xref: /llvm-project/llvm/lib/Object/MachOObjectFile.cpp (revision af9129468e4ac0ea5b2f17564b27a20485ba9484) 
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   // In MachO both relocatable and non-relocatable objects have addresses.
637   return getSymbolAddress(Symb, Val);
638 }
639 
640 void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
641   Sec.d.a++;
642 }
643 
644 error_code
645 MachOObjectFile::getSectionName(DataRefImpl Sec, StringRef &Result) const {
646   ArrayRef<char> Raw = getSectionRawName(Sec);
647   Result = parseSegmentOrSectionName(Raw.data());
648   return object_error::success;
649 }
650 
651 error_code
652 MachOObjectFile::getSectionAddress(DataRefImpl Sec, uint64_t &Res) const {
653   if (is64Bit()) {
654     MachO::section_64 Sect = getSection64(Sec);
655     Res = Sect.addr;
656   } else {
657     MachO::section Sect = getSection(Sec);
658     Res = Sect.addr;
659   }
660   return object_error::success;
661 }
662 
663 error_code
664 MachOObjectFile::getSectionSize(DataRefImpl Sec, uint64_t &Res) const {
665   if (is64Bit()) {
666     MachO::section_64 Sect = getSection64(Sec);
667     Res = Sect.size;
668   } else {
669     MachO::section Sect = getSection(Sec);
670     Res = Sect.size;
671   }
672 
673   return object_error::success;
674 }
675 
676 error_code
677 MachOObjectFile::getSectionContents(DataRefImpl Sec, StringRef &Res) const {
678   uint32_t Offset;
679   uint64_t Size;
680 
681   if (is64Bit()) {
682     MachO::section_64 Sect = getSection64(Sec);
683     Offset = Sect.offset;
684     Size = Sect.size;
685   } else {
686     MachO::section Sect = getSection(Sec);
687     Offset = Sect.offset;
688     Size = Sect.size;
689   }
690 
691   Res = this->getData().substr(Offset, Size);
692   return object_error::success;
693 }
694 
695 error_code
696 MachOObjectFile::getSectionAlignment(DataRefImpl Sec, uint64_t &Res) const {
697   uint32_t Align;
698   if (is64Bit()) {
699     MachO::section_64 Sect = getSection64(Sec);
700     Align = Sect.align;
701   } else {
702     MachO::section Sect = getSection(Sec);
703     Align = Sect.align;
704   }
705 
706   Res = uint64_t(1) << Align;
707   return object_error::success;
708 }
709 
710 error_code
711 MachOObjectFile::isSectionText(DataRefImpl Sec, bool &Res) const {
712   uint32_t Flags = getSectionFlags(this, Sec);
713   Res = Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
714   return object_error::success;
715 }
716 
717 error_code MachOObjectFile::isSectionData(DataRefImpl DRI, bool &Result) const {
718   // FIXME: Unimplemented.
719   Result = false;
720   return object_error::success;
721 }
722 
723 error_code MachOObjectFile::isSectionBSS(DataRefImpl DRI, bool &Result) const {
724   // FIXME: Unimplemented.
725   Result = false;
726   return object_error::success;
727 }
728 
729 error_code
730 MachOObjectFile::isSectionRequiredForExecution(DataRefImpl Sec,
731                                                bool &Result) const {
732   // FIXME: Unimplemented.
733   Result = true;
734   return object_error::success;
735 }
736 
737 error_code MachOObjectFile::isSectionVirtual(DataRefImpl Sec,
738                                              bool &Result) const {
739   // FIXME: Unimplemented.
740   Result = false;
741   return object_error::success;
742 }
743 
744 error_code
745 MachOObjectFile::isSectionZeroInit(DataRefImpl Sec, bool &Res) const {
746   uint32_t Flags = getSectionFlags(this, Sec);
747   unsigned SectionType = Flags & MachO::SECTION_TYPE;
748   Res = SectionType == MachO::S_ZEROFILL ||
749     SectionType == MachO::S_GB_ZEROFILL;
750   return object_error::success;
751 }
752 
753 error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
754                                                   bool &Result) const {
755   // Consider using the code from isSectionText to look for __const sections.
756   // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
757   // to use section attributes to distinguish code from data.
758 
759   // FIXME: Unimplemented.
