xref: /llvm-project/llvm/lib/Object/MachOObjectFile.cpp (revision 3acea39853d1a5ef2f3920c27f5748778fe53af9) 
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 using std::error_code;
32 
33 namespace object {
34 
35 struct nlist_base {
36   uint32_t n_strx;
37   uint8_t n_type;
38   uint8_t n_sect;
39   uint16_t n_desc;
40 };
41 
42 struct section_base {
43   char sectname[16];
44   char segname[16];
45 };
46 
47 template<typename T>
48 static void SwapValue(T &Value) {
49   Value = sys::SwapByteOrder(Value);
50 }
51 
52 template<typename T>
53 static void SwapStruct(T &Value);
54 
55 template<>
56 void SwapStruct(MachO::any_relocation_info &H) {
57   SwapValue(H.r_word0);
58   SwapValue(H.r_word1);
59 }
60 
61 template<>
62 void SwapStruct(MachO::load_command &L) {
63   SwapValue(L.cmd);
64   SwapValue(L.cmdsize);
65 }
66 
67 template<>
68 void SwapStruct(nlist_base &S) {
69   SwapValue(S.n_strx);
70   SwapValue(S.n_desc);
71 }
72 
73 template<>
74 void SwapStruct(MachO::section &S) {
75   SwapValue(S.addr);
76   SwapValue(S.size);
77   SwapValue(S.offset);
78   SwapValue(S.align);
79   SwapValue(S.reloff);
80   SwapValue(S.nreloc);
81   SwapValue(S.flags);
82   SwapValue(S.reserved1);
83   SwapValue(S.reserved2);
84 }
85 
86 template<>
87 void SwapStruct(MachO::section_64 &S) {
88   SwapValue(S.addr);
89   SwapValue(S.size);
90   SwapValue(S.offset);
91   SwapValue(S.align);
92   SwapValue(S.reloff);
93   SwapValue(S.nreloc);
94   SwapValue(S.flags);
95   SwapValue(S.reserved1);
96   SwapValue(S.reserved2);
97   SwapValue(S.reserved3);
98 }
99 
100 template<>
101 void SwapStruct(MachO::nlist &S) {
102   SwapValue(S.n_strx);
103   SwapValue(S.n_desc);
104   SwapValue(S.n_value);
105 }
106 
107 template<>
108 void SwapStruct(MachO::nlist_64 &S) {
109   SwapValue(S.n_strx);
110   SwapValue(S.n_desc);
111   SwapValue(S.n_value);
112 }
113 
114 template<>
115 void SwapStruct(MachO::mach_header &H) {
116   SwapValue(H.magic);
117   SwapValue(H.cputype);
118   SwapValue(H.cpusubtype);
119   SwapValue(H.filetype);
120   SwapValue(H.ncmds);
121   SwapValue(H.sizeofcmds);
122   SwapValue(H.flags);
123 }
124 
125 template<>
126 void SwapStruct(MachO::mach_header_64 &H) {
127   SwapValue(H.magic);
128   SwapValue(H.cputype);
129   SwapValue(H.cpusubtype);
130   SwapValue(H.filetype);
131   SwapValue(H.ncmds);
132   SwapValue(H.sizeofcmds);
133   SwapValue(H.flags);
134   SwapValue(H.reserved);
135 }
136 
137 template<>
138 void SwapStruct(MachO::symtab_command &C) {
139   SwapValue(C.cmd);
140   SwapValue(C.cmdsize);
141   SwapValue(C.symoff);
142   SwapValue(C.nsyms);
143   SwapValue(C.stroff);
144   SwapValue(C.strsize);
145 }
146 
147 template<>
148 void SwapStruct(MachO::dysymtab_command &C) {
149   SwapValue(C.cmd);
150   SwapValue(C.cmdsize);
151   SwapValue(C.ilocalsym);
152   SwapValue(C.nlocalsym);
153   SwapValue(C.iextdefsym);
154   SwapValue(C.nextdefsym);
155   SwapValue(C.iundefsym);
156   SwapValue(C.nundefsym);
157   SwapValue(C.tocoff);
158   SwapValue(C.ntoc);
159   SwapValue(C.modtaboff);
160   SwapValue(C.nmodtab);
161   SwapValue(C.extrefsymoff);
162   SwapValue(C.nextrefsyms);
163   SwapValue(C.indirectsymoff);
164   SwapValue(C.nindirectsyms);
165   SwapValue(C.extreloff);
166   SwapValue(C.nextrel);
167   SwapValue(C.locreloff);
168   SwapValue(C.nlocrel);
169 }
170 
171 template<>
172 void SwapStruct(MachO::linkedit_data_command &C) {
173   SwapValue(C.cmd);
174   SwapValue(C.cmdsize);
175   SwapValue(C.dataoff);
176   SwapValue(C.datasize);
177 }
178 
179 template<>
180 void SwapStruct(MachO::segment_command &C) {
181   SwapValue(C.cmd);
182   SwapValue(C.cmdsize);
183   SwapValue(C.vmaddr);
184   SwapValue(C.vmsize);
185   SwapValue(C.fileoff);
186   SwapValue(C.filesize);
187   SwapValue(C.maxprot);
188   SwapValue(C.initprot);
189   SwapValue(C.nsects);
190   SwapValue(C.flags);
191 }
192 
193 template<>
194 void SwapStruct(MachO::segment_command_64 &C) {
195   SwapValue(C.cmd);
196   SwapValue(C.cmdsize);
197   SwapValue(C.vmaddr);
198   SwapValue(C.vmsize);
199   SwapValue(C.fileoff);
200   SwapValue(C.filesize);
201   SwapValue(C.maxprot);
202   SwapValue(C.initprot);
203   SwapValue(C.nsects);
204   SwapValue(C.flags);
205 }
206 
207 template<>
208 void SwapStruct(uint32_t &C) {
209   SwapValue(C);
210 }
211 
212 template<>
213 void SwapStruct(MachO::linker_options_command &C) {
214   SwapValue(C.cmd);
215   SwapValue(C.cmdsize);
216   SwapValue(C.count);
217 }
218 
219 template<>
220 void SwapStruct(MachO::version_min_command&C) {
221   SwapValue(C.cmd);
222   SwapValue(C.cmdsize);
223   SwapValue(C.version);
224   SwapValue(C.reserved);
225 }
226 
227 template<>
228 void SwapStruct(MachO::dylib_command&C) {
229   SwapValue(C.cmd);
230   SwapValue(C.cmdsize);
231   SwapValue(C.dylib.name);
232   SwapValue(C.dylib.timestamp);
233   SwapValue(C.dylib.current_version);
234   SwapValue(C.dylib.compatibility_version);
235 }
236 
237 template<>
238 void SwapStruct(MachO::data_in_code_entry &C) {
239   SwapValue(C.offset);
240   SwapValue(C.length);
241   SwapValue(C.kind);
242 }
243 
244 template<typename T>
245 T getStruct(const MachOObjectFile *O, const char *P) {
246   T Cmd;
247   memcpy(&Cmd, P, sizeof(T));
248   if (O->isLittleEndian() != sys::IsLittleEndianHost)
249     SwapStruct(Cmd);
250   return Cmd;
251 }
252 
253 static uint32_t
254 getSegmentLoadCommandNumSections(const MachOObjectFile *O,
255                                  const MachOObjectFile::LoadCommandInfo &L) {
256   if (O->is64Bit()) {
257     MachO::segment_command_64 S = O->getSegment64LoadCommand(L);
258     return S.nsects;
259   }
260   MachO::segment_command S = O->getSegmentLoadCommand(L);
261   return S.nsects;
262 }
263 
264 static const char *
265 getSectionPtr(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
266               unsigned Sec) {
267   uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
268 
269   bool Is64 = O->is64Bit();
270   unsigned SegmentLoadSize = Is64 ? sizeof(MachO::segment_command_64) :
271                                     sizeof(MachO::segment_command);
272   unsigned SectionSize = Is64 ? sizeof(MachO::section_64) :
273                                 sizeof(MachO::section);
274 
275   uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
276   return reinterpret_cast<const char*>(SectionAddr);
277 }
278 
279 static const char *getPtr(const MachOObjectFile *O, size_t Offset) {
280   return O->getData().substr(Offset, 1).data();
281 }
282 
283 static nlist_base
284 getSymbolTableEntryBase(const MachOObjectFile *O, DataRefImpl DRI) {
285   const char *P = reinterpret_cast<const char *>(DRI.p);
286   return getStruct<nlist_base>(O, P);
287 }
288 
289 static StringRef parseSegmentOrSectionName(const char *P) {
290   if (P[15] == 0)
291     // Null terminated.
