xref: /llvm-project/llvm/lib/Object/MachOObjectFile.cpp (revision b4865d698be45ae548284720da4a60fd9f0e3f44) 
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/STLExtras.h"
17 #include "llvm/ADT/Triple.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 "llvm/Support/raw_ostream.h"
23 #include <cctype>
24 #include <cstring>
25 #include <limits>
26 
27 using namespace llvm;
28 using namespace object;
29 
30 namespace llvm {
31 namespace object {
32 
33 struct nlist_base {
34   uint32_t n_strx;
35   uint8_t n_type;
36   uint8_t n_sect;
37   uint16_t n_desc;
38 };
39 
40 struct section_base {
41   char sectname[16];
42   char segname[16];
43 };
44 
45 template<typename T>
46 static void SwapValue(T &Value) {
47   Value = sys::SwapByteOrder(Value);
48 }
49 
50 template<typename T>
51 static void SwapStruct(T &Value);
52 
53 template<>
54 void SwapStruct(MachO::any_relocation_info &H) {
55   SwapValue(H.r_word0);
56   SwapValue(H.r_word1);
57 }
58 
59 template<>
60 void SwapStruct(MachO::load_command &L) {
61   SwapValue(L.cmd);
62   SwapValue(L.cmdsize);
63 }
64 
65 template<>
66 void SwapStruct(nlist_base &S) {
67   SwapValue(S.n_strx);
68   SwapValue(S.n_desc);
69 }
70 
71 template<>
72 void SwapStruct(MachO::section &S) {
73   SwapValue(S.addr);
74   SwapValue(S.size);
75   SwapValue(S.offset);
76   SwapValue(S.align);
77   SwapValue(S.reloff);
78   SwapValue(S.nreloc);
79   SwapValue(S.flags);
80   SwapValue(S.reserved1);
81   SwapValue(S.reserved2);
82 }
83 
84 template<>
85 void SwapStruct(MachO::section_64 &S) {
86   SwapValue(S.addr);
87   SwapValue(S.size);
88   SwapValue(S.offset);
89   SwapValue(S.align);
90   SwapValue(S.reloff);
91   SwapValue(S.nreloc);
92   SwapValue(S.flags);
93   SwapValue(S.reserved1);
94   SwapValue(S.reserved2);
95   SwapValue(S.reserved3);
96 }
97 
98 template<>
99 void SwapStruct(MachO::nlist &S) {
100   SwapValue(S.n_strx);
101   SwapValue(S.n_desc);
102   SwapValue(S.n_value);
103 }
104 
105 template<>
106 void SwapStruct(MachO::nlist_64 &S) {
107   SwapValue(S.n_strx);
108   SwapValue(S.n_desc);
109   SwapValue(S.n_value);
110 }
111 
112 template<>
113 void SwapStruct(MachO::mach_header &H) {
114   SwapValue(H.magic);
115   SwapValue(H.cputype);
116   SwapValue(H.cpusubtype);
117   SwapValue(H.filetype);
118   SwapValue(H.ncmds);
119   SwapValue(H.sizeofcmds);
120   SwapValue(H.flags);
121 }
122 
123 template<>
124 void SwapStruct(MachO::mach_header_64 &H) {
125   SwapValue(H.magic);
126   SwapValue(H.cputype);
127   SwapValue(H.cpusubtype);
128   SwapValue(H.filetype);
129   SwapValue(H.ncmds);
130   SwapValue(H.sizeofcmds);
131   SwapValue(H.flags);
132   SwapValue(H.reserved);
133 }
134 
135 template<>
136 void SwapStruct(MachO::symtab_command &C) {
137   SwapValue(C.cmd);
138   SwapValue(C.cmdsize);
139   SwapValue(C.symoff);
140   SwapValue(C.nsyms);
141   SwapValue(C.stroff);
142   SwapValue(C.strsize);
143 }
144 
145 template<>
146 void SwapStruct(MachO::dysymtab_command &C) {
147   SwapValue(C.cmd);
148   SwapValue(C.cmdsize);
149   SwapValue(C.ilocalsym);
150   SwapValue(C.nlocalsym);
151   SwapValue(C.iextdefsym);
152   SwapValue(C.nextdefsym);
153   SwapValue(C.iundefsym);
154   SwapValue(C.nundefsym);
155   SwapValue(C.tocoff);
156   SwapValue(C.ntoc);
157   SwapValue(C.modtaboff);
158   SwapValue(C.nmodtab);
159   SwapValue(C.extrefsymoff);
160   SwapValue(C.nextrefsyms);
161   SwapValue(C.indirectsymoff);
162   SwapValue(C.nindirectsyms);
163   SwapValue(C.extreloff);
164   SwapValue(C.nextrel);
165   SwapValue(C.locreloff);
166   SwapValue(C.nlocrel);
167 }
168 
169 template<>
170 void SwapStruct(MachO::linkedit_data_command &C) {
171   SwapValue(C.cmd);
172   SwapValue(C.cmdsize);
173   SwapValue(C.dataoff);
174   SwapValue(C.datasize);
175 }
176 
177 template<>
178 void SwapStruct(MachO::segment_command &C) {
179   SwapValue(C.cmd);
180   SwapValue(C.cmdsize);
181   SwapValue(C.vmaddr);
182   SwapValue(C.vmsize);
183   SwapValue(C.fileoff);
184   SwapValue(C.filesize);
185   SwapValue(C.maxprot);
186   SwapValue(C.initprot);
187   SwapValue(C.nsects);
188   SwapValue(C.flags);
189 }
190 
191 template<>
192 void SwapStruct(MachO::segment_command_64 &C) {
193   SwapValue(C.cmd);
194   SwapValue(C.cmdsize);
195   SwapValue(C.vmaddr);
196   SwapValue(C.vmsize);
197   SwapValue(C.fileoff);
198   SwapValue(C.filesize);
199   SwapValue(C.maxprot);
200   SwapValue(C.initprot);
201   SwapValue(C.nsects);
202   SwapValue(C.flags);
203 }
204 
205 template<>
206 void SwapStruct(uint32_t &C) {
207   SwapValue(C);
208 }
209 
210 template<>
211 void SwapStruct(MachO::linker_options_command &C) {
212   SwapValue(C.cmd);
213   SwapValue(C.cmdsize);
214   SwapValue(C.count);
215 }
216 
217 template<>
218 void SwapStruct(MachO::version_min_command&C) {
219   SwapValue(C.cmd);
220   SwapValue(C.cmdsize);
221   SwapValue(C.version);
222   SwapValue(C.reserved);
223 }
224 
225 template<>
226 void SwapStruct(MachO::data_in_code_entry &C) {
227   SwapValue(C.offset);
228   SwapValue(C.length);
229   SwapValue(C.kind);
230 }
231 
232 template<typename T>
233 T getStruct(const MachOObjectFile *O, const char *P) {
234   T Cmd;
235   memcpy(&Cmd, P, sizeof(T));
236   if (O->isLittleEndian() != sys::IsLittleEndianHost)
237     SwapStruct(Cmd);
238   return Cmd;
239 }
240 
241 static uint32_t
242 getSegmentLoadCommandNumSections(const MachOObjectFile *O,
243                                  const MachOObjectFile::LoadCommandInfo &L) {
244   if (O->is64Bit()) {
245     MachO::segment_command_64 S = O->getSegment64LoadCommand(L);
246     return S.nsects;
247   }
248   MachO::segment_command S = O->getSegmentLoadCommand(L);
249   return S.nsects;
250 }
251 
252 static const char *
253 getSectionPtr(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
254               unsigned Sec) {
255   uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
256 
257   bool Is64 = O->is64Bit();
258   unsigned SegmentLoadSize = Is64 ? sizeof(MachO::segment_command_64) :
259                                     sizeof(MachO::segment_command);
260   unsigned SectionSize = Is64 ? sizeof(MachO::section_64) :
261                                 sizeof(MachO::section);
262 
263   uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
264   return reinterpret_cast<const char*>(SectionAddr);
265 }
266 
267 static const char *getPtr(const MachOObjectFile *O, size_t Offset) {
268   return O->getData().substr(Offset, 1).data();
269 }
270 
271 static nlist_base
272 getSymbolTableEntryBase(const MachOObjectFile *O, DataRefImpl DRI) {
273   const char *P = reinterpret_cast<const char *>(DRI.p);
274   return getStruct<nlist_base>(O, P);
275 }
276 
277 static StringRef parseSegmentOrSectionName(const char *P) {
278   if (P[15] == 0)
279     // Null terminated.
