xref: /llvm-project/llvm/lib/Object/MachOObjectFile.cpp (revision 78d5daf8ce65697cdff8ab7a8a8e03b215dda8f9) 
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 section_base {
35   char sectname[16];
36   char segname[16];
37 };
38 
39 template<typename T>
40 T getStruct(const MachOObjectFile *O, const char *P) {
41   T Cmd;
42   memcpy(&Cmd, P, sizeof(T));
43   if (O->isLittleEndian() != sys::IsLittleEndianHost)
44     MachO::swapStruct(Cmd);
45   return Cmd;
46 }
47 
48 static uint32_t
49 getSegmentLoadCommandNumSections(const MachOObjectFile *O,
50                                  const MachOObjectFile::LoadCommandInfo &L) {
51   if (O->is64Bit()) {
52     MachO::segment_command_64 S = O->getSegment64LoadCommand(L);
53     return S.nsects;
54   }
55   MachO::segment_command S = O->getSegmentLoadCommand(L);
56   return S.nsects;
57 }
58 
59 static const char *
60 getSectionPtr(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L,
61               unsigned Sec) {
62   uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
63 
64   bool Is64 = O->is64Bit();
65   unsigned SegmentLoadSize = Is64 ? sizeof(MachO::segment_command_64) :
66                                     sizeof(MachO::segment_command);
67   unsigned SectionSize = Is64 ? sizeof(MachO::section_64) :
68                                 sizeof(MachO::section);
69 
70   uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
71   return reinterpret_cast<const char*>(SectionAddr);
72 }
73 
74 static const char *getPtr(const MachOObjectFile *O, size_t Offset) {
75   return O->getData().substr(Offset, 1).data();
76 }
77 
78 static MachO::nlist_base
79 getSymbolTableEntryBase(const MachOObjectFile *O, DataRefImpl DRI) {
80   const char *P = reinterpret_cast<const char *>(DRI.p);
81   return getStruct<MachO::nlist_base>(O, P);
82 }
83 
84 static StringRef parseSegmentOrSectionName(const char *P) {
85   if (P[15] == 0)
86     // Null terminated.
87     return P;
88   // Not null terminated, so this is a 16 char string.
89   return StringRef(P, 16);
90 }
91 
92 // Helper to advance a section or symbol iterator multiple increments at a time.
93 template<class T>
94 static void advance(T &it, size_t Val) {
95   while (Val--)
96     ++it;
97 }
98 
99 static unsigned getCPUType(const MachOObjectFile *O) {
100   return O->getHeader().cputype;
101 }
102 
103 static void printRelocationTargetName(const MachOObjectFile *O,
104                                       const MachO::any_relocation_info &RE,
105                                       raw_string_ostream &fmt) {
106   bool IsScattered = O->isRelocationScattered(RE);
107 
108   // Target of a scattered relocation is an address.  In the interest of
109   // generating pretty output, scan through the symbol table looking for a
110   // symbol that aligns with that address.  If we find one, print it.
111   // Otherwise, we just print the hex address of the target.
112   if (IsScattered) {
113     uint32_t Val = O->getPlainRelocationSymbolNum(RE);
114 
115     for (const SymbolRef &Symbol : O->symbols()) {
116       std::error_code ec;
117       uint64_t Addr;
118       StringRef Name;
119 
120       if ((ec = Symbol.getAddress(Addr)))
121         report_fatal_error(ec.message());
122       if (Addr != Val)
123         continue;
124       if ((ec = Symbol.getName(Name)))
125         report_fatal_error(ec.message());
126       fmt << Name;
127       return;
128     }
129 
130     // If we couldn't find a symbol that this relocation refers to, try
131     // to find a section beginning instead.
132     for (const SectionRef &Section : O->sections()) {
133       std::error_code ec;
134       uint64_t Addr;
135       StringRef Name;
136 
137       if ((ec = Section.getAddress(Addr)))
138         report_fatal_error(ec.message());
139       if (Addr != Val)
140         continue;
141       if ((ec = Section.getName(Name)))
142         report_fatal_error(ec.message());
143       fmt << Name;
144       return;
145     }
146 
147     fmt << format("0x%x", Val);
148     return;
149   }
150 
151   StringRef S;
152   bool isExtern = O->getPlainRelocationExternal(RE);
153   uint64_t Val = O->getPlainRelocationSymbolNum(RE);
154 
155   if (isExtern) {
156     symbol_iterator SI = O->symbol_begin();
157     advance(SI, Val);
158     SI->getName(S);
159   } else {
160     section_iterator SI = O->section_begin();
161     // Adjust for the fact that sections are 1-indexed.
162     advance(SI, Val - 1);
163     SI->getName(S);
164   }
165 
166   fmt << S;
167 }
168 
169 static uint32_t
170 getPlainRelocationAddress(const MachO::any_relocation_info &RE) {
171   return RE.r_word0;
172 }
173 
174 static unsigned
175 getScatteredRelocationAddress(const MachO::any_relocation_info &RE) {
176   return RE.r_word0 & 0xffffff;
177 }
178 
179 static bool getPlainRelocationPCRel(const MachOObjectFile *O,
180                                     const MachO::any_relocation_info &RE) {
181   if (O->isLittleEndian())
182     return (RE.r_word1 >> 24) & 1;
183   return (RE.r_word1 >> 7) & 1;
184 }
185 
186 static bool
187 getScatteredRelocationPCRel(const MachOObjectFile *O,
188                             const MachO::any_relocation_info &RE) {
189   return (RE.r_word0 >> 30) & 1;
190 }
191 
192 static unsigned getPlainRelocationLength(const MachOObjectFile *O,
193                                          const MachO::any_relocation_info &RE) {
194   if (O->isLittleEndian())
195     return (RE.r_word1 >> 25) & 3;
196   return (RE.r_word1 >> 5) & 3;
197 }
198 
199 static unsigned
200 getScatteredRelocationLength(const MachO::any_relocation_info &RE) {
201   return (RE.r_word0 >> 28) & 3;
202 }
203 
204 static unsigned getPlainRelocationType(const MachOObjectFile *O,
205                                        const MachO::any_relocation_info &RE) {
206   if (O->isLittleEndian())
207     return RE.r_word1 >> 28;
208   return RE.r_word1 & 0xf;
209 }
210 
211 static unsigned
212 getScatteredRelocationType(const MachO::any_relocation_info &RE) {
213   return (RE.r_word0 >> 24) & 0xf;
214 }
215 
216 static uint32_t getSectionFlags(const MachOObjectFile *O,
217                                 DataRefImpl Sec) {
218   if (O->is64Bit()) {
219     MachO::section_64 Sect = O->getSection64(Sec);
220     return Sect.flags;
221   }
222   MachO::section Sect = O->getSection(Sec);
223   return Sect.flags;
224 }
225 
226 MachOObjectFile::MachOObjectFile(std::unique_ptr<MemoryBuffer> Object,
227                                  bool IsLittleEndian, bool Is64bits,
228                                  std::error_code &EC)
229     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), std::move(Object)),
230       SymtabLoadCmd(nullptr), DysymtabLoadCmd(nullptr),
231       DataInCodeLoadCmd(nullptr) {
232   uint32_t LoadCommandCount = this->getHeader().ncmds;
233   MachO::LoadCommandType SegmentLoadType = is64Bit() ?
234     MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT;
235 
236   MachOObjectFile::LoadCommandInfo Load = getFirstLoadCommandInfo();
237   for (unsigned I = 0; ; ++I) {
238     if (Load.C.cmd == MachO::LC_SYMTAB) {
239       assert(!SymtabLoadCmd && "Multiple symbol tables");
240       SymtabLoadCmd = Load.Ptr;
241     } else if (Load.C.cmd == MachO::LC_DYSYMTAB) {
242       assert(!DysymtabLoadCmd && "Multiple dynamic symbol tables");
243       DysymtabLoadCmd = Load.Ptr;
244     } else if (Load.C.cmd == MachO::LC_DATA_IN_CODE) {
245       assert(!DataInCodeLoadCmd && "Multiple data in code tables");
246       DataInCodeLoadCmd = Load.Ptr;
247     } else if (Load.C.cmd == SegmentLoadType) {
248       uint32_t NumSections = getSegmentLoadCommandNumSections(this, Load);
249       for (unsigned J = 0; J < NumSections; ++J) {
250         const char *Sec = getSectionPtr(this, Load, J);
251         Sections.push_back(Sec);
252       }
253     } else if (Load.C.cmd == MachO::LC_LOAD_DYLIB ||
254                Load.C.cmd == MachO::LC_LOAD_WEAK_DYLIB ||
255                Load.C.cmd == MachO::LC_LAZY_LOAD_DYLIB ||
256                Load.C.cmd == MachO::LC_REEXPORT_DYLIB ||
257                Load.C.cmd == MachO::LC_LOAD_UPWARD_DYLIB) {
258       Libraries.push_back(Load.Ptr);
259     }
260 
261     if (I == LoadCommandCount - 1)
262       break;
263     else
264       Load = getNextLoadCommandInfo(Load);
265   }
266 }
267 
268 void MachOObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
269   unsigned SymbolTableEntrySize = is64Bit() ?