292     return P;
293   // Not null terminated, so this is a 16 char string.
294   return StringRef(P, 16);
295 }
296 
297 // Helper to advance a section or symbol iterator multiple increments at a time.
298 template<class T>
299 static void advance(T &it, size_t Val) {
300   while (Val--)
301     ++it;
302 }
303 
304 static unsigned getCPUType(const MachOObjectFile *O) {
305   return O->getHeader().cputype;
306 }
307 
308 static void printRelocationTargetName(const MachOObjectFile *O,
309                                       const MachO::any_relocation_info &RE,
310                                       raw_string_ostream &fmt) {
311   bool IsScattered = O->isRelocationScattered(RE);
312 
313   // Target of a scattered relocation is an address.  In the interest of
314   // generating pretty output, scan through the symbol table looking for a
315   // symbol that aligns with that address.  If we find one, print it.
316   // Otherwise, we just print the hex address of the target.
317   if (IsScattered) {
318     uint32_t Val = O->getPlainRelocationSymbolNum(RE);
319 
320     for (const SymbolRef &Symbol : O->symbols()) {
321       std::error_code ec;
322       uint64_t Addr;
323       StringRef Name;
324 
325       if ((ec = Symbol.getAddress(Addr)))
326         report_fatal_error(ec.message());
327       if (Addr != Val)
328         continue;
329       if ((ec = Symbol.getName(Name)))
330         report_fatal_error(ec.message());
331       fmt << Name;
332       return;
333     }
334 
335     // If we couldn't find a symbol that this relocation refers to, try
336     // to find a section beginning instead.
337     for (const SectionRef &Section : O->sections()) {
338       std::error_code ec;
339       uint64_t Addr;
340       StringRef Name;
341 
342       if ((ec = Section.getAddress(Addr)))
343         report_fatal_error(ec.message());
344       if (Addr != Val)
345         continue;
346       if ((ec = Section.getName(Name)))
347         report_fatal_error(ec.message());
348       fmt << Name;
349       return;
350     }
351 
352     fmt << format("0x%x", Val);
353     return;
354   }
355 
356   StringRef S;
357   bool isExtern = O->getPlainRelocationExternal(RE);
358   uint64_t Val = O->getPlainRelocationSymbolNum(RE);
359 
360   if (isExtern) {
361     symbol_iterator SI = O->symbol_begin();
362     advance(SI, Val);
363     SI->getName(S);
364   } else {
365     section_iterator SI = O->section_begin();
366     // Adjust for the fact that sections are 1-indexed.
367     advance(SI, Val - 1);
368     SI->getName(S);
369   }
370 
371   fmt << S;
372 }
373 
374 static uint32_t
375 getPlainRelocationAddress(const MachO::any_relocation_info &RE) {
376   return RE.r_word0;
377 }
378 
379 static unsigned
380 getScatteredRelocationAddress(const MachO::any_relocation_info &RE) {
381   return RE.r_word0 & 0xffffff;
382 }
383 
384 static bool getPlainRelocationPCRel(const MachOObjectFile *O,
385                                     const MachO::any_relocation_info &RE) {
386   if (O->isLittleEndian())
387     return (RE.r_word1 >> 24) & 1;
388   return (RE.r_word1 >> 7) & 1;
389 }
390 
391 static bool
392 getScatteredRelocationPCRel(const MachOObjectFile *O,
393                             const MachO::any_relocation_info &RE) {
394   return (RE.r_word0 >> 30) & 1;
395 }
396 
397 static unsigned getPlainRelocationLength(const MachOObjectFile *O,
398                                          const MachO::any_relocation_info &RE) {
399   if (O->isLittleEndian())
400     return (RE.r_word1 >> 25) & 3;
401   return (RE.r_word1 >> 5) & 3;
402 }
403 
404 static unsigned
405 getScatteredRelocationLength(const MachO::any_relocation_info &RE) {
406   return (RE.r_word0 >> 28) & 3;
407 }
408 
409 static unsigned getPlainRelocationType(const MachOObjectFile *O,
410                                        const MachO::any_relocation_info &RE) {
411   if (O->isLittleEndian())
412     return RE.r_word1 >> 28;
413   return RE.r_word1 & 0xf;
414 }
415 
416 static unsigned
417 getScatteredRelocationType(const MachO::any_relocation_info &RE) {
418   return (RE.r_word0 >> 24) & 0xf;
419 }
420 
421 static uint32_t getSectionFlags(const MachOObjectFile *O,
422                                 DataRefImpl Sec) {
423   if (O->is64Bit()) {
424     MachO::section_64 Sect = O->getSection64(Sec);
425     return Sect.flags;
426   }
427   MachO::section Sect = O->getSection(Sec);
428   return Sect.flags;
429 }
430 
431 MachOObjectFile::MachOObjectFile(MemoryBuffer *Object, bool IsLittleEndian,
432                                  bool Is64bits, std::error_code &EC,
433                                  bool BufferOwned)
434     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object, BufferOwned),
435       SymtabLoadCmd(nullptr), DysymtabLoadCmd(nullptr),
436       DataInCodeLoadCmd(nullptr) {
437   uint32_t LoadCommandCount = this->getHeader().ncmds;
438   MachO::LoadCommandType SegmentLoadType = is64Bit() ?
439     MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT;
440 
441   MachOObjectFile::LoadCommandInfo Load = getFirstLoadCommandInfo();
442   for (unsigned I = 0; ; ++I) {
443     if (Load.C.cmd == MachO::LC_SYMTAB) {
444       assert(!SymtabLoadCmd && "Multiple symbol tables");
445       SymtabLoadCmd = Load.Ptr;
446     } else if (Load.C.cmd == MachO::LC_DYSYMTAB) {
447       assert(!DysymtabLoadCmd && "Multiple dynamic symbol tables");
448       DysymtabLoadCmd = Load.Ptr;
449     } else if (Load.C.cmd == MachO::LC_DATA_IN_CODE) {
450       assert(!DataInCodeLoadCmd && "Multiple data in code tables");
451       DataInCodeLoadCmd = Load.Ptr;
452     } else if (Load.C.cmd == SegmentLoadType) {
453       uint32_t NumSections = getSegmentLoadCommandNumSections(this, Load);
454       for (unsigned J = 0; J < NumSections; ++J) {
455         const char *Sec = getSectionPtr(this, Load, J);
456         Sections.push_back(Sec);
457       }
458     } else if (Load.C.cmd == MachO::LC_LOAD_DYLIB ||
459                Load.C.cmd == MachO::LC_LOAD_WEAK_DYLIB ||
460                Load.C.cmd == MachO::LC_LAZY_LOAD_DYLIB ||
461                Load.C.cmd == MachO::LC_REEXPORT_DYLIB ||
462                Load.C.cmd == MachO::LC_LOAD_UPWARD_DYLIB) {
463       Libraries.push_back(Load.Ptr);
464     }
465 
466     if (I == LoadCommandCount - 1)
467       break;
468     else
469       Load = getNextLoadCommandInfo(Load);
470   }
471 }
472 
473 void MachOObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
474   unsigned SymbolTableEntrySize = is64Bit() ?
475     sizeof(MachO::nlist_64) :
476     sizeof(MachO::nlist);
477   Symb.p += SymbolTableEntrySize;
478 }
479 
480 std::error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
481                                                StringRef &Res) const {
482   StringRef StringTable = getStringTableData();
483   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
484   const char *Start = &StringTable.data()[Entry.n_strx];
485   Res = StringRef(Start);
486   return object_error::success;
487 }
488 
489 // getIndirectName() returns the name of the alias'ed symbol who's string table
490 // index is in the n_value field.
