xref: /llvm-project/llvm/lib/Object/MachOObjectFile.cpp (revision 2946cd701067404b99c39fb29dc9c74bd7193eb3)
1 //===- MachOObjectFile.cpp - Mach-O object file binding -------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the MachOObjectFile class, which binds the MachOObject
10 // class to the generic ObjectFile wrapper.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/ADT/ArrayRef.h"
15 #include "llvm/ADT/None.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/StringSwitch.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/ADT/Twine.h"
22 #include "llvm/BinaryFormat/MachO.h"
23 #include "llvm/Object/Error.h"
24 #include "llvm/Object/MachO.h"
25 #include "llvm/Object/ObjectFile.h"
26 #include "llvm/Object/SymbolicFile.h"
27 #include "llvm/Support/DataExtractor.h"
28 #include "llvm/Support/Debug.h"
29 #include "llvm/Support/Error.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/Format.h"
32 #include "llvm/Support/Host.h"
33 #include "llvm/Support/LEB128.h"
34 #include "llvm/Support/MemoryBuffer.h"
35 #include "llvm/Support/SwapByteOrder.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include <algorithm>
38 #include <cassert>
39 #include <cstddef>
40 #include <cstdint>
41 #include <cstring>
42 #include <limits>
43 #include <list>
44 #include <memory>
45 #include <string>
46 #include <system_error>
47 
48 using namespace llvm;
49 using namespace object;
50 
51 namespace {
52 
53   struct section_base {
54     char sectname[16];
55     char segname[16];
56   };
57 
58 } // end anonymous namespace
59 
60 static Error malformedError(const Twine &Msg) {
61   return make_error<GenericBinaryError>("truncated or malformed object (" +
62                                             Msg + ")",
63                                         object_error::parse_failed);
64 }
65 
66 // FIXME: Replace all uses of this function with getStructOrErr.
67 template <typename T>
68 static T getStruct(const MachOObjectFile &O, const char *P) {
69   // Don't read before the beginning or past the end of the file
70   if (P < O.getData().begin() || P + sizeof(T) > O.getData().end())
71     report_fatal_error("Malformed MachO file.");
72 
73   T Cmd;
74   memcpy(&Cmd, P, sizeof(T));
75   if (O.isLittleEndian() != sys::IsLittleEndianHost)
76     MachO::swapStruct(Cmd);
77   return Cmd;
78 }
79 
80 template <typename T>
81 static Expected<T> getStructOrErr(const MachOObjectFile &O, const char *P) {
82   // Don't read before the beginning or past the end of the file
83   if (P < O.getData().begin() || P + sizeof(T) > O.getData().end())
84     return malformedError("Structure read out-of-range");
85 
86   T Cmd;
87   memcpy(&Cmd, P, sizeof(T));
88   if (O.isLittleEndian() != sys::IsLittleEndianHost)
89     MachO::swapStruct(Cmd);
90   return Cmd;
91 }
92 
93 static const char *
94 getSectionPtr(const MachOObjectFile &O, MachOObjectFile::LoadCommandInfo L,
95               unsigned Sec) {
96   uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
97 
98   bool Is64 = O.is64Bit();
99   unsigned SegmentLoadSize = Is64 ? sizeof(MachO::segment_command_64) :
100                                     sizeof(MachO::segment_command);
101   unsigned SectionSize = Is64 ? sizeof(MachO::section_64) :
102                                 sizeof(MachO::section);
103 
104   uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
105   return reinterpret_cast<const char*>(SectionAddr);
106 }
107 
108 static const char *getPtr(const MachOObjectFile &O, size_t Offset) {
109   assert(Offset <= O.getData().size());
110   return O.getData().data() + Offset;
111 }
112 
113 static MachO::nlist_base
114 getSymbolTableEntryBase(const MachOObjectFile &O, DataRefImpl DRI) {
115   const char *P = reinterpret_cast<const char *>(DRI.p);
116   return getStruct<MachO::nlist_base>(O, P);
117 }
118 
119 static StringRef parseSegmentOrSectionName(const char *P) {
120   if (P[15] == 0)
121     // Null terminated.
122     return P;
123   // Not null terminated, so this is a 16 char string.
