xref: /llvm-project/llvm/lib/Object/MachOObjectFile.cpp (revision ef5e867f16c9487b9279a26dd70bc34ff871317d) 
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 
32 namespace object {
33 
34 struct nlist_base {
35   uint32_t n_strx;
36   uint8_t n_type;
37   uint8_t n_sect;
38   uint16_t n_desc;
39 };
40 
41 struct section_base {
42   char sectname[16];
43   char segname[16];
44 };
45 
46 template<typename T>
47 static void SwapValue(T &Value) {
48   Value = sys::getSwappedBytes(Value);
49 }
50 
51 template<typename T>
52 static void SwapStruct(T &Value);
53 
54 template<>
55 void SwapStruct(MachO::any_relocation_info &H) {
56   SwapValue(H.r_word0);
57   SwapValue(H.r_word1);
58 }
59 
60 template<>
61 void SwapStruct(MachO::load_command &L) {
62   SwapValue(L.cmd);
63   SwapValue(L.cmdsize);
64 }
65 
66 template<>
67 void SwapStruct(nlist_base &S) {
68   SwapValue(S.n_strx);
69   SwapValue(S.n_desc);
70 }
71 
72 template<>
73 void SwapStruct(MachO::section &S) {
74   SwapValue(S.addr);
75   SwapValue(S.size);
76   SwapValue(S.offset);
77   SwapValue(S.align);
78   SwapValue(S.reloff);
79   SwapValue(S.nreloc);
80   SwapValue(S.flags);
81   SwapValue(S.reserved1);
82   SwapValue(S.reserved2);
83 }
84 
85 template<>
86 void SwapStruct(MachO::section_64 &S) {
87   SwapValue(S.addr);
88   SwapValue(S.size);
89   SwapValue(S.offset);
90   SwapValue(S.align);
91   SwapValue(S.reloff);
92   SwapValue(S.nreloc);
93   SwapValue(S.flags);
94   SwapValue(S.reserved1);
95   SwapValue(S.reserved2);
96   SwapValue(S.reserved3);
97 }
98 
99 template<>
100 void SwapStruct(MachO::nlist &S) {
101   SwapValue(S.n_strx);
102   SwapValue(S.n_desc);
103   SwapValue(S.n_value);
104 }
105 
106 template<>
107 void SwapStruct(MachO::nlist_64 &S) {
108   SwapValue(S.n_strx);
109   SwapValue(S.n_desc);
110   SwapValue(S.n_value);
111 }
112 
113 template<>
114 void SwapStruct(MachO::mach_header &H) {
115   SwapValue(H.magic);
116   SwapValue(H.cputype);
117   SwapValue(H.cpusubtype);
118   SwapValue(H.filetype);
119   SwapValue(H.ncmds);
120   SwapValue(H.sizeofcmds);
121   SwapValue(H.flags);
122 }
123 
124 template<>
125 void SwapStruct(MachO::mach_header_64 &H) {
126   SwapValue(H.magic);
127   SwapValue(H.cputype);
128   SwapValue(H.cpusubtype);
129   SwapValue(H.filetype);
130   SwapValue(H.ncmds);
131   SwapValue(H.sizeofcmds);
132   SwapValue(H.flags);
133   SwapValue(H.reserved);
134 }
135 
136 template<>
137 void SwapStruct(MachO::symtab_command &C) {
138   SwapValue(C.cmd);
139   SwapValue(C.cmdsize);
140   SwapValue(C.symoff);
141   SwapValue(C.nsyms);
142   SwapValue(C.stroff);
143   SwapValue(C.strsize);
144 }
145 
146 template<>
147 void SwapStruct(MachO::dysymtab_command &C) {
148   SwapValue(C.cmd);
149   SwapValue(C.cmdsize);
150   SwapValue(C.ilocalsym);
151   SwapValue(C.nlocalsym);
152   SwapValue(C.iextdefsym);
153   SwapValue(C.nextdefsym);
154   SwapValue(C.iundefsym);
155   SwapValue(C.nundefsym);
156   SwapValue(C.tocoff);
157   SwapValue(C.ntoc);
158   SwapValue(C.modtaboff);
159   SwapValue(C.nmodtab);
160   SwapValue(C.extrefsymoff);
161   SwapValue(C.nextrefsyms);
162   SwapValue(C.indirectsymoff);
163   SwapValue(C.nindirectsyms);
164   SwapValue(C.extreloff);
165   SwapValue(C.nextrel);
166   SwapValue(C.locreloff);
167   SwapValue(C.nlocrel);
168 }
169 
170 template<>
171 void SwapStruct(MachO::linkedit_data_command &C) {
172   SwapValue(C.cmd);
173   SwapValue(C.cmdsize);
174   SwapValue(C.dataoff);
175   SwapValue(C.datasize);
176 }
177 
178 template<>
179 void SwapStruct(MachO::segment_command &C) {
180   SwapValue(C.cmd);
181   SwapValue(C.cmdsize);
182   SwapValue(C.vmaddr);
183   SwapValue(C.vmsize);
184   SwapValue(C.fileoff);
185   SwapValue(C.filesize);
186   SwapValue(C.maxprot);
187   SwapValue(C.initprot);
188   SwapValue(C.nsects);
189   SwapValue(C.flags);
190 }
191 
192 template<>
193 void SwapStruct(MachO::segment_command_64 &C) {
194   SwapValue(C.cmd);
195   SwapValue(C.cmdsize);
196   SwapValue(C.vmaddr);
197   SwapValue(C.vmsize);
198   SwapValue(C.fileoff);
199   SwapValue(C.filesize);
200   SwapValue(C.maxprot);
201   SwapValue(C.initprot);
202   SwapValue(C.nsects);
203   SwapValue(C.flags);
204 }
205 
206 template<>
207 void SwapStruct(uint32_t &C) {
208   SwapValue(C);
209 }
210 
211 template<>
212 void SwapStruct(MachO::linker_options_command &C) {
213   SwapValue(C.cmd);
214   SwapValue(C.cmdsize);
215   SwapValue(C.count);
216 }
217 
218 template<>
219 void SwapStruct(MachO::version_min_command&C) {
220   SwapValue(C.cmd);
221   SwapValue(C.cmdsize);
222   SwapValue(C.version);
223   SwapValue(C.reserved);
224 }
225 
226 template<>
227 void SwapStruct(MachO::dylib_command&C) {
228   SwapValue(C.cmd);
229   SwapValue(C.cmdsize);
230   SwapValue(C.dylib.name);
231   SwapValue(C.dylib.timestamp);
232   SwapValue(C.dylib.current_version);
233   SwapValue(C.dylib.compatibility_version);
234 }
235 
236 template<>
237 void SwapStruct(MachO::data_in_code_entry &C) {
238   SwapValue(C.offset);
239   SwapValue(C.length);
240   SwapValue(C.kind);
241 }
242 
243 template<typename T>
244 T getStruct(const MachOObjectFile *O, const char *P) {
245   T Cmd;
246   memcpy(&Cmd, P, sizeof(T));
247   if (O->isLittleEndian() != sys::IsLittleEndianHost)
248     SwapStruct(Cmd);
249   return Cmd;
250 }
251 
252 static uint32_t
253 getSegmentLoadCommandNumSections(const MachOObjectFile *O,
254                                  const MachOObjectFile::LoadCommandInfo &L) {
255   if (O->is64Bit()) {
256     MachO::segment_command_64 S = O->getSegment64LoadCommand(L);
257     return S.nsects;
258   }
259   MachO::segment_command S = O->getSegmentLoadCommand(L);
260   return S.nsects;
261 }
262 
263 static const char *
264 getSectionPtr(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
265               unsigned Sec) {
266   uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
267 
268   bool Is64 = O->is64Bit();
269   unsigned SegmentLoadSize = Is64 ? sizeof(MachO::segment_command_64) :
270                                     sizeof(MachO::segment_command);
271   unsigned SectionSize = Is64 ? sizeof(MachO::section_64) :
272                                 sizeof(MachO::section);
273 
274   uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
275   return reinterpret_cast<const char*>(SectionAddr);
276 }
277 
278 static const char *getPtr(const MachOObjectFile *O, size_t Offset) {
279   return O->getData().substr(Offset, 1).data();
280 }
281 
282 static nlist_base
283 getSymbolTableEntryBase(const MachOObjectFile *O, DataRefImpl DRI) {
284   const char *P = reinterpret_cast<const char *>(DRI.p);
285   return getStruct<nlist_base>(O, P);
286 }
287 
288 static StringRef parseSegmentOrSectionName(const char *P) {
289   if (P[15] == 0)
290     // Null terminated.