270     sizeof(MachO::nlist_64) :
271     sizeof(MachO::nlist);
272   Symb.p += SymbolTableEntrySize;
273 }
274 
275 std::error_code MachOObjectFile::getSymbolName(DataRefImpl Symb,
276                                                StringRef &Res) const {
277   StringRef StringTable = getStringTableData();
278   MachO::nlist_base Entry = getSymbolTableEntryBase(this, Symb);
279   const char *Start = &StringTable.data()[Entry.n_strx];
280   Res = StringRef(Start);
281   return object_error::success;
282 }
283 
284 // getIndirectName() returns the name of the alias'ed symbol who's string table
285 // index is in the n_value field.
286 std::error_code MachOObjectFile::getIndirectName(DataRefImpl Symb,
287                                                  StringRef &Res) const {
288   StringRef StringTable = getStringTableData();
289   uint64_t NValue;
290   if (is64Bit()) {
291     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
292     NValue = Entry.n_value;
293     if ((Entry.n_type & MachO::N_TYPE) != MachO::N_INDR)
294       return object_error::parse_failed;
295   } else {
296     MachO::nlist Entry = getSymbolTableEntry(Symb);
297     NValue = Entry.n_value;
298     if ((Entry.n_type & MachO::N_TYPE) != MachO::N_INDR)
299       return object_error::parse_failed;
300   }
301   if (NValue >= StringTable.size())
302     return object_error::parse_failed;
303   const char *Start = &StringTable.data()[NValue];
304   Res = StringRef(Start);
305   return object_error::success;
306 }
307 
308 std::error_code MachOObjectFile::getSymbolAddress(DataRefImpl Symb,
309                                                   uint64_t &Res) const {
310   if (is64Bit()) {
311     MachO::nlist_64 Entry = getSymbol64TableEntry(Symb);
312     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
313         Entry.n_value == 0)
314       Res = UnknownAddressOrSize;
315     else
316       Res = Entry.n_value;
317   } else {
318     MachO::nlist Entry = getSymbolTableEntry(Symb);
319     if ((Entry.n_type & MachO::N_TYPE) == MachO::N_UNDF &&
320         Entry.n_value == 0)
321       Res = UnknownAddressOrSize;
322     else
323       Res = Entry.n_value;
324   }
325   return object_error::success;
326 }
327 
328 std::error_code MachOObjectFile::getSymbolAlignment(DataRefImpl DRI,
329                                                     uint32_t &Result) const {
330   uint32_t flags = getSymbolFlags(DRI);
331   if (flags & SymbolRef::SF_Common) {
332     MachO::nlist_base Entry = getSymbolTableEntryBase(this, DRI);
333     Result = 1 << MachO::GET_COMM_ALIGN(Entry.n_desc);
334   } else {
335     Result = 0;
336   }
337   return object_error::success;
338 }
339 
340 std::error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
341                                                uint64_t &Result) const {
342   uint64_t BeginOffset;
343   uint64_t EndOffset = 0;
344   uint8_t SectionIndex;
345 
346   MachO::nlist_base Entry = getSymbolTableEntryBase(this, DRI);
347   uint64_t Value;
348   getSymbolAddress(DRI, Value);
349   if (Value == UnknownAddressOrSize) {
350     Result = UnknownAddressOrSize;
351     return object_error::success;
352   }
353 
354   BeginOffset = Value;
355 
356   SectionIndex = Entry.n_sect;
357   if (!SectionIndex) {
358     uint32_t flags = getSymbolFlags(DRI);
359     if (flags & SymbolRef::SF_Common)
360       Result = Value;
361     else
362       Result = UnknownAddressOrSize;
363     return object_error::success;
364   }
365   // Unfortunately symbols are unsorted so we need to touch all
366   // symbols from load command
367   for (const SymbolRef &Symbol : symbols()) {
368     DataRefImpl DRI = Symbol.getRawDataRefImpl();
369     Entry = getSymbolTableEntryBase(this, DRI);
370     getSymbolAddress(DRI, Value);
371     if (Value == UnknownAddressOrSize)
372       continue;
373     if (Entry.n_sect == SectionIndex && Value > BeginOffset)
374       if (!EndOffset || Value < EndOffset)
375         EndOffset = Value;
376   }
377   if (!EndOffset) {
378     uint64_t Size;
379     DataRefImpl Sec;
380     Sec.d.a = SectionIndex-1;
381     getSectionSize(Sec, Size);
382     getSectionAddress(Sec, EndOffset);
383     EndOffset += Size;
384   }
385   Result = EndOffset - BeginOffset;
386   return object_error::success;
387 }
388 
389 std::error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
390                                                SymbolRef::Type &Res) const {
391   MachO::nlist_base Entry = getSymbolTableEntryBase(this, Symb);
392   uint8_t n_type = Entry.n_type;
393 
394   Res = SymbolRef::ST_Other;
395 
396   // If this is a STAB debugging symbol, we can do nothing more.
397   if (n_type & MachO::N_STAB) {
398     Res = SymbolRef::ST_Debug;
399     return object_error::success;
400   }
401 
402   switch (n_type & MachO::N_TYPE) {
403     case MachO::N_UNDF :
404       Res = SymbolRef::ST_Unknown;
405       break;
406     case MachO::N_SECT :
407       Res = SymbolRef::ST_Function;
408       break;
409   }
410   return object_error::success;
411 }
412 
413 uint32_t MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
414   MachO::nlist_base Entry = getSymbolTableEntryBase(this, DRI);
415 
416   uint8_t MachOType = Entry.n_type;
417   uint16_t MachOFlags = Entry.n_desc;
418 
419   uint32_t Result = SymbolRef::SF_None;
420 
421   if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF)
422     Result |= SymbolRef::SF_Undefined;
423 
424   if ((MachOType & MachO::N_TYPE) == MachO::N_INDR)
425     Result |= SymbolRef::SF_Indirect;
426 
427   if (MachOType & MachO::N_STAB)
428     Result |= SymbolRef::SF_FormatSpecific;
429 
430   if (MachOType & MachO::N_EXT) {
431     Result |= SymbolRef::SF_Global;
432     if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF) {
433       uint64_t Value;
434       getSymbolAddress(DRI, Value);
435       if (Value && Value != UnknownAddressOrSize)
436         Result |= SymbolRef::SF_Common;
437     }
438   }
439 
440   if (MachOFlags & (MachO::N_WEAK_REF | MachO::N_WEAK_DEF))
441     Result |= SymbolRef::SF_Weak;
442 
443   if ((MachOType & MachO::N_TYPE) == MachO::N_ABS)
444     Result |= SymbolRef::SF_Absolute;
445 
446   return Result;
447 }
448 
449 std::error_code MachOObjectFile::getSymbolSection(DataRefImpl Symb,
450                                                   section_iterator &Res) const {
451   MachO::nlist_base Entry = getSymbolTableEntryBase(this, Symb);
452   uint8_t index = Entry.n_sect;
453 
454   if (index == 0) {
455     Res = section_end();
456   } else {
457     DataRefImpl DRI;
458     DRI.d.a = index - 1;
459     Res = section_iterator(SectionRef(DRI, this));
460   }
461 
462   return object_error::success;
463 }
464 
465 void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
466   Sec.d.a++;
467 }
468 
469 std::error_code MachOObjectFile::getSectionName(DataRefImpl Sec,
470                                                 StringRef &Result) const {
471   ArrayRef<char> Raw = getSectionRawName(Sec);
472   Result = parseSegmentOrSectionName(Raw.data());
473   return object_error::success;
474 }
475 
476 std::error_code MachOObjectFile::getSectionAddress(DataRefImpl Sec,