124   return StringRef(P, 16);
125 }
126 
127 static unsigned getCPUType(const MachOObjectFile &O) {
128   return O.getHeader().cputype;
129 }
130 
131 static uint32_t
132 getPlainRelocationAddress(const MachO::any_relocation_info &RE) {
133   return RE.r_word0;
134 }
135 
136 static unsigned
137 getScatteredRelocationAddress(const MachO::any_relocation_info &RE) {
138   return RE.r_word0 & 0xffffff;
139 }
140 
141 static bool getPlainRelocationPCRel(const MachOObjectFile &O,
142                                     const MachO::any_relocation_info &RE) {
143   if (O.isLittleEndian())
144     return (RE.r_word1 >> 24) & 1;
145   return (RE.r_word1 >> 7) & 1;
146 }
147 
148 static bool
149 getScatteredRelocationPCRel(const MachO::any_relocation_info &RE) {
150   return (RE.r_word0 >> 30) & 1;
151 }
152 
153 static unsigned getPlainRelocationLength(const MachOObjectFile &O,
154                                          const MachO::any_relocation_info &RE) {
155   if (O.isLittleEndian())
156     return (RE.r_word1 >> 25) & 3;
157   return (RE.r_word1 >> 5) & 3;
158 }
159 
160 static unsigned
161 getScatteredRelocationLength(const MachO::any_relocation_info &RE) {
162   return (RE.r_word0 >> 28) & 3;
163 }
164 
165 static unsigned getPlainRelocationType(const MachOObjectFile &O,
166                                        const MachO::any_relocation_info &RE) {
167   if (O.isLittleEndian())
168     return RE.r_word1 >> 28;
169   return RE.r_word1 & 0xf;
170 }
171 
172 static uint32_t getSectionFlags(const MachOObjectFile &O,
173                                 DataRefImpl Sec) {
174   if (O.is64Bit()) {
175     MachO::section_64 Sect = O.getSection64(Sec);
176     return Sect.flags;
177   }
178   MachO::section Sect = O.getSection(Sec);
179   return Sect.flags;
180 }
181 
182 static Expected<MachOObjectFile::LoadCommandInfo>
183 getLoadCommandInfo(const MachOObjectFile &Obj, const char *Ptr,
184                    uint32_t LoadCommandIndex) {
185   if (auto CmdOrErr = getStructOrErr<MachO::load_command>(Obj, Ptr)) {
186     if (CmdOrErr->cmdsize + Ptr > Obj.getData().end())
187       return malformedError("load command " + Twine(LoadCommandIndex) +
188                             " extends past end of file");
189     if (CmdOrErr->cmdsize < 8)
190       return malformedError("load command " + Twine(LoadCommandIndex) +
191                             " with size less than 8 bytes");
192     return MachOObjectFile::LoadCommandInfo({Ptr, *CmdOrErr});
193   } else
194     return CmdOrErr.takeError();
195 }
196 
197 static Expected<MachOObjectFile::LoadCommandInfo>
198 getFirstLoadCommandInfo(const MachOObjectFile &Obj) {
199   unsigned HeaderSize = Obj.is64Bit() ? sizeof(MachO::mach_header_64)
200                                       : sizeof(MachO::mach_header);
201   if (sizeof(MachO::load_command) > Obj.getHeader().sizeofcmds)
202     return malformedError("load command 0 extends past the end all load "
203                           "commands in the file");
204   return getLoadCommandInfo(Obj, getPtr(Obj, HeaderSize), 0);
205 }
206 
207 static Expected<MachOObjectFile::LoadCommandInfo>
208 getNextLoadCommandInfo(const MachOObjectFile &Obj, uint32_t LoadCommandIndex,
209                        const MachOObjectFile::LoadCommandInfo &L) {
210   unsigned HeaderSize = Obj.is64Bit() ? sizeof(MachO::mach_header_64)
211                                       : sizeof(MachO::mach_header);
212   if (L.Ptr + L.C.cmdsize + sizeof(MachO::load_command) >
213       Obj.getData().data() + HeaderSize + Obj.getHeader().sizeofcmds)
214     return malformedError("load command " + Twine(LoadCommandIndex + 1) +
215                           " extends past the end all load commands in the file");
216   return getLoadCommandInfo(Obj, L.Ptr + L.C.cmdsize, LoadCommandIndex + 1);
217 }
218 
219 template <typename T>
220 static void parseHeader(const MachOObjectFile &Obj, T &Header,
221                         Error &Err) {
222   if (sizeof(T) > Obj.getData().size()) {
223     Err = malformedError("the mach header extends past the end of the "
224                          "file");
225     return;
226   }
227   if (auto HeaderOrErr = getStructOrErr<T>(Obj, getPtr(Obj, 0)))
228     Header = *HeaderOrErr;
229   else
230     Err = HeaderOrErr.takeError();
231 }
232 
233 // This is used to check for overlapping of Mach-O elements.
