template<>
-void SwapStruct(MachO::mach_header_64 &H) {
-  SwapValue(H.magic);
-  SwapValue(H.cputype);
-  SwapValue(H.cpusubtype);
-  SwapValue(H.filetype);
-  SwapValue(H.ncmds);
-  SwapValue(H.sizeofcmds);
-  SwapValue(H.flags);
-  SwapValue(H.reserved);
-}
-
-template<>
-void SwapStruct(MachO::symtab_command &C) {
-  SwapValue(C.cmd);
-  SwapValue(C.cmdsize);
-  SwapValue(C.symoff);
-  SwapValue(C.nsyms);
-  SwapValue(C.stroff);
-  SwapValue(C.strsize);
-}
-
-template<>
-void SwapStruct(MachO::dysymtab_command &C) {
-  SwapValue(C.cmd);
-  SwapValue(C.cmdsize);
-  SwapValue(C.ilocalsym);
-  SwapValue(C.nlocalsym);
-  SwapValue(C.iextdefsym);
-  SwapValue(C.nextdefsym);
-  SwapValue(C.iundefsym);
-  SwapValue(C.nundefsym);
-  SwapValue(C.tocoff);
-  SwapValue(C.ntoc);
-  SwapValue(C.modtaboff);
-  SwapValue(C.nmodtab);
-  SwapValue(C.extrefsymoff);
-  SwapValue(C.nextrefsyms);
-  SwapValue(C.indirectsymoff);
-  SwapValue(C.nindirectsyms);
-  SwapValue(C.extreloff);
-  SwapValue(C.nextrel);
-  SwapValue(C.locreloff);
-  SwapValue(C.nlocrel);
-}
-
-template<>
-void SwapStruct(MachO::linkedit_data_command &C) {
-  SwapValue(C.cmd);
-  SwapValue(C.cmdsize);
-  SwapValue(C.dataoff);
-  SwapValue(C.datasize);
-}
-
-template<>
-void SwapStruct(MachO::segment_command &C) {
-  SwapValue(C.cmd);
-  SwapValue(C.cmdsize);
-  SwapValue(C.vmaddr);
-  SwapValue(C.vmsize);
-  SwapValue(C.fileoff);
-  SwapValue(C.filesize);
-  SwapValue(C.maxprot);
-  SwapValue(C.initprot);
-  SwapValue(C.nsects);
-  SwapValue(C.flags);
-}
-
-template<>
-void SwapStruct(MachO::segment_command_64 &C) {
-  SwapValue(C.cmd);
-  SwapValue(C.cmdsize);
-  SwapValue(C.vmaddr);
-  SwapValue(C.vmsize);
-  SwapValue(C.fileoff);
-  SwapValue(C.filesize);
-  SwapValue(C.maxprot);
-  SwapValue(C.initprot);
-  SwapValue(C.nsects);
-  SwapValue(C.flags);
-}
-
-template<>
-void SwapStruct(uint32_t &C) {
-  SwapValue(C);
-}
-
-template<>
-void SwapStruct(MachO::linker_options_command &C) {
-  SwapValue(C.cmd);
-  SwapValue(C.cmdsize);
-  SwapValue(C.count);
-}
-
-template<>
-void SwapStruct(MachO::version_min_command&C) {
-  SwapValue(C.cmd);
-  SwapValue(C.cmdsize);
-  SwapValue(C.version);
-  SwapValue(C.reserved);
-}
-
-template<>
-void SwapStruct(MachO::dylib_command&C) {
-  SwapValue(C.cmd);
-  SwapValue(C.cmdsize);
-  SwapValue(C.dylib.name);
-  SwapValue(C.dylib.timestamp);
-  SwapValue(C.dylib.current_version);
-  SwapValue(C.dylib.compatibility_version);
-}
-
-template<>
-void SwapStruct(MachO::data_in_code_entry &C) {
-  SwapValue(C.offset);
-  SwapValue(C.length);
-  SwapValue(C.kind);
+namespace {
+  struct section_base {
+    char sectname[16];
+    char segname[16];
+  };
 }
 
 template<typename T>
-T getStruct(const MachOObjectFile *O, const char *P) {
+static T getStruct(const MachOObjectFile *O, const char *P) {
   T Cmd;
   memcpy(&Cmd, P, sizeof(T));
   if (O->isLittleEndian() != sys::IsLittleEndianHost)
-    SwapStruct(Cmd);
+    MachO::swapStruct(Cmd);
   return Cmd;
 }
 
@@ -278,10 +76,10 @@ static const char *getPtr(const MachOObjectFile *O, size_t Offset) {
   return O->getData().substr(Offset, 1).data();
 }
 
-static nlist_base
+static MachO::nlist_base
 getSymbolTableEntryBase(const MachOObjectFile *O, DataRefImpl DRI) {
   const char *P = reinterpret_cast<const char *>(DRI.p);
-  return getStruct<nlist_base>(O, P);
+  return getStruct<MachO::nlist_base>(O, P);
 }
 
 static StringRef parseSegmentOrSectionName(const char *P) {
@@ -316,7 +114,7 @@ static void printRelocationTargetName(const MachOObjectFile *O,
     uint32_t Val = O->getPlainRelocationSymbolNum(RE);
 
     for (const SymbolRef &Symbol : O->symbols()) {
-      error_code ec;
+      std::error_code ec;
       uint64_t Addr;
       StringRef Name;
 