291     return P;
292   // Not null terminated, so this is a 16 char string.
293   return StringRef(P, 16);
294 }
295 
296 // Helper to advance a section or symbol iterator multiple increments at a time.
297 template<class T>
298 static void advance(T &it, size_t Val) {
299   while (Val--)
300     ++it;
301 }
302 
303 static unsigned getCPUType(const MachOObjectFile *O) {
304   return O->getHeader().cputype;
305 }
306 
307 static void printRelocationTargetName(const MachOObjectFile *O,
308                                       const MachO::any_relocation_info &RE,
309                                       raw_string_ostream &fmt) {
310   bool IsScattered = O->isRelocationScattered(RE);
311 
312   // Target of a scattered relocation is an address.  In the interest of
313   // generating pretty output, scan through the symbol table looking for a
314   // symbol that aligns with that address.  If we find one, print it.
315   // Otherwise, we just print the hex address of the target.
316   if (IsScattered) {
317     uint32_t Val = O->getPlainRelocationSymbolNum(RE);
318 
319     for (const SymbolRef &Symbol : O->symbols()) {
320       std::error_code ec;
321       uint64_t Addr;
322       StringRef Name;
323 
324       if ((ec = Symbol.getAddress(Addr)))
325         report_fatal_error(ec.message());
326       if (Addr != Val)
327         continue;
328       if ((ec = Symbol.getName(Name)))
329         report_fatal_error(ec.message());
330       fmt << Name;
331       return;
332     }
333 
334     // If we couldn't find a symbol that this relocation refers to, try
335     // to find a section beginning instead.
336     for (const SectionRef &Section : O->sections()) {
337       std::error_code ec;
338       uint64_t Addr;
339       StringRef Name;
340 
341       if ((ec = Section.getAddress(Addr)))
342         report_fatal_error(ec.message());
343       if (Addr != Val)
344         continue;
345       if ((ec = Section.getName(Name)))
346         report_fatal_error(ec.message());
347       fmt << Name;
348       return;
349     }
350 
351     fmt << format("0x%x", Val);
352     return;
353   }
354 
355   StringRef S;
356   bool isExtern = O->getPlainRelocationExternal(RE);
357   uint64_t Val = O->getPlainRelocationSymbolNum(RE);
358 
359   if (isExtern) {
360     symbol_iterator SI = O->symbol_begin();
361     advance(SI, Val);
362     SI->getName(S);
363   } else {
364     section_iterator SI = O->section_begin();
365     // Adjust for the fact that sections are 1-indexed.
366     advance(SI, Val - 1);
367     SI->getName(S);
368   }
369 
370   fmt << S;
371 }
372 
373 static uint32_t
374 getPlainRelocationAddress(const MachO::any_relocation_info &RE) {
375   return RE.r_word0;
376 }
377 
378 static unsigned
379 getScatteredRelocationAddress(const MachO::any_relocation_info &RE) {
380   return RE.r_word0 & 0xffffff;
381 }
382 
383 static bool getPlainRelocationPCRel(const MachOObjectFile *O,
384                                     const MachO::any_relocation_info &RE) {
385   if (O->isLittleEndian())
386     return (RE.r_word1 >> 24) & 1;
387   return (RE.r_word1 >> 7) & 1;
388 }
389 
390 static bool
391 getScatteredRelocationPCRel(const MachOObjectFile *O,
392                             const MachO::any_relocation_info &RE) {
393   return (RE.r_word0 >> 30) & 1;
394 }
395 
396 static unsigned getPlainRelocationLength(const MachOObjectFile *O,
397                                          const MachO::any_relocation_info &RE) {
398   if (O->isLittleEndian())
399     return (RE.r_word1 >> 25) & 3;
400   return (RE.r_word1 >> 5) & 3;
401 }
402 
403 static unsigned
404 getScatteredRelocationLength(const MachO::any_relocation_info &RE) {
405   return (RE.r_word0 >> 28) & 3;
406 }
407 
408 static unsigned getPlainRelocationType(const MachOObjectFile *O,
409                                        const MachO::any_relocation_info &RE) {
410   if (O->isLittleEndian())
411     return RE.r_word1 >> 28;
412   return RE.r_word1 & 0xf;
413 }
414 
415 static unsigned
416 getScatteredRelocationType(const MachO::any_relocation_info &RE) {
417   return (RE.r_word0 >> 24) & 0xf;
418 }
419 
420 static uint32_t getSectionFlags(const MachOObjectFile *O,
421                                 DataRefImpl Sec) {
422   if (O->is64Bit()) {
423     MachO::section_64 Sect = O->getSection64(Sec);
424     return Sect.flags;
425   }
426   MachO::section Sect = O->getSection(Sec);
427   return Sect.flags;
428 }
429 
430 MachOObjectFile::MachOObjectFile(MemoryBuffer *Object, bool IsLittleEndian,
431                                  bool Is64bits, std::error_code &EC,
432                                  bool BufferOwned)
433     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object, BufferOwned),
434       SymtabLoadCmd(nullptr), DysymtabLoadCmd(nullptr),
435       DataInCodeLoadCmd(nullptr) {
436   uint32_t LoadCommandCount = this->getHeader().ncmds;
437   MachO::LoadCommandType SegmentLoadType = is64Bit() ?
438     MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT;
439 
440   MachOObjectFile::LoadCommandInfo Load = getFirstLoadCommandInfo();
441   for (unsigned I = 0; ; ++I) {
442     if (Load.C.cmd == MachO::LC_SYMTAB) {
443       assert(!SymtabLoadCmd && "Multiple symbol tables");
444       SymtabLoadCmd = Load.Ptr;
445     } else if (Load.C.cmd == MachO::LC_DYSYMTAB) {
446       assert(!DysymtabLoadCmd && "Multiple dynamic symbol tables");
447       DysymtabLoadCmd = Load.Ptr;
448     } else if (Load.C.cmd == MachO::LC_DATA_IN_CODE) {
449       assert(!DataInCodeLoadCmd && "Multiple data in code tables");
450       DataInCodeLoadCmd = Load.Ptr;
451     } else if (Load.C.cmd == SegmentLoadType) {
452       uint32_t NumSections = getSegmentLoadCommandNumSections(this, Load);
453       for (unsigned J = 0; J < NumSections; ++J) {
454         const char *Sec = getSectionPtr(this, Load, J);
455         Sections.push_back(Sec);
456       }
457     } else if (Load.C.cmd == MachO::LC_LOAD_DYLIB ||
458                Load.C.cmd == MachO::LC_LOAD_WEAK_DYLIB ||
459                Load.C.cmd == MachO::LC_LAZY_LOAD_DYLIB ||
460                Load.C.cmd == MachO::LC_REEXPORT_DYLIB ||
461                Load.C.cmd == MachO::LC_LOAD_UPWARD_DYLIB) {
462       Libraries.push_back(Load.Ptr);
463     }
464 
465     if (I == LoadCommandCount - 1)
466       break;
467     else
468       Load = getNextLoadCommandInfo(Load);
469   }
470 }
471 
472 void MachOObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
473   unsigned SymbolTableEntrySize = is64Bit() ?
474     sizeof(MachO::nlist_64) :
475     sizeof(MachO::nlist);
476   Symb.p += SymbolTableEntrySize;
477 }
478 
479 std::error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
480                                                StringRef &Res) const {
481   StringRef StringTable = getStringTableData();
482   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
483   const char *Start = &StringTable.data()[Entry.n_strx];
484   Res = StringRef(Start);
485   return object_error::success;
486 }
487 
488 // getIndirectName() returns the name of the alias'ed symbol who's string table
489 // index is in the n_value field.