234 struct MachOElement {
235   uint64_t Offset;
236   uint64_t Size;
237   const char *Name;
238 };
239 
240 static Error checkOverlappingElement(std::list<MachOElement> &Elements,
241                                      uint64_t Offset, uint64_t Size,
242                                      const char *Name) {
243   if (Size == 0)
244     return Error::success();
245 
246   for (auto it=Elements.begin() ; it != Elements.end(); ++it) {
247     auto E = *it;
248     if ((Offset >= E.Offset && Offset < E.Offset + E.Size) ||
249         (Offset + Size > E.Offset && Offset + Size < E.Offset + E.Size) ||
250         (Offset <= E.Offset && Offset + Size >= E.Offset + E.Size))
251       return malformedError(Twine(Name) + " at offset " + Twine(Offset) +
252                             " with a size of " + Twine(Size) + ", overlaps " +
253                             E.Name + " at offset " + Twine(E.Offset) + " with "
254                             "a size of " + Twine(E.Size));
255     auto nt = it;
256     nt++;
257     if (nt != Elements.end()) {
258       auto N = *nt;
259       if (Offset + Size <= N.Offset) {
260         Elements.insert(nt, {Offset, Size, Name});
261         return Error::success();
262       }
263     }
264   }
265   Elements.push_back({Offset, Size, Name});
266   return Error::success();
267 }
268 
269 // Parses LC_SEGMENT or LC_SEGMENT_64 load command, adds addresses of all
270 // sections to \param Sections, and optionally sets
271 // \param IsPageZeroSegment to true.
272 template <typename Segment, typename Section>
273 static Error parseSegmentLoadCommand(
274     const MachOObjectFile &Obj, const MachOObjectFile::LoadCommandInfo &Load,
275     SmallVectorImpl<const char *> &Sections, bool &IsPageZeroSegment,
276     uint32_t LoadCommandIndex, const char *CmdName, uint64_t SizeOfHeaders,
277     std::list<MachOElement> &Elements) {
278   const unsigned SegmentLoadSize = sizeof(Segment);
279   if (Load.C.cmdsize < SegmentLoadSize)
280     return malformedError("load command " + Twine(LoadCommandIndex) +
281                           " " + CmdName + " cmdsize too small");
282   if (auto SegOrErr = getStructOrErr<Segment>(Obj, Load.Ptr)) {
283     Segment S = SegOrErr.get();
284     const unsigned SectionSize = sizeof(Section);
285     uint64_t FileSize = Obj.getData().size();
286     if (S.nsects > std::numeric_limits<uint32_t>::max() / SectionSize ||
287         S.nsects * SectionSize > Load.C.cmdsize - SegmentLoadSize)
288       return malformedError("load command " + Twine(LoadCommandIndex) +
289                             " inconsistent cmdsize in " + CmdName +
290                             " for the number of sections");
291     for (unsigned J = 0; J < S.nsects; ++J) {
292       const char *Sec = getSectionPtr(Obj, Load, J);
293       Sections.push_back(Sec);
294       Section s = getStruct<Section>(Obj, Sec);
295       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
296           Obj.getHeader().filetype != MachO::MH_DSYM &&
297           s.flags != MachO::S_ZEROFILL &&
298           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
299           s.offset > FileSize)
300         return malformedError("offset field of section " + Twine(J) + " in " +
301                               CmdName + " command " + Twine(LoadCommandIndex) +
302                               " extends past the end of the file");
303       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
304           Obj.getHeader().filetype != MachO::MH_DSYM &&
305           s.flags != MachO::S_ZEROFILL &&
306           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL && S.fileoff == 0 &&
307           s.offset < SizeOfHeaders && s.size != 0)
308         return malformedError("offset field of section " + Twine(J) + " in " +
309                               CmdName + " command " + Twine(LoadCommandIndex) +
310                               " not past the headers of the file");
311       uint64_t BigSize = s.offset;
312       BigSize += s.size;
313       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
314           Obj.getHeader().filetype != MachO::MH_DSYM &&
315           s.flags != MachO::S_ZEROFILL &&
316           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
317           BigSize > FileSize)