@@ -333,7 +131,7 @@ static void printRelocationTargetName(const MachOObjectFile *O,
     // If we couldn't find a symbol that this relocation refers to, try
     // to find a section beginning instead.
     for (const SectionRef &Section : O->sections()) {
-      error_code ec;
+      std::error_code ec;
       uint64_t Addr;
       StringRef Name;
 
@@ -426,12 +224,11 @@ static uint32_t getSectionFlags(const MachOObjectFile *O,
   return Sect.flags;
 }
 
-MachOObjectFile::MachOObjectFile(MemoryBuffer *Object, bool IsLittleEndian,
-                                 bool Is64bits, error_code &EC,
-                                 bool BufferOwned)
-    : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object, BufferOwned),
+MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
+                                 bool Is64bits, std::error_code &EC)
+    : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object),
       SymtabLoadCmd(nullptr), DysymtabLoadCmd(nullptr),
-      DataInCodeLoadCmd(nullptr) {
+      DataInCodeLoadCmd(nullptr), DyldInfoLoadCmd(nullptr) {
   uint32_t LoadCommandCount = this->getHeader().ncmds;
   MachO::LoadCommandType SegmentLoadType = is64Bit() ?
     MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT;
@@ -447,6 +244,10 @@ MachOObjectFile::MachOObjectFile(MemoryBuffer *Object, bool IsLittleEndian,
     } else if (Load.C.cmd == MachO::LC_DATA_IN_CODE) {
       assert(!DataInCodeLoadCmd && "Multiple data in code tables");
       DataInCodeLoadCmd = Load.Ptr;
+    } else if (Load.C.cmd == MachO::LC_DYLD_INFO || 
+               Load.C.cmd == MachO::LC_DYLD_INFO_ONLY) {
+      assert(!DyldInfoLoadCmd && "Multiple dyldinfo load commands");
+      DyldInfoLoadCmd = Load.Ptr;
     } else if (Load.C.cmd == SegmentLoadType) {
       uint32_t NumSections = getSegmentLoadCommandNumSections(this, Load);
       for (unsigned J = 0; J < NumSections; ++J) {
@@ -475,10 +276,10 @@ void MachOObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
   Symb.p += SymbolTableEntrySize;
 }
 
-error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
-                                          StringRef &Res) const {
+std::error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
+                                               StringRef &Res) const {
   StringRef StringTable = getStringTableData();
-  nlist_base Entry = getSymbolTableEntryBase(this, Symb);
+  MachO::nlist_base Entry = getSymbolTableEntryBase(this, Symb);
   const char *Start = &StringTable.data()[Entry.n_strx];
   Res = StringRef(Start);
   return object_error::success;
@@ -486,8 +287,8 @@ error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
 
 // getIndirectName() returns the name of the alias'ed symbol who's string table
 // index is in the n_value field.
-error_code MachOObjectFile::getIndirectName(DataRefImpl Symb,
-                                            StringRef &Res) const {
+std::error_code MachOObjectFile::getIndirectName(DataRefImpl Symb,
+                                                 StringRef &Res) const {
   StringRef StringTable = getStringTableData();
   uint64_t NValue;
   if (is64Bit()) {
@@ -508,8 +309,8 @@ error_code MachOObjectFile::getIndirectName(DataRefImpl Symb,
   return object_error::success;
 }
 
-error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
-                                             uint64_t &Res) const {
+std::error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
+                                                  uint64_t &Res) const {
   if (is64Bit()) {
     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
@@ -528,11 +329,11 @@ error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
   return object_error::success;
 }
 
-error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
-                                               uint32_t &Result) const {
+std::error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
+                                                    uint32_t &Result) const {
   uint32_t flags = getSymbolFlags(DRI);
   if (flags & SymbolRef::SF_Common) {
-    nlist_base Entry = getSymbolTableEntryBase(this, DRI);
+    MachO::nlist_base Entry = getSymbolTableEntryBase(this, DRI);
     Result = 1 << MachO::GET_COMM_ALIGN(Entry.n_desc);
   } else {
     Result = 0;
@@ -540,13 +341,13 @@ error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
   return object_error::success;
 }
 
-error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
-                                          uint64_t &Result) const {
+std::error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
+                                               uint64_t &Result) const {
   uint64_t BeginOffset;
   uint64_t EndOffset = 0;
   uint8_t SectionIndex;
 
-  nlist_base Entry = getSymbolTableEntryBase(this, DRI);
+  MachO::nlist_base Entry = getSymbolTableEntryBase(this, DRI);
   uint64_t Value;
   getSymbolAddress(DRI, Value);
   if (Value == UnknownAddressOrSize) {
@@ -589,9 +390,9 @@ error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
   return object_error::success;
 }
 
-error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
-                                          SymbolRef::Type &Res) const {
-  nlist_base Entry = getSymbolTableEntryBase(this, Symb);
+std::error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
+                                               SymbolRef::Type &Res) const {
+  MachO::nlist_base Entry = getSymbolTableEntryBase(this, Symb);
   uint8_t n_type = Entry.n_type;
 