760   Result = false;
761   return object_error::success;
762 }
763 
764 error_code
765 MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
766                                        bool &Result) const {
767   SymbolRef::Type ST;
768   this->getSymbolType(Symb, ST);
769   if (ST == SymbolRef::ST_Unknown) {
770     Result = false;
771     return object_error::success;
772   }
773 
774   uint64_t SectBegin, SectEnd;
775   getSectionAddress(Sec, SectBegin);
776   getSectionSize(Sec, SectEnd);
777   SectEnd += SectBegin;
778 
779   uint64_t SymAddr;
780   getSymbolAddress(Symb, SymAddr);
781   Result = (SymAddr >= SectBegin) && (SymAddr < SectEnd);
782 
783   return object_error::success;
784 }
785 
786 relocation_iterator MachOObjectFile::section_rel_begin(DataRefImpl Sec) const {
787   uint32_t Offset;
788   if (is64Bit()) {
789     MachO::section_64 Sect = getSection64(Sec);
790     Offset = Sect.reloff;
791   } else {
792     MachO::section Sect = getSection(Sec);
793     Offset = Sect.reloff;
794   }
795 
796   DataRefImpl Ret;
797   Ret.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
798   return relocation_iterator(RelocationRef(Ret, this));
799 }
800 
801 relocation_iterator
802 MachOObjectFile::section_rel_end(DataRefImpl Sec) const {
803   uint32_t Offset;
804   uint32_t Num;
805   if (is64Bit()) {
806     MachO::section_64 Sect = getSection64(Sec);
807     Offset = Sect.reloff;
808     Num = Sect.nreloc;
809   } else {
810     MachO::section Sect = getSection(Sec);
811     Offset = Sect.reloff;
812     Num = Sect.nreloc;
813   }
814 
815   const MachO::any_relocation_info *P =
816     reinterpret_cast<const MachO::any_relocation_info *>(getPtr(this, Offset));
817 
818   DataRefImpl Ret;
819   Ret.p = reinterpret_cast<uintptr_t>(P + Num);
820   return relocation_iterator(RelocationRef(Ret, this));
821 }
822 
823 bool MachOObjectFile::section_rel_empty(DataRefImpl Sec) const {
824   if (is64Bit()) {
825     MachO::section_64 Sect = getSection64(Sec);
826     return Sect.nreloc == 0;
827   } else {
828     MachO::section Sect = getSection(Sec);
829     return Sect.nreloc == 0;
830   }
831 }
832 
833 void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
834   const MachO::any_relocation_info *P =
835     reinterpret_cast<const MachO::any_relocation_info *>(Rel.p);
836   Rel.p = reinterpret_cast<uintptr_t>(P + 1);
837 }
838 
839 error_code
840 MachOObjectFile::getRelocationAddress(DataRefImpl Rel, uint64_t &Res) const {
841   report_fatal_error("getRelocationAddress not implemented in MachOObjectFile");
842 }
843 
844 error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
845                                                 uint64_t &Res) const {
846   MachO::any_relocation_info RE = getRelocation(Rel);
847   Res = getAnyRelocationAddress(RE);
848   return object_error::success;
849 }
850 
851 symbol_iterator
852 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
853   MachO::any_relocation_info RE = getRelocation(Rel);
854   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
855   bool isExtern = getPlainRelocationExternal(RE);
856   if (!isExtern)
857     return symbol_end();
858 
859   MachO::symtab_command S = getSymtabLoadCommand();
860   unsigned SymbolTableEntrySize = is64Bit() ?
861     sizeof(MachO::nlist_64) :
862     sizeof(MachO::nlist);
863   uint64_t Offset = S.symoff + SymbolIdx * SymbolTableEntrySize;
864   DataRefImpl Sym;
865   Sym.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
866   return symbol_iterator(SymbolRef(Sym, this));
867 }
868 
869 error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
870                                               uint64_t &Res) const {
871   MachO::any_relocation_info RE = getRelocation(Rel);
872   Res = getAnyRelocationType(RE);
873   return object_error::success;
874 }
875 
876 error_code
877 MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
878                                        SmallVectorImpl<char> &Result) const {
879   StringRef res;
880   uint64_t RType;
881   getRelocationType(Rel, RType);
882 
883   unsigned Arch = this->getArch();
884 
885   switch (Arch) {
886     case Triple::x86: {
887       static const char *const Table[] =  {
888         "GENERIC_RELOC_VANILLA",
889         "GENERIC_RELOC_PAIR",
890         "GENERIC_RELOC_SECTDIFF",
891         "GENERIC_RELOC_PB_LA_PTR",
892         "GENERIC_RELOC_LOCAL_SECTDIFF",
893         "GENERIC_RELOC_TLV" };
894 
895       if (RType > 5)
896         res = "Unknown";
897       else
898         res = Table[RType];
899       break;