280     return P;
281   // Not null terminated, so this is a 16 char string.
282   return StringRef(P, 16);
283 }
284 
285 // Helper to advance a section or symbol iterator multiple increments at a time.
286 template<class T>
287 static void advance(T &it, size_t Val) {
288   while (Val--)
289     ++it;
290 }
291 
292 static unsigned getCPUType(const MachOObjectFile *O) {
293   return O->getHeader().cputype;
294 }
295 
296 static void printRelocationTargetName(const MachOObjectFile *O,
297                                       const MachO::any_relocation_info &RE,
298                                       raw_string_ostream &fmt) {
299   bool IsScattered = O->isRelocationScattered(RE);
300 
301   // Target of a scattered relocation is an address.  In the interest of
302   // generating pretty output, scan through the symbol table looking for a
303   // symbol that aligns with that address.  If we find one, print it.
304   // Otherwise, we just print the hex address of the target.
305   if (IsScattered) {
306     uint32_t Val = O->getPlainRelocationSymbolNum(RE);
307 
308     for (const SymbolRef &Symbol : O->symbols()) {
309       error_code ec;
310       uint64_t Addr;
311       StringRef Name;
312 
313       if ((ec = Symbol.getAddress(Addr)))
314         report_fatal_error(ec.message());
315       if (Addr != Val)
316         continue;
317       if ((ec = Symbol.getName(Name)))
318         report_fatal_error(ec.message());
319       fmt << Name;
320       return;
321     }
322 
323     // If we couldn't find a symbol that this relocation refers to, try
324     // to find a section beginning instead.
325     for (const SectionRef &Section : O->sections()) {
326       error_code ec;
327       uint64_t Addr;
328       StringRef Name;
329 
330       if ((ec = Section.getAddress(Addr)))
331         report_fatal_error(ec.message());
332       if (Addr != Val)
333         continue;
334       if ((ec = Section.getName(Name)))
335         report_fatal_error(ec.message());
336       fmt << Name;
337       return;
338     }
339 
340     fmt << format("0x%x", Val);
341     return;
342   }
343 
344   StringRef S;
345   bool isExtern = O->getPlainRelocationExternal(RE);
346   uint64_t Val = O->getPlainRelocationSymbolNum(RE);
347 
348   if (isExtern) {
349     symbol_iterator SI = O->symbol_begin();
350     advance(SI, Val);
351     SI->getName(S);
352   } else {
353     section_iterator SI = O->section_begin();
354     // Adjust for the fact that sections are 1-indexed.
355     advance(SI, Val - 1);
356     SI->getName(S);
357   }
358 
359   fmt << S;
360 }
361 
362 static uint32_t
363 getPlainRelocationAddress(const MachO::any_relocation_info &RE) {
364   return RE.r_word0;
365 }
366 
367 static unsigned
368 getScatteredRelocationAddress(const MachO::any_relocation_info &RE) {
369   return RE.r_word0 & 0xffffff;
370 }
371 
372 static bool getPlainRelocationPCRel(const MachOObjectFile *O,
373                                     const MachO::any_relocation_info &RE) {
374   if (O->isLittleEndian())
375     return (RE.r_word1 >> 24) & 1;
376   return (RE.r_word1 >> 7) & 1;
377 }
378 
379 static bool
380 getScatteredRelocationPCRel(const MachOObjectFile *O,
381                             const MachO::any_relocation_info &RE) {
382   return (RE.r_word0 >> 30) & 1;
383 }
384 
385 static unsigned getPlainRelocationLength(const MachOObjectFile *O,
386                                          const MachO::any_relocation_info &RE) {
387   if (O->isLittleEndian())
388     return (RE.r_word1 >> 25) & 3;
389   return (RE.r_word1 >> 5) & 3;
390 }
391 
392 static unsigned
393 getScatteredRelocationLength(const MachO::any_relocation_info &RE) {
394   return (RE.r_word0 >> 28) & 3;
395 }
396 
397 static unsigned getPlainRelocationType(const MachOObjectFile *O,
398                                        const MachO::any_relocation_info &RE) {
399   if (O->isLittleEndian())
400     return RE.r_word1 >> 28;
401   return RE.r_word1 & 0xf;
402 }
403 
404 static unsigned
405 getScatteredRelocationType(const MachO::any_relocation_info &RE) {
406   return (RE.r_word0 >> 24) & 0xf;
407 }
408 
409 static uint32_t getSectionFlags(const MachOObjectFile *O,
410                                 DataRefImpl Sec) {
411   if (O->is64Bit()) {
412     MachO::section_64 Sect = O->getSection64(Sec);
413     return Sect.flags;
414   }
415   MachO::section Sect = O->getSection(Sec);
416   return Sect.flags;
417 }
418 
419 MachOObjectFile::MachOObjectFile(MemoryBuffer *Object, bool IsLittleEndian,
420                                  bool Is64bits, error_code &EC,
421                                  bool BufferOwned)
422     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object, BufferOwned),
423       SymtabLoadCmd(NULL), DysymtabLoadCmd(NULL), DataInCodeLoadCmd(NULL) {
424   uint32_t LoadCommandCount = this->getHeader().ncmds;
425   MachO::LoadCommandType SegmentLoadType = is64Bit() ?
426     MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT;
427 
428   MachOObjectFile::LoadCommandInfo Load = getFirstLoadCommandInfo();
429   for (unsigned I = 0; ; ++I) {
430     if (Load.C.cmd == MachO::LC_SYMTAB) {
431       assert(!SymtabLoadCmd && "Multiple symbol tables");
432       SymtabLoadCmd = Load.Ptr;
433     } else if (Load.C.cmd == MachO::LC_DYSYMTAB) {
434       assert(!DysymtabLoadCmd && "Multiple dynamic symbol tables");
435       DysymtabLoadCmd = Load.Ptr;
436     } else if (Load.C.cmd == MachO::LC_DATA_IN_CODE) {
437       assert(!DataInCodeLoadCmd && "Multiple data in code tables");
438       DataInCodeLoadCmd = Load.Ptr;
439     } else if (Load.C.cmd == SegmentLoadType) {
440       uint32_t NumSections = getSegmentLoadCommandNumSections(this, Load);
441       for (unsigned J = 0; J < NumSections; ++J) {
442         const char *Sec = getSectionPtr(this, Load, J);
443         Sections.push_back(Sec);
444       }
445     }
446 
447     if (I == LoadCommandCount - 1)
448       break;
449     else
450       Load = getNextLoadCommandInfo(Load);
451   }
452 }
453 
454 void MachOObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
455   unsigned SymbolTableEntrySize = is64Bit() ?