   Res = SymbolRef::ST_Other;
@@ -614,7 +415,7 @@ error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
 }
 
 uint32_t MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
-  nlist_base Entry = getSymbolTableEntryBase(this, DRI);
+  MachO::nlist_base Entry = getSymbolTableEntryBase(this, DRI);
 
   uint8_t MachOType = Entry.n_type;
   uint16_t MachOFlags = Entry.n_desc;
@@ -643,16 +444,18 @@ uint32_t MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
   if (MachOFlags & (MachO::N_WEAK_REF | MachO::N_WEAK_DEF))
     Result |= SymbolRef::SF_Weak;
 
+  if (MachOFlags & (MachO::N_ARM_THUMB_DEF))
+    Result |= SymbolRef::SF_Thumb;
+
   if ((MachOType & MachO::N_TYPE) == MachO::N_ABS)
     Result |= SymbolRef::SF_Absolute;
 
   return Result;
 }
 
-error_code
-MachOObjectFile::getSymbolSection(DataRefImpl Symb,
-                                  section_iterator &Res) const {
-  nlist_base Entry = getSymbolTableEntryBase(this, Symb);
+std::error_code MachOObjectFile::getSymbolSection(DataRefImpl Symb,
+                                                  section_iterator &Res) const {
+  MachO::nlist_base Entry = getSymbolTableEntryBase(this, Symb);
   uint8_t index = Entry.n_sect;
 
   if (index == 0) {
@@ -670,15 +473,15 @@ void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
   Sec.d.a++;
 }
 
-error_code
-MachOObjectFile::getSectionName(DataRefImpl Sec, StringRef &Result) const {
+std::error_code MachOObjectFile::getSectionName(DataRefImpl Sec,
+                                                StringRef &Result) const {
   ArrayRef<char> Raw = getSectionRawName(Sec);
   Result = parseSegmentOrSectionName(Raw.data());
   return object_error::success;
 }
 
-error_code
-MachOObjectFile::getSectionAddress(DataRefImpl Sec, uint64_t &Res) const {
+std::error_code MachOObjectFile::getSectionAddress(DataRefImpl Sec,
+                                                   uint64_t &Res) const {
   if (is64Bit()) {
     MachO::section_64 Sect = getSection64(Sec);
     Res = Sect.addr;
@@ -689,8 +492,8 @@ MachOObjectFile::getSectionAddress(DataRefImpl Sec, uint64_t &Res) const {
   return object_error::success;
 }
 
-error_code
-MachOObjectFile::getSectionSize(DataRefImpl Sec, uint64_t &Res) const {
+std::error_code MachOObjectFile::getSectionSize(DataRefImpl Sec,
+                                                uint64_t &Res) const {
   if (is64Bit()) {
     MachO::section_64 Sect = getSection64(Sec);
     Res = Sect.size;
@@ -702,8 +505,8 @@ MachOObjectFile::getSectionSize(DataRefImpl Sec, uint64_t &Res) const {
   return object_error::success;
 }
 
-error_code
-MachOObjectFile::getSectionContents(DataRefImpl Sec, StringRef &Res) const {
+std::error_code MachOObjectFile::getSectionContents(DataRefImpl Sec,
+                                                    StringRef &Res) const {
   uint32_t Offset;
   uint64_t Size;
 
@@ -721,8 +524,8 @@ MachOObjectFile::getSectionContents(DataRefImpl Sec, StringRef &Res) const {
   return object_error::success;
 }
 
-error_code
-MachOObjectFile::getSectionAlignment(DataRefImpl Sec, uint64_t &Res) const {
+std::error_code MachOObjectFile::getSectionAlignment(DataRefImpl Sec,
+                                                     uint64_t &Res) const {
   uint32_t Align;
   if (is64Bit()) {
     MachO::section_64 Sect = getSection64(Sec);
@@ -736,14 +539,15 @@ MachOObjectFile::getSectionAlignment(DataRefImpl Sec, uint64_t &Res) const {
   return object_error::success;
 }
 
-error_code
-MachOObjectFile::isSectionText(DataRefImpl Sec, bool &Res) const {
+std::error_code MachOObjectFile::isSectionText(DataRefImpl Sec,
+                                               bool &Res) const {
   uint32_t Flags = getSectionFlags(this, Sec);
   Res = Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
   return object_error::success;
 }
 
-error_code MachOObjectFile::isSectionData(DataRefImpl Sec, bool &Result) const {
+std::error_code MachOObjectFile::isSectionData(DataRefImpl Sec,
+                                               bool &Result) const {
   uint32_t Flags = getSectionFlags(this, Sec);
   unsigned SectionType = Flags & MachO::SECTION_TYPE;
   Result = !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
@@ -752,7 +556,8 @@ error_code MachOObjectFile::isSectionData(DataRefImpl Sec, bool &Result) const {
   return object_error::success;
 }
 
-error_code MachOObjectFile::isSectionBSS(DataRefImpl Sec, bool &Result) const {
+std::error_code MachOObjectFile::isSectionBSS(DataRefImpl Sec,
+                                              bool &Result) const {
   uint32_t Flags = getSectionFlags(this, Sec);
   unsigned SectionType = Flags & MachO::SECTION_TYPE;
   Result = !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
@@ -761,7 +566,7 @@ error_code MachOObjectFile::isSectionBSS(DataRefImpl Sec, bool &Result) const {
   return object_error::success;
 }
 