477                                                    uint64_t &Res) const {
478   if (is64Bit()) {
479     MachO::section_64 Sect = getSection64(Sec);
480     Res = Sect.addr;
481   } else {
482     MachO::section Sect = getSection(Sec);
483     Res = Sect.addr;
484   }
485   return object_error::success;
486 }
487 
488 std::error_code MachOObjectFile::getSectionSize(DataRefImpl Sec,
489                                                 uint64_t &Res) const {
490   if (is64Bit()) {
491     MachO::section_64 Sect = getSection64(Sec);
492     Res = Sect.size;
493   } else {
494     MachO::section Sect = getSection(Sec);
495     Res = Sect.size;
496   }
497 
498   return object_error::success;
499 }
500 
501 std::error_code MachOObjectFile::getSectionContents(DataRefImpl Sec,
502                                                     StringRef &Res) const {
503   uint32_t Offset;
504   uint64_t Size;
505 
506   if (is64Bit()) {
507     MachO::section_64 Sect = getSection64(Sec);
508     Offset = Sect.offset;
509     Size = Sect.size;
510   } else {
511     MachO::section Sect = getSection(Sec);
512     Offset = Sect.offset;
513     Size = Sect.size;
514   }
515 
516   Res = this->getData().substr(Offset, Size);
517   return object_error::success;
518 }
519 
520 std::error_code MachOObjectFile::getSectionAlignment(DataRefImpl Sec,
521                                                      uint64_t &Res) const {
522   uint32_t Align;
523   if (is64Bit()) {
524     MachO::section_64 Sect = getSection64(Sec);
525     Align = Sect.align;
526   } else {
527     MachO::section Sect = getSection(Sec);
528     Align = Sect.align;
529   }
530 
531   Res = uint64_t(1) << Align;
532   return object_error::success;
533 }
534 
535 std::error_code MachOObjectFile::isSectionText(DataRefImpl Sec,
536                                                bool &Res) const {
537   uint32_t Flags = getSectionFlags(this, Sec);
538   Res = Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
539   return object_error::success;
540 }
541 
542 std::error_code MachOObjectFile::isSectionData(DataRefImpl Sec,
543                                                bool &Result) const {
544   uint32_t Flags = getSectionFlags(this, Sec);
545   unsigned SectionType = Flags & MachO::SECTION_TYPE;
546   Result = !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
547            !(SectionType == MachO::S_ZEROFILL ||
548              SectionType == MachO::S_GB_ZEROFILL);
549   return object_error::success;
550 }
551 
552 std::error_code MachOObjectFile::isSectionBSS(DataRefImpl Sec,
553                                               bool &Result) const {
554   uint32_t Flags = getSectionFlags(this, Sec);
555   unsigned SectionType = Flags & MachO::SECTION_TYPE;
556   Result = !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
557            (SectionType == MachO::S_ZEROFILL ||
558             SectionType == MachO::S_GB_ZEROFILL);
559   return object_error::success;
560 }
561 
562 std::error_code
563 MachOObjectFile::isSectionRequiredForExecution(DataRefImpl Sec,
564                                                bool &Result) const {
565   // FIXME: Unimplemented.
566   Result = true;
567   return object_error::success;
568 }
569 
570 std::error_code MachOObjectFile::isSectionVirtual(DataRefImpl Sec,
571                                                   bool &Result) const {
572   // FIXME: Unimplemented.
573   Result = false;
574   return object_error::success;
575 }
576 
577 std::error_code MachOObjectFile::isSectionZeroInit(DataRefImpl Sec,
578                                                    bool &Res) const {
579   uint32_t Flags = getSectionFlags(this, Sec);
580   unsigned SectionType = Flags & MachO::SECTION_TYPE;
581   Res = SectionType == MachO::S_ZEROFILL ||
582     SectionType == MachO::S_GB_ZEROFILL;
583   return object_error::success;
584 }
585 
586 std::error_code MachOObjectFile::isSectionReadOnlyData(DataRefImpl Sec,
587                                                        bool &Result) const {
588   // Consider using the code from isSectionText to look for __const sections.
589   // Alternately, emit S_ATTR_PURE_INSTRUCTIONS and/or S_ATTR_SOME_INSTRUCTIONS
590   // to use section attributes to distinguish code from data.
591 
592   // FIXME: Unimplemented.
593   Result = false;
594   return object_error::success;
595 }
596 
597 std::error_code MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec,
598                                                        DataRefImpl Symb,
599                                                        bool &Result) const {
600   SymbolRef::Type ST;
601   this->getSymbolType(Symb, ST);
602   if (ST == SymbolRef::ST_Unknown) {
603     Result = false;
604     return object_error::success;
605   }
606 
607   uint64_t SectBegin, SectEnd;
608   getSectionAddress(Sec, SectBegin);
609   getSectionSize(Sec, SectEnd);
610   SectEnd += SectBegin;
611 
612   uint64_t SymAddr;
613   getSymbolAddress(Symb, SymAddr);
614   Result = (SymAddr >= SectBegin) && (SymAddr < SectEnd);
615 
616   return object_error::success;
617 }
618 
619 relocation_iterator MachOObjectFile::section_rel_begin(DataRefImpl Sec) const {
620   DataRefImpl Ret;
621   Ret.d.a = Sec.d.a;
622   Ret.d.b = 0;
623   return relocation_iterator(RelocationRef(Ret, this));
624 }
625 
626 relocation_iterator
627 MachOObjectFile::section_rel_end(DataRefImpl Sec) const {
628   uint32_t Num;
629   if (is64Bit()) {
630     MachO::section_64 Sect = getSection64(Sec);
631     Num = Sect.nreloc;
632   } else {
633     MachO::section Sect = getSection(Sec);
634     Num = Sect.nreloc;
635   }
636 
637   DataRefImpl Ret;
638   Ret.d.a = Sec.d.a;
639   Ret.d.b = Num;
640   return relocation_iterator(RelocationRef(Ret, this));
641 }
642 
643 void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
644   ++Rel.d.b;
645 }
646 
647 std::error_code MachOObjectFile::getRelocationAddress(DataRefImpl Rel,
648                                                       uint64_t &Res) const {
649   uint64_t Offset;
650   getRelocationOffset(Rel, Offset);
651 
652   DataRefImpl Sec;
653   Sec.d.a = Rel.d.a;
654   uint64_t SecAddress;
655   getSectionAddress(Sec, SecAddress);
656   Res = SecAddress + Offset;
657   return object_error::success;
658 }
659 
660 std::error_code MachOObjectFile::getRelocationOffset(DataRefImpl Rel,
661                                                      uint64_t &Res) const {
662   assert(getHeader().filetype == MachO::MH_OBJECT &&
663          "Only implemented for MH_OBJECT");
664   MachO::any_relocation_info RE = getRelocation(Rel);
665   Res = getAnyRelocationAddress(RE);
666   return object_error::success;
667 }
668 
669 symbol_iterator
670 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
671   MachO::any_relocation_info RE = getRelocation(Rel);
672   if (isRelocationScattered(RE))
673     return symbol_end();
674 
675   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
676   bool isExtern = getPlainRelocationExternal(RE);
677   if (!isExtern)
678     return symbol_end();
679 
680   MachO::symtab_command S = getSymtabLoadCommand();
681   unsigned SymbolTableEntrySize = is64Bit() ?
