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      1 //===- MachOObjectFile.cpp - Mach-O object file binding ---------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines the MachOObjectFile class, which binds the MachOObject
     11 // class to the generic ObjectFile wrapper.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "llvm/Object/MachO.h"
     16 #include "llvm/ADT/Triple.h"
     17 #include "llvm/Object/MachOFormat.h"
     18 #include "llvm/Support/DataExtractor.h"
     19 #include "llvm/Support/Format.h"
     20 #include "llvm/Support/Host.h"
     21 #include "llvm/Support/MemoryBuffer.h"
     22 #include <cctype>
     23 #include <cstring>
     24 #include <limits>
     25 
     26 using namespace llvm;
     27 using namespace object;
     28 
     29 namespace llvm {
     30 namespace object {
     31 
     32 struct SymbolTableEntryBase {
     33   uint32_t StringIndex;
     34   uint8_t Type;
     35   uint8_t SectionIndex;
     36   uint16_t Flags;
     37 };
     38 
     39 struct SectionBase {
     40   char Name[16];
     41   char SegmentName[16];
     42 };
     43 
     44 template<typename T>
     45 static void SwapValue(T &Value) {
     46   Value = sys::SwapByteOrder(Value);
     47 }
     48 
     49 template<typename T>
     50 static void SwapStruct(T &Value);
     51 
     52 template<>
     53 void SwapStruct(macho::RelocationEntry &H) {
     54   SwapValue(H.Word0);
     55   SwapValue(H.Word1);
     56 }
     57 
     58 template<>
     59 void SwapStruct(macho::LoadCommand &L) {
     60   SwapValue(L.Type);
     61   SwapValue(L.Size);
     62 }
     63 
     64 template<>
     65 void SwapStruct(SymbolTableEntryBase &S) {
     66   SwapValue(S.StringIndex);
     67   SwapValue(S.Flags);
     68 }
     69 
     70 template<>
     71 void SwapStruct(macho::Section &S) {
     72   SwapValue(S.Address);
     73   SwapValue(S.Size);
     74   SwapValue(S.Offset);
     75   SwapValue(S.Align);
     76   SwapValue(S.RelocationTableOffset);
     77   SwapValue(S.NumRelocationTableEntries);
     78   SwapValue(S.Flags);
     79   SwapValue(S.Reserved1);
     80   SwapValue(S.Reserved2);
     81 }
     82 
     83 template<>
     84 void SwapStruct(macho::Section64 &S) {
     85   SwapValue(S.Address);
     86   SwapValue(S.Size);
     87   SwapValue(S.Offset);
     88   SwapValue(S.Align);
     89   SwapValue(S.RelocationTableOffset);
     90   SwapValue(S.NumRelocationTableEntries);
     91   SwapValue(S.Flags);
     92   SwapValue(S.Reserved1);
     93   SwapValue(S.Reserved2);
     94   SwapValue(S.Reserved3);
     95 }
     96 
     97 template<>
     98 void SwapStruct(macho::SymbolTableEntry &S) {
     99   SwapValue(S.StringIndex);
    100   SwapValue(S.Flags);
    101   SwapValue(S.Value);
    102 }
    103 
    104 template<>
    105 void SwapStruct(macho::Symbol64TableEntry &S) {
    106   SwapValue(S.StringIndex);
    107   SwapValue(S.Flags);
    108   SwapValue(S.Value);
    109 }
    110 
    111 template<>
    112 void SwapStruct(macho::Header &H) {
    113   SwapValue(H.Magic);
    114   SwapValue(H.CPUType);
    115   SwapValue(H.CPUSubtype);
    116   SwapValue(H.FileType);
    117   SwapValue(H.NumLoadCommands);
    118   SwapValue(H.SizeOfLoadCommands);
    119   SwapValue(H.Flags);
    120 }
    121 
    122 template<>
    123 void SwapStruct(macho::Header64Ext &E) {
    124   SwapValue(E.Reserved);
    125 }
    126 
    127 template<>
    128 void SwapStruct(macho::SymtabLoadCommand &C) {
    129   SwapValue(C.Type);
    130   SwapValue(C.Size);
    131   SwapValue(C.SymbolTableOffset);
    132   SwapValue(C.NumSymbolTableEntries);
    133   SwapValue(C.StringTableOffset);
    134   SwapValue(C.StringTableSize);
    135 }
    136 
    137 template<>
    138 void SwapStruct(macho::DysymtabLoadCommand &C) {
    139   SwapValue(C.Type);
    140   SwapValue(C.Size);
    141   SwapValue(C.LocalSymbolsIndex);
    142   SwapValue(C.NumLocalSymbols);
    143   SwapValue(C.ExternalSymbolsIndex);
    144   SwapValue(C.NumExternalSymbols);
    145   SwapValue(C.UndefinedSymbolsIndex);
    146   SwapValue(C.NumUndefinedSymbols);
    147   SwapValue(C.TOCOffset);
    148   SwapValue(C.NumTOCEntries);
    149   SwapValue(C.ModuleTableOffset);
    150   SwapValue(C.NumModuleTableEntries);
    151   SwapValue(C.ReferenceSymbolTableOffset);
    152   SwapValue(C.NumReferencedSymbolTableEntries);
    153   SwapValue(C.IndirectSymbolTableOffset);
    154   SwapValue(C.NumIndirectSymbolTableEntries);
    155   SwapValue(C.ExternalRelocationTableOffset);
    156   SwapValue(C.NumExternalRelocationTableEntries);
    157   SwapValue(C.LocalRelocationTableOffset);
    158   SwapValue(C.NumLocalRelocationTableEntries);
    159 }
    160 
    161 template<>
    162 void SwapStruct(macho::LinkeditDataLoadCommand &C) {
    163   SwapValue(C.Type);
    164   SwapValue(C.Size);
    165   SwapValue(C.DataOffset);
    166   SwapValue(C.DataSize);
    167 }
    168 
    169 template<>
    170 void SwapStruct(macho::SegmentLoadCommand &C) {
    171   SwapValue(C.Type);
    172   SwapValue(C.Size);
    173   SwapValue(C.VMAddress);
    174   SwapValue(C.VMSize);
    175   SwapValue(C.FileOffset);
    176   SwapValue(C.FileSize);
    177   SwapValue(C.MaxVMProtection);
    178   SwapValue(C.InitialVMProtection);
    179   SwapValue(C.NumSections);
    180   SwapValue(C.Flags);
    181 }
    182 
    183 template<>
    184 void SwapStruct(macho::Segment64LoadCommand &C) {
    185   SwapValue(C.Type);
    186   SwapValue(C.Size);
    187   SwapValue(C.VMAddress);
    188   SwapValue(C.VMSize);
    189   SwapValue(C.FileOffset);
    190   SwapValue(C.FileSize);
    191   SwapValue(C.MaxVMProtection);
    192   SwapValue(C.InitialVMProtection);
    193   SwapValue(C.NumSections);
    194   SwapValue(C.Flags);
    195 }
    196 
    197 template<>
    198 void SwapStruct(macho::IndirectSymbolTableEntry &C) {
    199   SwapValue(C.Index);
    200 }
    201 
    202 template<>
    203 void SwapStruct(macho::LinkerOptionsLoadCommand &C) {
    204   SwapValue(C.Type);
    205   SwapValue(C.Size);
    206   SwapValue(C.Count);
    207 }
    208 
    209 template<>
    210 void SwapStruct(macho::DataInCodeTableEntry &C) {
    211   SwapValue(C.Offset);
    212   SwapValue(C.Length);
    213   SwapValue(C.Kind);
    214 }
    215 
    216 template<typename T>
    217 T getStruct(const MachOObjectFile *O, const char *P) {
    218   T Cmd;
    219   memcpy(&Cmd, P, sizeof(T));
    220   if (O->isLittleEndian() != sys::IsLittleEndianHost)
    221     SwapStruct(Cmd);
    222   return Cmd;
    223 }
    224 
    225 static uint32_t
    226 getSegmentLoadCommandNumSections(const MachOObjectFile *O,
    227                                  const MachOObjectFile::LoadCommandInfo &L) {
    228   if (O->is64Bit()) {
    229     macho::Segment64LoadCommand S = O->getSegment64LoadCommand(L);
    230     return S.NumSections;
    231   }
    232   macho::SegmentLoadCommand S = O->getSegmentLoadCommand(L);
    233   return S.NumSections;
    234 }
    235 
    236 static const char *
    237 getSectionPtr(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
    238               unsigned Sec) {
    239   uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
    240 
    241   bool Is64 = O->is64Bit();
    242   unsigned SegmentLoadSize = Is64 ? sizeof(macho::Segment64LoadCommand) :
    243                                     sizeof(macho::SegmentLoadCommand);
    244   unsigned SectionSize = Is64 ? sizeof(macho::Section64) :
    245                                 sizeof(macho::Section);
    246 
    247   uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
    248   return reinterpret_cast<const char*>(SectionAddr);
    249 }
    250 
    251 static const char *getPtr(const MachOObjectFile *O, size_t Offset) {
    252   return O->getData().substr(Offset, 1).data();
    253 }
    254 
    255 static SymbolTableEntryBase
    256 getSymbolTableEntryBase(const MachOObjectFile *O, DataRefImpl DRI) {
    257   const char *P = reinterpret_cast<const char *>(DRI.p);
    258   return getStruct<SymbolTableEntryBase>(O, P);
    259 }
    260 
    261 static StringRef parseSegmentOrSectionName(const char *P) {
    262   if (P[15] == 0)
    263     // Null terminated.