456     sizeof(MachO::nlist_64) :
457     sizeof(MachO::nlist);
458   Symb.p += SymbolTableEntrySize;
459 }
460 
461 error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
462                                           StringRef &Res) const {
463   StringRef StringTable = getStringTableData();
464   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
465   const char *Start = &StringTable.data()[Entry.n_strx];
466   Res = StringRef(Start);
467   return object_error::success;
468 }
469 
470 error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
471                                              uint64_t &Res) const {
472   if (is64Bit()) {
473     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
474     Res = Entry.n_value;
475   } else {
476     MachO::nlist Entry = getSymbolTableEntry(Symb);
477     Res = Entry.n_value;
478   }
479   return object_error::success;
480 }
481 
482 error_code
483 MachOObjectFile::getSymbolFileOffset(DataRefImpl Symb,
484                                      uint64_t &Res) const {
485   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
486   getSymbolAddress(Symb, Res);
487   if (Entry.n_sect) {
488     uint64_t Delta;
489     DataRefImpl SecRel;
490     SecRel.d.a = Entry.n_sect-1;
491     if (is64Bit()) {
492       MachO::section_64 Sec = getSection64(SecRel);
493       Delta = Sec.offset - Sec.addr;
494     } else {
495       MachO::section Sec = getSection(SecRel);
496       Delta = Sec.offset - Sec.addr;
497     }
498 
499     Res += Delta;
500   }
501 
502   return object_error::success;
503 }
504 
505 error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
506                                                uint32_t &Result) const {
507   uint32_t flags = getSymbolFlags(DRI);
508   if (flags & SymbolRef::SF_Common) {
509     nlist_base Entry = getSymbolTableEntryBase(this, DRI);
510     Result = 1 << MachO::GET_COMM_ALIGN(Entry.n_desc);
511   } else {
512     Result = 0;
513   }
514   return object_error::success;
515 }
516 
517 error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
518                                           uint64_t &Result) const {
519   uint64_t BeginOffset;
520   uint64_t EndOffset = 0;
521   uint8_t SectionIndex;
522 
523   nlist_base Entry = getSymbolTableEntryBase(this, DRI);
524   uint64_t Value;
525   getSymbolAddress(DRI, Value);
526 
527   BeginOffset = Value;
528 
529   SectionIndex = Entry.n_sect;
530   if (!SectionIndex) {
531     uint32_t flags = getSymbolFlags(DRI);
532     if (flags & SymbolRef::SF_Common)
533       Result = Value;
534     else
535       Result = UnknownAddressOrSize;
536     return object_error::success;
537   }
538   // Unfortunately symbols are unsorted so we need to touch all
539   // symbols from load command
540   for (const SymbolRef &Symbol : symbols()) {
541     DataRefImpl DRI = Symbol.getRawDataRefImpl();
542     Entry = getSymbolTableEntryBase(this, DRI);
543     getSymbolAddress(DRI, Value);
544     if (Entry.n_sect == SectionIndex && Value > BeginOffset)
545       if (!EndOffset || Value < EndOffset)
546         EndOffset = Value;
547   }
548   if (!EndOffset) {
549     uint64_t Size;
550     DataRefImpl Sec;
551     Sec.d.a = SectionIndex-1;
552     getSectionSize(Sec, Size);
553     getSectionAddress(Sec, EndOffset);
554     EndOffset += Size;
555   }
556   Result = EndOffset - BeginOffset;
557   return object_error::success;
558 }
559 
560 error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
561                                           SymbolRef::Type &Res) const {
562   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
563   uint8_t n_type = Entry.n_type;
564 
565   Res = SymbolRef::ST_Other;
566 
567   // If this is a STAB debugging symbol, we can do nothing more.
568   if (n_type & MachO::N_STAB) {
569     Res = SymbolRef::ST_Debug;
570     return object_error::success;
571   }
572 
573   switch (n_type & MachO::N_TYPE) {
574     case MachO::N_UNDF :
575       Res = SymbolRef::ST_Unknown;
576       break;
577     case MachO::N_SECT :
578       Res = SymbolRef::ST_Function;
579       break;
580   }
581   return object_error::success;
582 }
583 
584 uint32_t MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
585   nlist_base Entry = getSymbolTableEntryBase(this, DRI);
586 
587   uint8_t MachOType = Entry.n_type;
588   uint16_t MachOFlags = Entry.n_desc;
589 
590   uint32_t Result = SymbolRef::SF_None;
591 
592   if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF)
593     Result |= SymbolRef::SF_Undefined;
594 
595   if (MachOType & MachO::N_STAB)
596     Result |= SymbolRef::SF_FormatSpecific;
597 
598   if (MachOType & MachO::N_EXT) {
599     Result |= SymbolRef::SF_Global;
600     if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF) {
601       uint64_t Value;
602       getSymbolAddress(DRI, Value);
603       if (Value)
604         Result |= SymbolRef::SF_Common;
605     }
606   }
607 
608   if (MachOFlags & (MachO::N_WEAK_REF | MachO::N_WEAK_DEF))
609     Result |= SymbolRef::SF_Weak;
610 
611   if ((MachOType & MachO::N_TYPE) == MachO::N_ABS)
612     Result |= SymbolRef::SF_Absolute;
613 
614   return Result;
615 }
616 
617 error_code
618 MachOObjectFile::getSymbolSection(DataRefImpl Symb,
619                                   section_iterator &Res) const {
620   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
621   uint8_t index = Entry.n_sect;
622 
623   if (index == 0) {
624     Res = section_end();
625   } else {
626     DataRefImpl DRI;
627     DRI.d.a = index - 1;
628     Res = section_iterator(SectionRef(DRI, this));
629   }
630 
631   return object_error::success;
632 }
633 
634 error_code MachOObjectFile::getSymbolValue(DataRefImpl Symb,
635                                            uint64_t &Val) const {
636   report_fatal_error("getSymbolValue unimplemented in MachOObjectFile");
637 }
638 
639 void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
640   Sec.d.a++;
641 }
642 
643 error_code
644 MachOObjectFile::getSectionName(DataRefImpl Sec, StringRef &Result) const {
645   ArrayRef<char> Raw = getSectionRawName(Sec);
646   Result = parseSegmentOrSectionName(Raw.data());
647   return object_error::success;
648 }
649 
650 error_code
651 MachOObjectFile::getSectionAddress(DataRefImpl Sec, uint64_t &Res) const {
652   if (is64Bit()) {
653     MachO::section_64 Sect = getSection64(Sec);
654     Res = Sect.addr;
655   } else {
656     MachO::section Sect = getSection(Sec);
657     Res = Sect.addr;
658   }
659   return object_error::success;
660 }
661 
662 error_code
663 MachOObjectFile::getSectionSize(DataRefImpl Sec, uint64_t &Res) const {
664   if (is64Bit()) {
665     MachO::section_64 Sect = getSection64(Sec);
666     Res = Sect.size;
667   } else {
668     MachO::section Sect = getSection(Sec);
669     Res = Sect.size;
670   }
671 
672   return object_error::success;
673 }
674 
675 error_code
676 MachOObjectFile::getSectionContents(DataRefImpl Sec, StringRef &Res) const {
677   uint32_t Offset;
678   uint64_t Size;
679 
680   if (is64Bit()) {
681     MachO::section_64 Sect = getSection64(Sec);
682     Offset = Sect.offset;
683     Size = Sect.size;
684   } else {
685     MachO::section Sect = getSection(Sec);
686     Offset = Sect.offset;
687     Size = Sect.size;
688   }
689 
690   Res = this->getData().substr(Offset, Size);
691   return object_error::success;
692 }
693 
694 error_code
695 MachOObjectFile::getSectionAlignment(DataRefImpl Sec, uint64_t &Res) const {
696   uint32_t Align;
697   if (is64Bit()) {
698     MachO::section_64 Sect = getSection64(Sec);
699     Align = Sect.align;
700   } else {
701     MachO::section Sect = getSection(Sec);
702     Align = Sect.align;
703   }
704 
705   Res = uint64_t(1) << Align;
706   return object_error::success;
707 }
708 
709 error_code
710 MachOObjectFile::isSectionText(DataRefImpl Sec, bool &Res) const {
711   uint32_t Flags = getSectionFlags(this, Sec);
712   Res = Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
713   return object_error::success;
714 }
715 
716 error_code MachOObjectFile::isSectionData(DataRefImpl DRI, bool &Result) const {
717   // FIXME: Unimplemented.