682     sizeof(MachO::nlist_64) :
683     sizeof(MachO::nlist);
684   uint64_t Offset = S.symoff + SymbolIdx * SymbolTableEntrySize;
685   DataRefImpl Sym;
686   Sym.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
687   return symbol_iterator(SymbolRef(Sym, this));
688 }
689 
690 std::error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
691                                                    uint64_t &Res) const {
692   MachO::any_relocation_info RE = getRelocation(Rel);
693   Res = getAnyRelocationType(RE);
694   return object_error::success;
695 }
696 
697 std::error_code
698 MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
699                                        SmallVectorImpl<char> &Result) const {
700   StringRef res;
701   uint64_t RType;
702   getRelocationType(Rel, RType);
703 
704   unsigned Arch = this->getArch();
705 
706   switch (Arch) {
707     case Triple::x86: {
708       static const char *const Table[] =  {
709         "GENERIC_RELOC_VANILLA",
710         "GENERIC_RELOC_PAIR",
711         "GENERIC_RELOC_SECTDIFF",
712         "GENERIC_RELOC_PB_LA_PTR",
713         "GENERIC_RELOC_LOCAL_SECTDIFF",
714         "GENERIC_RELOC_TLV" };
715 
716       if (RType > 5)
717         res = "Unknown";
718       else
719         res = Table[RType];
720       break;
721     }
722     case Triple::x86_64: {
723       static const char *const Table[] =  {
724         "X86_64_RELOC_UNSIGNED",
725         "X86_64_RELOC_SIGNED",
726         "X86_64_RELOC_BRANCH",
727         "X86_64_RELOC_GOT_LOAD",
728         "X86_64_RELOC_GOT",
729         "X86_64_RELOC_SUBTRACTOR",
730         "X86_64_RELOC_SIGNED_1",
731         "X86_64_RELOC_SIGNED_2",
732         "X86_64_RELOC_SIGNED_4",
733         "X86_64_RELOC_TLV" };
734 
735       if (RType > 9)
736         res = "Unknown";
737       else
738         res = Table[RType];
739       break;
740     }
741     case Triple::arm: {
742       static const char *const Table[] =  {
743         "ARM_RELOC_VANILLA",
744         "ARM_RELOC_PAIR",
745         "ARM_RELOC_SECTDIFF",
746         "ARM_RELOC_LOCAL_SECTDIFF",
747         "ARM_RELOC_PB_LA_PTR",
748         "ARM_RELOC_BR24",
749         "ARM_THUMB_RELOC_BR22",
750         "ARM_THUMB_32BIT_BRANCH",
751         "ARM_RELOC_HALF",
752         "ARM_RELOC_HALF_SECTDIFF" };
753 
754       if (RType > 9)
755         res = "Unknown";
756       else
757         res = Table[RType];
758       break;
759     }
760     case Triple::arm64:
761     case Triple::aarch64: {
762       static const char *const Table[] = {
763         "ARM64_RELOC_UNSIGNED",           "ARM64_RELOC_SUBTRACTOR",
764         "ARM64_RELOC_BRANCH26",           "ARM64_RELOC_PAGE21",
765         "ARM64_RELOC_PAGEOFF12",          "ARM64_RELOC_GOT_LOAD_PAGE21",
766         "ARM64_RELOC_GOT_LOAD_PAGEOFF12", "ARM64_RELOC_POINTER_TO_GOT",
767         "ARM64_RELOC_TLVP_LOAD_PAGE21",   "ARM64_RELOC_TLVP_LOAD_PAGEOFF12",
768         "ARM64_RELOC_ADDEND"
769       };
770 
771       if (RType >= array_lengthof(Table))
772         res = "Unknown";
773       else
774         res = Table[RType];
775       break;
776     }
777     case Triple::ppc: {
778       static const char *const Table[] =  {
779         "PPC_RELOC_VANILLA",
780         "PPC_RELOC_PAIR",
781         "PPC_RELOC_BR14",
782         "PPC_RELOC_BR24",
783         "PPC_RELOC_HI16",
784         "PPC_RELOC_LO16",
785         "PPC_RELOC_HA16",
786         "PPC_RELOC_LO14",
787         "PPC_RELOC_SECTDIFF",
788         "PPC_RELOC_PB_LA_PTR",
789         "PPC_RELOC_HI16_SECTDIFF",
790         "PPC_RELOC_LO16_SECTDIFF",
791         "PPC_RELOC_HA16_SECTDIFF",
792         "PPC_RELOC_JBSR",
793         "PPC_RELOC_LO14_SECTDIFF",
794         "PPC_RELOC_LOCAL_SECTDIFF" };
795 
796       if (RType > 15)
797         res = "Unknown";
798       else
799         res = Table[RType];
800       break;
801     }
802     case Triple::UnknownArch:
803       res = "Unknown";
804       break;
805   }
806   Result.append(res.begin(), res.end());
807   return object_error::success;
808 }
809 
810 std::error_code
811 MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
812                                           SmallVectorImpl<char> &Result) const {
813   MachO::any_relocation_info RE = getRelocation(Rel);
814 
815   unsigned Arch = this->getArch();
816 
817   std::string fmtbuf;
818   raw_string_ostream fmt(fmtbuf);
819   unsigned Type = this->getAnyRelocationType(RE);
820   bool IsPCRel = this->getAnyRelocationPCRel(RE);
821 
822   // Determine any addends that should be displayed with the relocation.
823   // These require decoding the relocation type, which is triple-specific.
824 
825   // X86_64 has entirely custom relocation types.
826   if (Arch == Triple::x86_64) {
827     bool isPCRel = getAnyRelocationPCRel(RE);
828 
829     switch (Type) {
830       case MachO::X86_64_RELOC_GOT_LOAD:
831       case MachO::X86_64_RELOC_GOT: {
832         printRelocationTargetName(this, RE, fmt);
833         fmt << "@GOT";
834         if (isPCRel) fmt << "PCREL";
835         break;
836       }
837       case MachO::X86_64_RELOC_SUBTRACTOR: {
838         DataRefImpl RelNext = Rel;
839         moveRelocationNext(RelNext);
840         MachO::any_relocation_info RENext = getRelocation(RelNext);
841 
842         // X86_64_RELOC_SUBTRACTOR must be followed by a relocation of type
843         // X86_64_RELOC_UNSIGNED.
844         // NOTE: Scattered relocations don't exist on x86_64.
845         unsigned RType = getAnyRelocationType(RENext);
846         if (RType != MachO::X86_64_RELOC_UNSIGNED)
847           report_fatal_error("Expected X86_64_RELOC_UNSIGNED after "
848                              "X86_64_RELOC_SUBTRACTOR.");
849 
850         // The X86_64_RELOC_UNSIGNED contains the minuend symbol;
851         // X86_64_RELOC_SUBTRACTOR contains the subtrahend.
852         printRelocationTargetName(this, RENext, fmt);
853         fmt << "-";
854         printRelocationTargetName(this, RE, fmt);
855         break;
856       }
857       case MachO::X86_64_RELOC_TLV:
858         printRelocationTargetName(this, RE, fmt);
859         fmt << "@TLV";
860         if (isPCRel) fmt << "P";
861         break;
862       case MachO::X86_64_RELOC_SIGNED_1:
863         printRelocationTargetName(this, RE, fmt);
864         fmt << "-1";
865         break;
866       case MachO::X86_64_RELOC_SIGNED_2:
867         printRelocationTargetName(this, RE, fmt);
868         fmt << "-2";
869         break;
870       case MachO::X86_64_RELOC_SIGNED_4:
871         printRelocationTargetName(this, RE, fmt);
872         fmt << "-4";
873         break;
874       default:
875         printRelocationTargetName(this, RE, fmt);
876         break;
877     }
878   // X86 and ARM share some relocation types in common.
879   } else if (Arch == Triple::x86 || Arch == Triple::arm ||
880              Arch == Triple::ppc) {
881     // Generic relocation types...
882     switch (Type) {
883       case MachO::GENERIC_RELOC_PAIR: // prints no info
884         return object_error::success;
885       case MachO::GENERIC_RELOC_SECTDIFF: {
886         DataRefImpl RelNext = Rel;
887         moveRelocationNext(RelNext);
888         MachO::any_relocation_info RENext = getRelocation(RelNext);
889 
890         // X86 sect diff's must be followed by a relocation of type
891         // GENERIC_RELOC_PAIR.
892         unsigned RType = getAnyRelocationType(RENext);
893 
894         if (RType != MachO::GENERIC_RELOC_PAIR)
895           report_fatal_error("Expected GENERIC_RELOC_PAIR after "
896                              "GENERIC_RELOC_SECTDIFF.");
897 
898         printRelocationTargetName(this, RE, fmt);
899         fmt << "-";
900         printRelocationTargetName(this, RENext, fmt);
901         break;
902       }
903     }
904 
905     if (Arch == Triple::x86 || Arch == Triple::ppc) {
906       switch (Type) {
907         case MachO::GENERIC_RELOC_LOCAL_SECTDIFF: {
908           DataRefImpl RelNext = Rel;
909           moveRelocationNext(RelNext);
910           MachO::any_relocation_info RENext = getRelocation(RelNext);
911 
912           // X86 sect diff's must be followed by a relocation of type
913           // GENERIC_RELOC_PAIR.