-error_code
+std::error_code
 MachOObjectFile::isSectionRequiredForExecution(DataRefImpl Sec,
                                                bool &Result) const {
   // FIXME: Unimplemented.
@@ -769,15 +574,15 @@ MachOObjectFile::isSectionRequiredForExecution(DataRefImpl Sec,
   return object_error::success;
 }
 
-error_code MachOObjectFile::isSectionVirtual(DataRefImpl Sec,
-                                             bool &Result) const {
+std::error_code MachOObjectFile::isSectionVirtual(DataRefImpl Sec,
+                                                  bool &Result) const {
   // FIXME: Unimplemented.
   Result = false;
   return object_error::success;
 }
 
-error_code
-MachOObjectFile::isSectionZeroInit(DataRefImpl Sec, bool &Res) const {
+std::error_code MachOObjectFile::isSectionZeroInit(DataRefImpl Sec,
+                                                   bool &Res) const {
   uint32_t Flags = getSectionFlags(this, Sec);
   unsigned SectionType = Flags & MachO::SECTION_TYPE;
   Res = SectionType == MachO::S_ZEROFILL ||
@@ -785,8 +590,8 @@ MachOObjectFile::isSectionZeroInit(DataRefImpl Sec, bool &Res) const {
   return object_error::success;
 }
 
-error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
-                                                  bool &Result) const {
+std::error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
+                                                       bool &Result) const {
   // Consider using the code from isSectionText to look for __const sections.
   // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
   // to use section attributes to distinguish code from data.
@@ -796,9 +601,9 @@ error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
   return object_error::success;
 }
 
-error_code
-MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
-                                       bool &Result) const {
+std::error_code MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec,
+                                                       DataRefImpl Symb,
+                                                       bool &Result) const {
   SymbolRef::Type ST;
   this->getSymbolType(Symb, ST);
   if (ST == SymbolRef::ST_Unknown) {
@@ -846,8 +651,8 @@ void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
   ++Rel.d.b;
 }
 
-error_code
-MachOObjectFile::getRelocationAddress(DataRefImpl Rel, uint64_t &Res) const {
+std::error_code MachOObjectFile::getRelocationAddress(DataRefImpl Rel,
+                                                      uint64_t &Res) const {
   uint64_t Offset;
   getRelocationOffset(Rel, Offset);
 
@@ -859,8 +664,8 @@ MachOObjectFile::getRelocationAddress(DataRefImpl Rel, uint64_t &Res) const {
   return object_error::success;
 }
 
-error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
-                                                uint64_t &Res) const {
+std::error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
+                                                     uint64_t &Res) const {
   assert(getHeader().filetype == MachO::MH_OBJECT &&
          "Only implemented for MH_OBJECT");
   MachO::any_relocation_info RE = getRelocation(Rel);
@@ -871,6 +676,9 @@ error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
 symbol_iterator
 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
   MachO::any_relocation_info RE = getRelocation(Rel);
+  if (isRelocationScattered(RE))
+    return symbol_end();
+
   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
   bool isExtern = getPlainRelocationExternal(RE);
   if (!isExtern)
@@ -886,14 +694,14 @@ MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
   return symbol_iterator(SymbolRef(Sym, this));
 }
 
-error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
-                                              uint64_t &Res) const {
+std::error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
+                                                   uint64_t &Res) const {
   MachO::any_relocation_info RE = getRelocation(Rel);
   Res = getAnyRelocationType(RE);
   return object_error::success;
 }
 
-error_code
+std::error_code
 MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
                                        SmallVectorImpl<char> &Result) const {
   StringRef res;
@@ -956,7 +764,6 @@ MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
         res = Table[RType];
       break;
     }
-    case Triple::arm64:
     case Triple::aarch64: {
       static const char *const Table[] = {
         "ARM64_RELOC_UNSIGNED",           "ARM64_RELOC_SUBTRACTOR",
@@ -1006,7 +813,7 @@ MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
   return object_error::success;
 }
 
-error_code
+std::error_code
 MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
                                           SmallVectorImpl<char> &Result) const {
   MachO::any_relocation_info RE = getRelocation(Rel);
@@ -1182,8 +989,8 @@ MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
   return object_error::success;
 }
 
-error_code
-MachOObjectFile::getRelocationHidden(DataRefImpl Rel, bool &Result) const {
+std::error_code MachOObjectFile::getRelocationHidden(DataRefImpl Rel,
+                                                     bool &Result) const {
   unsigned Arch = getArch();
   uint64_t Type;
   getRelocationType(Rel, Type);
@@ -1210,16 +1017,6 @@ MachOObjectFile::getRelocationHidden(DataRefImpl Rel, bool &Result) const {
   return object_error::success;
 }
 
-error_code MachOObjectFile::getLibraryNext(DataRefImpl LibData,
-                                           LibraryRef &Res) const {
-  report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
-}
-
-error_code MachOObjectFile::getLibraryPath(DataRefImpl LibData,
-                                           StringRef &Res) const {
-  report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
-}
-
 //
 // guessLibraryShortName() is passed a name of a dynamic library and returns a
 // guess on what the short name is.  Then name is returned as a substring of the
@@ -1367,8 +1164,8 @@ guess_qtx:
 // normal two-level namespace default (that is MH_TWOLEVEL in the header).
 // It is passed the index (0 - based) of the library as translated from
 // GET_LIBRARY_ORDINAL (1 - based).
-error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
-                                                       StringRef &Res) {
+std::error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
+                                                         StringRef &Res) const {
   if (Index >= Libraries.size())
     return object_error::parse_failed;
 