491 std::error_code MachOObjectFile::getIndirectName(DataRefImpl Symb,
492                                                  StringRef &Res) const {
493   StringRef StringTable = getStringTableData();
494   uint64_t NValue;
495   if (is64Bit()) {
496     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
497     NValue = Entry.n_value;
498     if ((Entry.n_type & MachO::N_TYPE) != MachO::N_INDR)
499       return object_error::parse_failed;
500   } else {
501     MachO::nlist Entry = getSymbolTableEntry(Symb);
502     NValue = Entry.n_value;
503     if ((Entry.n_type & MachO::N_TYPE) != MachO::N_INDR)
504       return object_error::parse_failed;
505   }
506   if (NValue >= StringTable.size())
507     return object_error::parse_failed;
508   const char *Start = &StringTable.data()[NValue];
509   Res = StringRef(Start);
510   return object_error::success;
511 }
512 
513 std::error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
514                                                   uint64_t &Res) const {
515   if (is64Bit()) {
516     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
517     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
518         Entry.n_value == 0)
519       Res = UnknownAddressOrSize;
520     else
521       Res = Entry.n_value;
522   } else {
523     MachO::nlist Entry = getSymbolTableEntry(Symb);
524     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
525         Entry.n_value == 0)
526       Res = UnknownAddressOrSize;
527     else
528       Res = Entry.n_value;
529   }
530   return object_error::success;
531 }
532 
533 std::error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
534                                                     uint32_t &Result) const {
535   uint32_t flags = getSymbolFlags(DRI);
536   if (flags & SymbolRef::SF_Common) {
537     nlist_base Entry = getSymbolTableEntryBase(this, DRI);
538     Result = 1 << MachO::GET_COMM_ALIGN(Entry.n_desc);
539   } else {
540     Result = 0;
541   }
542   return object_error::success;
543 }
544 
545 std::error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
546                                                uint64_t &Result) const {
547   uint64_t BeginOffset;
548   uint64_t EndOffset = 0;
549   uint8_t SectionIndex;
550 
551   nlist_base Entry = getSymbolTableEntryBase(this, DRI);
552   uint64_t Value;
553   getSymbolAddress(DRI, Value);
554   if (Value == UnknownAddressOrSize) {
555     Result = UnknownAddressOrSize;
556     return object_error::success;
557   }
558 
559   BeginOffset = Value;
560 
561   SectionIndex = Entry.n_sect;
562   if (!SectionIndex) {
563     uint32_t flags = getSymbolFlags(DRI);
564     if (flags & SymbolRef::SF_Common)
565       Result = Value;
566     else
567       Result = UnknownAddressOrSize;
568     return object_error::success;
569   }
570   // Unfortunately symbols are unsorted so we need to touch all
571   // symbols from load command
572   for (const SymbolRef &Symbol : symbols()) {
573     DataRefImpl DRI = Symbol.getRawDataRefImpl();
574     Entry = getSymbolTableEntryBase(this, DRI);
575     getSymbolAddress(DRI, Value);
576     if (Value == UnknownAddressOrSize)
577       continue;
578     if (Entry.n_sect == SectionIndex && Value > BeginOffset)
579       if (!EndOffset || Value < EndOffset)
580         EndOffset = Value;
581   }
582   if (!EndOffset) {
583     uint64_t Size;
584     DataRefImpl Sec;
585     Sec.d.a = SectionIndex-1;
586     getSectionSize(Sec, Size);
587     getSectionAddress(Sec, EndOffset);
588     EndOffset += Size;
589   }
590   Result = EndOffset - BeginOffset;
591   return object_error::success;
592 }
593 
594 std::error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
595                                                SymbolRef::Type &Res) const {
596   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
597   uint8_t n_type = Entry.n_type;
598 
599   Res = SymbolRef::ST_Other;
600 
601   // If this is a STAB debugging symbol, we can do nothing more.
602   if (n_type & MachO::N_STAB) {
603     Res = SymbolRef::ST_Debug;
604     return object_error::success;
605   }
606 
607   switch (n_type & MachO::N_TYPE) {
608     case MachO::N_UNDF :
609       Res = SymbolRef::ST_Unknown;
610       break;
611     case MachO::N_SECT :
612       Res = SymbolRef::ST_Function;
613       break;
614   }
615   return object_error::success;
616 }
617 
618 uint32_t MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
619   nlist_base Entry = getSymbolTableEntryBase(this, DRI);
620 
621   uint8_t MachOType = Entry.n_type;
622   uint16_t MachOFlags = Entry.n_desc;
623 
624   uint32_t Result = SymbolRef::SF_None;
625 
626   if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF)
627     Result |= SymbolRef::SF_Undefined;
628 
629   if ((MachOType & MachO::N_TYPE) == MachO::N_INDR)
630     Result |= SymbolRef::SF_Indirect;
631 
632   if (MachOType & MachO::N_STAB)
633     Result |= SymbolRef::SF_FormatSpecific;
634 
635   if (MachOType & MachO::N_EXT) {
636     Result |= SymbolRef::SF_Global;
637     if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF) {
638       uint64_t Value;
639       getSymbolAddress(DRI, Value);
640       if (Value && Value != UnknownAddressOrSize)
641         Result |= SymbolRef::SF_Common;
642     }
643   }
644 
645   if (MachOFlags & (MachO::N_WEAK_REF | MachO::N_WEAK_DEF))
646     Result |= SymbolRef::SF_Weak;
647 
648   if ((MachOType & MachO::N_TYPE) == MachO::N_ABS)
649     Result |= SymbolRef::SF_Absolute;
650 
651   return Result;
652 }
653 
654 std::error_code MachOObjectFile::getSymbolSection(DataRefImpl Symb,
655                                                   section_iterator &Res) const {
656   nlist_base Entry = getSymbolTableEntryBase(this, Symb);
657   uint8_t index = Entry.n_sect;
658 
659   if (index == 0) {
660     Res = section_end();
661   } else {
662     DataRefImpl DRI;
663     DRI.d.a = index - 1;
664     Res = section_iterator(SectionRef(DRI, this));
665   }
666 
667   return object_error::success;
668 }
669 
670 void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
671   Sec.d.a++;
672 }
673 
674 std::error_code MachOObjectFile::getSectionName(DataRefImpl Sec,
675                                                 StringRef &Result) const {
676   ArrayRef<char> Raw = getSectionRawName(Sec);
677   Result = parseSegmentOrSectionName(Raw.data());
678   return object_error::success;
679 }
680 
681 std::error_code MachOObjectFile::getSectionAddress(DataRefImpl Sec,
682                                                    uint64_t &Res) const {
683   if (is64Bit()) {
684     MachO::section_64 Sect = getSection64(Sec);
685     Res = Sect.addr;
686   } else {
687     MachO::section Sect = getSection(Sec);
688     Res = Sect.addr;
689   }
690   return object_error::success;
691 }
692 
693 std::error_code MachOObjectFile::getSectionSize(DataRefImpl Sec,
694                                                 uint64_t &Res) const {
695   if (is64Bit()) {
696     MachO::section_64 Sect = getSection64(Sec);
697     Res = Sect.size;
698   } else {
699     MachO::section Sect = getSection(Sec);
700     Res = Sect.size;
701   }
702 
703   return object_error::success;
704 }
705 
706 std::error_code MachOObjectFile::getSectionContents(DataRefImpl Sec,
707                                                     StringRef &Res) const {
708   uint32_t Offset;
709   uint64_t Size;
710 
711   if (is64Bit()) {
712     MachO::section_64 Sect = getSection64(Sec);
713     Offset = Sect.offset;
714     Size = Sect.size;
715   } else {
716     MachO::section Sect = getSection(Sec);
717     Offset = Sect.offset;
718     Size = Sect.size;
719   }
720 
721   Res = this->getData().substr(Offset, Size);
722   return object_error::success;
723 }
724 
725 std::error_code MachOObjectFile::getSectionAlignment(DataRefImpl Sec,
726                                                      uint64_t &Res) const {
727   uint32_t Align;
728   if (is64Bit()) {
729     MachO::section_64 Sect = getSection64(Sec);
730     Align = Sect.align;
731   } else {
732     MachO::section Sect = getSection(Sec);
733     Align = Sect.align;
734   }
735 
736   Res = uint64_t(1) << Align;
737   return object_error::success;
738 }
739 
740 std::error_code MachOObjectFile::isSectionText(DataRefImpl Sec,
741                                                bool &Res) const {
742   uint32_t Flags = getSectionFlags(this, Sec);
743   Res = Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
744   return object_error::success;
745 }
746 
747 std::error_code MachOObjectFile::isSectionData(DataRefImpl Sec,
748                                                bool &Result) const {
749   uint32_t Flags = getSectionFlags(this, Sec);
750   unsigned SectionType = Flags & MachO::SECTION_TYPE;
751   Result = !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
752            !(SectionType == MachO::S_ZEROFILL ||
753              SectionType == MachO::S_GB_ZEROFILL);
754   return object_error::success;
755 }
756 
757 std::error_code MachOObjectFile::isSectionBSS(DataRefImpl Sec,
758                                               bool &Result) const {
759   uint32_t Flags = getSectionFlags(this, Sec);
760   unsigned SectionType = Flags & MachO::SECTION_TYPE;
761   Result = !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
762            (SectionType == MachO::S_ZEROFILL ||
763             SectionType == MachO::S_GB_ZEROFILL);
764   return object_error::success;
765 }
766 
767 std::error_code
768 MachOObjectFile::isSectionRequiredForExecution(DataRefImpl Sec,
769                                                bool &Result) const {
770   // FIXME: Unimplemented.