914           unsigned RType = getAnyRelocationType(RENext);
915           if (RType != MachO::GENERIC_RELOC_PAIR)
916             report_fatal_error("Expected GENERIC_RELOC_PAIR after "
917                                "GENERIC_RELOC_LOCAL_SECTDIFF.");
918 
919           printRelocationTargetName(this, RE, fmt);
920           fmt << "-";
921           printRelocationTargetName(this, RENext, fmt);
922           break;
923         }
924         case MachO::GENERIC_RELOC_TLV: {
925           printRelocationTargetName(this, RE, fmt);
926           fmt << "@TLV";
927           if (IsPCRel) fmt << "P";
928           break;
929         }
930         default:
931           printRelocationTargetName(this, RE, fmt);
932       }
933     } else { // ARM-specific relocations
934       switch (Type) {
935         case MachO::ARM_RELOC_HALF:
936         case MachO::ARM_RELOC_HALF_SECTDIFF: {
937           // Half relocations steal a bit from the length field to encode
938           // whether this is an upper16 or a lower16 relocation.
939           bool isUpper = getAnyRelocationLength(RE) >> 1;
940 
941           if (isUpper)
942             fmt << ":upper16:(";
943           else
944             fmt << ":lower16:(";
945           printRelocationTargetName(this, RE, fmt);
946 
947           DataRefImpl RelNext = Rel;
948           moveRelocationNext(RelNext);
949           MachO::any_relocation_info RENext = getRelocation(RelNext);
950 
951           // ARM half relocs must be followed by a relocation of type
952           // ARM_RELOC_PAIR.
953           unsigned RType = getAnyRelocationType(RENext);
954           if (RType != MachO::ARM_RELOC_PAIR)
955             report_fatal_error("Expected ARM_RELOC_PAIR after "
956                                "ARM_RELOC_HALF");
957 
958           // NOTE: The half of the target virtual address is stashed in the
959           // address field of the secondary relocation, but we can't reverse
960           // engineer the constant offset from it without decoding the movw/movt
961           // instruction to find the other half in its immediate field.
962 
963           // ARM_RELOC_HALF_SECTDIFF encodes the second section in the
964           // symbol/section pointer of the follow-on relocation.
965           if (Type == MachO::ARM_RELOC_HALF_SECTDIFF) {
966             fmt << "-";
967             printRelocationTargetName(this, RENext, fmt);
968           }
969 
970           fmt << ")";
971           break;
972         }
973         default: {
974           printRelocationTargetName(this, RE, fmt);
975         }
976       }
977     }
978   } else
979     printRelocationTargetName(this, RE, fmt);
980 
981   fmt.flush();
982   Result.append(fmtbuf.begin(), fmtbuf.end());
983   return object_error::success;
984 }
985 
986 std::error_code MachOObjectFile::getRelocationHidden(DataRefImpl Rel,
987                                                      bool &Result) const {
988   unsigned Arch = getArch();
989   uint64_t Type;
990   getRelocationType(Rel, Type);
991 
992   Result = false;
993 
994   // On arches that use the generic relocations, GENERIC_RELOC_PAIR
995   // is always hidden.
996   if (Arch == Triple::x86 || Arch == Triple::arm || Arch == Triple::ppc) {
997     if (Type == MachO::GENERIC_RELOC_PAIR) Result = true;
998   } else if (Arch == Triple::x86_64) {
999     // On x86_64, X86_64_RELOC_UNSIGNED is hidden only when it follows
1000     // an X86_64_RELOC_SUBTRACTOR.
1001     if (Type == MachO::X86_64_RELOC_UNSIGNED && Rel.d.a > 0) {
1002       DataRefImpl RelPrev = Rel;
1003       RelPrev.d.a--;
1004       uint64_t PrevType;
1005       getRelocationType(RelPrev, PrevType);
1006       if (PrevType == MachO::X86_64_RELOC_SUBTRACTOR)
1007         Result = true;
1008     }
1009   }
1010 
1011   return object_error::success;
1012 }
1013 
1014 std::error_code MachOObjectFile::getLibraryNext(DataRefImpl LibData,
1015                                                 LibraryRef &Res) const {
1016   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1017 }
1018 
1019 std::error_code MachOObjectFile::getLibraryPath(DataRefImpl LibData,
1020                                                 StringRef &Res) const {
1021   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1022 }
1023 
1024 //
1025 // guessLibraryShortName() is passed a name of a dynamic library and returns a
1026 // guess on what the short name is.  Then name is returned as a substring of the
1027 // StringRef Name passed in.  The name of the dynamic library is recognized as
1028 // a framework if it has one of the two following forms:
1029 //      Foo.framework/Versions/A/Foo
1030 //      Foo.framework/Foo
1031 // Where A and Foo can be any string.  And may contain a trailing suffix
1032 // starting with an underbar.  If the Name is recognized as a framework then
1033 // isFramework is set to true else it is set to false.  If the Name has a
1034 // suffix then Suffix is set to the substring in Name that contains the suffix
1035 // else it is set to a NULL StringRef.
1036 //
1037 // The Name of the dynamic library is recognized as a library name if it has
1038 // one of the two following forms:
1039 //      libFoo.A.dylib
1040 //      libFoo.dylib
1041 // The library may have a suffix trailing the name Foo of the form:
1042 //      libFoo_profile.A.dylib
1043 //      libFoo_profile.dylib
1044 //
1045 // The Name of the dynamic library is also recognized as a library name if it
1046 // has the following form:
1047 //      Foo.qtx
1048 //
1049 // If the Name of the dynamic library is none of the forms above then a NULL
1050 // StringRef is returned.
1051 //
1052 StringRef MachOObjectFile::guessLibraryShortName(StringRef Name,
1053                                                  bool &isFramework,
1054                                                  StringRef &Suffix) {
1055   StringRef Foo, F, DotFramework, V, Dylib, Lib, Dot, Qtx;
1056   size_t a, b, c, d, Idx;
1057 
1058   isFramework = false;
1059   Suffix = StringRef();
1060 
1061   // Pull off the last component and make Foo point to it
1062   a = Name.rfind('/');
1063   if (a == Name.npos || a == 0)
1064     goto guess_library;
1065   Foo = Name.slice(a+1, Name.npos);
1066 
1067   // Look for a suffix starting with a '_'
1068   Idx = Foo.rfind('_');
1069   if (Idx != Foo.npos && Foo.size() >= 2) {
1070     Suffix = Foo.slice(Idx, Foo.npos);
1071     Foo = Foo.slice(0, Idx);
1072   }
1073 
1074   // First look for the form Foo.framework/Foo
1075   b = Name.rfind('/', a);
1076   if (b == Name.npos)
1077     Idx = 0;
1078   else
1079     Idx = b+1;
1080   F = Name.slice(Idx, Idx + Foo.size());
1081   DotFramework = Name.slice(Idx + Foo.size(),
1082                             Idx + Foo.size() + sizeof(".framework/")-1);
1083   if (F == Foo && DotFramework == ".framework/") {
1084     isFramework = true;
1085     return Foo;
1086   }
1087 
1088   // Next look for the form Foo.framework/Versions/A/Foo
1089   if (b == Name.npos)
1090     goto guess_library;
1091   c =  Name.rfind('/', b);
1092   if (c == Name.npos || c == 0)
1093     goto guess_library;
1094   V = Name.slice(c+1, Name.npos);
1095   if (!V.startswith("Versions/"))
1096     goto guess_library;
1097   d =  Name.rfind('/', c);
1098   if (d == Name.npos)
1099     Idx = 0;
1100   else
1101     Idx = d+1;
1102   F = Name.slice(Idx, Idx + Foo.size());
1103   DotFramework = Name.slice(Idx + Foo.size(),
1104                             Idx + Foo.size() + sizeof(".framework/")-1);
1105   if (F == Foo && DotFramework == ".framework/") {
1106     isFramework = true;
1107     return Foo;
1108   }
1109 
1110 guess_library:
1111   // pull off the suffix after the "." and make a point to it
1112   a = Name.rfind('.');
1113   if (a == Name.npos || a == 0)
1114     return StringRef();
1115   Dylib = Name.slice(a, Name.npos);
1116   if (Dylib != ".dylib")
1117     goto guess_qtx;
1118 
1119   // First pull off the version letter for the form Foo.A.dylib if any.
1120   if (a >= 3) {
1121     Dot = Name.slice(a-2, a-1);
1122     if (Dot == ".")
1123       a = a - 2;
1124   }
1125 
1126   b = Name.rfind('/', a);
1127   if (b == Name.npos)
1128     b = 0;
1129   else
1130     b = b+1;
1131   // ignore any suffix after an underbar like Foo_profile.A.dylib
1132   Idx = Name.find('_', b);
1133   if (Idx != Name.npos && Idx != b) {
1134     Lib = Name.slice(b, Idx);
1135     Suffix = Name.slice(Idx, a);
1136   }
1137   else
1138     Lib = Name.slice(b, a);
1139   // There are incorrect library names of the form:
1140   // libATS.A_profile.dylib so check for these.