@@ -1387,7 +1184,7 @@ error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
         LibrariesShortNames.push_back(StringRef());
         continue;
       }
-      char *P = (char *)(Libraries[i]) + D.dylib.name;
+      const char *P = (const char *)(Libraries[i]) + D.dylib.name;
       StringRef Name = StringRef(P);
       StringRef Suffix;
       bool isFramework;
@@ -1447,16 +1244,6 @@ section_iterator MachOObjectFile::section_end() const {
   return section_iterator(SectionRef(DRI, this));
 }
 
-library_iterator MachOObjectFile::needed_library_begin() const {
-  // TODO: implement
-  report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
-}
-
-library_iterator MachOObjectFile::needed_library_end() const {
-  // TODO: implement
-  report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
-}
-
 uint8_t MachOObjectFile::getBytesInAddress() const {
   return is64Bit() ? 8 : 4;
 }
@@ -1504,7 +1291,7 @@ Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
   case llvm::MachO::CPU_TYPE_ARM:
     return Triple::arm;
   case llvm::MachO::CPU_TYPE_ARM64:
-    return Triple::arm64;
+    return Triple::aarch64;
   case llvm::MachO::CPU_TYPE_POWERPC:
     return Triple::ppc;
   case llvm::MachO::CPU_TYPE_POWERPC64:
@@ -1514,13 +1301,181 @@ Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
   }
 }
 
+Triple MachOObjectFile::getArch(uint32_t CPUType, uint32_t CPUSubType,
+                                const char **McpuDefault) {
+  if (McpuDefault)
+    *McpuDefault = nullptr;
+
+  switch (CPUType) {
+  case MachO::CPU_TYPE_I386:
+    switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
+    case MachO::CPU_SUBTYPE_I386_ALL:
+      return Triple("i386-apple-darwin");
+    default:
+      return Triple();
+    }
+  case MachO::CPU_TYPE_X86_64:
+    switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
+    case MachO::CPU_SUBTYPE_X86_64_ALL:
+      return Triple("x86_64-apple-darwin");
+    case MachO::CPU_SUBTYPE_X86_64_H:
+      return Triple("x86_64h-apple-darwin");
+    default:
+      return Triple();
+    }
+  case MachO::CPU_TYPE_ARM:
+    switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
+    case MachO::CPU_SUBTYPE_ARM_V4T:
+      return Triple("armv4t-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V5TEJ:
+      return Triple("armv5e-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_XSCALE:
+      return Triple("xscale-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V6:
+      return Triple("armv6-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V6M:
+      if (McpuDefault)
+        *McpuDefault = "cortex-m0";
+      return Triple("armv6m-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7:
+      return Triple("armv7-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7EM:
+      if (McpuDefault)
+        *McpuDefault = "cortex-m4";
+      return Triple("armv7em-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7K:
+      return Triple("armv7k-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7M:
+      if (McpuDefault)
+        *McpuDefault = "cortex-m3";
+      return Triple("armv7m-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7S:
+      return Triple("armv7s-apple-darwin");
+    default:
+      return Triple();
+    }
+  case MachO::CPU_TYPE_ARM64:
+    switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
+    case MachO::CPU_SUBTYPE_ARM64_ALL:
+      return Triple("arm64-apple-darwin");
+    default:
+      return Triple();
+    }
+  case MachO::CPU_TYPE_POWERPC:
+    switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
+    case MachO::CPU_SUBTYPE_POWERPC_ALL:
+      return Triple("ppc-apple-darwin");
+    default:
+      return Triple();
+    }
+  case MachO::CPU_TYPE_POWERPC64:
+    switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
+    case MachO::CPU_SUBTYPE_POWERPC_ALL:
+      return Triple("ppc64-apple-darwin");
+    default:
+      return Triple();
+    }
+  default:
+    return Triple();
+  }
+}
+
+Triple MachOObjectFile::getThumbArch(uint32_t CPUType, uint32_t CPUSubType,
+                                     const char **McpuDefault) {
+  if (McpuDefault)
+    *McpuDefault = nullptr;
+
+  switch (CPUType) {
+  case MachO::CPU_TYPE_ARM:
+    switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
+    case MachO::CPU_SUBTYPE_ARM_V4T:
+      return Triple("thumbv4t-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V5TEJ:
+      return Triple("thumbv5e-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_XSCALE:
+      return Triple("xscale-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V6:
+      return Triple("thumbv6-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V6M:
+      if (McpuDefault)
+        *McpuDefault = "cortex-m0";
+      return Triple("thumbv6m-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7:
+      return Triple("thumbv7-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7EM:
+      if (McpuDefault)
+        *McpuDefault = "cortex-m4";
+      return Triple("thumbv7em-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7K:
+      return Triple("thumbv7k-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7M:
+      if (McpuDefault)
+        *McpuDefault = "cortex-m3";
+      return Triple("thumbv7m-apple-darwin");
+    case MachO::CPU_SUBTYPE_ARM_V7S:
+      return Triple("thumbv7s-apple-darwin");
+    default:
+      return Triple();
+    }
+  default:
+    return Triple();
+  }
+}
+
+Triple MachOObjectFile::getArch(uint32_t CPUType, uint32_t CPUSubType,
+                                const char **McpuDefault,
+                               Triple *ThumbTriple) {
+  Triple T = MachOObjectFile::getArch(CPUType, CPUSubType, McpuDefault);
+  *ThumbTriple = MachOObjectFile::getThumbArch(CPUType, CPUSubType,
+                                               McpuDefault);
+  return T;
+}
+
+Triple MachOObjectFile::getHostArch() {
+  return Triple(sys::getDefaultTargetTriple());
+}
+
+bool MachOObjectFile::isValidArch(StringRef ArchFlag) {
+  return StringSwitch<bool>(ArchFlag)
+      .Case("i386", true)
+      .Case("x86_64", true)
+      .Case("x86_64h", true)
+      .Case("armv4t", true)
+      .Case("arm", true)
+      .Case("armv5e", true)
+      .Case("armv6", true)
+      .Case("armv6m", true)
+      .Case("armv7em", true)
+      .Case("armv7k", true)
+      .Case("armv7m", true)
+      .Case("armv7s", true)
+      .Case("arm64", true)
+      .Case("ppc", true)
+      .Case("ppc64", true)
+      .Default(false);
+}
+
 unsigned MachOObjectFile::getArch() const {
   return getArch(getCPUType(this));
 }
 