900     }
901     case Triple::x86_64: {
902       static const char *const Table[] =  {
903         "X86_64_RELOC_UNSIGNED",
904         "X86_64_RELOC_SIGNED",
905         "X86_64_RELOC_BRANCH",
906         "X86_64_RELOC_GOT_LOAD",
907         "X86_64_RELOC_GOT",
908         "X86_64_RELOC_SUBTRACTOR",
909         "X86_64_RELOC_SIGNED_1",
910         "X86_64_RELOC_SIGNED_2",
911         "X86_64_RELOC_SIGNED_4",
912         "X86_64_RELOC_TLV" };
913 
914       if (RType > 9)
915         res = "Unknown";
916       else
917         res = Table[RType];
918       break;
919     }
920     case Triple::arm: {
921       static const char *const Table[] =  {
922         "ARM_RELOC_VANILLA",
923         "ARM_RELOC_PAIR",
924         "ARM_RELOC_SECTDIFF",
925         "ARM_RELOC_LOCAL_SECTDIFF",
926         "ARM_RELOC_PB_LA_PTR",
927         "ARM_RELOC_BR24",
928         "ARM_THUMB_RELOC_BR22",
929         "ARM_THUMB_32BIT_BRANCH",
930         "ARM_RELOC_HALF",
931         "ARM_RELOC_HALF_SECTDIFF" };
932 
933       if (RType > 9)
934         res = "Unknown";
935       else
936         res = Table[RType];
937       break;
938     }
939     case Triple::arm64:
940     case Triple::aarch64: {
941       static const char *const Table[] = {
942         "ARM64_RELOC_UNSIGNED",           "ARM64_RELOC_SUBTRACTOR",
943         "ARM64_RELOC_BRANCH26",           "ARM64_RELOC_PAGE21",
944         "ARM64_RELOC_PAGEOFF12",          "ARM64_RELOC_GOT_LOAD_PAGE21",
945         "ARM64_RELOC_GOT_LOAD_PAGEOFF12", "ARM64_RELOC_POINTER_TO_GOT",
946         "ARM64_RELOC_TLVP_LOAD_PAGE21",   "ARM64_RELOC_TLVP_LOAD_PAGEOFF12",
947         "ARM64_RELOC_ADDEND"
948       };
949 
950       if (RType >= array_lengthof(Table))
951         res = "Unknown";
952       else
953         res = Table[RType];
954       break;
955     }
956     case Triple::ppc: {
957       static const char *const Table[] =  {
958         "PPC_RELOC_VANILLA",
959         "PPC_RELOC_PAIR",
960         "PPC_RELOC_BR14",
961         "PPC_RELOC_BR24",
962         "PPC_RELOC_HI16",
963         "PPC_RELOC_LO16",
964         "PPC_RELOC_HA16",
965         "PPC_RELOC_LO14",
966         "PPC_RELOC_SECTDIFF",
967         "PPC_RELOC_PB_LA_PTR",
968         "PPC_RELOC_HI16_SECTDIFF",
969         "PPC_RELOC_LO16_SECTDIFF",
970         "PPC_RELOC_HA16_SECTDIFF",
971         "PPC_RELOC_JBSR",
972         "PPC_RELOC_LO14_SECTDIFF",
973         "PPC_RELOC_LOCAL_SECTDIFF" };
974 
975       if (RType > 15)
976         res = "Unknown";
977       else
978         res = Table[RType];
979       break;
980     }
981     case Triple::UnknownArch:
982       res = "Unknown";
983       break;
984   }
985   Result.append(res.begin(), res.end());
986   return object_error::success;
987 }
988 
989 error_code
990 MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
991                                           SmallVectorImpl<char> &Result) const {
992   MachO::any_relocation_info RE = getRelocation(Rel);
993 
994   unsigned Arch = this->getArch();
995 
996   std::string fmtbuf;
997   raw_string_ostream fmt(fmtbuf);
998   unsigned Type = this->getAnyRelocationType(RE);
999   bool IsPCRel = this->getAnyRelocationPCRel(RE);
1000 
1001   // Determine any addends that should be displayed with the relocation.
1002   // These require decoding the relocation type, which is triple-specific.
1003 
1004   // X86_64 has entirely custom relocation types.
1005   if (Arch == Triple::x86_64) {
1006     bool isPCRel = getAnyRelocationPCRel(RE);
1007 
1008     switch (Type) {
1009       case MachO::X86_64_RELOC_GOT_LOAD:
1010       case MachO::X86_64_RELOC_GOT: {
1011         printRelocationTargetName(this, RE, fmt);
1012         fmt << "@GOT";
1013         if (isPCRel) fmt << "PCREL";
1014         break;
1015       }
1016       case MachO::X86_64_RELOC_SUBTRACTOR: {
1017         DataRefImpl RelNext = Rel;
1018         RelNext.d.a++;
1019         MachO::any_relocation_info RENext = getRelocation(RelNext);
1020 
1021         // X86_64_RELOC_SUBTRACTOR must be followed by a relocation of type
1022         // X86_64_RELOC_UNSIGNED.
1023         // NOTE: Scattered relocations don't exist on x86_64.
1024         unsigned RType = getAnyRelocationType(RENext);
1025         if (RType != MachO::X86_64_RELOC_UNSIGNED)
1026           report_fatal_error("Expected X86_64_RELOC_UNSIGNED after "
1027                              "X86_64_RELOC_SUBTRACTOR.");
1028 
1029         // The X86_64_RELOC_UNSIGNED contains the minuend symbol;
1030         // X86_64_RELOC_SUBTRACTOR contains the subtrahend.