1141   if (Lib.size() >= 3) {
1142     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
1143     if (Dot == ".")
1144       Lib = Lib.slice(0, Lib.size()-2);
1145   }
1146   return Lib;
1147 
1148 guess_qtx:
1149   Qtx = Name.slice(a, Name.npos);
1150   if (Qtx != ".qtx")
1151     return StringRef();
1152   b = Name.rfind('/', a);
1153   if (b == Name.npos)
1154     Lib = Name.slice(0, a);
1155   else
1156     Lib = Name.slice(b+1, a);
1157   // There are library names of the form: QT.A.qtx so check for these.
1158   if (Lib.size() >= 3) {
1159     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
1160     if (Dot == ".")
1161       Lib = Lib.slice(0, Lib.size()-2);
1162   }
1163   return Lib;
1164 }
1165 
1166 // getLibraryShortNameByIndex() is used to get the short name of the library
1167 // for an undefined symbol in a linked Mach-O binary that was linked with the
1168 // normal two-level namespace default (that is MH_TWOLEVEL in the header).
1169 // It is passed the index (0 - based) of the library as translated from
1170 // GET_LIBRARY_ORDINAL (1 - based).
1171 std::error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
1172                                                             StringRef &Res) {
1173   if (Index >= Libraries.size())
1174     return object_error::parse_failed;
1175 
1176   MachO::dylib_command D =
1177     getStruct<MachO::dylib_command>(this, Libraries[Index]);
1178   if (D.dylib.name >= D.cmdsize)
1179     return object_error::parse_failed;
1180 
1181   // If the cache of LibrariesShortNames is not built up do that first for
1182   // all the Libraries.
1183   if (LibrariesShortNames.size() == 0) {
1184     for (unsigned i = 0; i < Libraries.size(); i++) {
1185       MachO::dylib_command D =
1186         getStruct<MachO::dylib_command>(this, Libraries[i]);
1187       if (D.dylib.name >= D.cmdsize) {
1188         LibrariesShortNames.push_back(StringRef());
1189         continue;
1190       }
1191       const char *P = (const char *)(Libraries[i]) + D.dylib.name;
1192       StringRef Name = StringRef(P);
1193       StringRef Suffix;
1194       bool isFramework;
1195       StringRef shortName = guessLibraryShortName(Name, isFramework, Suffix);
1196       if (shortName == StringRef())
1197         LibrariesShortNames.push_back(Name);
1198       else
1199         LibrariesShortNames.push_back(shortName);
1200     }
1201   }
1202 
1203   Res = LibrariesShortNames[Index];
1204   return object_error::success;
1205 }
1206 
1207 basic_symbol_iterator MachOObjectFile::symbol_begin_impl() const {
1208   return getSymbolByIndex(0);
1209 }
1210 
1211 basic_symbol_iterator MachOObjectFile::symbol_end_impl() const {
1212   DataRefImpl DRI;
1213   if (!SymtabLoadCmd)
1214     return basic_symbol_iterator(SymbolRef(DRI, this));
1215 
1216   MachO::symtab_command Symtab = getSymtabLoadCommand();
1217   unsigned SymbolTableEntrySize = is64Bit() ?
1218     sizeof(MachO::nlist_64) :
1219     sizeof(MachO::nlist);
1220   unsigned Offset = Symtab.symoff +
1221     Symtab.nsyms * SymbolTableEntrySize;
1222   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1223   return basic_symbol_iterator(SymbolRef(DRI, this));
1224 }
1225 
1226 basic_symbol_iterator MachOObjectFile::getSymbolByIndex(unsigned Index) const {
1227   DataRefImpl DRI;
1228   if (!SymtabLoadCmd)
1229     return basic_symbol_iterator(SymbolRef(DRI, this));
1230 
1231   MachO::symtab_command Symtab = getSymtabLoadCommand();
1232   assert(Index < Symtab.nsyms && "Requested symbol index is out of range.");
1233   unsigned SymbolTableEntrySize =
1234     is64Bit() ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
1235   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Symtab.symoff));
1236   DRI.p += Index * SymbolTableEntrySize;
1237   return basic_symbol_iterator(SymbolRef(DRI, this));
1238 }
1239 
1240 section_iterator MachOObjectFile::section_begin() const {
1241   DataRefImpl DRI;
1242   return section_iterator(SectionRef(DRI, this));
1243 }
1244 
1245 section_iterator MachOObjectFile::section_end() const {
1246   DataRefImpl DRI;
1247   DRI.d.a = Sections.size();
1248   return section_iterator(SectionRef(DRI, this));
1249 }
1250 
1251 library_iterator MachOObjectFile::needed_library_begin() const {
1252   // TODO: implement
1253   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1254 }
1255 
1256 library_iterator MachOObjectFile::needed_library_end() const {
1257   // TODO: implement
1258   report_fatal_error("Needed libraries unimplemented in MachOObjectFile");
1259 }
1260 
1261 uint8_t MachOObjectFile::getBytesInAddress() const {
1262   return is64Bit() ? 8 : 4;
1263 }
1264 
1265 StringRef MachOObjectFile::getFileFormatName() const {
1266   unsigned CPUType = getCPUType(this);
1267   if (!is64Bit()) {
1268     switch (CPUType) {
1269     case llvm::MachO::CPU_TYPE_I386:
1270       return "Mach-O 32-bit i386";
1271     case llvm::MachO::CPU_TYPE_ARM:
1272       return "Mach-O arm";
1273     case llvm::MachO::CPU_TYPE_POWERPC:
1274       return "Mach-O 32-bit ppc";
1275     default:
1276       assert((CPUType & llvm::MachO::CPU_ARCH_ABI64) == 0 &&
1277              "64-bit object file when we're not 64-bit?");
1278       return "Mach-O 32-bit unknown";
1279     }
1280   }
1281 
1282   // Make sure the cpu type has the correct mask.