490 std::error_code MachOObjectFile::getIndirectName(DataRefImpl Symb,
491                                                  StringRef &Res) const {
492   StringRef StringTable = getStringTableData();
493   uint64_t NValue;
494   if (is64Bit()) {
495     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
496     NValue = Entry.n_value;
497     if ((Entry.n_type & MachO::N_TYPE) != MachO::N_INDR)
498       return object_error::parse_failed;
499   } else {
500     MachO::nlist Entry = getSymbolTableEntry(Symb);
501     NValue = Entry.n_value;
502     if ((Entry.n_type & MachO::N_TYPE) != MachO::N_INDR)
503       return object_error::parse_failed;
504   }
505   if (NValue >= StringTable.size())
506     return object_error::parse_failed;
507   const char *Start = &StringTable.data()[NValue];
508   Res = StringRef(Start);
509   return object_error::success;
510 }
511 
512 std::error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
513                                                   uint64_t &Res) const {
514   if (is64Bit()) {
515     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
516     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
517         Entry.n_value == 0)
518       Res = UnknownAddressOrSize;
519     else
520       Res = Entry.n_value;
521   } else {
522     MachO::nlist Entry = getSymbolTableEntry(Symb);
523     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
524         Entry.n_value == 0)
525       Res = UnknownAddressOrSize;
526     else
527       Res = Entry.n_value;
528   }
529   return object_error::success;
530 }
531 
532 std::error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
533                                                     uint32_t &Result) const {
534   uint32_t flags = getSymbolFlags(DRI);
535   if (flags & SymbolRef::SF_Common) {
536     nlist_base Entry = getSymbolTableEntryBase(this, DRI);
537     Result = 1 << MachO::GET_COMM_ALIGN(Entry.n_desc);
538   } else {
539     Result = 0;
540   }
541   return object_error::success;
542 }
543 
544 std::error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
545                                                uint64_t &Result) const {
546   uint64_t BeginOffset;
547   uint64_t EndOffset = 0;
548   uint8_t SectionIndex;
549 
550   nlist_base Entry = getSymbolTableEntryBase(this, DRI);
551   uint64_t Value;
552   getSymbolAddress(DRI, Value);
553   if (Value == UnknownAddressOrSize) {
554     Result = UnknownAddressOrSize;
555     return object_error::success;
556   }
557 
558   BeginOffset = Value;
559 
560   SectionIndex = Entry.n_sect;
561   if (!SectionIndex) {
562     uint32_t flags = getSymbolFlags(DRI);
563     if (flags & SymbolRef::SF_Common)
564       Result = Value;
565     else
566       Result = UnknownAddressOrSize;
567     return object_error::success;
568   }
569   // Unfortunately symbols are unsorted so we need to touch all
570   // symbols from load command
571   for (const SymbolRef &Symbol : symbols()) {
572     DataRefImpl DRI = Symbol.getRawDataRefImpl();
573     Entry = getSymbolTableEntryBase(this, DRI);
574     getSymbolAddress(DRI, Value);
575     if (Value == UnknownAddressOrSize)
576       continue;
577     if (Entry.n_sect == SectionIndex && Value > BeginOffset)
578       if (!EndOffset || Value < EndOffset)
579         EndOffset = Value;
580   }
581   if (!EndOffset) {
582     uint64_t Size;
583     DataRefImpl Sec;
584     Sec.d.a = SectionIndex-1;
585     getSectionSize(Sec, Size);
586     getSectionAddress(Sec, EndOffset);
587     EndOffset += Size;
588   }
589   Result = EndOffset - BeginOffset;
590   return object_error::success;
591 }
592 
593 std::error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
594                                                SymbolRef::Type &Res) const {
595   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
596   uint8_t n_type = Entry.n_type;
597 
598   Res = SymbolRef::ST_Other;
599 
600   // If this is a STAB debugging symbol, we can do nothing more.
601   if (n_type & MachO::N_STAB) {
602     Res = SymbolRef::ST_Debug;
603     return object_error::success;
604   }
605 
606   switch (n_type & MachO::N_TYPE) {
607     case MachO::N_UNDF :
608       Res = SymbolRef::ST_Unknown;
609       break;
610     case MachO::N_SECT :
611       Res = SymbolRef::ST_Function;
612       break;
613   }
614   return object_error::success;
615 }
616 
617 uint32_t MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
618   nlist_base Entry = getSymbolTableEntryBase(this, DRI);
619 
620   uint8_t MachOType = Entry.n_type;
621   uint16_t MachOFlags = Entry.n_desc;
622 
623   uint32_t Result = SymbolRef::SF_None;
624 
625   if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF)
626     Result |= SymbolRef::SF_Undefined;
627 
628   if ((MachOType & MachO::N_TYPE) == MachO::N_INDR)
629     Result |= SymbolRef::SF_Indirect;
630 
631   if (MachOType & MachO::N_STAB)
632     Result |= SymbolRef::SF_FormatSpecific;
633 
634   if (MachOType & MachO::N_EXT) {
635     Result |= SymbolRef::SF_Global;
636     if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF) {
637       uint64_t Value;
638       getSymbolAddress(DRI, Value);
639       if (Value && Value != UnknownAddressOrSize)
640         Result |= SymbolRef::SF_Common;
641     }
642   }
643 
644   if (MachOFlags & (MachO::N_WEAK_REF | MachO::N_WEAK_DEF))
645     Result |= SymbolRef::SF_Weak;
646 
647   if ((MachOType & MachO::N_TYPE) == MachO::N_ABS)
648     Result |= SymbolRef::SF_Absolute;
649 
650   return Result;
651 }
652 
653 std::error_code MachOObjectFile::getSymbolSection(DataRefImpl Symb,
654                                                   section_iterator &Res) const {
655   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
656   uint8_t index = Entry.n_sect;
657 
658   if (index == 0) {
659     Res = section_end();
660   } else {
661     DataRefImpl DRI;
662     DRI.d.a = index - 1;
663     Res = section_iterator(SectionRef(DRI, this));
664   }
665 
666   return object_error::success;
667 }
668 
669 void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
670   Sec.d.a++;
671 }
672 
673 std::error_code MachOObjectFile::getSectionName(DataRefImpl Sec,
674                                                 StringRef &Result) const {
675   ArrayRef<char> Raw = getSectionRawName(Sec);
676   Result = parseSegmentOrSectionName(Raw.data());
677   return object_error::success;
678 }
679 
680 std::error_code MachOObjectFile::getSectionAddress(DataRefImpl Sec,
681                                                    uint64_t &Res) const {
682   if (is64Bit()) {
683     MachO::section_64 Sect = getSection64(Sec);
684     Res = Sect.addr;
685   } else {
686     MachO::section Sect = getSection(Sec);
687     Res = Sect.addr;
688   }
689   return object_error::success;
690 }
691 
692 std::error_code MachOObjectFile::getSectionSize(DataRefImpl Sec,
693                                                 uint64_t &Res) const {
694   if (is64Bit()) {
695     MachO::section_64 Sect = getSection64(Sec);
696     Res = Sect.size;
697   } else {
698     MachO::section Sect = getSection(Sec);
699     Res = Sect.size;
700   }
701 
702   return object_error::success;
703 }
704 
705 std::error_code MachOObjectFile::getSectionContents(DataRefImpl Sec,
706                                                     StringRef &Res) const {
707   uint32_t Offset;
708   uint64_t Size;
709 
710   if (is64Bit()) {
711     MachO::section_64 Sect = getSection64(Sec);
712     Offset = Sect.offset;
713     Size = Sect.size;
714   } else {
715     MachO::section Sect = getSection(Sec);
716     Offset = Sect.offset;
717     Size = Sect.size;
718   }
719 
720   Res = this->getData().substr(Offset, Size);
721   return object_error::success;
722 }
723 
724 std::error_code MachOObjectFile::getSectionAlignment(DataRefImpl Sec,
725                                                      uint64_t &Res) const {
726   uint32_t Align;
727   if (is64Bit()) {
728     MachO::section_64 Sect = getSection64(Sec);
729     Align = Sect.align;
730   } else {
731     MachO::section Sect = getSection(Sec);
732     Align = Sect.align;
733   }
734 
735   Res = uint64_t(1) << Align;
736   return object_error::success;
737 }
738 
739 std::error_code MachOObjectFile::isSectionText(DataRefImpl Sec,
740                                                bool &Res) const {
741   uint32_t Flags = getSectionFlags(this, Sec);
742   Res = Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
743   return object_error::success;
744 }
745 
746 std::error_code MachOObjectFile::isSectionData(DataRefImpl Sec,
747                                                bool &Result) const {
748   uint32_t Flags = getSectionFlags(this, Sec);
749   unsigned SectionType = Flags & MachO::SECTION_TYPE;
750   Result = !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
751            !(SectionType == MachO::S_ZEROFILL ||
752              SectionType == MachO::S_GB_ZEROFILL);
753   return object_error::success;
754 }
755 
756 std::error_code MachOObjectFile::isSectionBSS(DataRefImpl Sec,
757                                               bool &Result) const {
758   uint32_t Flags = getSectionFlags(this, Sec);
759   unsigned SectionType = Flags & MachO::SECTION_TYPE;
760   Result = !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
761            (SectionType == MachO::S_ZEROFILL ||
762             SectionType == MachO::S_GB_ZEROFILL);
763   return object_error::success;
764 }
765 
766 std::error_code
767 MachOObjectFile::isSectionRequiredForExecution(DataRefImpl Sec,
768                                                bool &Result) const {
769   // FIXME: Unimplemented.