318         return malformedError("offset field plus size field of section " +
319                               Twine(J) + " in " + CmdName + " command " +
320                               Twine(LoadCommandIndex) +
321                               " extends past the end of the file");
322       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
323           Obj.getHeader().filetype != MachO::MH_DSYM &&
324           s.flags != MachO::S_ZEROFILL &&
325           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
326           s.size > S.filesize)
327         return malformedError("size field of section " +
328                               Twine(J) + " in " + CmdName + " command " +
329                               Twine(LoadCommandIndex) +
330                               " greater than the segment");
331       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
332           Obj.getHeader().filetype != MachO::MH_DSYM && s.size != 0 &&
333           s.addr < S.vmaddr)
334         return malformedError("addr field of section " + Twine(J) + " in " +
335                               CmdName + " command " + Twine(LoadCommandIndex) +
336                               " less than the segment's vmaddr");
337       BigSize = s.addr;
338       BigSize += s.size;
339       uint64_t BigEnd = S.vmaddr;
340       BigEnd += S.vmsize;
341       if (S.vmsize != 0 && s.size != 0 && BigSize > BigEnd)
342         return malformedError("addr field plus size of section " + Twine(J) +
343                               " in " + CmdName + " command " +
344                               Twine(LoadCommandIndex) +
345                               " greater than than "
346                               "the segment's vmaddr plus vmsize");
347       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
348           Obj.getHeader().filetype != MachO::MH_DSYM &&
349           s.flags != MachO::S_ZEROFILL &&
350           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL)
351         if (Error Err = checkOverlappingElement(Elements, s.offset, s.size,
352                                                 "section contents"))
353           return Err;
354       if (s.reloff > FileSize)
355         return malformedError("reloff field of section " + Twine(J) + " in " +
356                               CmdName + " command " + Twine(LoadCommandIndex) +
357                               " extends past the end of the file");
358       BigSize = s.nreloc;
359       BigSize *= sizeof(struct MachO::relocation_info);
360       BigSize += s.reloff;
361       if (BigSize > FileSize)
362         return malformedError("reloff field plus nreloc field times sizeof("
363                               "struct relocation_info) of section " +
364                               Twine(J) + " in " + CmdName + " command " +
365                               Twine(LoadCommandIndex) +
366                               " extends past the end of the file");
367       if (Error Err = checkOverlappingElement(Elements, s.reloff, s.nreloc *
368                                               sizeof(struct
369                                               MachO::relocation_info),
370                                               "section relocation entries"))
371         return Err;
372     }
373     if (S.fileoff > FileSize)
374       return malformedError("load command " + Twine(LoadCommandIndex) +
375                             " fileoff field in " + CmdName +
376                             " extends past the end of the file");
377     uint64_t BigSize = S.fileoff;
378     BigSize += S.filesize;
379     if (BigSize > FileSize)
380       return malformedError("load command " + Twine(LoadCommandIndex) +
381                             " fileoff field plus filesize field in " +
382                             CmdName + " extends past the end of the file");
383     if (S.vmsize != 0 && S.filesize > S.vmsize)
384       return malformedError("load command " + Twine(LoadCommandIndex) +
385                             " filesize field in " + CmdName +
386                             " greater than vmsize field");
387     IsPageZeroSegment |= StringRef("__PAGEZERO").equals(S.segname);
388   } else
389     return SegOrErr.takeError();
390 
391   return Error::success();
392 }
393 