1283   assert((CPUType & llvm::MachO::CPU_ARCH_ABI64)
1284          == llvm::MachO::CPU_ARCH_ABI64 &&
1285          "32-bit object file when we're 64-bit?");
1286 
1287   switch (CPUType) {
1288   case llvm::MachO::CPU_TYPE_X86_64:
1289     return "Mach-O 64-bit x86-64";
1290   case llvm::MachO::CPU_TYPE_ARM64:
1291     return "Mach-O arm64";
1292   case llvm::MachO::CPU_TYPE_POWERPC64:
1293     return "Mach-O 64-bit ppc64";
1294   default:
1295     return "Mach-O 64-bit unknown";
1296   }
1297 }
1298 
1299 Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
1300   switch (CPUType) {
1301   case llvm::MachO::CPU_TYPE_I386:
1302     return Triple::x86;
1303   case llvm::MachO::CPU_TYPE_X86_64:
1304     return Triple::x86_64;
1305   case llvm::MachO::CPU_TYPE_ARM:
1306     return Triple::arm;
1307   case llvm::MachO::CPU_TYPE_ARM64:
1308     return Triple::arm64;
1309   case llvm::MachO::CPU_TYPE_POWERPC:
1310     return Triple::ppc;
1311   case llvm::MachO::CPU_TYPE_POWERPC64:
1312     return Triple::ppc64;
1313   default:
1314     return Triple::UnknownArch;
1315   }
1316 }
1317 
1318 Triple MachOObjectFile::getArch(uint32_t CPUType, uint32_t CPUSubType) {
1319   switch (CPUType) {
1320   case MachO::CPU_TYPE_I386:
1321     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
1322     case MachO::CPU_SUBTYPE_I386_ALL:
1323       return Triple("i386-apple-darwin");
1324     default:
1325       return Triple();
1326     }
1327   case MachO::CPU_TYPE_X86_64:
1328     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
1329     case MachO::CPU_SUBTYPE_X86_64_ALL:
1330       return Triple("x86_64-apple-darwin");
1331     case MachO::CPU_SUBTYPE_X86_64_H:
1332       return Triple("x86_64h-apple-darwin");
1333     default:
1334       return Triple();
1335     }
1336   case MachO::CPU_TYPE_ARM:
1337     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
1338     case MachO::CPU_SUBTYPE_ARM_V4T:
1339       return Triple("armv4t-apple-darwin");
1340     case MachO::CPU_SUBTYPE_ARM_V5TEJ:
1341       return Triple("armv5e-apple-darwin");
1342     case MachO::CPU_SUBTYPE_ARM_V6:
1343       return Triple("armv6-apple-darwin");
1344     case MachO::CPU_SUBTYPE_ARM_V6M:
1345       return Triple("armv6m-apple-darwin");
1346     case MachO::CPU_SUBTYPE_ARM_V7EM:
1347       return Triple("armv7em-apple-darwin");
1348     case MachO::CPU_SUBTYPE_ARM_V7K:
1349       return Triple("armv7k-apple-darwin");
1350     case MachO::CPU_SUBTYPE_ARM_V7M:
1351       return Triple("armv7m-apple-darwin");
1352     case MachO::CPU_SUBTYPE_ARM_V7S:
1353       return Triple("armv7s-apple-darwin");
1354     default:
1355       return Triple();
1356     }
1357   case MachO::CPU_TYPE_ARM64:
1358     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
1359     case MachO::CPU_SUBTYPE_ARM64_ALL:
1360       return Triple("arm64-apple-darwin");
1361     default:
1362       return Triple();
1363     }
1364   case MachO::CPU_TYPE_POWERPC:
1365     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
1366     case MachO::CPU_SUBTYPE_POWERPC_ALL:
1367       return Triple("ppc-apple-darwin");
1368     default:
1369       return Triple();
1370     }
1371   case MachO::CPU_TYPE_POWERPC64:
1372     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
1373     case MachO::CPU_SUBTYPE_POWERPC_ALL:
1374       return Triple("ppc64-apple-darwin");
1375     default:
1376       return Triple();
1377     }
1378   default:
1379     return Triple();
1380   }
1381 }
1382 
1383 Triple MachOObjectFile::getHostArch() {
1384   return Triple(sys::getDefaultTargetTriple());
1385 }
1386 
1387 Triple MachOObjectFile::getArch(StringRef ArchFlag) {
1388   if (ArchFlag == "i386")
1389     return Triple("i386-apple-darwin");
1390   else if (ArchFlag == "x86_64")
1391     return Triple("x86_64-apple-darwin");
1392   else if (ArchFlag == "x86_64h")
1393     return Triple("x86_64h-apple-darwin");
1394   else if (ArchFlag == "armv4t" || ArchFlag == "arm")
1395     return Triple("armv4t-apple-darwin");
1396   else if (ArchFlag == "armv5e")
1397     return Triple("armv5e-apple-darwin");
1398   else if (ArchFlag == "armv6")
1399     return Triple("armv6-apple-darwin");
1400   else if (ArchFlag == "armv6m")
1401     return Triple("armv6m-apple-darwin");
1402   else if (ArchFlag == "armv7em")
1403     return Triple("armv7em-apple-darwin");
1404   else if (ArchFlag == "armv7k")
1405     return Triple("armv7k-apple-darwin");
1406   else if (ArchFlag == "armv7k")
1407     return Triple("armv7m-apple-darwin");
1408   else if (ArchFlag == "armv7s")
1409     return Triple("armv7s-apple-darwin");
1410   else if (ArchFlag == "arm64")
1411     return Triple("arm64-apple-darwin");
1412   else if (ArchFlag == "ppc")
1413     return Triple("ppc-apple-darwin");
1414   else if (ArchFlag == "ppc64")
1415     return Triple("ppc64-apple-darwin");
1416   else
1417     return Triple();
1418 }
1419 
1420 unsigned MachOObjectFile::getArch() const {
1421   return getArch(getCPUType(this));
1422 }
1423 
1424 StringRef MachOObjectFile::getLoadName() const {
1425   // TODO: Implement
1426   report_fatal_error("get_load_name() unimplemented in MachOObjectFile");
1427 }
1428 
1429 relocation_iterator MachOObjectFile::section_rel_begin(unsigned Index) const {
1430   DataRefImpl DRI;
1431   DRI.d.a = Index;
1432   return section_rel_begin(DRI);
1433 }
1434 
1435 relocation_iterator MachOObjectFile::section_rel_end(unsigned Index) const {
1436   DataRefImpl DRI;
1437   DRI.d.a = Index;
1438   return section_rel_end(DRI);
1439 }
1440 
1441 dice_iterator MachOObjectFile::begin_dices() const {
1442   DataRefImpl DRI;
1443   if (!DataInCodeLoadCmd)
1444     return dice_iterator(DiceRef(DRI, this));
1445 
1446   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1447   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, DicLC.dataoff));
1448   return dice_iterator(DiceRef(DRI, this));
1449 }
1450 
1451 dice_iterator MachOObjectFile::end_dices() const {
1452   DataRefImpl DRI;
1453   if (!DataInCodeLoadCmd)
1454     return dice_iterator(DiceRef(DRI, this));
1455 
1456   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
1457   unsigned Offset = DicLC.dataoff + DicLC.datasize;
1458   DRI.p = reinterpret_cast<uintptr_t>(getPtr(this, Offset));
1459   return dice_iterator(DiceRef(DRI, this));
1460 }
1461 
1462 StringRef
1463 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
1464   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
1465   return parseSegmentOrSectionName(Raw.data());
1466 }
1467 
1468 ArrayRef<char>
1469 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
1470   const section_base *Base =
1471     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1472   return ArrayRef<char>(Base->sectname);
1473 }
1474 
1475 ArrayRef<char>
1476 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
1477   const section_base *Base =
1478     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
1479   return ArrayRef<char>(Base->segname);
1480 }
1481 
1482 bool
1483 MachOObjectFile::isRelocationScattered(const MachO::any_relocation_info &RE)
1484   const {
1485   if (getCPUType(this) == MachO::CPU_TYPE_X86_64)
1486     return false;
1487   return getPlainRelocationAddress(RE) & MachO::R_SCATTERED;
1488 }
1489 
1490 unsigned MachOObjectFile::getPlainRelocationSymbolNum(
1491     const MachO::any_relocation_info &RE) const {
1492   if (isLittleEndian())
1493     return RE.r_word1 & 0xffffff;
1494   return RE.r_word1 >> 8;
1495 }
1496 
1497 bool MachOObjectFile::getPlainRelocationExternal(
1498     const MachO::any_relocation_info &RE) const {
1499   if (isLittleEndian())
1500     return (RE.r_word1 >> 27) & 1;
1501   return (RE.r_word1 >> 4) & 1;
1502 }
1503 
1504 bool MachOObjectFile::getScatteredRelocationScattered(
1505     const MachO::any_relocation_info &RE) const {
1506   return RE.r_word0 >> 31;
1507 }
1508 
1509 uint32_t MachOObjectFile::getScatteredRelocationValue(
1510     const MachO::any_relocation_info &RE) const {
1511   return RE.r_word1;
1512 }
1513 
1514 unsigned MachOObjectFile::getAnyRelocationAddress(
1515     const MachO::any_relocation_info &RE) const {
1516   if (isRelocationScattered(RE))
1517     return getScatteredRelocationAddress(RE);
1518   return getPlainRelocationAddress(RE);
1519 }
1520 
1521 unsigned MachOObjectFile::getAnyRelocationPCRel(
1522     const MachO::any_relocation_info &RE) const {
1523   if (isRelocationScattered(RE))
1524     return getScatteredRelocationPCRel(this, RE);