718   Result = false;
719   return object_error::success;
720 }
721 
722 error_code MachOObjectFile::isSectionBSS(DataRefImpl DRI, bool &Result) const {
723   // FIXME: Unimplemented.
724   Result = false;
725   return object_error::success;
726 }
727 
728 error_code
729 MachOObjectFile::isSectionRequiredForExecution(DataRefImpl Sec,
730                                                bool &Result) const {
731   // FIXME: Unimplemented.
732   Result = true;
733   return object_error::success;
734 }
735 
736 error_code MachOObjectFile::isSectionVirtual(DataRefImpl Sec,
737                                              bool &Result) const {
738   // FIXME: Unimplemented.
739   Result = false;
740   return object_error::success;
741 }
742 
743 error_code
744 MachOObjectFile::isSectionZeroInit(DataRefImpl Sec, bool &Res) const {
745   uint32_t Flags = getSectionFlags(this, Sec);
746   unsigned SectionType = Flags & MachO::SECTION_TYPE;
747   Res = SectionType == MachO::S_ZEROFILL ||
748     SectionType == MachO::S_GB_ZEROFILL;
749   return object_error::success;
750 }
751 
752 error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
753                                                   bool &Result) const {
754   // Consider using the code from isSectionText to look for __const sections.
755   // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
756   // to use section attributes to distinguish code from data.
757 
758   // FIXME: Unimplemented.
759   Result = false;
760   return object_error::success;
761 }
762 
763 error_code
764 MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
765                                        bool &Result) const {
766   SymbolRef::Type ST;
767   this->getSymbolType(Symb, ST);
768   if (ST == SymbolRef::ST_Unknown) {
769     Result = false;
770     return object_error::success;
771   }
772 
773   uint64_t SectBegin, SectEnd;
774   getSectionAddress(Sec, SectBegin);
775   getSectionSize(Sec, SectEnd);
776   SectEnd += SectBegin;
777 
778   uint64_t SymAddr;
779   getSymbolAddress(Symb, SymAddr);
780   Result = (SymAddr >= SectBegin) && (SymAddr < SectEnd);
781 
782   return object_error::success;
783 }
784 
785 relocation_iterator MachOObjectFile::section_rel_begin(DataRefImpl Sec) const {
786   uint32_t Offset;
787   if (is64Bit()) {
788     MachO::section_64 Sect = getSection64(Sec);
789     Offset = Sect.reloff;
790   } else {
791     MachO::section Sect = getSection(Sec);
792     Offset = Sect.reloff;
793   }
794 
795   DataRefImpl Ret;
796   Ret.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
797   return relocation_iterator(RelocationRef(Ret, this));
798 }
799 
800 relocation_iterator
801 MachOObjectFile::section_rel_end(DataRefImpl Sec) const {
802   uint32_t Offset;
803   uint32_t Num;
804   if (is64Bit()) {
805     MachO::section_64 Sect = getSection64(Sec);
806     Offset = Sect.reloff;
807     Num = Sect.nreloc;
808   } else {
809     MachO::section Sect = getSection(Sec);
810     Offset = Sect.reloff;
811     Num = Sect.nreloc;
812   }
813 
814   const MachO::any_relocation_info *P =
815     reinterpret_cast<const MachO::any_relocation_info *>(getPtr(this, Offset));
816 
817   DataRefImpl Ret;
818   Ret.p = reinterpret_cast<uintptr_t>(P + Num);
819   return relocation_iterator(RelocationRef(Ret, this));
820 }
821 
822 bool MachOObjectFile::section_rel_empty(DataRefImpl Sec) const {
823   if (is64Bit()) {
824     MachO::section_64 Sect = getSection64(Sec);
825     return Sect.nreloc == 0;
826   } else {
827     MachO::section Sect = getSection(Sec);
828     return Sect.nreloc == 0;
829   }
830 }
831 
832 void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
833   const MachO::any_relocation_info *P =
834     reinterpret_cast<const MachO::any_relocation_info *>(Rel.p);
835   Rel.p = reinterpret_cast<uintptr_t>(P + 1);
836 }
837 
838 error_code
839 MachOObjectFile::getRelocationAddress(DataRefImpl Rel, uint64_t &Res) const {
840   report_fatal_error("getRelocationAddress not implemented in MachOObjectFile");
841 }
842 
843 error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
844                                                 uint64_t &Res) const {
845   MachO::any_relocation_info RE = getRelocation(Rel);
846   Res = getAnyRelocationAddress(RE);
847   return object_error::success;
848 }
849 
850 symbol_iterator
851 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
852   MachO::any_relocation_info RE = getRelocation(Rel);
853   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
854   bool isExtern = getPlainRelocationExternal(RE);
855   if (!isExtern)
856     return symbol_end();
857 
858   MachO::symtab_command S = getSymtabLoadCommand();
859   unsigned SymbolTableEntrySize = is64Bit() ?