394 static Error checkSymtabCommand(const MachOObjectFile &Obj,
395                                 const MachOObjectFile::LoadCommandInfo &Load,
396                                 uint32_t LoadCommandIndex,
397                                 const char **SymtabLoadCmd,
398                                 std::list<MachOElement> &Elements) {
399   if (Load.C.cmdsize < sizeof(MachO::symtab_command))
400     return malformedError("load command " + Twine(LoadCommandIndex) +
401                           " LC_SYMTAB cmdsize too small");
402   if (*SymtabLoadCmd != nullptr)
403     return malformedError("more than one LC_SYMTAB command");
404   MachO::symtab_command Symtab =
405     getStruct<MachO::symtab_command>(Obj, Load.Ptr);
406   if (Symtab.cmdsize != sizeof(MachO::symtab_command))
407     return malformedError("LC_SYMTAB command " + Twine(LoadCommandIndex) +
408                           " has incorrect cmdsize");
409   uint64_t FileSize = Obj.getData().size();
410   if (Symtab.symoff > FileSize)
411     return malformedError("symoff field of LC_SYMTAB command " +
412                           Twine(LoadCommandIndex) + " extends past the end "
413                           "of the file");
414   uint64_t SymtabSize = Symtab.nsyms;
415   const char *struct_nlist_name;
416   if (Obj.is64Bit()) {
417     SymtabSize *= sizeof(MachO::nlist_64);
418     struct_nlist_name = "struct nlist_64";
419   } else {
420     SymtabSize *= sizeof(MachO::nlist);
421     struct_nlist_name = "struct nlist";
422   }
423   uint64_t BigSize = SymtabSize;
424   BigSize += Symtab.symoff;
425   if (BigSize > FileSize)
426     return malformedError("symoff field plus nsyms field times sizeof(" +
427                           Twine(struct_nlist_name) + ") of LC_SYMTAB command " +
428                           Twine(LoadCommandIndex) + " extends past the end "
429                           "of the file");
430   if (Error Err = checkOverlappingElement(Elements, Symtab.symoff, SymtabSize,
431                                           "symbol table"))
432     return Err;
433   if (Symtab.stroff > FileSize)
434     return malformedError("stroff field of LC_SYMTAB command " +
435                           Twine(LoadCommandIndex) + " extends past the end "
436                           "of the file");
437   BigSize = Symtab.stroff;
438   BigSize += Symtab.strsize;
439   if (BigSize > FileSize)
440     return malformedError("stroff field plus strsize field of LC_SYMTAB "
441                           "command " + Twine(LoadCommandIndex) + " extends "
442                           "past the end of the file");
443   if (Error Err = checkOverlappingElement(Elements, Symtab.stroff,
444                                           Symtab.strsize, "string table"))
445     return Err;
446   *SymtabLoadCmd = Load.Ptr;
447   return Error::success();
448 }
449 
450 static Error checkDysymtabCommand(const MachOObjectFile &Obj,
451                                   const MachOObjectFile::LoadCommandInfo &Load,
452                                   uint32_t LoadCommandIndex,
453                                   const char **DysymtabLoadCmd,
454                                   std::list<MachOElement> &Elements) {
455   if (Load.C.cmdsize < sizeof(MachO::dysymtab_command))
456     return malformedError("load command " + Twine(LoadCommandIndex) +
457                           " LC_DYSYMTAB cmdsize too small");
458   if (*DysymtabLoadCmd != nullptr)
459     return malformedError("more than one LC_DYSYMTAB command");
460   MachO::dysymtab_command Dysymtab =
461     getStruct<MachO::dysymtab_command>(Obj, Load.Ptr);
462   if (Dysymtab.cmdsize != sizeof(MachO::dysymtab_command))
463     return malformedError("LC_DYSYMTAB command " + Twine(LoadCommandIndex) +
464                           " has incorrect cmdsize");
465   uint64_t FileSize = Obj.getData().size();
466   if (Dysymtab.tocoff > FileSize)
467     return malformedError("tocoff field of LC_DYSYMTAB command " +
468                           Twine(LoadCommandIndex) + " extends past the end of "
469                           "the file");
470   uint64_t BigSize = Dysymtab.ntoc;
471   BigSize *= sizeof(MachO::dylib_table_of_contents);
472   BigSize += Dysymtab.tocoff;
473   if (BigSize > FileSize)
474     return malformedError("tocoff field plus ntoc field times sizeof(struct "