770   Result = true;
771   return object_error::success;
772 }
773 
774 std::error_code MachOObjectFile::isSectionVirtual(DataRefImpl Sec,
775                                                   bool &Result) const {
776   // FIXME: Unimplemented.
777   Result = false;
778   return object_error::success;
779 }
780 
781 std::error_code MachOObjectFile::isSectionZeroInit(DataRefImpl Sec,
782                                                    bool &Res) const {
783   uint32_t Flags = getSectionFlags(this, Sec);
784   unsigned SectionType = Flags & MachO::SECTION_TYPE;
785   Res = SectionType == MachO::S_ZEROFILL ||
786     SectionType == MachO::S_GB_ZEROFILL;
787   return object_error::success;
788 }
789 
790 std::error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
791                                                        bool &Result) const {
792   // Consider using the code from isSectionText to look for __const sections.
793   // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
794   // to use section attributes to distinguish code from data.
795 
796   // FIXME: Unimplemented.
797   Result = false;
798   return object_error::success;
799 }
800 
801 std::error_code MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec,
802                                                        DataRefImpl Symb,
803                                                        bool &Result) const {
804   SymbolRef::Type ST;
805   this->getSymbolType(Symb, ST);
806   if (ST == SymbolRef::ST_Unknown) {
807     Result = false;
808     return object_error::success;
809   }
810 
811   uint64_t SectBegin, SectEnd;
812   getSectionAddress(Sec, SectBegin);
813   getSectionSize(Sec, SectEnd);
814   SectEnd += SectBegin;
815 
816   uint64_t SymAddr;
817   getSymbolAddress(Symb, SymAddr);
818   Result = (SymAddr >= SectBegin) && (SymAddr < SectEnd);
819 
820   return object_error::success;
821 }
822 
823 relocation_iterator MachOObjectFile::section_rel_begin(DataRefImpl Sec) const {
824   DataRefImpl Ret;
825   Ret.d.a = Sec.d.a;
826   Ret.d.b = 0;
827   return relocation_iterator(RelocationRef(Ret, this));
828 }
829 
830 relocation_iterator
831 MachOObjectFile::section_rel_end(DataRefImpl Sec) const {
832   uint32_t Num;
833   if (is64Bit()) {
834     MachO::section_64 Sect = getSection64(Sec);
835     Num = Sect.nreloc;
836   } else {
837     MachO::section Sect = getSection(Sec);
838     Num = Sect.nreloc;
839   }
840 
841   DataRefImpl Ret;
842   Ret.d.a = Sec.d.a;
843   Ret.d.b = Num;
844   return relocation_iterator(RelocationRef(Ret, this));
845 }
846 
847 void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
848   ++Rel.d.b;
849 }
850 
851 std::error_code MachOObjectFile::getRelocationAddress(DataRefImpl Rel,
852                                                       uint64_t &Res) const {
853   uint64_t Offset;
854   getRelocationOffset(Rel, Offset);
855 
856   DataRefImpl Sec;
857   Sec.d.a = Rel.d.a;
858   uint64_t SecAddress;
859   getSectionAddress(Sec, SecAddress);
860   Res = SecAddress + Offset;
861   return object_error::success;
862 }
863 
864 std::error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
865                                                      uint64_t &Res) const {
866   assert(getHeader().filetype == MachO::MH_OBJECT &&
867          "Only implemented for MH_OBJECT");
868   MachO::any_relocation_info RE = getRelocation(Rel);
869   Res = getAnyRelocationAddress(RE);
870   return object_error::success;
871 }
872 
873 symbol_iterator
874 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
875   MachO::any_relocation_info RE = getRelocation(Rel);
876   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
877   bool isExtern = getPlainRelocationExternal(RE);
878   if (!isExtern)
879     return symbol_end();
880 
881   MachO::symtab_command S = getSymtabLoadCommand();
882   unsigned SymbolTableEntrySize = is64Bit() ?
883     sizeof(MachO::nlist_64) :
884     sizeof(MachO::nlist);
885   uint64_t Offset = S.symoff + SymbolIdx * SymbolTableEntrySize;
886   DataRefImpl Sym;
887   Sym.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
888   return symbol_iterator(SymbolRef(Sym, this));
889 }
890 
891 std::error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
892                                                    uint64_t &Res) const {
893   MachO::any_relocation_info RE = getRelocation(Rel);
894   Res = getAnyRelocationType(RE);
895   return object_error::success;
896 }
897 
898 std::error_code
899 MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
900                                        SmallVectorImpl<char> &Result) const {
901   StringRef res;
902   uint64_t RType;
903   getRelocationType(Rel, RType);
904 
905   unsigned Arch = this->getArch();
906 
907   switch (Arch) {
908     case Triple::x86: {
909       static const char *const Table[] =  {
910         "GENERIC_RELOC_VANILLA",
911         "GENERIC_RELOC_PAIR",
912         "GENERIC_RELOC_SECTDIFF",
913         "GENERIC_RELOC_PB_LA_PTR",
914         "GENERIC_RELOC_LOCAL_SECTDIFF",
915         "GENERIC_RELOC_TLV" };
916 
917       if (RType > 5)
918         res = "Unknown";
919       else
920         res = Table[RType];
921       break;
922     }
923     case Triple::x86_64: {
924       static const char *const Table[] =  {
925         "X86_64_RELOC_UNSIGNED",
926         "X86_64_RELOC_SIGNED",
927         "X86_64_RELOC_BRANCH",
928         "X86_64_RELOC_GOT_LOAD",
929         "X86_64_RELOC_GOT",
930         "X86_64_RELOC_SUBTRACTOR",
931         "X86_64_RELOC_SIGNED_1",
932         "X86_64_RELOC_SIGNED_2",
933         "X86_64_RELOC_SIGNED_4",
934         "X86_64_RELOC_TLV" };
935 
936       if (RType > 9)
937         res = "Unknown";
938       else
939         res = Table[RType];
940       break;
941     }
942     case Triple::arm: {
943       static const char *const Table[] =  {
944         "ARM_RELOC_VANILLA",
945         "ARM_RELOC_PAIR",
946         "ARM_RELOC_SECTDIFF",
947         "ARM_RELOC_LOCAL_SECTDIFF",
948         "ARM_RELOC_PB_LA_PTR",
949         "ARM_RELOC_BR24",
950         "ARM_THUMB_RELOC_BR22",
951         "ARM_THUMB_32BIT_BRANCH",
952         "ARM_RELOC_HALF",
953         "ARM_RELOC_HALF_SECTDIFF" };
954 
955       if (RType > 9)
956         res = "Unknown";
957       else
958         res = Table[RType];
959       break;
960     }
961     case Triple::arm64:
962     case Triple::aarch64: {
963       static const char *const Table[] = {
964         "ARM64_RELOC_UNSIGNED",           "ARM64_RELOC_SUBTRACTOR",
965         "ARM64_RELOC_BRANCH26",           "ARM64_RELOC_PAGE21",
966         "ARM64_RELOC_PAGEOFF12",          "ARM64_RELOC_GOT_LOAD_PAGE21",
967         "ARM64_RELOC_GOT_LOAD_PAGEOFF12", "ARM64_RELOC_POINTER_TO_GOT",
968         "ARM64_RELOC_TLVP_LOAD_PAGE21",   "ARM64_RELOC_TLVP_LOAD_PAGEOFF12",
969         "ARM64_RELOC_ADDEND"
970       };
971 
972       if (RType >= array_lengthof(Table))
973         res = "Unknown";
974       else
975         res = Table[RType];
976       break;
977     }
978     case Triple::ppc: {
979       static const char *const Table[] =  {
980         "PPC_RELOC_VANILLA",
981         "PPC_RELOC_PAIR",
982         "PPC_RELOC_BR14",
983         "PPC_RELOC_BR24",
984         "PPC_RELOC_HI16",
985         "PPC_RELOC_LO16",
986         "PPC_RELOC_HA16",
987         "PPC_RELOC_LO14",
988         "PPC_RELOC_SECTDIFF",
989         "PPC_RELOC_PB_LA_PTR",
990         "PPC_RELOC_HI16_SECTDIFF",
991         "PPC_RELOC_LO16_SECTDIFF",
992         "PPC_RELOC_HA16_SECTDIFF",
993         "PPC_RELOC_JBSR",
994         "PPC_RELOC_LO14_SECTDIFF",
995         "PPC_RELOC_LOCAL_SECTDIFF" };
996 
997       if (RType > 15)
998         res = "Unknown";
999       else
1000         res = Table[RType];
1001       break;
1002     }
1003     case Triple::UnknownArch:
1004       res = "Unknown";
1005       break;
1006   }
1007   Result.append(res.begin(), res.end());
1008   return object_error::success;
1009 }
1010 
1011 std::error_code
1012 MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
1013                                           SmallVectorImpl<char> &Result) const {
1014   MachO::any_relocation_info RE = getRelocation(Rel);
1015 
1016   unsigned Arch = this->getArch();
1017 
1018   std::string fmtbuf;
1019   raw_string_ostream fmt(fmtbuf);
1020   unsigned Type = this->getAnyRelocationType(RE);
1021   bool IsPCRel = this->getAnyRelocationPCRel(RE);
1022 
1023   // Determine any addends that should be displayed with the relocation.