    264     return P;
    265   // Not null terminated, so this is a 16 char string.
    266   return StringRef(P, 16);
    267 }
    268 
    269 // Helper to advance a section or symbol iterator multiple increments at a time.
    270 template<class T>
    271 static error_code advance(T &it, size_t Val) {
    272   error_code ec;
    273   while (Val--) {
    274     it.increment(ec);
    275   }
    276   return ec;
    277 }
    278 
    279 template<class T>
    280 static void advanceTo(T &it, size_t Val) {
    281   if (error_code ec = advance(it, Val))
    282     report_fatal_error(ec.message());
    283 }
    284 
    285 static unsigned getCPUType(const MachOObjectFile *O) {
    286   return O->getHeader().CPUType;
    287 }
    288 
    289 static void printRelocationTargetName(const MachOObjectFile *O,
    290                                       const macho::RelocationEntry &RE,
    291                                       raw_string_ostream &fmt) {
    292   bool IsScattered = O->isRelocationScattered(RE);
    293 
    294   // Target of a scattered relocation is an address.  In the interest of
    295   // generating pretty output, scan through the symbol table looking for a
    296   // symbol that aligns with that address.  If we find one, print it.
    297   // Otherwise, we just print the hex address of the target.
    298   if (IsScattered) {
    299     uint32_t Val = O->getPlainRelocationSymbolNum(RE);
    300 
    301     error_code ec;
    302     for (symbol_iterator SI = O->begin_symbols(), SE = O->end_symbols();
    303          SI != SE; SI.increment(ec)) {
    304       if (ec) report_fatal_error(ec.message());
    305 
    306       uint64_t Addr;
    307       StringRef Name;
    308 
    309       if ((ec = SI->getAddress(Addr)))
    310         report_fatal_error(ec.message());
    311       if (Addr != Val) continue;
    312       if ((ec = SI->getName(Name)))
    313         report_fatal_error(ec.message());
    314       fmt << Name;
    315       return;
    316     }
    317 
    318     // If we couldn't find a symbol that this relocation refers to, try
    319     // to find a section beginning instead.
    320     for (section_iterator SI = O->begin_sections(), SE = O->end_sections();
    321          SI != SE; SI.increment(ec)) {
    322       if (ec) report_fatal_error(ec.message());
    323 
    324       uint64_t Addr;
    325       StringRef Name;
    326 
    327       if ((ec = SI->getAddress(Addr)))
    328         report_fatal_error(ec.message());
    329       if (Addr != Val) continue;
    330       if ((ec = SI->getName(Name)))
    331         report_fatal_error(ec.message());
    332       fmt << Name;
    333       return;
    334     }
    335 
    336     fmt << format("0x%x", Val);
    337     return;
    338   }
    339 
    340   StringRef S;
    341   bool isExtern = O->getPlainRelocationExternal(RE);
    342   uint64_t Val = O->getPlainRelocationSymbolNum(RE);
    343 
    344   if (isExtern) {
    345     symbol_iterator SI = O->begin_symbols();
    346     advanceTo(SI, Val);
    347     SI->getName(S);
    348   } else {
    349     section_iterator SI = O->begin_sections();
    350     // Adjust for the fact that sections are 1-indexed.
    351     advanceTo(SI, Val - 1);
    352     SI->getName(S);
    353   }
    354 
    355   fmt << S;
    356 }
    357 
    358 static uint32_t getPlainRelocationAddress(const macho::RelocationEntry &RE) {
    359   return RE.Word0;
    360 }
    361 
    362 static unsigned
    363 getScatteredRelocationAddress(const macho::RelocationEntry &RE) {
    364   return RE.Word0 & 0xffffff;
    365 }
    366 
    367 static bool getPlainRelocationPCRel(const MachOObjectFile *O,
    368                                     const macho::RelocationEntry &RE) {
    369   if (O->isLittleEndian())
    370     return (RE.Word1 >> 24) & 1;
    371   return (RE.Word1 >> 7) & 1;
    372 }
    373 
    374 static bool
    375 getScatteredRelocationPCRel(const MachOObjectFile *O,
    376                             const macho::RelocationEntry &RE) {
    377   return (RE.Word0 >> 30) & 1;
    378 }
    379 
    380 static unsigned getPlainRelocationLength(const MachOObjectFile *O,
    381                                          const macho::RelocationEntry &RE) {
    382   if (O->isLittleEndian())
    383     return (RE.Word1 >> 25) & 3;
    384   return (RE.Word1 >> 5) & 3;
    385 }
    386 
    387 static unsigned
    388 getScatteredRelocationLength(const macho::RelocationEntry &RE) {
    389   return (RE.Word0 >> 28) & 3;
    390 }
    391 
    392 static unsigned getPlainRelocationType(const MachOObjectFile *O,
    393                                        const macho::RelocationEntry &RE) {
    394   if (O->isLittleEndian())
    395     return RE.Word1 >> 28;
    396   return RE.Word1 & 0xf;
    397 }
    398 
    399 static unsigned getScatteredRelocationType(const macho::RelocationEntry &RE) {
    400   return (RE.Word0 >> 24) & 0xf;
    401 }
    402 
    403 static uint32_t getSectionFlags(const MachOObjectFile *O,
    404                                 DataRefImpl Sec) {
    405   if (O->is64Bit()) {
    406     macho::Section64 Sect = O->getSection64(Sec);
    407     return Sect.Flags;
    408   }
    409   macho::Section Sect = O->getSection(Sec);
    410   return Sect.Flags;
    411 }
    412 
    413 MachOObjectFile::MachOObjectFile(MemoryBuffer *Object,
    414                                  bool IsLittleEndian, bool Is64bits,
    415                                  error_code &ec)
    416     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object),
    417       SymtabLoadCmd(NULL), DysymtabLoadCmd(NULL), DataInCodeLoadCmd(NULL) {
    418   uint32_t LoadCommandCount = this->getHeader().NumLoadCommands;
    419   macho::LoadCommandType SegmentLoadType = is64Bit() ?
    420     macho::LCT_Segment64 : macho::LCT_Segment;
    421 
    422   MachOObjectFile::LoadCommandInfo Load = getFirstLoadCommandInfo();
    423   for (unsigned I = 0; ; ++I) {
    424     if (Load.C.Type == macho::LCT_Symtab) {
    425       assert(!SymtabLoadCmd && "Multiple symbol tables");
    426       SymtabLoadCmd = Load.Ptr;
    427     } else if (Load.C.Type == macho::LCT_Dysymtab) {
    428       assert(!DysymtabLoadCmd && "Multiple dynamic symbol tables");
    429       DysymtabLoadCmd = Load.Ptr;
    430     } else if (Load.C.Type == macho::LCT_DataInCode) {
    431       assert(!DataInCodeLoadCmd && "Multiple data in code tables");
    432       DataInCodeLoadCmd = Load.Ptr;
    433     } else if (Load.C.Type == SegmentLoadType) {
    434       uint32_t NumSections = getSegmentLoadCommandNumSections(this, Load);
    435       for (unsigned J = 0; J < NumSections; ++J) {
    436         const char *Sec = getSectionPtr(this, Load, J);
    437         Sections.push_back(Sec);
    438       }
    439     }
    440 
    441     if (I == LoadCommandCount - 1)
    442       break;
    443     else
    444       Load = getNextLoadCommandInfo(Load);
    445   }
    446 }
    447 
    448 error_code MachOObjectFile::getSymbolNext(DataRefImpl Symb,
    449                                           SymbolRef &Res) const {
    450   unsigned SymbolTableEntrySize = is64Bit() ?