860     sizeof(MachO::nlist_64) :
861     sizeof(MachO::nlist);
862   uint64_t Offset = S.symoff + SymbolIdx * SymbolTableEntrySize;
863   DataRefImpl Sym;
864   Sym.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
865   return symbol_iterator(SymbolRef(Sym, this));
866 }
867 
868 error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
869                                               uint64_t &Res) const {
870   MachO::any_relocation_info RE = getRelocation(Rel);
871   Res = getAnyRelocationType(RE);
872   return object_error::success;
873 }
874 
875 error_code
876 MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
877                                        SmallVectorImpl<char> &Result) const {
878   StringRef res;
879   uint64_t RType;
880   getRelocationType(Rel, RType);
881 
882   unsigned Arch = this->getArch();
883 
884   switch (Arch) {
885     case Triple::x86: {
886       static const char *const Table[] =  {
887         "GENERIC_RELOC_VANILLA",
888         "GENERIC_RELOC_PAIR",
889         "GENERIC_RELOC_SECTDIFF",
890         "GENERIC_RELOC_PB_LA_PTR",
891         "GENERIC_RELOC_LOCAL_SECTDIFF",
892         "GENERIC_RELOC_TLV" };
893 
894       if (RType > 5)
895         res = "Unknown";
896       else
897         res = Table[RType];
898       break;
899     }
900     case Triple::x86_64: {
901       static const char *const Table[] =  {
902         "X86_64_RELOC_UNSIGNED",
903         "X86_64_RELOC_SIGNED",
904         "X86_64_RELOC_BRANCH",
905         "X86_64_RELOC_GOT_LOAD",
906         "X86_64_RELOC_GOT",
907         "X86_64_RELOC_SUBTRACTOR",
908         "X86_64_RELOC_SIGNED_1",
909         "X86_64_RELOC_SIGNED_2",
910         "X86_64_RELOC_SIGNED_4",
911         "X86_64_RELOC_TLV" };
912 
913       if (RType > 9)
914         res = "Unknown";
915       else
916         res = Table[RType];
917       break;
918     }
919     case Triple::arm: {
920       static const char *const Table[] =  {
921         "ARM_RELOC_VANILLA",
922         "ARM_RELOC_PAIR",
923         "ARM_RELOC_SECTDIFF",
924         "ARM_RELOC_LOCAL_SECTDIFF",
925         "ARM_RELOC_PB_LA_PTR",
926         "ARM_RELOC_BR24",
927         "ARM_THUMB_RELOC_BR22",
928         "ARM_THUMB_32BIT_BRANCH",
929         "ARM_RELOC_HALF",
930         "ARM_RELOC_HALF_SECTDIFF" };
931 
932       if (RType > 9)
933         res = "Unknown";
934       else
935         res = Table[RType];
936       break;
937     }
938     case Triple::arm64:
939     case Triple::aarch64: {
940       static const char *const Table[] = {
941         "ARM64_RELOC_UNSIGNED",           "ARM64_RELOC_SUBTRACTOR",
942         "ARM64_RELOC_BRANCH26",           "ARM64_RELOC_PAGE21",
943         "ARM64_RELOC_PAGEOFF12",          "ARM64_RELOC_GOT_LOAD_PAGE21",
944         "ARM64_RELOC_GOT_LOAD_PAGEOFF12", "ARM64_RELOC_POINTER_TO_GOT",
945         "ARM64_RELOC_TLVP_LOAD_PAGE21",   "ARM64_RELOC_TLVP_LOAD_PAGEOFF12",
946         "ARM64_RELOC_ADDEND"
947       };
948 
949       if (RType >= array_lengthof(Table))
950         res = "Unknown";
951       else
952         res = Table[RType];
953       break;
954     }
955     case Triple::ppc: {
956       static const char *const Table[] =  {
957         "PPC_RELOC_VANILLA",
958         "PPC_RELOC_PAIR",
959         "PPC_RELOC_BR14",
960         "PPC_RELOC_BR24",
961         "PPC_RELOC_HI16",
962         "PPC_RELOC_LO16",
963         "PPC_RELOC_HA16",
964         "PPC_RELOC_LO14",
965         "PPC_RELOC_SECTDIFF",
966         "PPC_RELOC_PB_LA_PTR",
967         "PPC_RELOC_HI16_SECTDIFF",
968         "PPC_RELOC_LO16_SECTDIFF",
969         "PPC_RELOC_HA16_SECTDIFF",
970         "PPC_RELOC_JBSR",
971         "PPC_RELOC_LO14_SECTDIFF",
972         "PPC_RELOC_LOCAL_SECTDIFF" };
973 
974       if (RType > 15)
975         res = "Unknown";
976       else
977         res = Table[RType];
978       break;
979     }
980     case Triple::UnknownArch:
981       res = "Unknown";
982       break;
983   }
984   Result.append(res.begin(), res.end());
985   return object_error::success;
986 }
987 
988 error_code
989 MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
990                                           SmallVectorImpl<char> &Result) const {
991   MachO::any_relocation_info RE = getRelocation(Rel);
992 
993   unsigned Arch = this->getArch();
994 
995   std::string fmtbuf;
996   raw_string_ostream fmt(fmtbuf);
997   unsigned Type = this->getAnyRelocationType(RE);
998   bool IsPCRel = this->getAnyRelocationPCRel(RE);
999 
1000   // Determine any addends that should be displayed with the relocation.
1001   // These require decoding the relocation type, which is triple-specific.
1002 
1003   // X86_64 has entirely custom relocation types.
1004   if (Arch == Triple::x86_64) {
1005     bool isPCRel = getAnyRelocationPCRel(RE);
1006 
1007     switch (Type) {
1008       case MachO::X86_64_RELOC_GOT_LOAD:
1009       case MachO::X86_64_RELOC_GOT: {
1010         printRelocationTargetName(this, RE, fmt);
1011         fmt << "@GOT";
1012         if (isPCRel) fmt << "PCREL";
1013         break;
1014       }
1015       case MachO::X86_64_RELOC_SUBTRACTOR: {
1016         DataRefImpl RelNext = Rel;
1017         RelNext.d.a++;
1018         MachO::any_relocation_info RENext = getRelocation(RelNext);
1019 
1020         // X86_64_RELOC_SUBTRACTOR must be followed by a relocation of type
1021         // X86_64_RELOC_UNSIGNED.
1022         // NOTE: Scattered relocations don't exist on x86_64.
1023         unsigned RType = getAnyRelocationType(RENext);
1024         if (RType != MachO::X86_64_RELOC_UNSIGNED)
1025           report_fatal_error("Expected X86_64_RELOC_UNSIGNED after "
1026                              "X86_64_RELOC_SUBTRACTOR.");
1027 
1028         // The X86_64_RELOC_UNSIGNED contains the minuend symbol;
1029         // X86_64_RELOC_SUBTRACTOR contains the subtrahend.
1030         printRelocationTargetName(this, RENext, fmt);
1031         fmt << "-";
1032         printRelocationTargetName(this, RE, fmt);
1033         break;
1034       }
1035       case MachO::X86_64_RELOC_TLV:
1036         printRelocationTargetName(this, RE, fmt);
1037         fmt << "@TLV";
1038         if (isPCRel) fmt << "P";
1039         break;
1040       case MachO::X86_64_RELOC_SIGNED_1:
1041         printRelocationTargetName(this, RE, fmt);
1042         fmt << "-1";
1043         break;
1044       case MachO::X86_64_RELOC_SIGNED_2:
1045         printRelocationTargetName(this, RE, fmt);
1046         fmt << "-2";
1047         break;
1048       case MachO::X86_64_RELOC_SIGNED_4:
1049         printRelocationTargetName(this, RE, fmt);
1050         fmt << "-4";
1051         break;
1052       default:
1053         printRelocationTargetName(this, RE, fmt);
1054         break;
1055     }
1056   // X86 and ARM share some relocation types in common.
1057   } else if (Arch == Triple::x86 || Arch == Triple::arm ||
1058              Arch == Triple::ppc) {
1059     // Generic relocation types...
1060     switch (Type) {
1061       case MachO::GENERIC_RELOC_PAIR: // prints no info
1062         return object_error::success;
1063       case MachO::GENERIC_RELOC_SECTDIFF: {
1064         DataRefImpl RelNext = Rel;
1065         RelNext.d.a++;
1066         MachO::any_relocation_info RENext = getRelocation(RelNext);
1067 
1068         // X86 sect diff's must be followed by a relocation of type
1069         // GENERIC_RELOC_PAIR.