1024   // These require decoding the relocation type, which is triple-specific.
1025 
1026   // X86_64 has entirely custom relocation types.
1027   if (Arch == Triple::x86_64) {
1028     bool isPCRel = getAnyRelocationPCRel(RE);
1029 
1030     switch (Type) {
1031       case MachO::X86_64_RELOC_GOT_LOAD:
1032       case MachO::X86_64_RELOC_GOT: {
1033         printRelocationTargetName(this, RE, fmt);
1034         fmt << "@GOT";
1035         if (isPCRel) fmt << "PCREL";
1036         break;
1037       }
1038       case MachO::X86_64_RELOC_SUBTRACTOR: {
1039         DataRefImpl RelNext = Rel;
1040         moveRelocationNext(RelNext);
1041         MachO::any_relocation_info RENext = getRelocation(RelNext);
1042 
1043         // X86_64_RELOC_SUBTRACTOR must be followed by a relocation of type
1044         // X86_64_RELOC_UNSIGNED.
1045         // NOTE: Scattered relocations don't exist on x86_64.
1046         unsigned RType = getAnyRelocationType(RENext);
1047         if (RType != MachO::X86_64_RELOC_UNSIGNED)
1048           report_fatal_error("Expected X86_64_RELOC_UNSIGNED after "
1049                              "X86_64_RELOC_SUBTRACTOR.");
1050 
1051         // The X86_64_RELOC_UNSIGNED contains the minuend symbol;
1052         // X86_64_RELOC_SUBTRACTOR contains the subtrahend.
1053         printRelocationTargetName(this, RENext, fmt);
1054         fmt << "-";
1055         printRelocationTargetName(this, RE, fmt);
1056         break;
1057       }
1058       case MachO::X86_64_RELOC_TLV:
1059         printRelocationTargetName(this, RE, fmt);
1060         fmt << "@TLV";
1061         if (isPCRel) fmt << "P";
1062         break;
1063       case MachO::X86_64_RELOC_SIGNED_1:
1064         printRelocationTargetName(this, RE, fmt);
1065         fmt << "-1";
1066         break;
1067       case MachO::X86_64_RELOC_SIGNED_2:
1068         printRelocationTargetName(this, RE, fmt);
1069         fmt << "-2";
1070         break;
1071       case MachO::X86_64_RELOC_SIGNED_4:
1072         printRelocationTargetName(this, RE, fmt);
1073         fmt << "-4";
1074         break;
1075       default:
1076         printRelocationTargetName(this, RE, fmt);
1077         break;
1078     }
1079   // X86 and ARM share some relocation types in common.
1080   } else if (Arch == Triple::x86 || Arch == Triple::arm ||
1081              Arch == Triple::ppc) {
1082     // Generic relocation types...
1083     switch (Type) {
1084       case MachO::GENERIC_RELOC_PAIR: // prints no info
1085         return object_error::success;
1086       case MachO::GENERIC_RELOC_SECTDIFF: {
1087         DataRefImpl RelNext = Rel;
1088         moveRelocationNext(RelNext);
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 
1095         if (RType != MachO::GENERIC_RELOC_PAIR)
1096           report_fatal_error("Expected GENERIC_RELOC_PAIR after "
1097                              "GENERIC_RELOC_SECTDIFF.");
1098 
1099         printRelocationTargetName(this, RE, fmt);
1100         fmt << "-";
1101         printRelocationTargetName(this, RENext, fmt);
1102         break;
1103       }
1104     }
1105 
1106     if (Arch == Triple::x86 || Arch == Triple::ppc) {
1107       switch (Type) {
1108         case MachO::GENERIC_RELOC_LOCAL_SECTDIFF: {
1109           DataRefImpl RelNext = Rel;
1110           moveRelocationNext(RelNext);
1111           MachO::any_relocation_info RENext = getRelocation(RelNext);
1112 
1113           // X86 sect diff's must be followed by a relocation of type
1114           // GENERIC_RELOC_PAIR.
1115           unsigned RType = getAnyRelocationType(RENext);
1116           if (RType != MachO::GENERIC_RELOC_PAIR)
1117             report_fatal_error("Expected GENERIC_RELOC_PAIR after "
1118                                "GENERIC_RELOC_LOCAL_SECTDIFF.");
1119 
1120           printRelocationTargetName(this, RE, fmt);
1121           fmt << "-";
1122           printRelocationTargetName(this, RENext, fmt);
1123           break;
1124         }
1125         case MachO::GENERIC_RELOC_TLV: {
1126           printRelocationTargetName(this, RE, fmt);
1127           fmt << "@TLV";
1128           if (IsPCRel) fmt << "P";
1129           break;
1130         }
1131         default:
1132           printRelocationTargetName(this, RE, fmt);
1133       }
1134     } else { // ARM-specific relocations
1135       switch (Type) {
1136         case MachO::ARM_RELOC_HALF:
1137         case MachO::ARM_RELOC_HALF_SECTDIFF: {
1138           // Half relocations steal a bit from the length field to encode
1139           // whether this is an upper16 or a lower16 relocation.
1140           bool isUpper = getAnyRelocationLength(RE) >> 1;
1141 
1142           if (isUpper)
1143             fmt << ":upper16:(";
1144           else
1145             fmt << ":lower16:(";
1146           printRelocationTargetName(this, RE, fmt);
1147 
1148           DataRefImpl RelNext = Rel;
1149           moveRelocationNext(RelNext);
1150           MachO::any_relocation_info RENext = getRelocation(RelNext);
1151 
1152           // ARM half relocs must be followed by a relocation of type
1153           // ARM_RELOC_PAIR.
1154           unsigned RType = getAnyRelocationType(RENext);
1155           if (RType != MachO::ARM_RELOC_PAIR)
1156             report_fatal_error("Expected ARM_RELOC_PAIR after "
1157                                "ARM_RELOC_HALF");
1158 
1159           // NOTE: The half of the target virtual address is stashed in the
1160           // address field of the secondary relocation, but we can't reverse
1161           // engineer the constant offset from it without decoding the movw/movt
1162           // instruction to find the other half in its immediate field.
1163 
1164           // ARM_RELOC_HALF_SECTDIFF encodes the second section in the
1165           // symbol/section pointer of the follow-on relocation.
1166           if (Type == MachO::ARM_RELOC_HALF_SECTDIFF) {
1167             fmt << "-";
1168             printRelocationTargetName(this, RENext, fmt);
1169           }
1170 
1171           fmt << ")";
1172           break;
1173         }
1174         default: {
1175           printRelocationTargetName(this, RE, fmt);
1176         }
1177       }
1178     }
1179   } else
1180     printRelocationTargetName(this, RE, fmt);
1181 
1182   fmt.flush();
1183   Result.append(fmtbuf.begin(), fmtbuf.end());
1184   return object_error::success;
1185 }
1186 
1187 std::error_code MachOObjectFile::getRelocationHidden(DataRefImpl Rel,
1188                                                      bool &Result) const {
1189   unsigned Arch = getArch();
1190   uint64_t Type;
1191   getRelocationType(Rel, Type);
1192 
1193   Result = false;
1194 
1195   // On arches that use the generic relocations, GENERIC_RELOC_PAIR
1196   // is always hidden.
1197   if (Arch == Triple::x86 || Arch == Triple::arm || Arch == Triple::ppc) {
1198     if (Type == MachO::GENERIC_RELOC_PAIR) Result = true;
1199   } else if (Arch == Triple::x86_64) {
1200     // On x86_64, X86_64_RELOC_UNSIGNED is hidden only when it follows
1201     // an X86_64_RELOC_SUBTRACTOR.