771   Result = true;
772   return object_error::success;
773 }
774 
775 std::error_code MachOObjectFile::isSectionVirtual(DataRefImpl Sec,
776                                                   bool &Result) const {
777   // FIXME: Unimplemented.
778   Result = false;
779   return object_error::success;
780 }
781 
782 std::error_code MachOObjectFile::isSectionZeroInit(DataRefImpl Sec,
783                                                    bool &Res) const {
784   uint32_t Flags = getSectionFlags(this, Sec);
785   unsigned SectionType = Flags & MachO::SECTION_TYPE;
786   Res = SectionType == MachO::S_ZEROFILL ||
787     SectionType == MachO::S_GB_ZEROFILL;
788   return object_error::success;
789 }
790 
791 std::error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
792                                                        bool &Result) const {
793   // Consider using the code from isSectionText to look for __const sections.
794   // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
795   // to use section attributes to distinguish code from data.
796 
797   // FIXME: Unimplemented.
798   Result = false;
799   return object_error::success;
800 }
801 
802 std::error_code MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec,
803                                                        DataRefImpl Symb,
804                                                        bool &Result) const {
805   SymbolRef::Type ST;
806   this->getSymbolType(Symb, ST);
807   if (ST == SymbolRef::ST_Unknown) {
808     Result = false;
809     return object_error::success;
810   }
811 
812   uint64_t SectBegin, SectEnd;
813   getSectionAddress(Sec, SectBegin);
814   getSectionSize(Sec, SectEnd);
815   SectEnd += SectBegin;
816 
817   uint64_t SymAddr;
818   getSymbolAddress(Symb, SymAddr);
819   Result = (SymAddr >= SectBegin) && (SymAddr < SectEnd);
820 
821   return object_error::success;
822 }
823 
824 relocation_iterator MachOObjectFile::section_rel_begin(DataRefImpl Sec) const {
825   DataRefImpl Ret;
826   Ret.d.a = Sec.d.a;
827   Ret.d.b = 0;
828   return relocation_iterator(RelocationRef(Ret, this));
829 }
830 
831 relocation_iterator
832 MachOObjectFile::section_rel_end(DataRefImpl Sec) const {
833   uint32_t Num;
834   if (is64Bit()) {
835     MachO::section_64 Sect = getSection64(Sec);
836     Num = Sect.nreloc;
837   } else {
838     MachO::section Sect = getSection(Sec);
839     Num = Sect.nreloc;
840   }
841 
842   DataRefImpl Ret;
843   Ret.d.a = Sec.d.a;
844   Ret.d.b = Num;
845   return relocation_iterator(RelocationRef(Ret, this));
846 }
847 
848 void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
849   ++Rel.d.b;
850 }
851 
852 std::error_code MachOObjectFile::getRelocationAddress(DataRefImpl Rel,
853                                                       uint64_t &Res) const {
854   uint64_t Offset;
855   getRelocationOffset(Rel, Offset);
856 
857   DataRefImpl Sec;
858   Sec.d.a = Rel.d.a;
859   uint64_t SecAddress;
860   getSectionAddress(Sec, SecAddress);
861   Res = SecAddress + Offset;
862   return object_error::success;
863 }
864 
865 std::error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
866                                                      uint64_t &Res) const {
867   assert(getHeader().filetype == MachO::MH_OBJECT &&
868          "Only implemented for MH_OBJECT");
869   MachO::any_relocation_info RE = getRelocation(Rel);
870   Res = getAnyRelocationAddress(RE);
871   return object_error::success;
872 }
873 
874 symbol_iterator
875 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
876   MachO::any_relocation_info RE = getRelocation(Rel);
877   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
878   bool isExtern = getPlainRelocationExternal(RE);
879   if (!isExtern)
880     return symbol_end();
881 
882   MachO::symtab_command S = getSymtabLoadCommand();
883   unsigned SymbolTableEntrySize = is64Bit() ?
884     sizeof(MachO::nlist_64) :
885     sizeof(MachO::nlist);
886   uint64_t Offset = S.symoff + SymbolIdx * SymbolTableEntrySize;
887   DataRefImpl Sym;
888   Sym.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
889   return symbol_iterator(SymbolRef(Sym, this));
890 }
891 
892 std::error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
893                                                    uint64_t &Res) const {
894   MachO::any_relocation_info RE = getRelocation(Rel);
895   Res = getAnyRelocationType(RE);
896   return object_error::success;
897 }
898 
899 std::error_code
900 MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
901                                        SmallVectorImpl<char> &Result) const {
902   StringRef res;
903   uint64_t RType;
904   getRelocationType(Rel, RType);
905 
906   unsigned Arch = this->getArch();
907 
908   switch (Arch) {
909     case Triple::x86: {
910       static const char *const Table[] =  {
911         "GENERIC_RELOC_VANILLA",
912         "GENERIC_RELOC_PAIR",
913         "GENERIC_RELOC_SECTDIFF",
914         "GENERIC_RELOC_PB_LA_PTR",
915         "GENERIC_RELOC_LOCAL_SECTDIFF",
916         "GENERIC_RELOC_TLV" };
917 
918       if (RType > 5)
919         res = "Unknown";
920       else
921         res = Table[RType];
922       break;
923     }
924     case Triple::x86_64: {
925       static const char *const Table[] =  {
926         "X86_64_RELOC_UNSIGNED",
927         "X86_64_RELOC_SIGNED",
928         "X86_64_RELOC_BRANCH",
929         "X86_64_RELOC_GOT_LOAD",
930         "X86_64_RELOC_GOT",
931         "X86_64_RELOC_SUBTRACTOR",
932         "X86_64_RELOC_SIGNED_1",
933         "X86_64_RELOC_SIGNED_2",
934         "X86_64_RELOC_SIGNED_4",
935         "X86_64_RELOC_TLV" };
936 
937       if (RType > 9)
938         res = "Unknown";
939       else
940         res = Table[RType];
941       break;
942     }
943     case Triple::arm: {
944       static const char *const Table[] =  {
945         "ARM_RELOC_VANILLA",
946         "ARM_RELOC_PAIR",
947         "ARM_RELOC_SECTDIFF",
948         "ARM_RELOC_LOCAL_SECTDIFF",
949         "ARM_RELOC_PB_LA_PTR",
950         "ARM_RELOC_BR24",
951         "ARM_THUMB_RELOC_BR22",
952         "ARM_THUMB_32BIT_BRANCH",
953         "ARM_RELOC_HALF",
954         "ARM_RELOC_HALF_SECTDIFF" };
955 
956       if (RType > 9)
957         res = "Unknown";
958       else
959         res = Table[RType];
960       break;
961     }
962     case Triple::arm64:
963     case Triple::aarch64: {
964       static const char *const Table[] = {
965         "ARM64_RELOC_UNSIGNED",           "ARM64_RELOC_SUBTRACTOR",
966         "ARM64_RELOC_BRANCH26",           "ARM64_RELOC_PAGE21",
967         "ARM64_RELOC_PAGEOFF12",          "ARM64_RELOC_GOT_LOAD_PAGE21",
968         "ARM64_RELOC_GOT_LOAD_PAGEOFF12", "ARM64_RELOC_POINTER_TO_GOT",
969         "ARM64_RELOC_TLVP_LOAD_PAGE21",   "ARM64_RELOC_TLVP_LOAD_PAGEOFF12",
970         "ARM64_RELOC_ADDEND"
971       };
972 
973       if (RType >= array_lengthof(Table))
974         res = "Unknown";
975       else
976         res = Table[RType];
977       break;
978     }
979     case Triple::ppc: {
980       static const char *const Table[] =  {
981         "PPC_RELOC_VANILLA",
982         "PPC_RELOC_PAIR",
983         "PPC_RELOC_BR14",
984         "PPC_RELOC_BR24",
985         "PPC_RELOC_HI16",
986         "PPC_RELOC_LO16",
987         "PPC_RELOC_HA16",
988         "PPC_RELOC_LO14",
989         "PPC_RELOC_SECTDIFF",
990         "PPC_RELOC_PB_LA_PTR",
991         "PPC_RELOC_HI16_SECTDIFF",
992         "PPC_RELOC_LO16_SECTDIFF",
993         "PPC_RELOC_HA16_SECTDIFF",
994         "PPC_RELOC_JBSR",
995         "PPC_RELOC_LO14_SECTDIFF",
996         "PPC_RELOC_LOCAL_SECTDIFF" };
997 
998       if (RType > 15)
999         res = "Unknown";
1000       else
1001         res = Table[RType];
1002       break;
1003     }
1004     case Triple::UnknownArch:
1005       res = "Unknown";
1006       break;
1007   }
1008   Result.append(res.begin(), res.end());
1009   return object_error::success;
1010 }
1011 
1012 std::error_code
1013 MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
1014                                           SmallVectorImpl<char> &Result) const {
1015   MachO::any_relocation_info RE = getRelocation(Rel);
1016 
1017   unsigned Arch = this->getArch();
1018 
1019   std::string fmtbuf;
1020   raw_string_ostream fmt(fmtbuf);
1021   unsigned Type = this->getAnyRelocationType(RE);
1022   bool IsPCRel = this->getAnyRelocationPCRel(RE);
1023 
1024   // Determine any addends that should be displayed with the relocation.