1031         printRelocationTargetName(this, RENext, fmt);
1032         fmt << "-";
1033         printRelocationTargetName(this, RE, fmt);
1034         break;
1035       }
1036       case MachO::X86_64_RELOC_TLV:
1037         printRelocationTargetName(this, RE, fmt);
1038         fmt << "@TLV";
1039         if (isPCRel) fmt << "P";
1040         break;
1041       case MachO::X86_64_RELOC_SIGNED_1:
1042         printRelocationTargetName(this, RE, fmt);
1043         fmt << "-1";
1044         break;
1045       case MachO::X86_64_RELOC_SIGNED_2:
1046         printRelocationTargetName(this, RE, fmt);
1047         fmt << "-2";
1048         break;
1049       case MachO::X86_64_RELOC_SIGNED_4:
1050         printRelocationTargetName(this, RE, fmt);
1051         fmt << "-4";
1052         break;
1053       default:
1054         printRelocationTargetName(this, RE, fmt);
1055         break;
1056     }
1057   // X86 and ARM share some relocation types in common.
1058   } else if (Arch == Triple::x86 || Arch == Triple::arm ||
1059              Arch == Triple::ppc) {
1060     // Generic relocation types...
1061     switch (Type) {
1062       case MachO::GENERIC_RELOC_PAIR: // prints no info
1063         return object_error::success;
1064       case MachO::GENERIC_RELOC_SECTDIFF: {
1065         DataRefImpl RelNext = Rel;
1066         RelNext.d.a++;
1067         MachO::any_relocation_info RENext = getRelocation(RelNext);
1068 
1069         // X86 sect diff's must be followed by a relocation of type
1070         // GENERIC_RELOC_PAIR.
1071         unsigned RType = getAnyRelocationType(RENext);
1072 
1073         if (RType != MachO::GENERIC_RELOC_PAIR)
1074           report_fatal_error("Expected GENERIC_RELOC_PAIR after "
1075                              "GENERIC_RELOC_SECTDIFF.");
1076 
1077         printRelocationTargetName(this, RE, fmt);
1078         fmt << "-";
1079         printRelocationTargetName(this, RENext, fmt);
1080         break;
1081       }
1082     }
1083 
1084     if (Arch == Triple::x86 || Arch == Triple::ppc) {
1085       switch (Type) {
1086         case MachO::GENERIC_RELOC_LOCAL_SECTDIFF: {
1087           DataRefImpl RelNext = Rel;
1088           RelNext.d.a++;
1089           MachO::any_relocation_info RENext = getRelocation(RelNext);
1090 
1091           // X86 sect diff's must be followed by a relocation of type
1092           // GENERIC_RELOC_PAIR.
1093           unsigned RType = getAnyRelocationType(RENext);
1094           if (RType != MachO::GENERIC_RELOC_PAIR)
1095             report_fatal_error("Expected GENERIC_RELOC_PAIR after "
1096                                "GENERIC_RELOC_LOCAL_SECTDIFF.");
1097 
1098           printRelocationTargetName(this, RE, fmt);
1099           fmt << "-";
1100           printRelocationTargetName(this, RENext, fmt);
1101           break;
1102         }
1103         case MachO::GENERIC_RELOC_TLV: {
1104           printRelocationTargetName(this, RE, fmt);
1105           fmt << "@TLV";
1106           if (IsPCRel) fmt << "P";
1107           break;
1108         }
1109         default:
1110           printRelocationTargetName(this, RE, fmt);
1111       }
1112     } else { // ARM-specific relocations
1113       switch (Type) {
1114         case MachO::ARM_RELOC_HALF:
1115         case MachO::ARM_RELOC_HALF_SECTDIFF: {
1116           // Half relocations steal a bit from the length field to encode
1117           // whether this is an upper16 or a lower16 relocation.
1118           bool isUpper = getAnyRelocationLength(RE) >> 1;
1119 
1120           if (isUpper)
1121             fmt << ":upper16:(";
1122           else
1123             fmt << ":lower16:(";
1124           printRelocationTargetName(this, RE, fmt);
1125 
1126           DataRefImpl RelNext = Rel;
1127           RelNext.d.a++;
1128           MachO::any_relocation_info RENext = getRelocation(RelNext);
1129 
1130           // ARM half relocs must be followed by a relocation of type
1131           // ARM_RELOC_PAIR.
1132           unsigned RType = getAnyRelocationType(RENext);
1133           if (RType != MachO::ARM_RELOC_PAIR)
1134             report_fatal_error("Expected ARM_RELOC_PAIR after "
1135                                "ARM_RELOC_HALF");
1136 
1137           // NOTE: The half of the target virtual address is stashed in the
1138           // address field of the secondary relocation, but we can't reverse
1139           // engineer the constant offset from it without decoding the movw/movt
1140           // instruction to find the other half in its immediate field.