1202     if (Type == MachO::X86_64_RELOC_UNSIGNED && Rel.d.a > 0) {
1203       DataRefImpl RelPrev = Rel;
1204       RelPrev.d.a--;
1205       uint64_t PrevType;
1206       getRelocationType(RelPrev, PrevType);
1207       if (PrevType == MachO::X86_64_RELOC_SUBTRACTOR)
1208         Result = true;
1209     }
1210   }
1211 
1212   return object_error::success;
1213 }
1214 
1215 std::error_code MachOObjectFile::getLibraryNext(DataRefImpl LibData,
1216                                                 LibraryRef &Res) const {
1217   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1218 }
1219 
1220 std::error_code MachOObjectFile::getLibraryPath(DataRefImpl LibData,
1221                                                 StringRef &Res) const {
1222   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1223 }
1224 
1225 //
1226 // guessLibraryShortName() is passed a name of a dynamic library and returns a
1227 // guess on what the short name is.  Then name is returned as a substring of the
1228 // StringRef Name passed in.  The name of the dynamic library is recognized as
1229 // a framework if it has one of the two following forms:
1230 //      Foo.framework/Versions/A/Foo
1231 //      Foo.framework/Foo
1232 // Where A and Foo can be any string.  And may contain a trailing suffix
1233 // starting with an underbar.  If the Name is recognized as a framework then
1234 // isFramework is set to true else it is set to false.  If the Name has a
1235 // suffix then Suffix is set to the substring in Name that contains the suffix
1236 // else it is set to a NULL StringRef.
1237 //
1238 // The Name of the dynamic library is recognized as a library name if it has
1239 // one of the two following forms:
1240 //      libFoo.A.dylib
1241 //      libFoo.dylib
1242 // The library may have a suffix trailing the name Foo of the form:
1243 //      libFoo_profile.A.dylib
1244 //      libFoo_profile.dylib
1245 //
1246 // The Name of the dynamic library is also recognized as a library name if it
1247 // has the following form:
1248 //      Foo.qtx
1249 //
1250 // If the Name of the dynamic library is none of the forms above then a NULL
1251 // StringRef is returned.
1252 //
1253 StringRef MachOObjectFile::guessLibraryShortName(StringRef Name,
1254                                                  bool &isFramework,
1255                                                  StringRef &Suffix) {
1256   StringRef Foo, F, DotFramework, V, Dylib, Lib, Dot, Qtx;
1257   size_t a, b, c, d, Idx;
1258 
1259   isFramework = false;
1260   Suffix = StringRef();
1261 
1262   // Pull off the last component and make Foo point to it
1263   a = Name.rfind('/');
1264   if (a == Name.npos || a == 0)
1265     goto guess_library;
1266   Foo = Name.slice(a+1, Name.npos);
1267 
1268   // Look for a suffix starting with a '_'
1269   Idx = Foo.rfind('_');
1270   if (Idx != Foo.npos && Foo.size() >= 2) {
1271     Suffix = Foo.slice(Idx, Foo.npos);
1272     Foo = Foo.slice(0, Idx);
1273   }
1274 
1275   // First look for the form Foo.framework/Foo
1276   b = Name.rfind('/', a);
1277   if (b == Name.npos)
1278     Idx = 0;
1279   else
1280     Idx = b+1;
1281   F = Name.slice(Idx, Idx + Foo.size());
1282   DotFramework = Name.slice(Idx + Foo.size(),
1283                             Idx + Foo.size() + sizeof(".framework/")-1);
1284   if (F == Foo && DotFramework == ".framework/") {
1285     isFramework = true;
1286     return Foo;
1287   }
1288 
1289   // Next look for the form Foo.framework/Versions/A/Foo
1290   if (b == Name.npos)
1291     goto guess_library;
1292   c =  Name.rfind('/', b);
1293   if (c == Name.npos || c == 0)
1294     goto guess_library;
1295   V = Name.slice(c+1, Name.npos);
1296   if (!V.startswith("Versions/"))
1297     goto guess_library;
1298   d =  Name.rfind('/', c);
1299   if (d == Name.npos)
1300     Idx = 0;
1301   else
1302     Idx = d+1;
1303   F = Name.slice(Idx, Idx + Foo.size());
1304   DotFramework = Name.slice(Idx + Foo.size(),
1305                             Idx + Foo.size() + sizeof(".framework/")-1);
1306   if (F == Foo && DotFramework == ".framework/") {
1307     isFramework = true;
1308     return Foo;
1309   }
1310 
1311 guess_library:
1312   // pull off the suffix after the "." and make a point to it
1313   a = Name.rfind('.');
1314   if (a == Name.npos || a == 0)
1315     return StringRef();
1316   Dylib = Name.slice(a, Name.npos);
1317   if (Dylib != ".dylib")
1318     goto guess_qtx;
1319 
1320   // First pull off the version letter for the form Foo.A.dylib if any.
1321   if (a >= 3) {
1322     Dot = Name.slice(a-2, a-1);
1323     if (Dot == ".")
1324       a = a - 2;
1325   }
1326 
1327   b = Name.rfind('/', a);
1328   if (b == Name.npos)
1329     b = 0;
1330   else
1331     b = b+1;
1332   // ignore any suffix after an underbar like Foo_profile.A.dylib
1333   Idx = Name.find('_', b);
1334   if (Idx != Name.npos && Idx != b) {
1335     Lib = Name.slice(b, Idx);
1336     Suffix = Name.slice(Idx, a);
1337   }
1338   else
1339     Lib = Name.slice(b, a);
1340   // There are incorrect library names of the form:
1341   // libATS.A_profile.dylib so check for these.
1342   if (Lib.size() >= 3) {
1343     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
1344     if (Dot == ".")
1345       Lib = Lib.slice(0, Lib.size()-2);
1346   }
1347   return Lib;
1348 
1349 guess_qtx:
1350   Qtx = Name.slice(a, Name.npos);
1351   if (Qtx != ".qtx")
1352     return StringRef();
1353   b = Name.rfind('/', a);
1354   if (b == Name.npos)
1355     Lib = Name.slice(0, a);
1356   else
1357     Lib = Name.slice(b+1, a);
1358   // There are library names of the form: QT.A.qtx so check for these.
1359   if (Lib.size() >= 3) {
1360     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
1361     if (Dot == ".")
1362       Lib = Lib.slice(0, Lib.size()-2);
1363   }
1364   return Lib;
1365 }
1366 
1367 // getLibraryShortNameByIndex() is used to get the short name of the library
1368 // for an undefined symbol in a linked Mach-O binary that was linked with the
1369 // normal two-level namespace default (that is MH_TWOLEVEL in the header).
1370 // It is passed the index (0 - based) of the library as translated from
1371 // GET_LIBRARY_ORDINAL (1 - based).
1372 std::error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
1373                                                             StringRef &Res) {
1374   if (Index >= Libraries.size())
1375     return object_error::parse_failed;
1376 
1377   MachO::dylib_command D =
1378     getStruct<MachO::dylib_command>(this, Libraries[Index]);
1379   if (D.dylib.name >= D.cmdsize)
1380     return object_error::parse_failed;
1381 
1382   // If the cache of LibrariesShortNames is not built up do that first for
1383   // all the Libraries.
1384   if (LibrariesShortNames.size() == 0) {
1385     for (unsigned i = 0; i < Libraries.size(); i++) {
1386       MachO::dylib_command D =
1387         getStruct<MachO::dylib_command>(this, Libraries[i]);
1388       if (D.dylib.name >= D.cmdsize) {
1389         LibrariesShortNames.push_back(StringRef());
1390         continue;
1391       }
1392       char *P = (char *)(Libraries[i]) + D.dylib.name;
1393       StringRef Name = StringRef(P);
1394       StringRef Suffix;
1395       bool isFramework;
1396       StringRef shortName = guessLibraryShortName(Name, isFramework, Suffix);
1397       if (shortName == StringRef())
1398         LibrariesShortNames.push_back(Name);
1399       else
1400         LibrariesShortNames.push_back(shortName);
1401     }
1402   }
1403 
1404   Res = LibrariesShortNames[Index];
1405   return object_error::success;
1406 }
1407 
1408 basic_symbol_iterator MachOObjectFile::symbol_begin_impl() const {
1409   return getSymbolByIndex(0);
1410 }
1411 
1412 basic_symbol_iterator MachOObjectFile::symbol_end_impl() const {
1413   DataRefImpl DRI;
1414   if (!SymtabLoadCmd)
1415     return basic_symbol_iterator(SymbolRef(DRI, this));
1416 
1417   MachO::symtab_command Symtab = getSymtabLoadCommand();
1418   unsigned SymbolTableEntrySize = is64Bit() ?