-StringRef MachOObjectFile::getLoadName() const {
-  // TODO: Implement
-  report_fatal_error("get_load_name() unimplemented in MachOObjectFile");
+Triple MachOObjectFile::getArch(const char **McpuDefault,
+                                Triple *ThumbTriple) const {
+  Triple T;
+  if (is64Bit()) {
+    MachO::mach_header_64 H_64;
+    H_64 = getHeader64();
+    T = MachOObjectFile::getArch(H_64.cputype, H_64.cpusubtype, McpuDefault);
+    *ThumbTriple = MachOObjectFile::getThumbArch(H_64.cputype, H_64.cpusubtype,
+                                                 McpuDefault);
+  } else {
+    MachO::mach_header H;
+    H = getHeader();
+    T = MachOObjectFile::getArch(H.cputype, H.cpusubtype, McpuDefault);
+    *ThumbTriple = MachOObjectFile::getThumbArch(H.cputype, H.cpusubtype,
+                                                 McpuDefault);
+  }
+  return T;
 }
 
 relocation_iterator MachOObjectFile::section_rel_begin(unsigned Index) const {
@@ -1556,6 +1511,183 @@ dice_iterator MachOObjectFile::end_dices() const {
   return dice_iterator(DiceRef(DRI, this));
 }
 