1025   // These require decoding the relocation type, which is triple-specific.
1026 
1027   // X86_64 has entirely custom relocation types.
1028   if (Arch == Triple::x86_64) {
1029     bool isPCRel = getAnyRelocationPCRel(RE);
1030 
1031     switch (Type) {
1032       case MachO::X86_64_RELOC_GOT_LOAD:
1033       case MachO::X86_64_RELOC_GOT: {
1034         printRelocationTargetName(this, RE, fmt);
1035         fmt << "@GOT";
1036         if (isPCRel) fmt << "PCREL";
1037         break;
1038       }
1039       case MachO::X86_64_RELOC_SUBTRACTOR: {
1040         DataRefImpl RelNext = Rel;
1041         moveRelocationNext(RelNext);
1042         MachO::any_relocation_info RENext = getRelocation(RelNext);
1043 
1044         // X86_64_RELOC_SUBTRACTOR must be followed by a relocation of type
1045         // X86_64_RELOC_UNSIGNED.
1046         // NOTE: Scattered relocations don't exist on x86_64.
1047         unsigned RType = getAnyRelocationType(RENext);
1048         if (RType != MachO::X86_64_RELOC_UNSIGNED)
1049           report_fatal_error("Expected X86_64_RELOC_UNSIGNED after "
1050                              "X86_64_RELOC_SUBTRACTOR.");
1051 
1052         // The X86_64_RELOC_UNSIGNED contains the minuend symbol;
1053         // X86_64_RELOC_SUBTRACTOR contains the subtrahend.
1054         printRelocationTargetName(this, RENext, fmt);
1055         fmt << "-";
1056         printRelocationTargetName(this, RE, fmt);
1057         break;
1058       }
1059       case MachO::X86_64_RELOC_TLV:
1060         printRelocationTargetName(this, RE, fmt);
1061         fmt << "@TLV";
1062         if (isPCRel) fmt << "P";
1063         break;
1064       case MachO::X86_64_RELOC_SIGNED_1:
1065         printRelocationTargetName(this, RE, fmt);
1066         fmt << "-1";
1067         break;
1068       case MachO::X86_64_RELOC_SIGNED_2:
1069         printRelocationTargetName(this, RE, fmt);
1070         fmt << "-2";
1071         break;
1072       case MachO::X86_64_RELOC_SIGNED_4:
1073         printRelocationTargetName(this, RE, fmt);
1074         fmt << "-4";
1075         break;
1076       default:
1077         printRelocationTargetName(this, RE, fmt);
1078         break;
1079     }
1080   // X86 and ARM share some relocation types in common.
1081   } else if (Arch == Triple::x86 || Arch == Triple::arm ||
1082              Arch == Triple::ppc) {
1083     // Generic relocation types...
1084     switch (Type) {
1085       case MachO::GENERIC_RELOC_PAIR: // prints no info
1086         return object_error::success;
1087       case MachO::GENERIC_RELOC_SECTDIFF: {
1088         DataRefImpl RelNext = Rel;
1089         moveRelocationNext(RelNext);
1090         MachO::any_relocation_info RENext = getRelocation(RelNext);
1091 
1092         // X86 sect diff's must be followed by a relocation of type
1093         // GENERIC_RELOC_PAIR.
1094         unsigned RType = getAnyRelocationType(RENext);
1095 
1096         if (RType != MachO::GENERIC_RELOC_PAIR)
1097           report_fatal_error("Expected GENERIC_RELOC_PAIR after "
1098                              "GENERIC_RELOC_SECTDIFF.");
1099 
1100         printRelocationTargetName(this, RE, fmt);
1101         fmt << "-";
1102         printRelocationTargetName(this, RENext, fmt);
1103         break;
1104       }
1105     }
1106 
1107     if (Arch == Triple::x86 || Arch == Triple::ppc) {
1108       switch (Type) {
1109         case MachO::GENERIC_RELOC_LOCAL_SECTDIFF: {
1110           DataRefImpl RelNext = Rel;
1111           moveRelocationNext(RelNext);
1112           MachO::any_relocation_info RENext = getRelocation(RelNext);
1113 
1114           // X86 sect diff's must be followed by a relocation of type
1115           // GENERIC_RELOC_PAIR.
1116           unsigned RType = getAnyRelocationType(RENext);
1117           if (RType != MachO::GENERIC_RELOC_PAIR)
1118             report_fatal_error("Expected GENERIC_RELOC_PAIR after "
1119                                "GENERIC_RELOC_LOCAL_SECTDIFF.");
1120 
1121           printRelocationTargetName(this, RE, fmt);
1122           fmt << "-";
1123           printRelocationTargetName(this, RENext, fmt);
1124           break;
1125         }
1126         case MachO::GENERIC_RELOC_TLV: {
1127           printRelocationTargetName(this, RE, fmt);
1128           fmt << "@TLV";
1129           if (IsPCRel) fmt << "P";
1130           break;
1131         }
1132         default:
1133           printRelocationTargetName(this, RE, fmt);
1134       }
1135     } else { // ARM-specific relocations
1136       switch (Type) {
1137         case MachO::ARM_RELOC_HALF:
1138         case MachO::ARM_RELOC_HALF_SECTDIFF: {
1139           // Half relocations steal a bit from the length field to encode
1140           // whether this is an upper16 or a lower16 relocation.
1141           bool isUpper = getAnyRelocationLength(RE) >> 1;
1142 
1143           if (isUpper)
1144             fmt << ":upper16:(";
1145           else
1146             fmt << ":lower16:(";
1147           printRelocationTargetName(this, RE, fmt);
1148 
1149           DataRefImpl RelNext = Rel;
1150           moveRelocationNext(RelNext);
1151           MachO::any_relocation_info RENext = getRelocation(RelNext);
1152 
1153           // ARM half relocs must be followed by a relocation of type
1154           // ARM_RELOC_PAIR.
1155           unsigned RType = getAnyRelocationType(RENext);
1156           if (RType != MachO::ARM_RELOC_PAIR)
1157             report_fatal_error("Expected ARM_RELOC_PAIR after "
1158                                "ARM_RELOC_HALF");
1159 
1160           // NOTE: The half of the target virtual address is stashed in the
1161           // address field of the secondary relocation, but we can't reverse
1162           // engineer the constant offset from it without decoding the movw/movt
1163           // instruction to find the other half in its immediate field.
1164 
1165           // ARM_RELOC_HALF_SECTDIFF encodes the second section in the
1166           // symbol/section pointer of the follow-on relocation.
1167           if (Type == MachO::ARM_RELOC_HALF_SECTDIFF) {
1168             fmt << "-";
1169             printRelocationTargetName(this, RENext, fmt);
1170           }
1171 
1172           fmt << ")";
1173           break;
1174         }
1175         default: {
1176           printRelocationTargetName(this, RE, fmt);
1177         }
1178       }
1179     }
1180   } else
1181     printRelocationTargetName(this, RE, fmt);
1182 
1183   fmt.flush();
1184   Result.append(fmtbuf.begin(), fmtbuf.end());
1185   return object_error::success;
1186 }
1187 
1188 std::error_code MachOObjectFile::getRelocationHidden(DataRefImpl Rel,
1189                                                      bool &Result) const {
1190   unsigned Arch = getArch();
1191   uint64_t Type;
1192   getRelocationType(Rel, Type);
1193 
1194   Result = false;
1195 
1196   // On arches that use the generic relocations, GENERIC_RELOC_PAIR
1197   // is always hidden.
1198   if (Arch == Triple::x86 || Arch == Triple::arm || Arch == Triple::ppc) {
1199     if (Type == MachO::GENERIC_RELOC_PAIR) Result = true;
1200   } else if (Arch == Triple::x86_64) {
1201     // On x86_64, X86_64_RELOC_UNSIGNED is hidden only when it follows
1202     // an X86_64_RELOC_SUBTRACTOR.