1419     sizeof(MachO::nlist_64) :
1420     sizeof(MachO::nlist);
1421   unsigned Offset = Symtab.symoff +
1422     Symtab.nsyms * SymbolTableEntrySize;
1423   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1424   return basic_symbol_iterator(SymbolRef(DRI, this));
1425 }
1426 
1427 basic_symbol_iterator MachOObjectFile::getSymbolByIndex(unsigned Index) const {
1428   DataRefImpl DRI;
1429   if (!SymtabLoadCmd)
1430     return basic_symbol_iterator(SymbolRef(DRI, this));
1431 
1432   MachO::symtab_command Symtab = getSymtabLoadCommand();
1433   assert(Index < Symtab.nsyms && "Requested symbol index is out of range.");
1434   unsigned SymbolTableEntrySize =
1435     is64Bit() ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
1436   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Symtab.symoff));
1437   DRI.p += Index * SymbolTableEntrySize;
1438   return basic_symbol_iterator(SymbolRef(DRI, this));
1439 }
1440 
1441 section_iterator MachOObjectFile::section_begin() const {
1442   DataRefImpl DRI;
1443   return section_iterator(SectionRef(DRI, this));
1444 }
1445 
1446 section_iterator MachOObjectFile::section_end() const {
1447   DataRefImpl DRI;
1448   DRI.d.a = Sections.size();
1449   return section_iterator(SectionRef(DRI, this));
1450 }
1451 
1452 library_iterator MachOObjectFile::needed_library_begin() const {
1453   // TODO: implement
1454   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1455 }
1456 
1457 library_iterator MachOObjectFile::needed_library_end() const {
1458   // TODO: implement
1459   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1460 }
1461 
1462 uint8_t MachOObjectFile::getBytesInAddress() const {
1463   return is64Bit() ? 8 : 4;
1464 }
1465 
1466 StringRef MachOObjectFile::getFileFormatName() const {
1467   unsigned CPUType = getCPUType(this);
1468   if (!is64Bit()) {
1469     switch (CPUType) {
1470     case llvm::MachO::CPU_TYPE_I386:
1471       return "Mach-O 32-bit i386";
1472     case llvm::MachO::CPU_TYPE_ARM:
1473       return "Mach-O arm";
1474     case llvm::MachO::CPU_TYPE_POWERPC:
1475       return "Mach-O 32-bit ppc";
1476     default:
1477       assert((CPUType & llvm::MachO::CPU_ARCH_ABI64) == 0 &&
1478              "64-bit object file when we're not 64-bit?");
1479       return "Mach-O 32-bit unknown";
1480     }
1481   }
1482 
1483   // Make sure the cpu type has the correct mask.
1484   assert((CPUType & llvm::MachO::CPU_ARCH_ABI64)
1485          == llvm::MachO::CPU_ARCH_ABI64 &&
1486          "32-bit object file when we're 64-bit?");
1487 
1488   switch (CPUType) {
1489   case llvm::MachO::CPU_TYPE_X86_64:
1490     return "Mach-O 64-bit x86-64";
1491   case llvm::MachO::CPU_TYPE_ARM64:
1492     return "Mach-O arm64";
1493   case llvm::MachO::CPU_TYPE_POWERPC64:
1494     return "Mach-O 64-bit ppc64";
1495   default:
1496     return "Mach-O 64-bit unknown";
1497   }
1498 }
1499 
1500 Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
1501   switch (CPUType) {
1502   case llvm::MachO::CPU_TYPE_I386:
1503     return Triple::x86;
1504   case llvm::MachO::CPU_TYPE_X86_64:
1505     return Triple::x86_64;
1506   case llvm::MachO::CPU_TYPE_ARM:
1507     return Triple::arm;
1508   case llvm::MachO::CPU_TYPE_ARM64:
1509     return Triple::arm64;
1510   case llvm::MachO::CPU_TYPE_POWERPC:
1511     return Triple::ppc;
1512   case llvm::MachO::CPU_TYPE_POWERPC64:
1513     return Triple::ppc64;
1514   default:
1515     return Triple::UnknownArch;
1516   }
1517 }
1518 
1519 unsigned MachOObjectFile::getArch() const {
1520   return getArch(getCPUType(this));
1521 }
1522 
1523 StringRef MachOObjectFile::getLoadName() const {
1524   // TODO: Implement
1525   report_fatal_error("get_load_name() unimplemented in MachOObjectFile");
1526 }
1527 
1528 relocation_iterator MachOObjectFile::section_rel_begin(unsigned Index) const {
1529   DataRefImpl DRI;
1530   DRI.d.a = Index;
1531   return section_rel_begin(DRI);
1532 }
1533 
1534 relocation_iterator MachOObjectFile::section_rel_end(unsigned Index) const {
1535   DataRefImpl DRI;
1536   DRI.d.a = Index;
1537   return section_rel_end(DRI);
1538 }
1539 
1540 dice_iterator MachOObjectFile::begin_dices() const {
1541   DataRefImpl DRI;
1542   if (!DataInCodeLoadCmd)
1543     return dice_iterator(DiceRef(DRI, this));
1544 
1545   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1546   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, DicLC.dataoff));
1547   return dice_iterator(DiceRef(DRI, this));
1548 }
1549 
1550 dice_iterator MachOObjectFile::end_dices() const {
1551   DataRefImpl DRI;
1552   if (!DataInCodeLoadCmd)
1553     return dice_iterator(DiceRef(DRI, this));
1554 
1555   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1556   unsigned Offset = DicLC.dataoff + DicLC.datasize;
1557   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1558   return dice_iterator(DiceRef(DRI, this));
1559 }
1560 
1561 StringRef
1562 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
1563   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
1564   return parseSegmentOrSectionName(Raw.data());
1565 }
1566 
1567 ArrayRef<char>
1568 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
1569   const section_base *Base =
1570     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1571   return ArrayRef<char>(Base->sectname);
1572 }
1573 
1574 ArrayRef<char>
1575 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
1576   const section_base *Base =
1577     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1578   return ArrayRef<char>(Base->segname);
1579 }
1580 
1581 bool
1582 MachOObjectFile::isRelocationScattered(const MachO::any_relocation_info &RE)
1583   const {
1584   if (getCPUType(this) == MachO::CPU_TYPE_X86_64)
1585     return false;
1586   return getPlainRelocationAddress(RE) & MachO::R_SCATTERED;
1587 }
1588 
1589 unsigned MachOObjectFile::getPlainRelocationSymbolNum(
1590     const MachO::any_relocation_info &RE) const {
1591   if (isLittleEndian())
1592     return RE.r_word1 & 0xffffff;
1593   return RE.r_word1 >> 8;
1594 }
1595 
1596 bool MachOObjectFile::getPlainRelocationExternal(
1597     const MachO::any_relocation_info &RE) const {
1598   if (isLittleEndian())
1599     return (RE.r_word1 >> 27) & 1;
1600   return (RE.r_word1 >> 4) & 1;
1601 }
1602 
1603 bool MachOObjectFile::getScatteredRelocationScattered(
1604     const MachO::any_relocation_info &RE) const {
1605   return RE.r_word0 >> 31;
1606 }
1607 
1608 uint32_t MachOObjectFile::getScatteredRelocationValue(
1609     const MachO::any_relocation_info &RE) const {
1610   return RE.r_word1;
1611 }
1612 
1613 unsigned MachOObjectFile::getAnyRelocationAddress(
1614     const MachO::any_relocation_info &RE) const {
1615   if (isRelocationScattered(RE))
1616     return getScatteredRelocationAddress(RE);
1617   return getPlainRelocationAddress(RE);
1618 }
1619 
1620 unsigned MachOObjectFile::getAnyRelocationPCRel(
1621     const MachO::any_relocation_info &RE) const {
1622   if (isRelocationScattered(RE))
1623     return getScatteredRelocationPCRel(this, RE);
1624   return getPlainRelocationPCRel(this, RE);
1625 }
1626 
1627 unsigned MachOObjectFile::getAnyRelocationLength(
1628     const MachO::any_relocation_info &RE) const {
1629   if (isRelocationScattered(RE))
1630     return getScatteredRelocationLength(RE);
1631   return getPlainRelocationLength(this, RE);
1632 }
1633 
1634 unsigned
1635 MachOObjectFile::getAnyRelocationType(
1636                                    const MachO::any_relocation_info &RE) const {
1637   if (isRelocationScattered(RE))
1638     return getScatteredRelocationType(RE);
1639   return getPlainRelocationType(this, RE);
1640 }
1641 
1642 SectionRef
1643 MachOObjectFile::getRelocationSection(