1070         unsigned RType = getAnyRelocationType(RENext);
1071 
1072         if (RType != MachO::GENERIC_RELOC_PAIR)
1073           report_fatal_error("Expected GENERIC_RELOC_PAIR after "
1074                              "GENERIC_RELOC_SECTDIFF.");
1075 
1076         printRelocationTargetName(this, RE, fmt);
1077         fmt << "-";
1078         printRelocationTargetName(this, RENext, fmt);
1079         break;
1080       }
1081     }
1082 
1083     if (Arch == Triple::x86 || Arch == Triple::ppc) {
1084       switch (Type) {
1085         case MachO::GENERIC_RELOC_LOCAL_SECTDIFF: {
1086           DataRefImpl RelNext = Rel;
1087           RelNext.d.a++;
1088           MachO::any_relocation_info RENext = getRelocation(RelNext);
1089 
1090           // X86 sect diff's must be followed by a relocation of type
1091           // GENERIC_RELOC_PAIR.
1092           unsigned RType = getAnyRelocationType(RENext);
1093           if (RType != MachO::GENERIC_RELOC_PAIR)
1094             report_fatal_error("Expected GENERIC_RELOC_PAIR after "
1095                                "GENERIC_RELOC_LOCAL_SECTDIFF.");
1096 
1097           printRelocationTargetName(this, RE, fmt);
1098           fmt << "-";
1099           printRelocationTargetName(this, RENext, fmt);
1100           break;
1101         }
1102         case MachO::GENERIC_RELOC_TLV: {
1103           printRelocationTargetName(this, RE, fmt);
1104           fmt << "@TLV";
1105           if (IsPCRel) fmt << "P";
1106           break;
1107         }
1108         default:
1109           printRelocationTargetName(this, RE, fmt);
1110       }
1111     } else { // ARM-specific relocations
1112       switch (Type) {
1113         case MachO::ARM_RELOC_HALF:
1114         case MachO::ARM_RELOC_HALF_SECTDIFF: {
1115           // Half relocations steal a bit from the length field to encode
1116           // whether this is an upper16 or a lower16 relocation.
1117           bool isUpper = getAnyRelocationLength(RE) >> 1;
1118 
1119           if (isUpper)
1120             fmt << ":upper16:(";
1121           else
1122             fmt << ":lower16:(";
1123           printRelocationTargetName(this, RE, fmt);
1124 
1125           DataRefImpl RelNext = Rel;
1126           RelNext.d.a++;
1127           MachO::any_relocation_info RENext = getRelocation(RelNext);
1128 
1129           // ARM half relocs must be followed by a relocation of type
1130           // ARM_RELOC_PAIR.
1131           unsigned RType = getAnyRelocationType(RENext);
1132           if (RType != MachO::ARM_RELOC_PAIR)
1133             report_fatal_error("Expected ARM_RELOC_PAIR after "
1134                                "ARM_RELOC_HALF");
1135 
1136           // NOTE: The half of the target virtual address is stashed in the
1137           // address field of the secondary relocation, but we can't reverse
1138           // engineer the constant offset from it without decoding the movw/movt
1139           // instruction to find the other half in its immediate field.
1140 
1141           // ARM_RELOC_HALF_SECTDIFF encodes the second section in the
1142           // symbol/section pointer of the follow-on relocation.
1143           if (Type == MachO::ARM_RELOC_HALF_SECTDIFF) {
1144             fmt << "-";
1145             printRelocationTargetName(this, RENext, fmt);
1146           }
1147 
1148           fmt << ")";
1149           break;
1150         }
1151         default: {
1152           printRelocationTargetName(this, RE, fmt);
1153         }
1154       }
1155     }
1156   } else
1157     printRelocationTargetName(this, RE, fmt);
1158 
1159   fmt.flush();
1160   Result.append(fmtbuf.begin(), fmtbuf.end());
1161   return object_error::success;
1162 }
1163 
1164 error_code
1165 MachOObjectFile::getRelocationHidden(DataRefImpl Rel, bool &Result) const {
1166   unsigned Arch = getArch();
1167   uint64_t Type;
1168   getRelocationType(Rel, Type);
1169 
1170   Result = false;
1171 
1172   // On arches that use the generic relocations, GENERIC_RELOC_PAIR
1173   // is always hidden.
1174   if (Arch == Triple::x86 || Arch == Triple::arm || Arch == Triple::ppc) {
1175     if (Type == MachO::GENERIC_RELOC_PAIR) Result = true;
1176   } else if (Arch == Triple::x86_64) {
1177     // On x86_64, X86_64_RELOC_UNSIGNED is hidden only when it follows
1178     // an X86_64_RELOC_SUBTRACTOR.
1179     if (Type == MachO::X86_64_RELOC_UNSIGNED && Rel.d.a > 0) {
1180       DataRefImpl RelPrev = Rel;
1181       RelPrev.d.a--;
1182       uint64_t PrevType;
1183       getRelocationType(RelPrev, PrevType);
1184       if (PrevType == MachO::X86_64_RELOC_SUBTRACTOR)
1185         Result = true;
1186     }
1187   }
1188 
1189   return object_error::success;
1190 }
1191 
1192 error_code MachOObjectFile::getLibraryNext(DataRefImpl LibData,
1193                                            LibraryRef &Res) const {
1194   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1195 }
1196 
1197 error_code MachOObjectFile::getLibraryPath(DataRefImpl LibData,
1198                                            StringRef &Res) const {
1199   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1200 }
1201 
1202 basic_symbol_iterator MachOObjectFile::symbol_begin_impl() const {
1203   DataRefImpl DRI;
1204   if (!SymtabLoadCmd)
1205     return basic_symbol_iterator(SymbolRef(DRI, this));
1206 
1207   MachO::symtab_command Symtab = getSymtabLoadCommand();
1208   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Symtab.symoff));
1209   return basic_symbol_iterator(SymbolRef(DRI, this));
1210 }
1211 
1212 basic_symbol_iterator MachOObjectFile::symbol_end_impl() const {
1213   DataRefImpl DRI;
1214   if (!SymtabLoadCmd)
1215     return basic_symbol_iterator(SymbolRef(DRI, this));
1216 
1217   MachO::symtab_command Symtab = getSymtabLoadCommand();
1218   unsigned SymbolTableEntrySize = is64Bit() ?
1219     sizeof(MachO::nlist_64) :
1220     sizeof(MachO::nlist);
1221   unsigned Offset = Symtab.symoff +
1222     Symtab.nsyms * SymbolTableEntrySize;
1223   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1224   return basic_symbol_iterator(SymbolRef(DRI, this));
1225 }
1226 
1227 section_iterator MachOObjectFile::section_begin() const {
1228   DataRefImpl DRI;
1229   return section_iterator(SectionRef(DRI, this));
1230 }
1231 
1232 section_iterator MachOObjectFile::section_end() const {
1233   DataRefImpl DRI;
1234   DRI.d.a = Sections.size();
1235   return section_iterator(SectionRef(DRI, this));
1236 }
1237 
1238 library_iterator MachOObjectFile::needed_library_begin() const {
1239   // TODO: implement
1240   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1241 }
1242 
1243 library_iterator MachOObjectFile::needed_library_end() const {
1244   // TODO: implement
1245   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1246 }
1247 
1248 uint8_t MachOObjectFile::getBytesInAddress() const {
1249   return is64Bit() ? 8 : 4;
1250 }
1251 
1252 StringRef MachOObjectFile::getFileFormatName() const {
1253   unsigned CPUType = getCPUType(this);
1254   if (!is64Bit()) {
1255     switch (CPUType) {
1256     case llvm::MachO::CPU_TYPE_I386:
1257       return "Mach-O 32-bit i386";
1258     case llvm::MachO::CPU_TYPE_ARM:
1259       return "Mach-O arm";
1260     case llvm::MachO::CPU_TYPE_POWERPC:
1261       return "Mach-O 32-bit ppc";
1262     default:
1263       assert((CPUType & llvm::MachO::CPU_ARCH_ABI64) == 0 &&
1264              "64-bit object file when we're not 64-bit?");
1265       return "Mach-O 32-bit unknown";
1266     }
1267   }
1268 
1269   // Make sure the cpu type has the correct mask.