1203     if (Type == MachO::X86_64_RELOC_UNSIGNED && Rel.d.a > 0) {
1204       DataRefImpl RelPrev = Rel;
1205       RelPrev.d.a--;
1206       uint64_t PrevType;
1207       getRelocationType(RelPrev, PrevType);
1208       if (PrevType == MachO::X86_64_RELOC_SUBTRACTOR)
1209         Result = true;
1210     }
1211   }
1212 
1213   return object_error::success;
1214 }
1215 
1216 std::error_code MachOObjectFile::getLibraryNext(DataRefImpl LibData,
1217                                                 LibraryRef &Res) const {
1218   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1219 }
1220 
1221 std::error_code MachOObjectFile::getLibraryPath(DataRefImpl LibData,
1222                                                 StringRef &Res) const {
1223   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1224 }
1225 
1226 //
1227 // guessLibraryShortName() is passed a name of a dynamic library and returns a
1228 // guess on what the short name is.  Then name is returned as a substring of the
1229 // StringRef Name passed in.  The name of the dynamic library is recognized as
1230 // a framework if it has one of the two following forms:
1231 //      Foo.framework/Versions/A/Foo
1232 //      Foo.framework/Foo
1233 // Where A and Foo can be any string.  And may contain a trailing suffix
1234 // starting with an underbar.  If the Name is recognized as a framework then
1235 // isFramework is set to true else it is set to false.  If the Name has a
1236 // suffix then Suffix is set to the substring in Name that contains the suffix
1237 // else it is set to a NULL StringRef.
1238 //
1239 // The Name of the dynamic library is recognized as a library name if it has
1240 // one of the two following forms:
1241 //      libFoo.A.dylib
1242 //      libFoo.dylib
1243 // The library may have a suffix trailing the name Foo of the form:
1244 //      libFoo_profile.A.dylib
1245 //      libFoo_profile.dylib
1246 //
1247 // The Name of the dynamic library is also recognized as a library name if it
1248 // has the following form:
1249 //      Foo.qtx
1250 //
1251 // If the Name of the dynamic library is none of the forms above then a NULL
1252 // StringRef is returned.
1253 //
1254 StringRef MachOObjectFile::guessLibraryShortName(StringRef Name,
1255                                                  bool &isFramework,
1256                                                  StringRef &Suffix) {
1257   StringRef Foo, F, DotFramework, V, Dylib, Lib, Dot, Qtx;
1258   size_t a, b, c, d, Idx;
1259 
1260   isFramework = false;
1261   Suffix = StringRef();
1262 
1263   // Pull off the last component and make Foo point to it
1264   a = Name.rfind('/');
1265   if (a == Name.npos || a == 0)
1266     goto guess_library;
1267   Foo = Name.slice(a+1, Name.npos);
1268 
1269   // Look for a suffix starting with a '_'
1270   Idx = Foo.rfind('_');
1271   if (Idx != Foo.npos && Foo.size() >= 2) {
1272     Suffix = Foo.slice(Idx, Foo.npos);
1273     Foo = Foo.slice(0, Idx);
1274   }
1275 
1276   // First look for the form Foo.framework/Foo
1277   b = Name.rfind('/', a);
1278   if (b == Name.npos)
1279     Idx = 0;
1280   else
1281     Idx = b+1;
1282   F = Name.slice(Idx, Idx + Foo.size());
1283   DotFramework = Name.slice(Idx + Foo.size(),
1284                             Idx + Foo.size() + sizeof(".framework/")-1);
1285   if (F == Foo && DotFramework == ".framework/") {
1286     isFramework = true;
1287     return Foo;
1288   }
1289 
1290   // Next look for the form Foo.framework/Versions/A/Foo
1291   if (b == Name.npos)
1292     goto guess_library;
1293   c =  Name.rfind('/', b);
1294   if (c == Name.npos || c == 0)
1295     goto guess_library;
1296   V = Name.slice(c+1, Name.npos);
1297   if (!V.startswith("Versions/"))
1298     goto guess_library;
1299   d =  Name.rfind('/', c);
1300   if (d == Name.npos)
1301     Idx = 0;
1302   else
1303     Idx = d+1;
1304   F = Name.slice(Idx, Idx + Foo.size());
1305   DotFramework = Name.slice(Idx + Foo.size(),
1306                             Idx + Foo.size() + sizeof(".framework/")-1);
1307   if (F == Foo && DotFramework == ".framework/") {
1308     isFramework = true;
1309     return Foo;
1310   }
1311 
1312 guess_library:
1313   // pull off the suffix after the "." and make a point to it
1314   a = Name.rfind('.');
1315   if (a == Name.npos || a == 0)
1316     return StringRef();
1317   Dylib = Name.slice(a, Name.npos);
1318   if (Dylib != ".dylib")
1319     goto guess_qtx;
1320 
1321   // First pull off the version letter for the form Foo.A.dylib if any.
1322   if (a >= 3) {
1323     Dot = Name.slice(a-2, a-1);
1324     if (Dot == ".")
1325       a = a - 2;
1326   }
1327 
1328   b = Name.rfind('/', a);
1329   if (b == Name.npos)
1330     b = 0;
1331   else
1332     b = b+1;
1333   // ignore any suffix after an underbar like Foo_profile.A.dylib
1334   Idx = Name.find('_', b);
1335   if (Idx != Name.npos && Idx != b) {
1336     Lib = Name.slice(b, Idx);
1337     Suffix = Name.slice(Idx, a);
1338   }
1339   else
1340     Lib = Name.slice(b, a);
1341   // There are incorrect library names of the form:
1342   // libATS.A_profile.dylib so check for these.
1343   if (Lib.size() >= 3) {
1344     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
1345     if (Dot == ".")
1346       Lib = Lib.slice(0, Lib.size()-2);
1347   }
1348   return Lib;
1349 
1350 guess_qtx:
1351   Qtx = Name.slice(a, Name.npos);
1352   if (Qtx != ".qtx")
1353     return StringRef();
1354   b = Name.rfind('/', a);
1355   if (b == Name.npos)
1356     Lib = Name.slice(0, a);
1357   else
1358     Lib = Name.slice(b+1, a);
1359   // There are library names of the form: QT.A.qtx so check for these.
1360   if (Lib.size() >= 3) {
1361     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
1362     if (Dot == ".")
1363       Lib = Lib.slice(0, Lib.size()-2);
1364   }
1365   return Lib;
1366 }
1367 
1368 // getLibraryShortNameByIndex() is used to get the short name of the library
1369 // for an undefined symbol in a linked Mach-O binary that was linked with the
1370 // normal two-level namespace default (that is MH_TWOLEVEL in the header).
1371 // It is passed the index (0 - based) of the library as translated from
1372 // GET_LIBRARY_ORDINAL (1 - based).
1373 std::error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
1374                                                             StringRef &Res) {
1375   if (Index >= Libraries.size())
1376     return object_error::parse_failed;
1377 
1378   MachO::dylib_command D =
1379     getStruct<MachO::dylib_command>(this, Libraries[Index]);
1380   if (D.dylib.name >= D.cmdsize)
1381     return object_error::parse_failed;
1382 
1383   // If the cache of LibrariesShortNames is not built up do that first for
1384   // all the Libraries.
1385   if (LibrariesShortNames.size() == 0) {
1386     for (unsigned i = 0; i < Libraries.size(); i++) {
1387       MachO::dylib_command D =
1388         getStruct<MachO::dylib_command>(this, Libraries[i]);
1389       if (D.dylib.name >= D.cmdsize) {
1390         LibrariesShortNames.push_back(StringRef());
1391         continue;
1392       }
1393       char *P = (char *)(Libraries[i]) + D.dylib.name;
1394       StringRef Name = StringRef(P);
1395       StringRef Suffix;
1396       bool isFramework;
1397       StringRef shortName = guessLibraryShortName(Name, isFramework, Suffix);
1398       if (shortName == StringRef())
1399         LibrariesShortNames.push_back(Name);
1400       else
1401         LibrariesShortNames.push_back(shortName);
1402     }
1403   }
1404 
1405   Res = LibrariesShortNames[Index];
1406   return object_error::success;
1407 }
1408 
1409 basic_symbol_iterator MachOObjectFile::symbol_begin_impl() const {
1410   return getSymbolByIndex(0);
1411 }
1412 
1413 basic_symbol_iterator MachOObjectFile::symbol_end_impl() const {
1414   DataRefImpl DRI;
1415   if (!SymtabLoadCmd)
1416     return basic_symbol_iterator(SymbolRef(DRI, this));
1417 
1418   MachO::symtab_command Symtab = getSymtabLoadCommand();
1419   unsigned SymbolTableEntrySize = is64Bit() ?