+ExportEntry::ExportEntry(ArrayRef<uint8_t> T) 
+  : Trie(T), Malformed(false), Done(false) { }
+
+void ExportEntry::moveToFirst() {
+  pushNode(0);
+  pushDownUntilBottom();
+}
+
+void ExportEntry::moveToEnd() {
+  Stack.clear();
+  Done = true;
+}
+
+bool ExportEntry::operator==(const ExportEntry &Other) const {
+  // Common case, one at end, other iterating from begin. 
+  if (Done || Other.Done)
+    return (Done == Other.Done);
+  // Not equal if different stack sizes.
+  if (Stack.size() != Other.Stack.size())
+    return false;
+  // Not equal if different cumulative strings.
+  if (!CumulativeString.str().equals(Other.CumulativeString.str()))
+    return false;
+  // Equal if all nodes in both stacks match.
+  for (unsigned i=0; i < Stack.size(); ++i) {
+    if (Stack[i].Start != Other.Stack[i].Start)
+      return false;
+  }
+  return true;  
+}
+
+uint64_t ExportEntry::readULEB128(const uint8_t *&Ptr) {
+  unsigned Count;
+  uint64_t Result = decodeULEB128(Ptr, &Count);
+  Ptr += Count;
+  if (Ptr > Trie.end()) {
+    Ptr = Trie.end();
+    Malformed = true;
+  }
+  return Result;
+}
+
+StringRef ExportEntry::name() const {
+  return CumulativeString.str();
+}
+
+uint64_t ExportEntry::flags() const {
+  return Stack.back().Flags;
+}
+
+uint64_t ExportEntry::address() const {
+  return Stack.back().Address;
+}
+
+uint64_t ExportEntry::other() const {
+  return Stack.back().Other;
+}
+
+StringRef ExportEntry::otherName() const {
+  const char* ImportName = Stack.back().ImportName;
+  if (ImportName)
+    return StringRef(ImportName);
+  return StringRef();
+}
+
+uint32_t ExportEntry::nodeOffset() const {
+  return Stack.back().Start - Trie.begin();
+}
+
+ExportEntry::NodeState::NodeState(const uint8_t *Ptr) 
+  : Start(Ptr), Current(Ptr), Flags(0), Address(0), Other(0), 
+    ImportName(nullptr), ChildCount(0), NextChildIndex(0),  
+    ParentStringLength(0), IsExportNode(false) {
+}
+
+void ExportEntry::pushNode(uint64_t offset) {
+  const uint8_t *Ptr = Trie.begin() + offset;
+  NodeState State(Ptr);
+  uint64_t ExportInfoSize = readULEB128(State.Current);
+  State.IsExportNode = (ExportInfoSize != 0);
+  const uint8_t* Children = State.Current + ExportInfoSize;
+  if (State.IsExportNode) {
+    State.Flags = readULEB128(State.Current);
+    if (State.Flags & MachO::EXPORT_SYMBOL_FLAGS_REEXPORT) {
+      State.Address = 0;
+      State.Other = readULEB128(State.Current); // dylib ordinal
+      State.ImportName = reinterpret_cast<const char*>(State.Current);
+    } else {
+      State.Address = readULEB128(State.Current);
+      if (State.Flags & MachO::EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER)
+        State.Other = readULEB128(State.Current); 
+    }
+  }
+  State.ChildCount = *Children;
+  State.Current = Children + 1;
+  State.NextChildIndex = 0;
+  State.ParentStringLength = CumulativeString.size();
+  Stack.push_back(State);
+}
+
+void ExportEntry::pushDownUntilBottom() {
+  while (Stack.back().NextChildIndex < Stack.back().ChildCount) {
+    NodeState &Top = Stack.back();
+    CumulativeString.resize(Top.ParentStringLength);
+    for (;*Top.Current != 0; Top.Current++) {
+      char C = *Top.Current;
+      CumulativeString.push_back(C);
+    }
+    Top.Current += 1;
+    uint64_t childNodeIndex = readULEB128(Top.Current);
+    Top.NextChildIndex += 1;
+    pushNode(childNodeIndex);
+  }
+  if (!Stack.back().IsExportNode) {
+    Malformed = true;
+    moveToEnd();
+  }
+}
+
+// We have a trie data structure and need a way to walk it that is compatible
+// with the C++ iterator model. The solution is a non-recursive depth first
+// traversal where the iterator contains a stack of parent nodes along with a
+// string that is the accumulation of all edge strings along the parent chain
+// to this point.
+//
+// There is one “export” node for each exported symbol.  But because some
+// symbols may be a prefix of another symbol (e.g. _dup and _dup2), an export
+// node may have child nodes too.  
+//
+// The algorithm for moveNext() is to keep moving down the leftmost unvisited
+// child until hitting a node with no children (which is an export node or
+// else the trie is malformed). On the way down, each node is pushed on the
+// stack ivar.  If there is no more ways down, it pops up one and tries to go
+// down a sibling path until a childless node is reached.
+void ExportEntry::moveNext() {
+  if (Stack.empty() || !Stack.back().IsExportNode) {
+    Malformed = true;
+    moveToEnd();
+    return;
+  }
+
+  Stack.pop_back();
+  while (!Stack.empty()) {
+    NodeState &Top = Stack.back();
+    if (Top.NextChildIndex < Top.ChildCount) {
+      pushDownUntilBottom();
+      // Now at the next export node.
+      return;
+    } else {
+      if (Top.IsExportNode) {
+        // This node has no children but is itself an export node.
+        CumulativeString.resize(Top.ParentStringLength);
+        return;
+      }
+      Stack.pop_back();
+    }
+  }
+  Done = true;
+}
+
+iterator_range<export_iterator> 
+MachOObjectFile::exports(ArrayRef<uint8_t> Trie) {
+  ExportEntry Start(Trie);
+  Start.moveToFirst();
+
+  ExportEntry Finish(Trie);
+  Finish.moveToEnd();
+
+  return iterator_range<export_iterator>(export_iterator(Start), 
+                                         export_iterator(Finish));
+}
+
+iterator_range<export_iterator> MachOObjectFile::exports() const {
+  return exports(getDyldInfoExportsTrie());
+}
+
+
 StringRef
 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
@@ -1566,14 +1698,14 @@ ArrayRef<char>
 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
   const section_base *Base =
     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
-  return ArrayRef<char>(Base->sectname);
+  return makeArrayRef(Base->sectname);
 }
 
 ArrayRef<char>
 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
   const section_base *Base =
     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
-  return ArrayRef<char>(Base->segname);
+  return makeArrayRef(Base->segname);
 }
 
 bool
@@ -1724,6 +1856,37 @@ MachOObjectFile::getVersionMinLoadCommand(const LoadCommandInfo &L) const {
   return getStruct<MachO::version_min_command>(this, L.Ptr);
 }
 
+MachO::dylib_command
+MachOObjectFile::getDylibIDLoadCommand(const LoadCommandInfo &L) const {
+  return getStruct<MachO::dylib_command>(this, L.Ptr);
+}
+
+MachO::dyld_info_command
+MachOObjectFile::getDyldInfoLoadCommand(const LoadCommandInfo &L) const {
+  return getStruct<MachO::dyld_info_command>(this, L.Ptr);
+}
+
+MachO::dylinker_command
+MachOObjectFile::getDylinkerCommand(const LoadCommandInfo &L) const {
+  return getStruct<MachO::dylinker_command>(this, L.Ptr);
+}
+
+MachO::uuid_command
+MachOObjectFile::getUuidCommand(const LoadCommandInfo &L) const {
+  return getStruct<MachO::uuid_command>(this, L.Ptr);
+}
+
+MachO::source_version_command
+MachOObjectFile::getSourceVersionCommand(const LoadCommandInfo &L) const {
+  return getStruct<MachO::source_version_command>(this, L.Ptr);
+}
+
+MachO::entry_point_command
+MachOObjectFile::getEntryPointCommand(const LoadCommandInfo &L) const {
+  return getStruct<MachO::entry_point_command>(this, L.Ptr);
+}
+
+
 MachO::any_relocation_info
 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
   DataRefImpl Sec;
@@ -1793,6 +1956,62 @@ MachOObjectFile::getDataInCodeLoadCommand() const {
   return Cmd;
 }
 