1270   assert((CPUType & llvm::MachO::CPU_ARCH_ABI64)
1271          == llvm::MachO::CPU_ARCH_ABI64 &&
1272          "32-bit object file when we're 64-bit?");
1273 
1274   switch (CPUType) {
1275   case llvm::MachO::CPU_TYPE_X86_64:
1276     return "Mach-O 64-bit x86-64";
1277   case llvm::MachO::CPU_TYPE_ARM64:
1278     return "Mach-O arm64";
1279   case llvm::MachO::CPU_TYPE_POWERPC64:
1280     return "Mach-O 64-bit ppc64";
1281   default:
1282     return "Mach-O 64-bit unknown";
1283   }
1284 }
1285 
1286 Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
1287   switch (CPUType) {
1288   case llvm::MachO::CPU_TYPE_I386:
1289     return Triple::x86;
1290   case llvm::MachO::CPU_TYPE_X86_64:
1291     return Triple::x86_64;
1292   case llvm::MachO::CPU_TYPE_ARM:
1293     return Triple::arm;
1294   case llvm::MachO::CPU_TYPE_ARM64:
1295     return Triple::arm64;
1296   case llvm::MachO::CPU_TYPE_POWERPC:
1297     return Triple::ppc;
1298   case llvm::MachO::CPU_TYPE_POWERPC64:
1299     return Triple::ppc64;
1300   default:
1301     return Triple::UnknownArch;
1302   }
1303 }
1304 
1305 unsigned MachOObjectFile::getArch() const {
1306   return getArch(getCPUType(this));
1307 }
1308 
1309 StringRef MachOObjectFile::getLoadName() const {
1310   // TODO: Implement
1311   report_fatal_error("get_load_name() unimplemented in MachOObjectFile");
1312 }
1313 
1314 relocation_iterator MachOObjectFile::section_rel_begin(unsigned Index) const {
1315   DataRefImpl DRI;
1316   DRI.d.a = Index;
1317   return section_rel_begin(DRI);
1318 }
1319 
1320 relocation_iterator MachOObjectFile::section_rel_end(unsigned Index) const {
1321   DataRefImpl DRI;
1322   DRI.d.a = Index;
1323   return section_rel_end(DRI);
1324 }
1325 
1326 dice_iterator MachOObjectFile::begin_dices() const {
1327   DataRefImpl DRI;
1328   if (!DataInCodeLoadCmd)
1329     return dice_iterator(DiceRef(DRI, this));
1330 
1331   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1332   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, DicLC.dataoff));
1333   return dice_iterator(DiceRef(DRI, this));
1334 }
1335 
1336 dice_iterator MachOObjectFile::end_dices() const {
1337   DataRefImpl DRI;
1338   if (!DataInCodeLoadCmd)
1339     return dice_iterator(DiceRef(DRI, this));
1340 
1341   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1342   unsigned Offset = DicLC.dataoff + DicLC.datasize;
1343   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1344   return dice_iterator(DiceRef(DRI, this));
1345 }
1346 
1347 StringRef
1348 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
1349   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
1350   return parseSegmentOrSectionName(Raw.data());
1351 }
1352 
1353 ArrayRef<char>
1354 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
1355   const section_base *Base =
1356     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1357   return ArrayRef<char>(Base->sectname);
1358 }
1359 
1360 ArrayRef<char>
1361 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
1362   const section_base *Base =
1363     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1364   return ArrayRef<char>(Base->segname);
1365 }
1366 
1367 bool
1368 MachOObjectFile::isRelocationScattered(const MachO::any_relocation_info &RE)
1369   const {
1370   if (getCPUType(this) == MachO::CPU_TYPE_X86_64)
1371     return false;
1372   return getPlainRelocationAddress(RE) & MachO::R_SCATTERED;
1373 }
1374 
1375 unsigned MachOObjectFile::getPlainRelocationSymbolNum(
1376     const MachO::any_relocation_info &RE) const {
1377   if (isLittleEndian())
1378     return RE.r_word1 & 0xffffff;
1379   return RE.r_word1 >> 8;
1380 }
1381 
1382 bool MachOObjectFile::getPlainRelocationExternal(
1383     const MachO::any_relocation_info &RE) const {
1384   if (isLittleEndian())
1385     return (RE.r_word1 >> 27) & 1;
1386   return (RE.r_word1 >> 4) & 1;
1387 }
1388 
1389 bool MachOObjectFile::getScatteredRelocationScattered(
1390     const MachO::any_relocation_info &RE) const {
1391   return RE.r_word0 >> 31;
1392 }
1393 
1394 uint32_t MachOObjectFile::getScatteredRelocationValue(
1395     const MachO::any_relocation_info &RE) const {
1396   return RE.r_word1;
1397 }
1398 
1399 unsigned MachOObjectFile::getAnyRelocationAddress(
1400     const MachO::any_relocation_info &RE) const {
1401   if (isRelocationScattered(RE))
1402     return getScatteredRelocationAddress(RE);
1403   return getPlainRelocationAddress(RE);
1404 }
1405 
1406 unsigned MachOObjectFile::getAnyRelocationPCRel(
1407     const MachO::any_relocation_info &RE) const {
1408   if (isRelocationScattered(RE))
1409     return getScatteredRelocationPCRel(this, RE);
1410   return getPlainRelocationPCRel(this, RE);
1411 }
1412 
1413 unsigned MachOObjectFile::getAnyRelocationLength(
1414     const MachO::any_relocation_info &RE) const {
1415   if (isRelocationScattered(RE))
1416     return getScatteredRelocationLength(RE);
1417   return getPlainRelocationLength(this, RE);
1418 }
1419 
1420 unsigned
1421 MachOObjectFile::getAnyRelocationType(
1422                                    const MachO::any_relocation_info &RE) const {
1423   if (isRelocationScattered(RE))
1424     return getScatteredRelocationType(RE);
1425   return getPlainRelocationType(this, RE);
1426 }
1427 
1428 SectionRef
1429 MachOObjectFile::getRelocationSection(
1430                                    const MachO::any_relocation_info &RE) const {
1431   if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
1432     return *section_end();
1433   unsigned SecNum = getPlainRelocationSymbolNum(RE) - 1;
1434   DataRefImpl DRI;
1435   DRI.d.a = SecNum;
1436   return SectionRef(DRI, this);
1437 }
1438 
1439 MachOObjectFile::LoadCommandInfo
1440 MachOObjectFile::getFirstLoadCommandInfo() const {
1441   MachOObjectFile::LoadCommandInfo Load;
1442 
1443   unsigned HeaderSize = is64Bit() ? sizeof(MachO::mach_header_64) :
1444                                     sizeof(MachO::mach_header);
1445   Load.Ptr = getPtr(this, HeaderSize);
1446   Load.C = getStruct<MachO::load_command>(this, Load.Ptr);
1447   return Load;
1448 }
1449 
1450 MachOObjectFile::LoadCommandInfo
1451 MachOObjectFile::getNextLoadCommandInfo(const LoadCommandInfo &L) const {
1452   MachOObjectFile::LoadCommandInfo Next;
1453   Next.Ptr = L.Ptr + L.C.cmdsize;