1525   return getPlainRelocationPCRel(this, RE);
1526 }
1527 
1528 unsigned MachOObjectFile::getAnyRelocationLength(
1529     const MachO::any_relocation_info &RE) const {
1530   if (isRelocationScattered(RE))
1531     return getScatteredRelocationLength(RE);
1532   return getPlainRelocationLength(this, RE);
1533 }
1534 
1535 unsigned
1536 MachOObjectFile::getAnyRelocationType(
1537                                    const MachO::any_relocation_info &RE) const {
1538   if (isRelocationScattered(RE))
1539     return getScatteredRelocationType(RE);
1540   return getPlainRelocationType(this, RE);
1541 }
1542 
1543 SectionRef
1544 MachOObjectFile::getRelocationSection(
1545                                    const MachO::any_relocation_info &RE) const {
1546   if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
1547     return *section_end();
1548   unsigned SecNum = getPlainRelocationSymbolNum(RE) - 1;
1549   DataRefImpl DRI;
1550   DRI.d.a = SecNum;
1551   return SectionRef(DRI, this);
1552 }
1553 
1554 MachOObjectFile::LoadCommandInfo
1555 MachOObjectFile::getFirstLoadCommandInfo() const {
1556   MachOObjectFile::LoadCommandInfo Load;
1557 
1558   unsigned HeaderSize = is64Bit() ? sizeof(MachO::mach_header_64) :
1559                                     sizeof(MachO::mach_header);
1560   Load.Ptr = getPtr(this, HeaderSize);
1561   Load.C = getStruct<MachO::load_command>(this, Load.Ptr);
1562   return Load;
1563 }
1564 
1565 MachOObjectFile::LoadCommandInfo
1566 MachOObjectFile::getNextLoadCommandInfo(const LoadCommandInfo &L) const {
1567   MachOObjectFile::LoadCommandInfo Next;
1568   Next.Ptr = L.Ptr + L.C.cmdsize;
1569   Next.C = getStruct<MachO::load_command>(this, Next.Ptr);
1570   return Next;
1571 }
1572 
1573 MachO::section MachOObjectFile::getSection(DataRefImpl DRI) const {
1574   return getStruct<MachO::section>(this, Sections[DRI.d.a]);
1575 }
1576 
1577 MachO::section_64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
1578   return getStruct<MachO::section_64>(this, Sections[DRI.d.a]);
1579 }
1580 
1581 MachO::section MachOObjectFile::getSection(const LoadCommandInfo &L,
1582                                            unsigned Index) const {
1583   const char *Sec = getSectionPtr(this, L, Index);
1584   return getStruct<MachO::section>(this, Sec);
1585 }
1586 
1587 MachO::section_64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
1588                                                 unsigned Index) const {
1589   const char *Sec = getSectionPtr(this, L, Index);
1590   return getStruct<MachO::section_64>(this, Sec);
1591 }
1592 
1593 MachO::nlist
1594 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
1595   const char *P = reinterpret_cast<const char *>(DRI.p);
1596   return getStruct<MachO::nlist>(this, P);
1597 }
1598 
1599 MachO::nlist_64
1600 MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI) const {
1601   const char *P = reinterpret_cast<const char *>(DRI.p);
1602   return getStruct<MachO::nlist_64>(this, P);
1603 }
1604 
1605 MachO::linkedit_data_command
1606 MachOObjectFile::getLinkeditDataLoadCommand(const LoadCommandInfo &L) const {
1607   return getStruct<MachO::linkedit_data_command>(this, L.Ptr);
1608 }
1609 
1610 MachO::segment_command
1611 MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
1612   return getStruct<MachO::segment_command>(this, L.Ptr);
1613 }
1614 
1615 MachO::segment_command_64
1616 MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
1617   return getStruct<MachO::segment_command_64>(this, L.Ptr);
1618 }
1619 
1620 MachO::linker_options_command
1621 MachOObjectFile::getLinkerOptionsLoadCommand(const LoadCommandInfo &L) const {
1622   return getStruct<MachO::linker_options_command>(this, L.Ptr);
1623 }
1624 
1625 MachO::version_min_command
1626 MachOObjectFile::getVersionMinLoadCommand(const LoadCommandInfo &L) const {
1627   return getStruct<MachO::version_min_command>(this, L.Ptr);
1628 }
1629 
1630 MachO::dylib_command
1631 MachOObjectFile::getDylibIDLoadCommand(const LoadCommandInfo &L) const {
1632   return getStruct<MachO::dylib_command>(this, L.Ptr);
1633 }
1634 
1635 
1636 MachO::any_relocation_info
1637 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
1638   DataRefImpl Sec;
1639   Sec.d.a = Rel.d.a;
1640   uint32_t Offset;
1641   if (is64Bit()) {
1642     MachO::section_64 Sect = getSection64(Sec);
1643     Offset = Sect.reloff;
1644   } else {
1645     MachO::section Sect = getSection(Sec);
1646     Offset = Sect.reloff;
1647   }
1648 
1649   auto P = reinterpret_cast<const MachO::any_relocation_info *>(
1650       getPtr(this, Offset)) + Rel.d.b;
1651   return getStruct<MachO::any_relocation_info>(
1652       this, reinterpret_cast<const char *>(P));
1653 }
1654 
1655 MachO::data_in_code_entry
1656 MachOObjectFile::getDice(DataRefImpl Rel) const {
1657   const char *P = reinterpret_cast<const char *>(Rel.p);
1658   return getStruct<MachO::data_in_code_entry>(this, P);
1659 }
1660 
1661 MachO::mach_header MachOObjectFile::getHeader() const {
1662   return getStruct<MachO::mach_header>(this, getPtr(this, 0));
1663 }
1664 
1665 MachO::mach_header_64 MachOObjectFile::getHeader64() const {
1666   return getStruct<MachO::mach_header_64>(this, getPtr(this, 0));
1667 }
1668 
1669 uint32_t MachOObjectFile::getIndirectSymbolTableEntry(
1670                                              const MachO::dysymtab_command &DLC,
1671                                              unsigned Index) const {
1672   uint64_t Offset = DLC.indirectsymoff + Index * sizeof(uint32_t);
1673   return getStruct<uint32_t>(this, getPtr(this, Offset));
1674 }
1675 
1676 MachO::data_in_code_entry
1677 MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
1678                                          unsigned Index) const {
1679   uint64_t Offset = DataOffset + Index * sizeof(MachO::data_in_code_entry);
1680   return getStruct<MachO::data_in_code_entry>(this, getPtr(this, Offset));
1681 }
1682 
1683 MachO::symtab_command MachOObjectFile::getSymtabLoadCommand() const {
1684   return getStruct<MachO::symtab_command>(this, SymtabLoadCmd);
1685 }
1686 
1687 MachO::dysymtab_command MachOObjectFile::getDysymtabLoadCommand() const {
1688   return getStruct<MachO::dysymtab_command>(this, DysymtabLoadCmd);
1689 }
1690 
1691 MachO::linkedit_data_command
1692 MachOObjectFile::getDataInCodeLoadCommand() const {
1693   if (DataInCodeLoadCmd)
1694     return getStruct<MachO::linkedit_data_command>(this, DataInCodeLoadCmd);
1695 
1696   // If there is no DataInCodeLoadCmd return a load command with zero'ed fields.
1697   MachO::linkedit_data_command Cmd;
1698   Cmd.cmd = MachO::LC_DATA_IN_CODE;
1699   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
1700   Cmd.dataoff = 0;
1701   Cmd.datasize = 0;
1702   return Cmd;
1703 }
1704 
1705 StringRef MachOObjectFile::getStringTableData() const {
1706   MachO::symtab_command S = getSymtabLoadCommand();
1707   return getData().substr(S.stroff, S.strsize);
1708 }
1709 
1710 bool MachOObjectFile::is64Bit() const {
1711   return getType() == getMachOType(false, true) ||
1712     getType() == getMachOType(true, true);
1713 }
1714 
1715 void MachOObjectFile::ReadULEB128s(uint64_t Index,
1716                                    SmallVectorImpl<uint64_t> &Out) const {
1717   DataExtractor extractor(ObjectFile::getData(), true, 0);
1718 
1719   uint32_t offset = Index;
1720   uint64_t data = 0;
1721   while (uint64_t delta = extractor.getULEB128(&offset)) {
1722     data += delta;
1723     Out.push_back(data);
1724   }
1725 }
1726 
1727 ErrorOr<ObjectFile *>
1728 ObjectFile::createMachOObjectFile(std::unique_ptr<MemoryBuffer> &Buffer) {
1729   StringRef Magic = Buffer->getBuffer().slice(0, 4);
1730   std::error_code EC;
1731   std::unique_ptr<MachOObjectFile> Ret;
1732   if (Magic == "\xFE\xED\xFA\xCE")
1733     Ret.reset(new MachOObjectFile(std::move(Buffer), false, false, EC));
1734   else if (Magic == "\xCE\xFA\xED\xFE")
1735     Ret.reset(new MachOObjectFile(std::move(Buffer), true, false, EC));
1736   else if (Magic == "\xFE\xED\xFA\xCF")
1737     Ret.reset(new MachOObjectFile(std::move(Buffer), false, true, EC));
1738   else if (Magic == "\xCF\xFA\xED\xFE")
1739     Ret.reset(new MachOObjectFile(std::move(Buffer), true, true, EC));
1740   else
1741     return object_error::parse_failed;
1742 
1743   if (EC)
1744     return EC;
1745   return Ret.release();
1746 }
1747 
1748 } // end namespace object
1749 } // end namespace llvm
1750