1141 
1142           // ARM_RELOC_HALF_SECTDIFF encodes the second section in the
1143           // symbol/section pointer of the follow-on relocation.
1144           if (Type == MachO::ARM_RELOC_HALF_SECTDIFF) {
1145             fmt << "-";
1146             printRelocationTargetName(this, RENext, fmt);
1147           }
1148 
1149           fmt << ")";
1150           break;
1151         }
1152         default: {
1153           printRelocationTargetName(this, RE, fmt);
1154         }
1155       }
1156     }
1157   } else
1158     printRelocationTargetName(this, RE, fmt);
1159 
1160   fmt.flush();
1161   Result.append(fmtbuf.begin(), fmtbuf.end());
1162   return object_error::success;
1163 }
1164 
1165 error_code
1166 MachOObjectFile::getRelocationHidden(DataRefImpl Rel, bool &Result) const {
1167   unsigned Arch = getArch();
1168   uint64_t Type;
1169   getRelocationType(Rel, Type);
1170 
1171   Result = false;
1172 
1173   // On arches that use the generic relocations, GENERIC_RELOC_PAIR
1174   // is always hidden.
1175   if (Arch == Triple::x86 || Arch == Triple::arm || Arch == Triple::ppc) {
1176     if (Type == MachO::GENERIC_RELOC_PAIR) Result = true;
1177   } else if (Arch == Triple::x86_64) {
1178     // On x86_64, X86_64_RELOC_UNSIGNED is hidden only when it follows
1179     // an X86_64_RELOC_SUBTRACTOR.
1180     if (Type == MachO::X86_64_RELOC_UNSIGNED && Rel.d.a > 0) {
1181       DataRefImpl RelPrev = Rel;
1182       RelPrev.d.a--;
1183       uint64_t PrevType;
1184       getRelocationType(RelPrev, PrevType);
1185       if (PrevType == MachO::X86_64_RELOC_SUBTRACTOR)
1186         Result = true;
1187     }
1188   }
1189 
1190   return object_error::success;
1191 }
1192 
1193 error_code MachOObjectFile::getLibraryNext(DataRefImpl LibData,
1194                                            LibraryRef &Res) const {
1195   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1196 }
1197 
1198 error_code MachOObjectFile::getLibraryPath(DataRefImpl LibData,
1199                                            StringRef &Res) const {
1200   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1201 }
1202 
1203 basic_symbol_iterator MachOObjectFile::symbol_begin_impl() const {
1204   DataRefImpl DRI;
1205   if (!SymtabLoadCmd)
1206     return basic_symbol_iterator(SymbolRef(DRI, this));
1207 
1208   MachO::symtab_command Symtab = getSymtabLoadCommand();
1209   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Symtab.symoff));
1210   return basic_symbol_iterator(SymbolRef(DRI, this));
1211 }
1212 
1213 basic_symbol_iterator MachOObjectFile::symbol_end_impl() const {
1214   DataRefImpl DRI;
1215   if (!SymtabLoadCmd)
1216     return basic_symbol_iterator(SymbolRef(DRI, this));
1217 
1218   MachO::symtab_command Symtab = getSymtabLoadCommand();
1219   unsigned SymbolTableEntrySize = is64Bit() ?
1220     sizeof(MachO::nlist_64) :
1221     sizeof(MachO::nlist);
1222   unsigned Offset = Symtab.symoff +
1223     Symtab.nsyms * SymbolTableEntrySize;
1224   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1225   return basic_symbol_iterator(SymbolRef(DRI, this));
1226 }
1227 
1228 section_iterator MachOObjectFile::section_begin() const {
1229   DataRefImpl DRI;
1230   return section_iterator(SectionRef(DRI, this));
1231 }
1232 
1233 section_iterator MachOObjectFile::section_end() const {
1234   DataRefImpl DRI;
1235   DRI.d.a = Sections.size();
1236   return section_iterator(SectionRef(DRI, this));
1237 }
1238 
1239 library_iterator MachOObjectFile::needed_library_begin() const {
1240   // TODO: implement
1241   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1242 }
1243 
1244 library_iterator MachOObjectFile::needed_library_end() const {
1245   // TODO: implement
1246   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1247 }
1248 
1249 uint8_t MachOObjectFile::getBytesInAddress() const {
1250   return is64Bit() ? 8 : 4;
1251 }
1252 
1253 StringRef MachOObjectFile::getFileFormatName() const {
1254   unsigned CPUType = getCPUType(this);
1255   if (!is64Bit()) {
1256     switch (CPUType) {
1257     case llvm::MachO::CPU_TYPE_I386:
1258       return "Mach-O 32-bit i386";
1259     case llvm::MachO::CPU_TYPE_ARM:
1260       return "Mach-O arm";
1261     case llvm::MachO::CPU_TYPE_POWERPC:
1262       return "Mach-O 32-bit ppc";
1263     default:
1264       assert((CPUType & llvm::MachO::CPU_ARCH_ABI64) == 0 &&
1265              "64-bit object file when we're not 64-bit?");
1266       return "Mach-O 32-bit unknown";
1267     }
1268   }
1269 
1270   // Make sure the cpu type has the correct mask.