    451     sizeof(macho::Symbol64TableEntry) :
    452     sizeof(macho::SymbolTableEntry);
    453   Symb.p += SymbolTableEntrySize;
    454   Res = SymbolRef(Symb, this);
    455   return object_error::success;
    456 }
    457 
    458 error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
    459                                           StringRef &Res) const {
    460   StringRef StringTable = getStringTableData();
    461   SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, Symb);
    462   const char *Start = &StringTable.data()[Entry.StringIndex];
    463   Res = StringRef(Start);
    464   return object_error::success;
    465 }
    466 
    467 error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
    468                                              uint64_t &Res) const {
    469   if (is64Bit()) {
    470     macho::Symbol64TableEntry Entry = getSymbol64TableEntry(Symb);
    471     Res = Entry.Value;
    472   } else {
    473     macho::SymbolTableEntry Entry = getSymbolTableEntry(Symb);
    474     Res = Entry.Value;
    475   }
    476   return object_error::success;
    477 }
    478 
    479 error_code
    480 MachOObjectFile::getSymbolFileOffset(DataRefImpl Symb,
    481                                      uint64_t &Res) const {
    482   SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, Symb);
    483   getSymbolAddress(Symb, Res);
    484   if (Entry.SectionIndex) {
    485     uint64_t Delta;
    486     DataRefImpl SecRel;
    487     SecRel.d.a = Entry.SectionIndex-1;
    488     if (is64Bit()) {
    489       macho::Section64 Sec = getSection64(SecRel);
    490       Delta = Sec.Offset - Sec.Address;
    491     } else {
    492       macho::Section Sec = getSection(SecRel);
    493       Delta = Sec.Offset - Sec.Address;
    494     }
    495 
    496     Res += Delta;
    497   }
    498 
    499   return object_error::success;
    500 }
    501 
    502 error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
    503                                                uint32_t &Result) const {
    504   uint32_t flags;
    505   this->getSymbolFlags(DRI, flags);
    506   if (flags & SymbolRef::SF_Common) {
    507     SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, DRI);
    508     Result = 1 << MachO::GET_COMM_ALIGN(Entry.Flags);
    509   } else {
    510     Result = 0;
    511   }
    512   return object_error::success;
    513 }
    514 
    515 error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
    516                                           uint64_t &Result) const {
    517   uint64_t BeginOffset;
    518   uint64_t EndOffset = 0;
    519   uint8_t SectionIndex;
    520 
    521   SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, DRI);
    522   uint64_t Value;
    523   getSymbolAddress(DRI, Value);
    524 
    525   BeginOffset = Value;
    526 
    527   SectionIndex = Entry.SectionIndex;
    528   if (!SectionIndex) {
    529     uint32_t flags = SymbolRef::SF_None;
    530     this->getSymbolFlags(DRI, flags);
    531     if (flags & SymbolRef::SF_Common)
    532       Result = Value;
    533     else
    534       Result = UnknownAddressOrSize;
    535     return object_error::success;
    536   }
    537   // Unfortunately symbols are unsorted so we need to touch all
    538   // symbols from load command
    539   error_code ec;
    540   for (symbol_iterator I = begin_symbols(), E = end_symbols(); I != E;
    541        I.increment(ec)) {
    542     DataRefImpl DRI = I->getRawDataRefImpl();
    543     Entry = getSymbolTableEntryBase(this, DRI);
    544     getSymbolAddress(DRI, Value);
    545     if (Entry.SectionIndex == SectionIndex && Value > BeginOffset)
    546       if (!EndOffset || Value < EndOffset)
    547         EndOffset = Value;
    548   }
    549   if (!EndOffset) {
    550     uint64_t Size;
    551     DataRefImpl Sec;
    552     Sec.d.a = SectionIndex-1;
    553     getSectionSize(Sec, Size);
    554     getSectionAddress(Sec, EndOffset);
    555     EndOffset += Size;
    556   }
    557   Result = EndOffset - BeginOffset;
    558   return object_error::success;
    559 }
    560 
    561 error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
    562                                           SymbolRef::Type &Res) const {
    563   SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, Symb);
    564   uint8_t n_type = Entry.Type;
    565 
    566   Res = SymbolRef::ST_Other;
    567 
    568   // If this is a STAB debugging symbol, we can do nothing more.
    569   if (n_type & MachO::NlistMaskStab) {
    570     Res = SymbolRef::ST_Debug;
    571     return object_error::success;
    572   }
    573 
    574   switch (n_type & MachO::NlistMaskType) {
    575     case MachO::NListTypeUndefined :
    576       Res = SymbolRef::ST_Unknown;
    577       break;
    578     case MachO::NListTypeSection :
    579       Res = SymbolRef::ST_Function;
    580       break;
    581   }
    582   return object_error::success;
    583 }
    584 
    585 error_code MachOObjectFile::getSymbolNMTypeChar(DataRefImpl Symb,
    586                                                 char &Res) const {
    587   SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, Symb);
    588   uint8_t Type = Entry.Type;
    589   uint16_t Flags = Entry.Flags;
    590 
    591   char Char;
    592   switch (Type & macho::STF_TypeMask) {
    593     case macho::STT_Undefined:
    594       Char = 'u';
    595       break;
    596     case macho::STT_Absolute:
    597     case macho::STT_Section:
    598       Char = 's';
    599       break;
    600     default:
    601       Char = '?';
    602       break;
    603   }
    604 
    605   if (Flags & (macho::STF_External | macho::STF_PrivateExtern))
    606     Char = toupper(static_cast<unsigned char>(Char));
    607   Res = Char;
    608   return object_error::success;
    609 }
    610 
    611 error_code MachOObjectFile::getSymbolFlags(DataRefImpl DRI,
    612                                            uint32_t &Result) const {
    613   SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, DRI);
    614 
    615   uint8_t MachOType = Entry.Type;
    616   uint16_t MachOFlags = Entry.Flags;
    617 
    618   // TODO: Correctly set SF_ThreadLocal
    619   Result = SymbolRef::SF_None;
    620 
    621   if ((MachOType & MachO::NlistMaskType) == MachO::NListTypeUndefined)
    622     Result |= SymbolRef::SF_Undefined;
    623 
    624   if (MachOFlags & macho::STF_StabsEntryMask)
    625     Result |= SymbolRef::SF_FormatSpecific;
    626 
    627   if (MachOType & MachO::NlistMaskExternal) {
    628     Result |= SymbolRef::SF_Global;
    629     if ((MachOType & MachO::NlistMaskType) == MachO::NListTypeUndefined) {
    630       uint64_t Value;
    631       getSymbolAddress(DRI, Value);
    632       if (Value)
    633         Result |= SymbolRef::SF_Common;
    634     }
    635   }
    636 
    637   if (MachOFlags & (MachO::NListDescWeakRef | MachO::NListDescWeakDef))
    638     Result |= SymbolRef::SF_Weak;
    639 
    640   if ((MachOType & MachO::NlistMaskType) == MachO::NListTypeAbsolute)
    641     Result |= SymbolRef::SF_Absolute;
    642 
    643   return object_error::success;
    644 }
    645 
    646 error_code
    647 MachOObjectFile::getSymbolSection(DataRefImpl Symb,
    648                                   section_iterator &Res) const {
    649   SymbolTableEntryBase Entry = getSymbolTableEntryBase(this, Symb);
    650   uint8_t index = Entry.SectionIndex;
    651 
    652   if (index == 0) {
    653     Res = end_sections();
    654   } else {
    655     DataRefImpl DRI;
    656     DRI.d.a = index - 1;
    657     Res = section_iterator(SectionRef(DRI, this));
    658   }
    659 
    660   return object_error::success;
    661 }
    662 
    663 error_code MachOObjectFile::getSymbolValue(DataRefImpl Symb,
    664                                            uint64_t &Val) const {
    665   report_fatal_error("getSymbolValue unimplemented in MachOObjectFile");