+ArrayRef<uint8_t> MachOObjectFile::getDyldInfoRebaseOpcodes() const {
+  if (!DyldInfoLoadCmd) 
+    return ArrayRef<uint8_t>();
+
+  MachO::dyld_info_command DyldInfo 
+                   = getStruct<MachO::dyld_info_command>(this, DyldInfoLoadCmd);
+  const uint8_t *Ptr = reinterpret_cast<const uint8_t*>(
+                                             getPtr(this, DyldInfo.rebase_off));
+  return ArrayRef<uint8_t>(Ptr, DyldInfo.rebase_size);
+}
+
+ArrayRef<uint8_t> MachOObjectFile::getDyldInfoBindOpcodes() const {
+  if (!DyldInfoLoadCmd) 
+    return ArrayRef<uint8_t>();
+
+  MachO::dyld_info_command DyldInfo 
+                   = getStruct<MachO::dyld_info_command>(this, DyldInfoLoadCmd);
+  const uint8_t *Ptr = reinterpret_cast<const uint8_t*>(
+                                               getPtr(this, DyldInfo.bind_off));
+  return ArrayRef<uint8_t>(Ptr, DyldInfo.bind_size);
+}
+
+ArrayRef<uint8_t> MachOObjectFile::getDyldInfoWeakBindOpcodes() const {
+  if (!DyldInfoLoadCmd) 
+    return ArrayRef<uint8_t>();
+
+  MachO::dyld_info_command DyldInfo 
+                   = getStruct<MachO::dyld_info_command>(this, DyldInfoLoadCmd);
+  const uint8_t *Ptr = reinterpret_cast<const uint8_t*>(
+                                          getPtr(this, DyldInfo.weak_bind_off));
+  return ArrayRef<uint8_t>(Ptr, DyldInfo.weak_bind_size);
+}
+
+ArrayRef<uint8_t> MachOObjectFile::getDyldInfoLazyBindOpcodes() const {
+  if (!DyldInfoLoadCmd) 
+    return ArrayRef<uint8_t>();
+
+  MachO::dyld_info_command DyldInfo 
+                   = getStruct<MachO::dyld_info_command>(this, DyldInfoLoadCmd);
+  const uint8_t *Ptr = reinterpret_cast<const uint8_t*>(
+                                          getPtr(this, DyldInfo.lazy_bind_off));
+  return ArrayRef<uint8_t>(Ptr, DyldInfo.lazy_bind_size);
+}
+
+ArrayRef<uint8_t> MachOObjectFile::getDyldInfoExportsTrie() const {
+  if (!DyldInfoLoadCmd) 
+    return ArrayRef<uint8_t>();
+
+  MachO::dyld_info_command DyldInfo 
+                   = getStruct<MachO::dyld_info_command>(this, DyldInfoLoadCmd);
+  const uint8_t *Ptr = reinterpret_cast<const uint8_t*>(
+                                             getPtr(this, DyldInfo.export_off));
+  return ArrayRef<uint8_t>(Ptr, DyldInfo.export_size);
+}
+
+
 StringRef MachOObjectFile::getStringTableData() const {
   MachO::symtab_command S = getSymtabLoadCommand();
   return getData().substr(S.stroff, S.strsize);
@@ -1815,28 +2034,28 @@ void MachOObjectFile::ReadULEB128s(uint64_t Index,
   }
 }
 
-ErrorOr<ObjectFile *> ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer,
-                                                        bool BufferOwned) {
-  StringRef Magic = Buffer->getBuffer().slice(0, 4);
-  error_code EC;
+bool MachOObjectFile::isRelocatableObject() const {
+  return getHeader().filetype == MachO::MH_OBJECT;
+}
+
+ErrorOr<std::unique_ptr<MachOObjectFile>>
+ObjectFile::createMachOObjectFile(MemoryBufferRef Buffer) {
+  StringRef Magic = Buffer.getBuffer().slice(0, 4);
+  std::error_code EC;
   std::unique_ptr<MachOObjectFile> Ret;
   if (Magic == "\xFE\xED\xFA\xCE")
-    Ret.reset(new MachOObjectFile(Buffer, false, false, EC, BufferOwned));
+    Ret.reset(new MachOObjectFile(Buffer, false, false, EC));
   else if (Magic == "\xCE\xFA\xED\xFE")
-    Ret.reset(new MachOObjectFile(Buffer, true, false, EC, BufferOwned));
+    Ret.reset(new MachOObjectFile(Buffer, true, false, EC));
   else if (Magic == "\xFE\xED\xFA\xCF")
-    Ret.reset(new MachOObjectFile(Buffer, false, true, EC, BufferOwned));
+    Ret.reset(new MachOObjectFile(Buffer, false, true, EC));
   else if (Magic == "\xCF\xFA\xED\xFE")
-    Ret.reset(new MachOObjectFile(Buffer, true, true, EC, BufferOwned));
-  else {
-    delete Buffer;
+    Ret.reset(new MachOObjectFile(Buffer, true, true, EC));
+  else
     return object_error::parse_failed;
-  }
 
   if (EC)
     return EC;
-  return Ret.release();
+  return std::move(Ret);
 }
 
-} // end namespace object
-} // end namespace llvm