1271   assert((CPUType & llvm::MachO::CPU_ARCH_ABI64)
1272          == llvm::MachO::CPU_ARCH_ABI64 &&
1273          "32-bit object file when we're 64-bit?");
1274 
1275   switch (CPUType) {
1276   case llvm::MachO::CPU_TYPE_X86_64:
1277     return "Mach-O 64-bit x86-64";
1278   case llvm::MachO::CPU_TYPE_ARM64:
1279     return "Mach-O arm64";
1280   case llvm::MachO::CPU_TYPE_POWERPC64:
1281     return "Mach-O 64-bit ppc64";
1282   default:
1283     return "Mach-O 64-bit unknown";
1284   }
1285 }
1286 
1287 Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
1288   switch (CPUType) {
1289   case llvm::MachO::CPU_TYPE_I386:
1290     return Triple::x86;
1291   case llvm::MachO::CPU_TYPE_X86_64:
1292     return Triple::x86_64;
1293   case llvm::MachO::CPU_TYPE_ARM:
1294     return Triple::arm;
1295   case llvm::MachO::CPU_TYPE_ARM64:
1296     return Triple::arm64;
1297   case llvm::MachO::CPU_TYPE_POWERPC:
1298     return Triple::ppc;
1299   case llvm::MachO::CPU_TYPE_POWERPC64:
1300     return Triple::ppc64;
1301   default:
1302     return Triple::UnknownArch;
1303   }
1304 }
1305 
1306 unsigned MachOObjectFile::getArch() const {
1307   return getArch(getCPUType(this));
1308 }
1309 
1310 StringRef MachOObjectFile::getLoadName() const {
1311   // TODO: Implement
1312   report_fatal_error("get_load_name() unimplemented in MachOObjectFile");
1313 }
1314 
1315 relocation_iterator MachOObjectFile::section_rel_begin(unsigned Index) const {
1316   DataRefImpl DRI;
1317   DRI.d.a = Index;
1318   return section_rel_begin(DRI);
1319 }
1320 
1321 relocation_iterator MachOObjectFile::section_rel_end(unsigned Index) const {
1322   DataRefImpl DRI;
1323   DRI.d.a = Index;
1324   return section_rel_end(DRI);
1325 }
1326 
1327 dice_iterator MachOObjectFile::begin_dices() const {
1328   DataRefImpl DRI;
1329   if (!DataInCodeLoadCmd)
1330     return dice_iterator(DiceRef(DRI, this));
1331 
1332   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1333   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, DicLC.dataoff));
1334   return dice_iterator(DiceRef(DRI, this));
1335 }
1336 
1337 dice_iterator MachOObjectFile::end_dices() const {
1338   DataRefImpl DRI;
1339   if (!DataInCodeLoadCmd)
1340     return dice_iterator(DiceRef(DRI, this));
1341 
1342   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1343   unsigned Offset = DicLC.dataoff + DicLC.datasize;
1344   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1345   return dice_iterator(DiceRef(DRI, this));
1346 }
1347 
1348 StringRef
1349 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
1350   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
1351   return parseSegmentOrSectionName(Raw.data());
1352 }
1353 
1354 ArrayRef<char>
1355 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
1356   const section_base *Base =
1357     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1358   return ArrayRef<char>(Base->sectname);
1359 }
1360 
1361 ArrayRef<char>
1362 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
1363   const section_base *Base =
1364     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1365   return ArrayRef<char>(Base->segname);
1366 }
1367 
1368 bool
1369 MachOObjectFile::isRelocationScattered(const MachO::any_relocation_info &RE)
1370   const {
1371   if (getCPUType(this) == MachO::CPU_TYPE_X86_64)
1372     return false;
1373   return getPlainRelocationAddress(RE) & MachO::R_SCATTERED;
1374 }
1375 
1376 unsigned MachOObjectFile::getPlainRelocationSymbolNum(
1377     const MachO::any_relocation_info &RE) const {
1378   if (isLittleEndian())
1379     return RE.r_word1 & 0xffffff;
1380   return RE.r_word1 >> 8;
1381 }
1382 
1383 bool MachOObjectFile::getPlainRelocationExternal(
1384     const MachO::any_relocation_info &RE) const {
1385   if (isLittleEndian())
1386     return (RE.r_word1 >> 27) & 1;
1387   return (RE.r_word1 >> 4) & 1;
1388 }
1389 
1390 bool MachOObjectFile::getScatteredRelocationScattered(
1391     const MachO::any_relocation_info &RE) const {
1392   return RE.r_word0 >> 31;
1393 }
1394 
1395 uint32_t MachOObjectFile::getScatteredRelocationValue(
1396     const MachO::any_relocation_info &RE) const {
1397   return RE.r_word1;
1398 }
1399 