    666 }
    667 
    668 error_code MachOObjectFile::getSectionNext(DataRefImpl Sec,
    669                                            SectionRef &Res) const {
    670   Sec.d.a++;
    671   Res = SectionRef(Sec, this);
    672   return object_error::success;
    673 }
    674 
    675 error_code
    676 MachOObjectFile::getSectionName(DataRefImpl Sec, StringRef &Result) const {
    677   ArrayRef<char> Raw = getSectionRawName(Sec);
    678   Result = parseSegmentOrSectionName(Raw.data());
    679   return object_error::success;
    680 }
    681 
    682 error_code
    683 MachOObjectFile::getSectionAddress(DataRefImpl Sec, uint64_t &Res) const {
    684   if (is64Bit()) {
    685     macho::Section64 Sect = getSection64(Sec);
    686     Res = Sect.Address;
    687   } else {
    688     macho::Section Sect = getSection(Sec);
    689     Res = Sect.Address;
    690   }
    691   return object_error::success;
    692 }
    693 
    694 error_code
    695 MachOObjectFile::getSectionSize(DataRefImpl Sec, uint64_t &Res) const {
    696   if (is64Bit()) {
    697     macho::Section64 Sect = getSection64(Sec);
    698     Res = Sect.Size;
    699   } else {
    700     macho::Section Sect = getSection(Sec);
    701     Res = Sect.Size;
    702   }
    703 
    704   return object_error::success;
    705 }
    706 
    707 error_code
    708 MachOObjectFile::getSectionContents(DataRefImpl Sec, StringRef &Res) const {
    709   uint32_t Offset;
    710   uint64_t Size;
    711 
    712   if (is64Bit()) {
    713     macho::Section64 Sect = getSection64(Sec);
    714     Offset = Sect.Offset;
    715     Size = Sect.Size;
    716   } else {
    717     macho::Section Sect =getSection(Sec);
    718     Offset = Sect.Offset;
    719     Size = Sect.Size;
    720   }
    721 
    722   Res = this->getData().substr(Offset, Size);
    723   return object_error::success;
    724 }
    725 
    726 error_code
    727 MachOObjectFile::getSectionAlignment(DataRefImpl Sec, uint64_t &Res) const {
    728   uint32_t Align;
    729   if (is64Bit()) {
    730     macho::Section64 Sect = getSection64(Sec);
    731     Align = Sect.Align;
    732   } else {
    733     macho::Section Sect = getSection(Sec);
    734     Align = Sect.Align;
    735   }
    736 
    737   Res = uint64_t(1) << Align;
    738   return object_error::success;
    739 }
    740 
    741 error_code
    742 MachOObjectFile::isSectionText(DataRefImpl Sec, bool &Res) const {
    743   uint32_t Flags = getSectionFlags(this, Sec);
    744   Res = Flags & macho::SF_PureInstructions;
    745   return object_error::success;
    746 }
    747 
    748 error_code MachOObjectFile::isSectionData(DataRefImpl DRI, bool &Result) const {
    749   // FIXME: Unimplemented.
    750   Result = false;
    751   return object_error::success;
    752 }
    753 
    754 error_code MachOObjectFile::isSectionBSS(DataRefImpl DRI, bool &Result) const {
    755   // FIXME: Unimplemented.
    756   Result = false;
    757   return object_error::success;
    758 }
    759 
    760 error_code
    761 MachOObjectFile::isSectionRequiredForExecution(DataRefImpl Sec,
    762                                                bool &Result) const {
    763   // FIXME: Unimplemented.
    764   Result = true;
    765   return object_error::success;
    766 }
    767 
    768 error_code MachOObjectFile::isSectionVirtual(DataRefImpl Sec,
    769                                              bool &Result) const {
    770   // FIXME: Unimplemented.
    771   Result = false;
    772   return object_error::success;
    773 }
    774 
    775 error_code
    776 MachOObjectFile::isSectionZeroInit(DataRefImpl Sec, bool &Res) const {
    777   uint32_t Flags = getSectionFlags(this, Sec);
    778   unsigned SectionType = Flags & MachO::SectionFlagMaskSectionType;
    779   Res = SectionType == MachO::SectionTypeZeroFill ||
    780     SectionType == MachO::SectionTypeZeroFillLarge;
    781   return object_error::success;
    782 }
    783 
    784 error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
    785                                                   bool &Result) const {
    786   // Consider using the code from isSectionText to look for __const sections.
    787   // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
    788   // to use section attributes to distinguish code from data.
    789 
    790   // FIXME: Unimplemented.
    791   Result = false;
    792   return object_error::success;
    793 }
    794 
    795 error_code
    796 MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
    797                                        bool &Result) const {
    798   SymbolRef::Type ST;
    799   this->getSymbolType(Symb, ST);
    800   if (ST == SymbolRef::ST_Unknown) {
    801     Result = false;
    802     return object_error::success;
    803   }
    804 
    805   uint64_t SectBegin, SectEnd;
    806   getSectionAddress(Sec, SectBegin);
    807   getSectionSize(Sec, SectEnd);
    808   SectEnd += SectBegin;
    809 
    810   uint64_t SymAddr;
    811   getSymbolAddress(Symb, SymAddr);
    812   Result = (SymAddr >= SectBegin) && (SymAddr < SectEnd);
    813 
    814   return object_error::success;
    815 }
    816 
    817 relocation_iterator MachOObjectFile::getSectionRelBegin(DataRefImpl Sec) const {
    818   uint32_t Offset;
    819   if (is64Bit()) {
    820     macho::Section64 Sect = getSection64(Sec);
    821     Offset = Sect.RelocationTableOffset;
    822   } else {
    823     macho::Section Sect = getSection(Sec);
    824     Offset = Sect.RelocationTableOffset;
    825   }
    826 
    827   DataRefImpl Ret;
    828   Ret.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
    829   return relocation_iterator(RelocationRef(Ret, this));
    830 }
    831 
    832 relocation_iterator
    833 MachOObjectFile::getSectionRelEnd(DataRefImpl Sec) const {
    834   uint32_t Offset;
    835   uint32_t Num;
    836   if (is64Bit()) {
    837     macho::Section64 Sect = getSection64(Sec);
    838     Offset = Sect.RelocationTableOffset;
    839     Num = Sect.NumRelocationTableEntries;
    840   } else {
    841     macho::Section Sect = getSection(Sec);
    842     Offset = Sect.RelocationTableOffset;
    843     Num = Sect.NumRelocationTableEntries;
    844   }
    845 
    846   const macho::RelocationEntry *P =
    847     reinterpret_cast<const macho::RelocationEntry*>(getPtr(this, Offset));
    848 
    849   DataRefImpl Ret;
    850   Ret.p = reinterpret_cast<uintptr_t>(P + Num);
    851   return relocation_iterator(RelocationRef(Ret, this));
    852 }
    853 
    854 error_code MachOObjectFile::getRelocationNext(DataRefImpl Rel,
    855                                               RelocationRef &Res) const {
    856   const macho::RelocationEntry *P =
    857     reinterpret_cast<const macho::RelocationEntry *>(Rel.p);
    858   Rel.p = reinterpret_cast<uintptr_t>(P + 1);
    859   Res = RelocationRef(Rel, this);
    860   return object_error::success;
    861 }
    862 
    863 error_code
    864 MachOObjectFile::getRelocationAddress(DataRefImpl Rel, uint64_t &Res) const {
    865   report_fatal_error("getRelocationAddress not implemented in MachOObjectFile");
    866 }
    867 
    868 error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
    869                                                 uint64_t &Res) const {
    870   macho::RelocationEntry RE = getRelocation(Rel);
    871   Res = getAnyRelocationAddress(RE);
    872   return object_error::success;
    873 }
    874 
    875 symbol_iterator
    876 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
    877   macho::RelocationEntry RE = getRelocation(Rel);
    878   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
    879   bool isExtern = getPlainRelocationExternal(RE);
    880   if (!isExtern)
    881     return end_symbols();
    882 
    883   macho::SymtabLoadCommand S = getSymtabLoadCommand();
    884   unsigned SymbolTableEntrySize = is64Bit() ?