1644                                    const MachO::any_relocation_info &RE) const {
1645   if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
1646     return *section_end();
1647   unsigned SecNum = getPlainRelocationSymbolNum(RE) - 1;
1648   DataRefImpl DRI;
1649   DRI.d.a = SecNum;
1650   return SectionRef(DRI, this);
1651 }
1652 
1653 MachOObjectFile::LoadCommandInfo
1654 MachOObjectFile::getFirstLoadCommandInfo() const {
1655   MachOObjectFile::LoadCommandInfo Load;
1656 
1657   unsigned HeaderSize = is64Bit() ? sizeof(MachO::mach_header_64) :
1658                                     sizeof(MachO::mach_header);
1659   Load.Ptr = getPtr(this, HeaderSize);
1660   Load.C = getStruct<MachO::load_command>(this, Load.Ptr);
1661   return Load;
1662 }
1663 
1664 MachOObjectFile::LoadCommandInfo
1665 MachOObjectFile::getNextLoadCommandInfo(const LoadCommandInfo &L) const {
1666   MachOObjectFile::LoadCommandInfo Next;
1667   Next.Ptr = L.Ptr + L.C.cmdsize;
1668   Next.C = getStruct<MachO::load_command>(this, Next.Ptr);
1669   return Next;
1670 }
1671 
1672 MachO::section MachOObjectFile::getSection(DataRefImpl DRI) const {
1673   return getStruct<MachO::section>(this, Sections[DRI.d.a]);
1674 }
1675 
1676 MachO::section_64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
1677   return getStruct<MachO::section_64>(this, Sections[DRI.d.a]);
1678 }
1679 
1680 MachO::section MachOObjectFile::getSection(const LoadCommandInfo &L,
1681                                            unsigned Index) const {
1682   const char *Sec = getSectionPtr(this, L, Index);
1683   return getStruct<MachO::section>(this, Sec);
1684 }
1685 
1686 MachO::section_64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
1687                                                 unsigned Index) const {
1688   const char *Sec = getSectionPtr(this, L, Index);
1689   return getStruct<MachO::section_64>(this, Sec);
1690 }
1691 
1692 MachO::nlist
1693 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
1694   const char *P = reinterpret_cast<const char *>(DRI.p);
1695   return getStruct<MachO::nlist>(this, P);
1696 }
1697 
1698 MachO::nlist_64
1699 MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI) const {
1700   const char *P = reinterpret_cast<const char *>(DRI.p);
1701   return getStruct<MachO::nlist_64>(this, P);
1702 }
1703 
1704 MachO::linkedit_data_command
1705 MachOObjectFile::getLinkeditDataLoadCommand(const LoadCommandInfo &L) const {
1706   return getStruct<MachO::linkedit_data_command>(this, L.Ptr);
1707 }
1708 
1709 MachO::segment_command
1710 MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
1711   return getStruct<MachO::segment_command>(this, L.Ptr);
1712 }
1713 
1714 MachO::segment_command_64
1715 MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
1716   return getStruct<MachO::segment_command_64>(this, L.Ptr);
1717 }
1718 
1719 MachO::linker_options_command
1720 MachOObjectFile::getLinkerOptionsLoadCommand(const LoadCommandInfo &L) const {
1721   return getStruct<MachO::linker_options_command>(this, L.Ptr);
1722 }
1723 
1724 MachO::version_min_command
1725 MachOObjectFile::getVersionMinLoadCommand(const LoadCommandInfo &L) const {
1726   return getStruct<MachO::version_min_command>(this, L.Ptr);
1727 }
1728 
1729 MachO::any_relocation_info
1730 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
1731   DataRefImpl Sec;
1732   Sec.d.a = Rel.d.a;
1733   uint32_t Offset;
1734   if (is64Bit()) {
1735     MachO::section_64 Sect = getSection64(Sec);
1736     Offset = Sect.reloff;
1737   } else {
1738     MachO::section Sect = getSection(Sec);
1739     Offset = Sect.reloff;
1740   }
1741 
1742   auto P = reinterpret_cast<const MachO::any_relocation_info *>(
1743       getPtr(this, Offset)) + Rel.d.b;
1744   return getStruct<MachO::any_relocation_info>(
1745       this, reinterpret_cast<const char *>(P));
1746 }
1747 
1748 MachO::data_in_code_entry
1749 MachOObjectFile::getDice(DataRefImpl Rel) const {
1750   const char *P = reinterpret_cast<const char *>(Rel.p);
1751   return getStruct<MachO::data_in_code_entry>(this, P);
1752 }
1753 
1754 MachO::mach_header MachOObjectFile::getHeader() const {
1755   return getStruct<MachO::mach_header>(this, getPtr(this, 0));
1756 }
1757 
1758 MachO::mach_header_64 MachOObjectFile::getHeader64() const {
1759   return getStruct<MachO::mach_header_64>(this, getPtr(this, 0));
1760 }
1761 
1762 uint32_t MachOObjectFile::getIndirectSymbolTableEntry(
1763                                              const MachO::dysymtab_command &DLC,
1764                                              unsigned Index) const {
1765   uint64_t Offset = DLC.indirectsymoff + Index * sizeof(uint32_t);
1766   return getStruct<uint32_t>(this, getPtr(this, Offset));
1767 }
1768 
1769 MachO::data_in_code_entry
1770 MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
1771                                          unsigned Index) const {
1772   uint64_t Offset = DataOffset + Index * sizeof(MachO::data_in_code_entry);
1773   return getStruct<MachO::data_in_code_entry>(this, getPtr(this, Offset));
1774 }
1775 
1776 MachO::symtab_command MachOObjectFile::getSymtabLoadCommand() const {
1777   return getStruct<MachO::symtab_command>(this, SymtabLoadCmd);
1778 }
1779 
1780 MachO::dysymtab_command MachOObjectFile::getDysymtabLoadCommand() const {
1781   return getStruct<MachO::dysymtab_command>(this, DysymtabLoadCmd);
1782 }
1783 
1784 MachO::linkedit_data_command
1785 MachOObjectFile::getDataInCodeLoadCommand() const {
1786   if (DataInCodeLoadCmd)
1787     return getStruct<MachO::linkedit_data_command>(this, DataInCodeLoadCmd);
1788 
1789   // If there is no DataInCodeLoadCmd return a load command with zero'ed fields.
1790   MachO::linkedit_data_command Cmd;
1791   Cmd.cmd = MachO::LC_DATA_IN_CODE;
1792   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
1793   Cmd.dataoff = 0;
1794   Cmd.datasize = 0;
1795   return Cmd;
1796 }
1797 
1798 StringRef MachOObjectFile::getStringTableData() const {
1799   MachO::symtab_command S = getSymtabLoadCommand();
1800   return getData().substr(S.stroff, S.strsize);
1801 }
1802 
1803 bool MachOObjectFile::is64Bit() const {
1804   return getType() == getMachOType(false, true) ||
1805     getType() == getMachOType(true, true);
1806 }
1807 
1808 void MachOObjectFile::ReadULEB128s(uint64_t Index,
1809                                    SmallVectorImpl<uint64_t> &Out) const {
1810   DataExtractor extractor(ObjectFile::getData(), true, 0);
1811 
1812   uint32_t offset = Index;
1813   uint64_t data = 0;
1814   while (uint64_t delta = extractor.getULEB128(&offset)) {
1815     data += delta;
1816     Out.push_back(data);
1817   }
1818 }
1819 
1820 ErrorOr<ObjectFile *> ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer,
1821                                                         bool BufferOwned) {
1822   StringRef Magic = Buffer->getBuffer().slice(0, 4);
1823   std::error_code EC;
1824   std::unique_ptr<MachOObjectFile> Ret;
1825   if (Magic == "\xFE\xED\xFA\xCE")
1826     Ret.reset(new MachOObjectFile(Buffer, false, false, EC, BufferOwned));
1827   else if (Magic == "\xCE\xFA\xED\xFE")
1828     Ret.reset(new MachOObjectFile(Buffer, true, false, EC, BufferOwned));
1829   else if (Magic == "\xFE\xED\xFA\xCF")
1830     Ret.reset(new MachOObjectFile(Buffer, false, true, EC, BufferOwned));
1831   else if (Magic == "\xCF\xFA\xED\xFE")
1832     Ret.reset(new MachOObjectFile(Buffer, true, true, EC, BufferOwned));
1833   else {
1834     delete Buffer;
1835     return object_error::parse_failed;
1836   }
1837 
1838   if (EC)
1839     return EC;
1840   return Ret.release();
1841 }
1842 
1843 } // end namespace object
1844 } // end namespace llvm
1845