1400 unsigned MachOObjectFile::getAnyRelocationAddress(
1401     const MachO::any_relocation_info &RE) const {
1402   if (isRelocationScattered(RE))
1403     return getScatteredRelocationAddress(RE);
1404   return getPlainRelocationAddress(RE);
1405 }
1406 
1407 unsigned MachOObjectFile::getAnyRelocationPCRel(
1408     const MachO::any_relocation_info &RE) const {
1409   if (isRelocationScattered(RE))
1410     return getScatteredRelocationPCRel(this, RE);
1411   return getPlainRelocationPCRel(this, RE);
1412 }
1413 
1414 unsigned MachOObjectFile::getAnyRelocationLength(
1415     const MachO::any_relocation_info &RE) const {
1416   if (isRelocationScattered(RE))
1417     return getScatteredRelocationLength(RE);
1418   return getPlainRelocationLength(this, RE);
1419 }
1420 
1421 unsigned
1422 MachOObjectFile::getAnyRelocationType(
1423                                    const MachO::any_relocation_info &RE) const {
1424   if (isRelocationScattered(RE))
1425     return getScatteredRelocationType(RE);
1426   return getPlainRelocationType(this, RE);
1427 }
1428 
1429 SectionRef
1430 MachOObjectFile::getRelocationSection(
1431                                    const MachO::any_relocation_info &RE) const {
1432   if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
1433     return *section_end();
1434   unsigned SecNum = getPlainRelocationSymbolNum(RE) - 1;
1435   DataRefImpl DRI;
1436   DRI.d.a = SecNum;
1437   return SectionRef(DRI, this);
1438 }
1439 
1440 MachOObjectFile::LoadCommandInfo
1441 MachOObjectFile::getFirstLoadCommandInfo() const {
1442   MachOObjectFile::LoadCommandInfo Load;
1443 
1444   unsigned HeaderSize = is64Bit() ? sizeof(MachO::mach_header_64) :
1445                                     sizeof(MachO::mach_header);
1446   Load.Ptr = getPtr(this, HeaderSize);
1447   Load.C = getStruct<MachO::load_command>(this, Load.Ptr);
1448   return Load;
1449 }
1450 
1451 MachOObjectFile::LoadCommandInfo
1452 MachOObjectFile::getNextLoadCommandInfo(const LoadCommandInfo &L) const {
1453   MachOObjectFile::LoadCommandInfo Next;
1454   Next.Ptr = L.Ptr + L.C.cmdsize;
1455   Next.C = getStruct<MachO::load_command>(this, Next.Ptr);
1456   return Next;
1457 }
1458 
1459 MachO::section MachOObjectFile::getSection(DataRefImpl DRI) const {
1460   return getStruct<MachO::section>(this, Sections[DRI.d.a]);
1461 }
1462 
1463 MachO::section_64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
1464   return getStruct<MachO::section_64>(this, Sections[DRI.d.a]);
1465 }
1466 
1467 MachO::section MachOObjectFile::getSection(const LoadCommandInfo &L,
1468                                            unsigned Index) const {
1469   const char *Sec = getSectionPtr(this, L, Index);
1470   return getStruct<MachO::section>(this, Sec);
1471 }
1472 
1473 MachO::section_64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
1474                                                 unsigned Index) const {
1475   const char *Sec = getSectionPtr(this, L, Index);
1476   return getStruct<MachO::section_64>(this, Sec);
1477 }
1478 
1479 MachO::nlist
1480 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
1481   const char *P = reinterpret_cast<const char *>(DRI.p);
1482   return getStruct<MachO::nlist>(this, P);
1483 }
1484 
1485 MachO::nlist_64
1486 MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI) const {
1487   const char *P = reinterpret_cast<const char *>(DRI.p);
1488   return getStruct<MachO::nlist_64>(this, P);
1489 }
1490 
1491 MachO::linkedit_data_command
1492 MachOObjectFile::getLinkeditDataLoadCommand(const LoadCommandInfo &L) const {
1493   return getStruct<MachO::linkedit_data_command>(this, L.Ptr);
1494 }
1495 
1496 MachO::segment_command
1497 MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
1498   return getStruct<MachO::segment_command>(this, L.Ptr);
1499 }
1500 
1501 MachO::segment_command_64
1502 MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
1503   return getStruct<MachO::segment_command_64>(this, L.Ptr);
1504 }
1505 
1506 MachO::linker_options_command
1507 MachOObjectFile::getLinkerOptionsLoadCommand(const LoadCommandInfo &L) const {
1508   return getStruct<MachO::linker_options_command>(this, L.Ptr);
1509 }
1510 
1511 MachO::version_min_command