    885     sizeof(macho::Symbol64TableEntry) :
    886     sizeof(macho::SymbolTableEntry);
    887   uint64_t Offset = S.SymbolTableOffset + SymbolIdx * SymbolTableEntrySize;
    888   DataRefImpl Sym;
    889   Sym.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
    890   return symbol_iterator(SymbolRef(Sym, this));
    891 }
    892 
    893 error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
    894                                               uint64_t &Res) const {
    895   macho::RelocationEntry RE = getRelocation(Rel);
    896   Res = getAnyRelocationType(RE);
    897   return object_error::success;
    898 }
    899 
    900 error_code
    901 MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
    902                                        SmallVectorImpl<char> &Result) const {
    903   StringRef res;
    904   uint64_t RType;
    905   getRelocationType(Rel, RType);
    906 
    907   unsigned Arch = this->getArch();
    908 
    909   switch (Arch) {
    910     case Triple::x86: {
    911       static const char *const Table[] =  {
    912         "GENERIC_RELOC_VANILLA",
    913         "GENERIC_RELOC_PAIR",
    914         "GENERIC_RELOC_SECTDIFF",
    915         "GENERIC_RELOC_PB_LA_PTR",
    916         "GENERIC_RELOC_LOCAL_SECTDIFF",
    917         "GENERIC_RELOC_TLV" };
    918 
    919       if (RType > 6)
    920         res = "Unknown";
    921       else
    922         res = Table[RType];
    923       break;
    924     }
    925     case Triple::x86_64: {
    926       static const char *const Table[] =  {
    927         "X86_64_RELOC_UNSIGNED",
    928         "X86_64_RELOC_SIGNED",
    929         "X86_64_RELOC_BRANCH",
    930         "X86_64_RELOC_GOT_LOAD",
    931         "X86_64_RELOC_GOT",
    932         "X86_64_RELOC_SUBTRACTOR",
    933         "X86_64_RELOC_SIGNED_1",
    934         "X86_64_RELOC_SIGNED_2",
    935         "X86_64_RELOC_SIGNED_4",
    936         "X86_64_RELOC_TLV" };
    937 
    938       if (RType > 9)
    939         res = "Unknown";
    940       else
    941         res = Table[RType];
    942       break;
    943     }
    944     case Triple::arm: {
    945       static const char *const Table[] =  {
    946         "ARM_RELOC_VANILLA",
    947         "ARM_RELOC_PAIR",
    948         "ARM_RELOC_SECTDIFF",
    949         "ARM_RELOC_LOCAL_SECTDIFF",
    950         "ARM_RELOC_PB_LA_PTR",
    951         "ARM_RELOC_BR24",
    952         "ARM_THUMB_RELOC_BR22",
    953         "ARM_THUMB_32BIT_BRANCH",
    954         "ARM_RELOC_HALF",
    955         "ARM_RELOC_HALF_SECTDIFF" };
    956 
    957       if (RType > 9)
    958         res = "Unknown";
    959       else
    960         res = Table[RType];
    961       break;
    962     }
    963     case Triple::ppc: {
    964       static const char *const Table[] =  {
    965         "PPC_RELOC_VANILLA",
    966         "PPC_RELOC_PAIR",
    967         "PPC_RELOC_BR14",
    968         "PPC_RELOC_BR24",
    969         "PPC_RELOC_HI16",
    970         "PPC_RELOC_LO16",
    971         "PPC_RELOC_HA16",
    972         "PPC_RELOC_LO14",
    973         "PPC_RELOC_SECTDIFF",
    974         "PPC_RELOC_PB_LA_PTR",
    975         "PPC_RELOC_HI16_SECTDIFF",
    976         "PPC_RELOC_LO16_SECTDIFF",
    977         "PPC_RELOC_HA16_SECTDIFF",
    978         "PPC_RELOC_JBSR",
    979         "PPC_RELOC_LO14_SECTDIFF",
    980         "PPC_RELOC_LOCAL_SECTDIFF" };
    981 
    982       res = Table[RType];
    983       break;
    984     }
    985     case Triple::UnknownArch:
    986       res = "Unknown";
    987       break;
    988   }
    989   Result.append(res.begin(), res.end());
    990   return object_error::success;
    991 }
    992 
    993 error_code
    994 MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
    995                                           SmallVectorImpl<char> &Result) const {
    996   macho::RelocationEntry RE = getRelocation(Rel);
    997 
    998   unsigned Arch = this->getArch();
    999 
   1000   std::string fmtbuf;
   1001   raw_string_ostream fmt(fmtbuf);
   1002   unsigned Type = this->getAnyRelocationType(RE);
   1003   bool IsPCRel = this->getAnyRelocationPCRel(RE);
   1004 
   1005   // Determine any addends that should be displayed with the relocation.
   1006   // These require decoding the relocation type, which is triple-specific.
   1007 
   1008   // X86_64 has entirely custom relocation types.
   1009   if (Arch == Triple::x86_64) {
   1010     bool isPCRel = getAnyRelocationPCRel(RE);
   1011 
   1012     switch (Type) {
   1013       case macho::RIT_X86_64_GOTLoad:   // X86_64_RELOC_GOT_LOAD
   1014       case macho::RIT_X86_64_GOT: {     // X86_64_RELOC_GOT
   1015         printRelocationTargetName(this, RE, fmt);
   1016         fmt << "@GOT";
   1017         if (isPCRel) fmt << "PCREL";
   1018         break;
   1019       }
   1020       case macho::RIT_X86_64_Subtractor: { // X86_64_RELOC_SUBTRACTOR
   1021         DataRefImpl RelNext = Rel;
   1022         RelNext.d.a++;
   1023         macho::RelocationEntry RENext = getRelocation(RelNext);
   1024 
   1025         // X86_64_SUBTRACTOR must be followed by a relocation of type
   1026         // X86_64_RELOC_UNSIGNED.
   1027         // NOTE: Scattered relocations don't exist on x86_64.
   1028         unsigned RType = getAnyRelocationType(RENext);
   1029         if (RType != 0)
   1030           report_fatal_error("Expected X86_64_RELOC_UNSIGNED after "
   1031                              "X86_64_RELOC_SUBTRACTOR.");
   1032 
   1033         // The X86_64_RELOC_UNSIGNED contains the minuend symbol,
   1034         // X86_64_SUBTRACTOR contains to the subtrahend.
   1035         printRelocationTargetName(this, RENext, fmt);
   1036         fmt << "-";
   1037         printRelocationTargetName(this, RE, fmt);
   1038         break;
   1039       }
   1040       case macho::RIT_X86_64_TLV:
   1041         printRelocationTargetName(this, RE, fmt);
   1042         fmt << "@TLV";
   1043         if (isPCRel) fmt << "P";
   1044         break;
   1045       case macho::RIT_X86_64_Signed1: // X86_64_RELOC_SIGNED1
   1046         printRelocationTargetName(this, RE, fmt);
   1047         fmt << "-1";
   1048         break;
   1049       case macho::RIT_X86_64_Signed2: // X86_64_RELOC_SIGNED2
   1050         printRelocationTargetName(this, RE, fmt);
   1051         fmt << "-2";
   1052         break;
   1053       case macho::RIT_X86_64_Signed4: // X86_64_RELOC_SIGNED4
   1054         printRelocationTargetName(this, RE, fmt);
   1055         fmt << "-4";
   1056         break;
   1057       default:
   1058         printRelocationTargetName(this, RE, fmt);
   1059         break;
   1060     }
   1061   // X86 and ARM share some relocation types in common.
   1062   } else if (Arch == Triple::x86 || Arch == Triple::arm) {
   1063     // Generic relocation types...