1420     sizeof(MachO::nlist_64) :
1421     sizeof(MachO::nlist);
1422   unsigned Offset = Symtab.symoff +
1423     Symtab.nsyms * SymbolTableEntrySize;
1424   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1425   return basic_symbol_iterator(SymbolRef(DRI, this));
1426 }
1427 
1428 basic_symbol_iterator MachOObjectFile::getSymbolByIndex(unsigned Index) const {
1429   DataRefImpl DRI;
1430   if (!SymtabLoadCmd)
1431     return basic_symbol_iterator(SymbolRef(DRI, this));
1432 
1433   MachO::symtab_command Symtab = getSymtabLoadCommand();
1434   assert(Index < Symtab.nsyms && "Requested symbol index is out of range.");
1435   unsigned SymbolTableEntrySize =
1436     is64Bit() ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
1437   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Symtab.symoff));
1438   DRI.p += Index * SymbolTableEntrySize;
1439   return basic_symbol_iterator(SymbolRef(DRI, this));
1440 }
1441 
1442 section_iterator MachOObjectFile::section_begin() const {
1443   DataRefImpl DRI;
1444   return section_iterator(SectionRef(DRI, this));
1445 }
1446 
1447 section_iterator MachOObjectFile::section_end() const {
1448   DataRefImpl DRI;
1449   DRI.d.a = Sections.size();
1450   return section_iterator(SectionRef(DRI, this));
1451 }
1452 
1453 library_iterator MachOObjectFile::needed_library_begin() const {
1454   // TODO: implement
1455   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1456 }
1457 
1458 library_iterator MachOObjectFile::needed_library_end() const {
1459   // TODO: implement
1460   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1461 }
1462 
1463 uint8_t MachOObjectFile::getBytesInAddress() const {
1464   return is64Bit() ? 8 : 4;
1465 }
1466 
1467 StringRef MachOObjectFile::getFileFormatName() const {
1468   unsigned CPUType = getCPUType(this);
1469   if (!is64Bit()) {
1470     switch (CPUType) {
1471     case llvm::MachO::CPU_TYPE_I386:
1472       return "Mach-O 32-bit i386";
1473     case llvm::MachO::CPU_TYPE_ARM:
1474       return "Mach-O arm";
1475     case llvm::MachO::CPU_TYPE_POWERPC:
1476       return "Mach-O 32-bit ppc";
1477     default:
1478       assert((CPUType & llvm::MachO::CPU_ARCH_ABI64) == 0 &&
1479              "64-bit object file when we're not 64-bit?");
1480       return "Mach-O 32-bit unknown";
1481     }
1482   }
1483 
1484   // Make sure the cpu type has the correct mask.
1485   assert((CPUType & llvm::MachO::CPU_ARCH_ABI64)
1486          == llvm::MachO::CPU_ARCH_ABI64 &&
1487          "32-bit object file when we're 64-bit?");
1488 
1489   switch (CPUType) {
1490   case llvm::MachO::CPU_TYPE_X86_64:
1491     return "Mach-O 64-bit x86-64";
1492   case llvm::MachO::CPU_TYPE_ARM64:
1493     return "Mach-O arm64";
1494   case llvm::MachO::CPU_TYPE_POWERPC64:
1495     return "Mach-O 64-bit ppc64";
1496   default:
1497     return "Mach-O 64-bit unknown";
1498   }
1499 }
1500 
1501 Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
1502   switch (CPUType) {
1503   case llvm::MachO::CPU_TYPE_I386:
1504     return Triple::x86;
1505   case llvm::MachO::CPU_TYPE_X86_64:
1506     return Triple::x86_64;
1507   case llvm::MachO::CPU_TYPE_ARM:
1508     return Triple::arm;
1509   case llvm::MachO::CPU_TYPE_ARM64:
1510     return Triple::arm64;
1511   case llvm::MachO::CPU_TYPE_POWERPC:
1512     return Triple::ppc;
1513   case llvm::MachO::CPU_TYPE_POWERPC64:
1514     return Triple::ppc64;
1515   default:
1516     return Triple::UnknownArch;
1517   }
1518 }
1519 
1520 unsigned MachOObjectFile::getArch() const {
1521   return getArch(getCPUType(this));
1522 }
1523 
1524 StringRef MachOObjectFile::getLoadName() const {
1525   // TODO: Implement
1526   report_fatal_error("get_load_name() unimplemented in MachOObjectFile");
1527 }
1528 
1529 relocation_iterator MachOObjectFile::section_rel_begin(unsigned Index) const {
1530   DataRefImpl DRI;
1531   DRI.d.a = Index;
1532   return section_rel_begin(DRI);
1533 }
1534 
1535 relocation_iterator MachOObjectFile::section_rel_end(unsigned Index) const {
1536   DataRefImpl DRI;
1537   DRI.d.a = Index;
1538   return section_rel_end(DRI);
1539 }
1540 
1541 dice_iterator MachOObjectFile::begin_dices() const {
1542   DataRefImpl DRI;
1543   if (!DataInCodeLoadCmd)
1544     return dice_iterator(DiceRef(DRI, this));
1545 
1546   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1547   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, DicLC.dataoff));
1548   return dice_iterator(DiceRef(DRI, this));
1549 }
1550 
1551 dice_iterator MachOObjectFile::end_dices() const {
1552   DataRefImpl DRI;
1553   if (!DataInCodeLoadCmd)
1554     return dice_iterator(DiceRef(DRI, this));
1555 
1556   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1557   unsigned Offset = DicLC.dataoff + DicLC.datasize;
1558   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1559   return dice_iterator(DiceRef(DRI, this));
1560 }
1561 
1562 StringRef
1563 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
1564   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
1565   return parseSegmentOrSectionName(Raw.data());
1566 }
1567 
1568 ArrayRef<char>
1569 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
1570   const section_base *Base =
1571     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1572   return ArrayRef<char>(Base->sectname);
1573 }
1574 
1575 ArrayRef<char>
1576 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
1577   const section_base *Base =
1578     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1579   return ArrayRef<char>(Base->segname);
1580 }
1581 
1582 bool
1583 MachOObjectFile::isRelocationScattered(const MachO::any_relocation_info &RE)
1584   const {
1585   if (getCPUType(this) == MachO::CPU_TYPE_X86_64)
1586     return false;
1587   return getPlainRelocationAddress(RE) & MachO::R_SCATTERED;
1588 }
1589 
1590 unsigned MachOObjectFile::getPlainRelocationSymbolNum(
1591     const MachO::any_relocation_info &RE) const {
1592   if (isLittleEndian())
1593     return RE.r_word1 & 0xffffff;
1594   return RE.r_word1 >> 8;
1595 }
1596 
1597 bool MachOObjectFile::getPlainRelocationExternal(
1598     const MachO::any_relocation_info &RE) const {
1599   if (isLittleEndian())
1600     return (RE.r_word1 >> 27) & 1;
1601   return (RE.r_word1 >> 4) & 1;
1602 }
1603 
1604 bool MachOObjectFile::getScatteredRelocationScattered(
1605     const MachO::any_relocation_info &RE) const {
1606   return RE.r_word0 >> 31;
1607 }
1608 
1609 uint32_t MachOObjectFile::getScatteredRelocationValue(
1610     const MachO::any_relocation_info &RE) const {
1611   return RE.r_word1;
1612 }
1613 
1614 unsigned MachOObjectFile::getAnyRelocationAddress(
1615     const MachO::any_relocation_info &RE) const {
1616   if (isRelocationScattered(RE))
1617     return getScatteredRelocationAddress(RE);
1618   return getPlainRelocationAddress(RE);
1619 }
1620 
1621 unsigned MachOObjectFile::getAnyRelocationPCRel(
1622     const MachO::any_relocation_info &RE) const {
1623   if (isRelocationScattered(RE))
1624     return getScatteredRelocationPCRel(this, RE);
1625   return getPlainRelocationPCRel(this, RE);
1626 }
1627 
1628 unsigned MachOObjectFile::getAnyRelocationLength(
1629     const MachO::any_relocation_info &RE) const {
1630   if (isRelocationScattered(RE))
1631     return getScatteredRelocationLength(RE);
1632   return getPlainRelocationLength(this, RE);
1633 }
1634 
1635 unsigned
1636 MachOObjectFile::getAnyRelocationType(
1637                                    const MachO::any_relocation_info &RE) const {
1638   if (isRelocationScattered(RE))
1639     return getScatteredRelocationType(RE);
1640   return getPlainRelocationType(this, RE);
1641 }
1642 
1643 SectionRef
1644 MachOObjectFile::getRelocationSection(