1454   Next.C = getStruct<MachO::load_command>(this, Next.Ptr);
1455   return Next;
1456 }
1457 
1458 MachO::section MachOObjectFile::getSection(DataRefImpl DRI) const {
1459   return getStruct<MachO::section>(this, Sections[DRI.d.a]);
1460 }
1461 
1462 MachO::section_64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
1463   return getStruct<MachO::section_64>(this, Sections[DRI.d.a]);
1464 }
1465 
1466 MachO::section MachOObjectFile::getSection(const LoadCommandInfo &L,
1467                                            unsigned Index) const {
1468   const char *Sec = getSectionPtr(this, L, Index);
1469   return getStruct<MachO::section>(this, Sec);
1470 }
1471 
1472 MachO::section_64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
1473                                                 unsigned Index) const {
1474   const char *Sec = getSectionPtr(this, L, Index);
1475   return getStruct<MachO::section_64>(this, Sec);
1476 }
1477 
1478 MachO::nlist
1479 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
1480   const char *P = reinterpret_cast<const char *>(DRI.p);
1481   return getStruct<MachO::nlist>(this, P);
1482 }
1483 
1484 MachO::nlist_64
1485 MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI) const {
1486   const char *P = reinterpret_cast<const char *>(DRI.p);
1487   return getStruct<MachO::nlist_64>(this, P);
1488 }
1489 
1490 MachO::linkedit_data_command
1491 MachOObjectFile::getLinkeditDataLoadCommand(const LoadCommandInfo &L) const {
1492   return getStruct<MachO::linkedit_data_command>(this, L.Ptr);
1493 }
1494 
1495 MachO::segment_command
1496 MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
1497   return getStruct<MachO::segment_command>(this, L.Ptr);
1498 }
1499 
1500 MachO::segment_command_64
1501 MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
1502   return getStruct<MachO::segment_command_64>(this, L.Ptr);
1503 }
1504 
1505 MachO::linker_options_command
1506 MachOObjectFile::getLinkerOptionsLoadCommand(const LoadCommandInfo &L) const {
1507   return getStruct<MachO::linker_options_command>(this, L.Ptr);
1508 }
1509 
1510 MachO::version_min_command
1511 MachOObjectFile::getVersionMinLoadCommand(const LoadCommandInfo &L) const {
1512   return getStruct<MachO::version_min_command>(this, L.Ptr);
1513 }
1514 
1515 MachO::any_relocation_info
1516 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
1517   const char *P = reinterpret_cast<const char *>(Rel.p);
1518   return getStruct<MachO::any_relocation_info>(this, P);
1519 }
1520 
1521 MachO::data_in_code_entry
1522 MachOObjectFile::getDice(DataRefImpl Rel) const {
1523   const char *P = reinterpret_cast<const char *>(Rel.p);
1524   return getStruct<MachO::data_in_code_entry>(this, P);
1525 }
1526 
1527 MachO::mach_header MachOObjectFile::getHeader() const {
1528   return getStruct<MachO::mach_header>(this, getPtr(this, 0));
1529 }
1530 
1531 MachO::mach_header_64 MachOObjectFile::getHeader64() const {
1532   return getStruct<MachO::mach_header_64>(this, getPtr(this, 0));
1533 }
1534 
1535 uint32_t MachOObjectFile::getIndirectSymbolTableEntry(
1536                                              const MachO::dysymtab_command &DLC,
1537                                              unsigned Index) const {
1538   uint64_t Offset = DLC.indirectsymoff + Index * sizeof(uint32_t);
1539   return getStruct<uint32_t>(this, getPtr(this, Offset));
1540 }
1541 
1542 MachO::data_in_code_entry
1543 MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
1544                                          unsigned Index) const {
1545   uint64_t Offset = DataOffset + Index * sizeof(MachO::data_in_code_entry);
1546   return getStruct<MachO::data_in_code_entry>(this, getPtr(this, Offset));
1547 }
1548 
1549 MachO::symtab_command MachOObjectFile::getSymtabLoadCommand() const {
1550   return getStruct<MachO::symtab_command>(this, SymtabLoadCmd);
1551 }
1552 
1553 MachO::dysymtab_command MachOObjectFile::getDysymtabLoadCommand() const {
1554   return getStruct<MachO::dysymtab_command>(this, DysymtabLoadCmd);
1555 }
1556 
1557 MachO::linkedit_data_command
1558 MachOObjectFile::getDataInCodeLoadCommand() const {
1559   if (DataInCodeLoadCmd)
1560     return getStruct<MachO::linkedit_data_command>(this, DataInCodeLoadCmd);
1561 
1562   // If there is no DataInCodeLoadCmd return a load command with zero'ed fields.
1563   MachO::linkedit_data_command Cmd;
1564   Cmd.cmd = MachO::LC_DATA_IN_CODE;
1565   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
1566   Cmd.dataoff = 0;
1567   Cmd.datasize = 0;
1568   return Cmd;
1569 }
1570 
1571 StringRef MachOObjectFile::getStringTableData() const {
1572   MachO::symtab_command S = getSymtabLoadCommand();
1573   return getData().substr(S.stroff, S.strsize);
1574 }
1575 
1576 bool MachOObjectFile::is64Bit() const {
1577   return getType() == getMachOType(false, true) ||
1578     getType() == getMachOType(true, true);
1579 }
1580 
1581 void MachOObjectFile::ReadULEB128s(uint64_t Index,
1582                                    SmallVectorImpl<uint64_t> &Out) const {
1583   DataExtractor extractor(ObjectFile::getData(), true, 0);
1584 
1585   uint32_t offset = Index;
1586   uint64_t data = 0;
1587   while (uint64_t delta = extractor.getULEB128(&offset)) {
1588     data += delta;
1589     Out.push_back(data);
1590   }
1591 }
1592 
1593 ErrorOr<ObjectFile *> ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer,
1594                                                         bool BufferOwned) {
1595   StringRef Magic = Buffer->getBuffer().slice(0, 4);
1596   error_code EC;
1597   std::unique_ptr<MachOObjectFile> Ret;
1598   if (Magic == "\xFE\xED\xFA\xCE")
1599     Ret.reset(new MachOObjectFile(Buffer, false, false, EC, BufferOwned));
1600   else if (Magic == "\xCE\xFA\xED\xFE")
1601     Ret.reset(new MachOObjectFile(Buffer, true, false, EC, BufferOwned));
1602   else if (Magic == "\xFE\xED\xFA\xCF")
1603     Ret.reset(new MachOObjectFile(Buffer, false, true, EC, BufferOwned));
1604   else if (Magic == "\xCF\xFA\xED\xFE")
1605     Ret.reset(new MachOObjectFile(Buffer, true, true, EC, BufferOwned));
1606   else {
1607     delete Buffer;
1608     return object_error::parse_failed;
1609   }
1610 
1611   if (EC)
1612     return EC;
1613   return Ret.release();
1614 }
1615 
1616 } // end namespace object
1617 } // end namespace llvm
1618