   1064     switch (Type) {
   1065       case macho::RIT_Pair: // GENERIC_RELOC_PAIR - prints no info
   1066         return object_error::success;
   1067       case macho::RIT_Difference: { // GENERIC_RELOC_SECTDIFF
   1068         DataRefImpl RelNext = Rel;
   1069         RelNext.d.a++;
   1070         macho::RelocationEntry RENext = getRelocation(RelNext);
   1071 
   1072         // X86 sect diff's must be followed by a relocation of type
   1073         // GENERIC_RELOC_PAIR.
   1074         unsigned RType = getAnyRelocationType(RENext);
   1075 
   1076         if (RType != 1)
   1077           report_fatal_error("Expected GENERIC_RELOC_PAIR after "
   1078                              "GENERIC_RELOC_SECTDIFF.");
   1079 
   1080         printRelocationTargetName(this, RE, fmt);
   1081         fmt << "-";
   1082         printRelocationTargetName(this, RENext, fmt);
   1083         break;
   1084       }
   1085     }
   1086 
   1087     if (Arch == Triple::x86) {
   1088       // All X86 relocations that need special printing were already
   1089       // handled in the generic code.
   1090       switch (Type) {
   1091         case macho::RIT_Generic_LocalDifference:{// GENERIC_RELOC_LOCAL_SECTDIFF
   1092           DataRefImpl RelNext = Rel;
   1093           RelNext.d.a++;
   1094           macho::RelocationEntry RENext = getRelocation(RelNext);
   1095 
   1096           // X86 sect diff's must be followed by a relocation of type
   1097           // GENERIC_RELOC_PAIR.
   1098           unsigned RType = getAnyRelocationType(RENext);
   1099           if (RType != 1)
   1100             report_fatal_error("Expected GENERIC_RELOC_PAIR after "
   1101                                "GENERIC_RELOC_LOCAL_SECTDIFF.");
   1102 
   1103           printRelocationTargetName(this, RE, fmt);
   1104           fmt << "-";
   1105           printRelocationTargetName(this, RENext, fmt);
   1106           break;
   1107         }
   1108         case macho::RIT_Generic_TLV: {
   1109           printRelocationTargetName(this, RE, fmt);
   1110           fmt << "@TLV";
   1111           if (IsPCRel) fmt << "P";
   1112           break;
   1113         }
   1114         default:
   1115           printRelocationTargetName(this, RE, fmt);
   1116       }
   1117     } else { // ARM-specific relocations
   1118       switch (Type) {
   1119         case macho::RIT_ARM_Half:             // ARM_RELOC_HALF
   1120         case macho::RIT_ARM_HalfDifference: { // ARM_RELOC_HALF_SECTDIFF
   1121           // Half relocations steal a bit from the length field to encode
   1122           // whether this is an upper16 or a lower16 relocation.
   1123           bool isUpper = getAnyRelocationLength(RE) >> 1;
   1124 
   1125           if (isUpper)
   1126             fmt << ":upper16:(";
   1127           else
   1128             fmt << ":lower16:(";
   1129           printRelocationTargetName(this, RE, fmt);
   1130 
   1131           DataRefImpl RelNext = Rel;
   1132           RelNext.d.a++;
   1133           macho::RelocationEntry RENext = getRelocation(RelNext);
   1134 
   1135           // ARM half relocs must be followed by a relocation of type
   1136           // ARM_RELOC_PAIR.
   1137           unsigned RType = getAnyRelocationType(RENext);
   1138           if (RType != 1)
   1139             report_fatal_error("Expected ARM_RELOC_PAIR after "
   1140                                "GENERIC_RELOC_HALF");
   1141 
   1142           // NOTE: The half of the target virtual address is stashed in the
   1143           // address field of the secondary relocation, but we can't reverse
   1144           // engineer the constant offset from it without decoding the movw/movt
   1145           // instruction to find the other half in its immediate field.
   1146 
   1147           // ARM_RELOC_HALF_SECTDIFF encodes the second section in the
   1148           // symbol/section pointer of the follow-on relocation.
   1149           if (Type == macho::RIT_ARM_HalfDifference) {
   1150             fmt << "-";
   1151             printRelocationTargetName(this, RENext, fmt);
   1152           }
   1153 
   1154           fmt << ")";
   1155           break;
   1156         }
   1157         default: {
   1158           printRelocationTargetName(this, RE, fmt);
   1159         }
   1160       }
   1161     }
   1162   } else
   1163     printRelocationTargetName(this, RE, fmt);
   1164 
   1165   fmt.flush();
   1166   Result.append(fmtbuf.begin(), fmtbuf.end());
   1167   return object_error::success;
   1168 }
   1169 
   1170 error_code
   1171 MachOObjectFile::getRelocationHidden(DataRefImpl Rel, bool &Result) const {
   1172   unsigned Arch = getArch();
   1173   uint64_t Type;
   1174   getRelocationType(Rel, Type);
   1175 
   1176   Result = false;
   1177 
   1178   // On arches that use the generic relocations, GENERIC_RELOC_PAIR
   1179   // is always hidden.
   1180   if (Arch == Triple::x86 || Arch == Triple::arm) {
   1181     if (Type == macho::RIT_Pair) Result = true;
   1182   } else if (Arch == Triple::x86_64) {
   1183     // On x86_64, X86_64_RELOC_UNSIGNED is hidden only when it follows
   1184     // an X86_64_RELOC_SUBTRACTOR.
   1185     if (Type == macho::RIT_X86_64_Unsigned && Rel.d.a > 0) {
   1186       DataRefImpl RelPrev = Rel;
   1187       RelPrev.d.a--;
   1188       uint64_t PrevType;
   1189       getRelocationType(RelPrev, PrevType);
   1190       if (PrevType == macho::RIT_X86_64_Subtractor)
   1191         Result = true;
   1192     }
   1193   }
   1194 
   1195   return object_error::success;
   1196 }
   1197 
   1198 error_code MachOObjectFile::getLibraryNext(DataRefImpl LibData,
   1199                                            LibraryRef &Res) const {
   1200   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
   1201 }
   1202 
   1203 error_code MachOObjectFile::getLibraryPath(DataRefImpl LibData,
   1204                                            StringRef &Res) const {
   1205   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
   1206 }
   1207 
   1208 symbol_iterator MachOObjectFile::begin_symbols() const {
   1209   DataRefImpl DRI;
   1210   if (!SymtabLoadCmd)
   1211     return symbol_iterator(SymbolRef(DRI, this));
   1212 
   1213   macho::SymtabLoadCommand Symtab = getSymtabLoadCommand();
   1214   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Symtab.SymbolTableOffset));
   1215   return symbol_iterator(SymbolRef(DRI, this));
   1216 }
   1217 
   1218 symbol_iterator MachOObjectFile::end_symbols() const {
   1219   DataRefImpl DRI;
   1220   if (!SymtabLoadCmd)
   1221     return symbol_iterator(SymbolRef(DRI, this));
   1222 
   1223   macho::SymtabLoadCommand Symtab = getSymtabLoadCommand();
   1224   unsigned SymbolTableEntrySize = is64Bit() ?