1645                                    const MachO::any_relocation_info &RE) const {
1646   if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
1647     return *section_end();
1648   unsigned SecNum = getPlainRelocationSymbolNum(RE) - 1;
1649   DataRefImpl DRI;
1650   DRI.d.a = SecNum;
1651   return SectionRef(DRI, this);
1652 }
1653 
1654 MachOObjectFile::LoadCommandInfo
1655 MachOObjectFile::getFirstLoadCommandInfo() const {
1656   MachOObjectFile::LoadCommandInfo Load;
1657 
1658   unsigned HeaderSize = is64Bit() ? sizeof(MachO::mach_header_64) :
1659                                     sizeof(MachO::mach_header);
1660   Load.Ptr = getPtr(this, HeaderSize);
1661   Load.C = getStruct<MachO::load_command>(this, Load.Ptr);
1662   return Load;
1663 }
1664 
1665 MachOObjectFile::LoadCommandInfo
1666 MachOObjectFile::getNextLoadCommandInfo(const LoadCommandInfo &L) const {
1667   MachOObjectFile::LoadCommandInfo Next;
1668   Next.Ptr = L.Ptr + L.C.cmdsize;
1669   Next.C = getStruct<MachO::load_command>(this, Next.Ptr);
1670   return Next;
1671 }
1672 
1673 MachO::section MachOObjectFile::getSection(DataRefImpl DRI) const {
1674   return getStruct<MachO::section>(this, Sections[DRI.d.a]);
1675 }
1676 
1677 MachO::section_64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
1678   return getStruct<MachO::section_64>(this, Sections[DRI.d.a]);
1679 }
1680 
1681 MachO::section MachOObjectFile::getSection(const LoadCommandInfo &L,
1682                                            unsigned Index) const {
1683   const char *Sec = getSectionPtr(this, L, Index);
1684   return getStruct<MachO::section>(this, Sec);
1685 }
1686 
1687 MachO::section_64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
1688                                                 unsigned Index) const {
1689   const char *Sec = getSectionPtr(this, L, Index);
1690   return getStruct<MachO::section_64>(this, Sec);
1691 }
1692 
1693 MachO::nlist
1694 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
1695   const char *P = reinterpret_cast<const char *>(DRI.p);
1696   return getStruct<MachO::nlist>(this, P);
1697 }
1698 
1699 MachO::nlist_64
1700 MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI) const {
1701   const char *P = reinterpret_cast<const char *>(DRI.p);
1702   return getStruct<MachO::nlist_64>(this, P);
1703 }
1704 
1705 MachO::linkedit_data_command
1706 MachOObjectFile::getLinkeditDataLoadCommand(const LoadCommandInfo &L) const {
1707   return getStruct<MachO::linkedit_data_command>(this, L.Ptr);
1708 }
1709 
1710 MachO::segment_command
1711 MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
1712   return getStruct<MachO::segment_command>(this, L.Ptr);
1713 }
1714 
1715 MachO::segment_command_64
1716 MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
1717   return getStruct<MachO::segment_command_64>(this, L.Ptr);
1718 }
1719 
1720 MachO::linker_options_command
1721 MachOObjectFile::getLinkerOptionsLoadCommand(const LoadCommandInfo &L) const {
1722   return getStruct<MachO::linker_options_command>(this, L.Ptr);
1723 }
1724 
1725 MachO::version_min_command
1726 MachOObjectFile::getVersionMinLoadCommand(const LoadCommandInfo &L) const {
1727   return getStruct<MachO::version_min_command>(this, L.Ptr);
1728 }
1729 
1730 MachO::any_relocation_info
1731 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
1732   DataRefImpl Sec;
1733   Sec.d.a = Rel.d.a;
1734   uint32_t Offset;
1735   if (is64Bit()) {
1736     MachO::section_64 Sect = getSection64(Sec);
1737     Offset = Sect.reloff;
1738   } else {
1739     MachO::section Sect = getSection(Sec);
1740     Offset = Sect.reloff;
1741   }
1742 
1743   auto P = reinterpret_cast<const MachO::any_relocation_info *>(
1744       getPtr(this, Offset)) + Rel.d.b;
1745   return getStruct<MachO::any_relocation_info>(
1746       this, reinterpret_cast<const char *>(P));
1747 }
1748 
1749 MachO::data_in_code_entry
1750 MachOObjectFile::getDice(DataRefImpl Rel) const {
1751   const char *P = reinterpret_cast<const char *>(Rel.p);
1752   return getStruct<MachO::data_in_code_entry>(this, P);
1753 }
1754 
1755 MachO::mach_header MachOObjectFile::getHeader() const {
1756   return getStruct<MachO::mach_header>(this, getPtr(this, 0));
1757 }
1758 
1759 MachO::mach_header_64 MachOObjectFile::getHeader64() const {
1760   return getStruct<MachO::mach_header_64>(this, getPtr(this, 0));
1761 }
1762 
1763 uint32_t MachOObjectFile::getIndirectSymbolTableEntry(
1764                                              const MachO::dysymtab_command &DLC,
1765                                              unsigned Index) const {
1766   uint64_t Offset = DLC.indirectsymoff + Index * sizeof(uint32_t);
1767   return getStruct<uint32_t>(this, getPtr(this, Offset));
1768 }
1769 
1770 MachO::data_in_code_entry
1771 MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
1772                                          unsigned Index) const {
1773   uint64_t Offset = DataOffset + Index * sizeof(MachO::data_in_code_entry);
1774   return getStruct<MachO::data_in_code_entry>(this, getPtr(this, Offset));
1775 }
1776 
1777 MachO::symtab_command MachOObjectFile::getSymtabLoadCommand() const {
1778   return getStruct<MachO::symtab_command>(this, SymtabLoadCmd);
1779 }
1780 
1781 MachO::dysymtab_command MachOObjectFile::getDysymtabLoadCommand() const {
1782   return getStruct<MachO::dysymtab_command>(this, DysymtabLoadCmd);
1783 }
1784 
1785 MachO::linkedit_data_command
1786 MachOObjectFile::getDataInCodeLoadCommand() const {
1787   if (DataInCodeLoadCmd)
1788     return getStruct<MachO::linkedit_data_command>(this, DataInCodeLoadCmd);
1789 
1790   // If there is no DataInCodeLoadCmd return a load command with zero'ed fields.
1791   MachO::linkedit_data_command Cmd;
1792   Cmd.cmd = MachO::LC_DATA_IN_CODE;
1793   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
1794   Cmd.dataoff = 0;
1795   Cmd.datasize = 0;
1796   return Cmd;
1797 }
1798 
1799 StringRef MachOObjectFile::getStringTableData() const {
1800   MachO::symtab_command S = getSymtabLoadCommand();
1801   return getData().substr(S.stroff, S.strsize);
1802 }
1803 
1804 bool MachOObjectFile::is64Bit() const {
1805   return getType() == getMachOType(false, true) ||
1806     getType() == getMachOType(true, true);
1807 }
1808 
1809 void MachOObjectFile::ReadULEB128s(uint64_t Index,
1810                                    SmallVectorImpl<uint64_t> &Out) const {
1811   DataExtractor extractor(ObjectFile::getData(), true, 0);
1812 
1813   uint32_t offset = Index;
1814   uint64_t data = 0;
1815   while (uint64_t delta = extractor.getULEB128(&offset)) {
1816     data += delta;
1817     Out.push_back(data);
1818   }
1819 }
1820 
1821 ErrorOr<ObjectFile *> ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer,
1822                                                         bool BufferOwned) {
1823   StringRef Magic = Buffer->getBuffer().slice(0, 4);
1824   std::error_code EC;
1825   std::unique_ptr<MachOObjectFile> Ret;
1826   if (Magic == "\xFE\xED\xFA\xCE")
1827     Ret.reset(new MachOObjectFile(Buffer, false, false, EC, BufferOwned));
1828   else if (Magic == "\xCE\xFA\xED\xFE")
1829     Ret.reset(new MachOObjectFile(Buffer, true, false, EC, BufferOwned));
1830   else if (Magic == "\xFE\xED\xFA\xCF")
1831     Ret.reset(new MachOObjectFile(Buffer, false, true, EC, BufferOwned));
1832   else if (Magic == "\xCF\xFA\xED\xFE")
1833     Ret.reset(new MachOObjectFile(Buffer, true, true, EC, BufferOwned));
1834   else {
1835     delete Buffer;
1836     return object_error::parse_failed;
1837   }
1838 
1839   if (EC)
1840     return EC;
1841   return Ret.release();
1842 }
1843 
1844 } // end namespace object
1845 } // end namespace llvm
1846