1512 MachOObjectFile::getVersionMinLoadCommand(const LoadCommandInfo &L) const {
1513   return getStruct<MachO::version_min_command>(this, L.Ptr);
1514 }
1515 
1516 MachO::any_relocation_info
1517 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
1518   const char *P = reinterpret_cast<const char *>(Rel.p);
1519   return getStruct<MachO::any_relocation_info>(this, P);
1520 }
1521 
1522 MachO::data_in_code_entry
1523 MachOObjectFile::getDice(DataRefImpl Rel) const {
1524   const char *P = reinterpret_cast<const char *>(Rel.p);
1525   return getStruct<MachO::data_in_code_entry>(this, P);
1526 }
1527 
1528 MachO::mach_header MachOObjectFile::getHeader() const {
1529   return getStruct<MachO::mach_header>(this, getPtr(this, 0));
1530 }
1531 
1532 MachO::mach_header_64 MachOObjectFile::getHeader64() const {
1533   return getStruct<MachO::mach_header_64>(this, getPtr(this, 0));
1534 }
1535 
1536 uint32_t MachOObjectFile::getIndirectSymbolTableEntry(
1537                                              const MachO::dysymtab_command &DLC,
1538                                              unsigned Index) const {
1539   uint64_t Offset = DLC.indirectsymoff + Index * sizeof(uint32_t);
1540   return getStruct<uint32_t>(this, getPtr(this, Offset));
1541 }
1542 
1543 MachO::data_in_code_entry
1544 MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
1545                                          unsigned Index) const {
1546   uint64_t Offset = DataOffset + Index * sizeof(MachO::data_in_code_entry);
1547   return getStruct<MachO::data_in_code_entry>(this, getPtr(this, Offset));
1548 }
1549 
1550 MachO::symtab_command MachOObjectFile::getSymtabLoadCommand() const {
1551   return getStruct<MachO::symtab_command>(this, SymtabLoadCmd);
1552 }
1553 
1554 MachO::dysymtab_command MachOObjectFile::getDysymtabLoadCommand() const {
1555   return getStruct<MachO::dysymtab_command>(this, DysymtabLoadCmd);
1556 }
1557 
1558 MachO::linkedit_data_command
1559 MachOObjectFile::getDataInCodeLoadCommand() const {
1560   if (DataInCodeLoadCmd)
1561     return getStruct<MachO::linkedit_data_command>(this, DataInCodeLoadCmd);
1562 
1563   // If there is no DataInCodeLoadCmd return a load command with zero'ed fields.
1564   MachO::linkedit_data_command Cmd;
1565   Cmd.cmd = MachO::LC_DATA_IN_CODE;
1566   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
1567   Cmd.dataoff = 0;
1568   Cmd.datasize = 0;
1569   return Cmd;
1570 }
1571 
1572 StringRef MachOObjectFile::getStringTableData() const {
1573   MachO::symtab_command S = getSymtabLoadCommand();
1574   return getData().substr(S.stroff, S.strsize);
1575 }
1576 
1577 bool MachOObjectFile::is64Bit() const {
1578   return getType() == getMachOType(false, true) ||
1579     getType() == getMachOType(true, true);
1580 }
1581 
1582 void MachOObjectFile::ReadULEB128s(uint64_t Index,
1583                                    SmallVectorImpl<uint64_t> &Out) const {
1584   DataExtractor extractor(ObjectFile::getData(), true, 0);
1585 
1586   uint32_t offset = Index;
1587   uint64_t data = 0;
1588   while (uint64_t delta = extractor.getULEB128(&offset)) {
1589     data += delta;
1590     Out.push_back(data);
1591   }
1592 }
1593 
1594 ErrorOr<ObjectFile *> ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer,
1595                                                         bool BufferOwned) {
1596   StringRef Magic = Buffer->getBuffer().slice(0, 4);
1597   error_code EC;
1598   std::unique_ptr<MachOObjectFile> Ret;
1599   if (Magic == "\xFE\xED\xFA\xCE")
1600     Ret.reset(new MachOObjectFile(Buffer, false, false, EC, BufferOwned));
1601   else if (Magic == "\xCE\xFA\xED\xFE")
1602     Ret.reset(new MachOObjectFile(Buffer, true, false, EC, BufferOwned));
1603   else if (Magic == "\xFE\xED\xFA\xCF")
1604     Ret.reset(new MachOObjectFile(Buffer, false, true, EC, BufferOwned));
1605   else if (Magic == "\xCF\xFA\xED\xFE")
1606     Ret.reset(new MachOObjectFile(Buffer, true, true, EC, BufferOwned));
1607   else {
1608     delete Buffer;
1609     return object_error::parse_failed;
1610   }
1611 
1612   if (EC)
1613     return EC;
1614   return Ret.release();
1615 }
1616 
1617 } // end namespace object
1618 } // end namespace llvm
1619