   1225     sizeof(macho::Symbol64TableEntry) :
   1226     sizeof(macho::SymbolTableEntry);
   1227   unsigned Offset = Symtab.SymbolTableOffset +
   1228     Symtab.NumSymbolTableEntries * SymbolTableEntrySize;
   1229   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
   1230   return symbol_iterator(SymbolRef(DRI, this));
   1231 }
   1232 
   1233 symbol_iterator MachOObjectFile::begin_dynamic_symbols() const {
   1234   // TODO: implement
   1235   report_fatal_error("Dynamic symbols unimplemented in MachOObjectFile");
   1236 }
   1237 
   1238 symbol_iterator MachOObjectFile::end_dynamic_symbols() const {
   1239   // TODO: implement
   1240   report_fatal_error("Dynamic symbols unimplemented in MachOObjectFile");
   1241 }
   1242 
   1243 section_iterator MachOObjectFile::begin_sections() const {
   1244   DataRefImpl DRI;
   1245   return section_iterator(SectionRef(DRI, this));
   1246 }
   1247 
   1248 section_iterator MachOObjectFile::end_sections() const {
   1249   DataRefImpl DRI;
   1250   DRI.d.a = Sections.size();
   1251   return section_iterator(SectionRef(DRI, this));
   1252 }
   1253 
   1254 library_iterator MachOObjectFile::begin_libraries_needed() const {
   1255   // TODO: implement
   1256   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
   1257 }
   1258 
   1259 library_iterator MachOObjectFile::end_libraries_needed() const {
   1260   // TODO: implement
   1261   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
   1262 }
   1263 
   1264 uint8_t MachOObjectFile::getBytesInAddress() const {
   1265   return is64Bit() ? 8 : 4;
   1266 }
   1267 
   1268 StringRef MachOObjectFile::getFileFormatName() const {
   1269   unsigned CPUType = getCPUType(this);
   1270   if (!is64Bit()) {
   1271     switch (CPUType) {
   1272     case llvm::MachO::CPUTypeI386:
   1273       return "Mach-O 32-bit i386";
   1274     case llvm::MachO::CPUTypeARM:
   1275       return "Mach-O arm";
   1276     case llvm::MachO::CPUTypePowerPC:
   1277       return "Mach-O 32-bit ppc";
   1278     default:
   1279       assert((CPUType & llvm::MachO::CPUArchABI64) == 0 &&
   1280              "64-bit object file when we're not 64-bit?");
   1281       return "Mach-O 32-bit unknown";
   1282     }
   1283   }
   1284 
   1285   // Make sure the cpu type has the correct mask.
   1286   assert((CPUType & llvm::MachO::CPUArchABI64)
   1287          == llvm::MachO::CPUArchABI64 &&
   1288          "32-bit object file when we're 64-bit?");
   1289 
   1290   switch (CPUType) {
   1291   case llvm::MachO::CPUTypeX86_64:
   1292     return "Mach-O 64-bit x86-64";
   1293   case llvm::MachO::CPUTypePowerPC64:
   1294     return "Mach-O 64-bit ppc64";
   1295   default:
   1296     return "Mach-O 64-bit unknown";
   1297   }
   1298 }
   1299 
   1300 Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
   1301   switch (CPUType) {
   1302   case llvm::MachO::CPUTypeI386:
   1303     return Triple::x86;
   1304   case llvm::MachO::CPUTypeX86_64:
   1305     return Triple::x86_64;
   1306   case llvm::MachO::CPUTypeARM:
   1307     return Triple::arm;
   1308   case llvm::MachO::CPUTypePowerPC:
   1309     return Triple::ppc;
   1310   case llvm::MachO::CPUTypePowerPC64:
   1311     return Triple::ppc64;
   1312   default:
   1313     return Triple::UnknownArch;
   1314   }
   1315 }
   1316 
   1317 unsigned MachOObjectFile::getArch() const {
   1318   return getArch(getCPUType(this));
   1319 }
   1320 
   1321 StringRef MachOObjectFile::getLoadName() const {
   1322   // TODO: Implement
   1323   report_fatal_error("get_load_name() unimplemented in MachOObjectFile");
   1324 }
   1325 
   1326 relocation_iterator MachOObjectFile::getSectionRelBegin(unsigned Index) const {
   1327   DataRefImpl DRI;
   1328   DRI.d.a = Index;
   1329   return getSectionRelBegin(DRI);
   1330 }
   1331 
   1332 relocation_iterator MachOObjectFile::getSectionRelEnd(unsigned Index) const {
   1333   DataRefImpl DRI;
   1334   DRI.d.a = Index;
   1335   return getSectionRelEnd(DRI);
   1336 }
   1337 
   1338 dice_iterator MachOObjectFile::begin_dices() const {
   1339   DataRefImpl DRI;
   1340   if (!DataInCodeLoadCmd)
   1341     return dice_iterator(DiceRef(DRI, this));
   1342 
   1343   macho::LinkeditDataLoadCommand DicLC = getDataInCodeLoadCommand();
   1344   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, DicLC.DataOffset));
   1345   return dice_iterator(DiceRef(DRI, this));
   1346 }
   1347 
   1348 dice_iterator MachOObjectFile::end_dices() const {
   1349   DataRefImpl DRI;
   1350   if (!DataInCodeLoadCmd)
   1351     return dice_iterator(DiceRef(DRI, this));
   1352 
   1353   macho::LinkeditDataLoadCommand DicLC = getDataInCodeLoadCommand();
   1354   unsigned Offset = DicLC.DataOffset + DicLC.DataSize;
   1355   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
   1356   return dice_iterator(DiceRef(DRI, this));
   1357 }
   1358 
   1359 StringRef
   1360 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
   1361   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
   1362   return parseSegmentOrSectionName(Raw.data());
   1363 }
   1364 
   1365 ArrayRef<char>
   1366 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
   1367   const SectionBase *Base =
   1368     reinterpret_cast<const SectionBase*>(Sections[Sec.d.a]);
   1369   return ArrayRef<char>(Base->Name);
   1370 }
   1371 
   1372 ArrayRef<char>
   1373 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
   1374   const SectionBase *Base =
   1375     reinterpret_cast<const SectionBase*>(Sections[Sec.d.a]);
   1376   return ArrayRef<char>(Base->SegmentName);
   1377 }
   1378 
   1379 bool
   1380 MachOObjectFile::isRelocationScattered(const macho::RelocationEntry &RE)
   1381   const {
   1382   if (getCPUType(this) == llvm::MachO::CPUTypeX86_64)
   1383     return false;
   1384   return getPlainRelocationAddress(RE) & macho::RF_Scattered;
   1385 }
   1386 
   1387 unsigned MachOObjectFile::getPlainRelocationSymbolNum(
   1388     const macho::RelocationEntry &RE) const {
   1389   if (isLittleEndian())
   1390     return RE.Word1 & 0xffffff;
   1391   return RE.Word1 >> 8;
   1392 }
   1393 
   1394 bool MachOObjectFile::getPlainRelocationExternal(
   1395     const macho::RelocationEntry &RE) const {
   1396   if (isLittleEndian())
   1397     return (RE.Word1 >> 27) & 1;
   1398   return (RE.Word1 >> 4) & 1;
   1399 }
   1400 
   1401 bool MachOObjectFile::getScatteredRelocationScattered(
   1402     const macho::RelocationEntry &RE) const {
   1403   return RE.Word0 >> 31;
   1404 }
   1405 
   1406 uint32_t MachOObjectFile::getScatteredRelocationValue(
   1407     const macho::RelocationEntry &RE) const {
   1408   return RE.Word1;
   1409 }
   1410 
   1411 unsigned MachOObjectFile::getAnyRelocationAddress(
   1412     const macho::RelocationEntry &RE) const {
   1413   if (isRelocationScattered(RE))
   1414     return getScatteredRelocationAddress(RE);
   1415   return getPlainRelocationAddress(RE);
   1416 }
   1417 
   1418 unsigned
   1419 MachOObjectFile::getAnyRelocationPCRel(const macho::RelocationEntry &RE) const {
   1420   if (isRelocationScattered(RE))
   1421     return getScatteredRelocationPCRel(this, RE);
   1422   return getPlainRelocationPCRel(this, RE);
   1423 }
   1424 
   1425 unsigned MachOObjectFile::getAnyRelocationLength(
   1426     const macho::RelocationEntry &RE) const {
   1427   if (isRelocationScattered(RE))
   1428     return getScatteredRelocationLength(RE);
   1429   return getPlainRelocationLength(this, RE);
   1430 }
   1431 
   1432 unsigned
   1433 MachOObjectFile::getAnyRelocationType(const macho::RelocationEntry &RE) const {
   1434   if (isRelocationScattered(RE))
   1435     return getScatteredRelocationType(RE);
   1436   return getPlainRelocationType(this, RE);
   1437 }
   1438 
   1439 SectionRef
   1440 MachOObjectFile::getRelocationSection(const macho::RelocationEntry &RE) const {
   1441   if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
   1442     return *end_sections();
   1443   unsigned SecNum = getPlainRelocationSymbolNum(RE) - 1;
   1444   DataRefImpl DRI;
   1445   DRI.d.a = SecNum;
   1446   return SectionRef(DRI, this);
   1447 }
   1448 
   1449 MachOObjectFile::LoadCommandInfo
   1450 MachOObjectFile::getFirstLoadCommandInfo() const {
   1451   MachOObjectFile::LoadCommandInfo Load;
   1452 
   1453   unsigned HeaderSize = is64Bit() ? macho::Header64Size : macho::Header32Size;
   1454   Load.Ptr = getPtr(this, HeaderSize);
   1455   Load.C = getStruct<macho::LoadCommand>(this, Load.Ptr);
   1456   return Load;
   1457 }
   1458 
   1459 MachOObjectFile::LoadCommandInfo
   1460 MachOObjectFile::getNextLoadCommandInfo(const LoadCommandInfo &L) const {
   1461   MachOObjectFile::LoadCommandInfo Next;
   1462   Next.Ptr = L.Ptr + L.C.Size;
   1463   Next.C = getStruct<macho::LoadCommand>(this, Next.Ptr);
   1464   return Next;
   1465 }
   1466 
   1467 macho::Section MachOObjectFile::getSection(DataRefImpl DRI) const {
   1468   return getStruct<macho::Section>(this, Sections[DRI.d.a]);
   1469 }
   1470 
   1471 macho::Section64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
   1472   return getStruct<macho::Section64>(this, Sections[DRI.d.a]);
   1473 }
   1474 
   1475 macho::Section MachOObjectFile::getSection(const LoadCommandInfo &L,
   1476                                            unsigned Index) const {
   1477   const char *Sec = getSectionPtr(this, L, Index);
   1478   return getStruct<macho::Section>(this, Sec);
   1479 }
   1480 
   1481 macho::Section64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
   1482                                                unsigned Index) const {
   1483   const char *Sec = getSectionPtr(this, L, Index);
   1484   return getStruct<macho::Section64>(this, Sec);
   1485 }
   1486 
   1487 macho::SymbolTableEntry
   1488 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
   1489   const char *P = reinterpret_cast<const char *>(DRI.p);
   1490   return getStruct<macho::SymbolTableEntry>(this, P);
   1491 }
   1492 
   1493 macho::Symbol64TableEntry
   1494 MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI) const {
   1495   const char *P = reinterpret_cast<const char *>(DRI.p);
   1496   return getStruct<macho::Symbol64TableEntry>(this, P);
   1497 }
   1498 
   1499 macho::LinkeditDataLoadCommand MachOObjectFile::getLinkeditDataLoadCommand(
   1500     const MachOObjectFile::LoadCommandInfo &L) const {
   1501   return getStruct<macho::LinkeditDataLoadCommand>(this, L.Ptr);
   1502 }
   1503 
   1504 macho::SegmentLoadCommand
   1505 MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
   1506   return getStruct<macho::SegmentLoadCommand>(this, L.Ptr);
   1507 }
   1508 
   1509 macho::Segment64LoadCommand
   1510 MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
   1511   return getStruct<macho::Segment64LoadCommand>(this, L.Ptr);
   1512 }
   1513 
   1514 macho::LinkerOptionsLoadCommand
   1515 MachOObjectFile::getLinkerOptionsLoadCommand(const LoadCommandInfo &L) const {
   1516   return getStruct<macho::LinkerOptionsLoadCommand>(this, L.Ptr);
   1517 }
   1518 
   1519 macho::RelocationEntry
   1520 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
   1521   const char *P = reinterpret_cast<const char *>(Rel.p);
   1522   return getStruct<macho::RelocationEntry>(this, P);
   1523 }
   1524 
   1525 macho::DataInCodeTableEntry
   1526 MachOObjectFile::getDice(DataRefImpl Rel) const {
   1527   const char *P = reinterpret_cast<const char *>(Rel.p);
   1528   return getStruct<macho::DataInCodeTableEntry>(this, P);
   1529 }
   1530 
   1531 macho::Header MachOObjectFile::getHeader() const {
   1532   return getStruct<macho::Header>(this, getPtr(this, 0));
   1533 }
   1534 
   1535 macho::Header64Ext MachOObjectFile::getHeader64Ext() const {
   1536   return
   1537     getStruct<macho::Header64Ext>(this, getPtr(this, sizeof(macho::Header)));
   1538 }
   1539 
   1540 macho::IndirectSymbolTableEntry MachOObjectFile::getIndirectSymbolTableEntry(
   1541                                           const macho::DysymtabLoadCommand &DLC,
   1542                                           unsigned Index) const {
   1543   uint64_t Offset = DLC.IndirectSymbolTableOffset +
   1544     Index * sizeof(macho::IndirectSymbolTableEntry);
   1545   return getStruct<macho::IndirectSymbolTableEntry>(this, getPtr(this, Offset));
   1546 }
   1547 
   1548 macho::DataInCodeTableEntry
   1549 MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
   1550                                          unsigned Index) const {
   1551   uint64_t Offset = DataOffset + Index * sizeof(macho::DataInCodeTableEntry);
   1552   return getStruct<macho::DataInCodeTableEntry>(this, getPtr(this, Offset));
   1553 }
   1554 
   1555 macho::SymtabLoadCommand MachOObjectFile::getSymtabLoadCommand() const {
   1556   return getStruct<macho::SymtabLoadCommand>(this, SymtabLoadCmd);
   1557 }
   1558 
   1559 macho::DysymtabLoadCommand MachOObjectFile::getDysymtabLoadCommand() const {
   1560   return getStruct<macho::DysymtabLoadCommand>(this, DysymtabLoadCmd);
   1561 }
   1562 
   1563 macho::LinkeditDataLoadCommand
   1564 MachOObjectFile::getDataInCodeLoadCommand() const {
   1565   if (DataInCodeLoadCmd)
   1566     return getStruct<macho::LinkeditDataLoadCommand>(this, DataInCodeLoadCmd);
   1567 
   1568   // If there is no DataInCodeLoadCmd return a load command with zero'ed fields.
   1569   macho::LinkeditDataLoadCommand Cmd;
   1570   Cmd.Type = macho::LCT_DataInCode;
   1571   Cmd.Size = macho::LinkeditLoadCommandSize;
   1572   Cmd.DataOffset = 0;
   1573   Cmd.DataSize = 0;
   1574   return Cmd;
   1575 }
   1576 
   1577 StringRef MachOObjectFile::getStringTableData() const {
   1578   macho::SymtabLoadCommand S = getSymtabLoadCommand();
   1579   return getData().substr(S.StringTableOffset, S.StringTableSize);
   1580 }
   1581 
   1582 bool MachOObjectFile::is64Bit() const {
   1583   return getType() == getMachOType(false, true) ||
   1584     getType() == getMachOType(true, true);
   1585 }
   1586 
   1587 void MachOObjectFile::ReadULEB128s(uint64_t Index,
   1588                                    SmallVectorImpl<uint64_t> &Out) const {
   1589   DataExtractor extractor(ObjectFile::getData(), true, 0);
   1590 
   1591   uint32_t offset = Index;
   1592   uint64_t data = 0;
   1593   while (uint64_t delta = extractor.getULEB128(&offset)) {
   1594     data += delta;
   1595     Out.push_back(data);
   1596   }
   1597 }
   1598 
   1599 ObjectFile *ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer) {
   1600   StringRef Magic = Buffer->getBuffer().slice(0, 4);
   1601   error_code ec;
   1602   OwningPtr<ObjectFile> Ret;
   1603   if (Magic == "\xFE\xED\xFA\xCE")
   1604     Ret.reset(new MachOObjectFile(Buffer, false, false, ec));
   1605   else if (Magic == "\xCE\xFA\xED\xFE")
   1606     Ret.reset(new MachOObjectFile(Buffer, true, false, ec));
   1607   else if (Magic == "\xFE\xED\xFA\xCF")
   1608     Ret.reset(new MachOObjectFile(Buffer, false, true, ec));
   1609   else if (Magic == "\xCF\xFA\xED\xFE")
   1610     Ret.reset(new MachOObjectFile(Buffer, true, true, ec));
   1611   else {
   1612     delete Buffer;
   1613     return NULL;
   1614   }
   1615 
   1616   if (ec)
   1617     return NULL;
   1618   return Ret.take();
   1619 }
   1620 
   1621 } // end namespace object
   1622 } // end namespace llvm
   1623