475                           "dylib_table_of_contents) of LC_DYSYMTAB command " +
476                           Twine(LoadCommandIndex) + " extends past the end of "
477                           "the file");
478   if (Error Err = checkOverlappingElement(Elements, Dysymtab.tocoff,
479                                           Dysymtab.ntoc * sizeof(struct
480                                           MachO::dylib_table_of_contents),
481                                           "table of contents"))
482     return Err;
483   if (Dysymtab.modtaboff > FileSize)
484     return malformedError("modtaboff field of LC_DYSYMTAB command " +
485                           Twine(LoadCommandIndex) + " extends past the end of "
486                           "the file");
487   BigSize = Dysymtab.nmodtab;
488   const char *struct_dylib_module_name;
489   uint64_t sizeof_modtab;
490   if (Obj.is64Bit()) {
491     sizeof_modtab = sizeof(MachO::dylib_module_64);
492     struct_dylib_module_name = "struct dylib_module_64";
493   } else {
494     sizeof_modtab = sizeof(MachO::dylib_module);
495     struct_dylib_module_name = "struct dylib_module";
496   }
497   BigSize *= sizeof_modtab;
498   BigSize += Dysymtab.modtaboff;
499   if (BigSize > FileSize)
500     return malformedError("modtaboff field plus nmodtab field times sizeof(" +
501                           Twine(struct_dylib_module_name) + ") of LC_DYSYMTAB "
502                           "command " + Twine(LoadCommandIndex) + " extends "
503                           "past the end of the file");
504   if (Error Err = checkOverlappingElement(Elements, Dysymtab.modtaboff,
505                                           Dysymtab.nmodtab * sizeof_modtab,
506                                           "module table"))
507     return Err;
508   if (Dysymtab.extrefsymoff > FileSize)
509     return malformedError("extrefsymoff field of LC_DYSYMTAB command " +
510                           Twine(LoadCommandIndex) + " extends past the end of "
511                           "the file");
512   BigSize = Dysymtab.nextrefsyms;
513   BigSize *= sizeof(MachO::dylib_reference);
514   BigSize += Dysymtab.extrefsymoff;
515   if (BigSize > FileSize)
516     return malformedError("extrefsymoff field plus nextrefsyms field times "
517                           "sizeof(struct dylib_reference) of LC_DYSYMTAB "
518                           "command " + Twine(LoadCommandIndex) + " extends "
519                           "past the end of the file");
520   if (Error Err = checkOverlappingElement(Elements, Dysymtab.extrefsymoff,
521                                           Dysymtab.nextrefsyms *
522                                               sizeof(MachO::dylib_reference),
523                                           "reference table"))
524     return Err;
525   if (Dysymtab.indirectsymoff > FileSize)
526     return malformedError("indirectsymoff field of LC_DYSYMTAB command " +
527                           Twine(LoadCommandIndex) + " extends past the end of "
528                           "the file");
529   BigSize = Dysymtab.nindirectsyms;
530   BigSize *= sizeof(uint32_t);
531   BigSize += Dysymtab.indirectsymoff;
532   if (BigSize > FileSize)
533     return malformedError("indirectsymoff field plus nindirectsyms field times "
534                           "sizeof(uint32_t) of LC_DYSYMTAB command " +
535                           Twine(LoadCommandIndex) + " extends past the end of "
536                           "the file");
537   if (Error Err = checkOverlappingElement(Elements, Dysymtab.indirectsymoff,
538                                           Dysymtab.nindirectsyms *
539                                           sizeof(uint32_t),
540                                           "indirect table"))
541     return Err;
542   if (Dysymtab.extreloff > FileSize)
543     return malformedError("extreloff field of LC_DYSYMTAB command " +
544                           Twine(LoadCommandIndex) + " extends past the end of "
545                           "the file");
546   BigSize = Dysymtab.nextrel;
547   BigSize *= sizeof(MachO::relocation_info);
548   BigSize += Dysymtab.extreloff;
549   if (BigSize > FileSize)
550     return malformedError("extreloff field plus nextrel field times sizeof"
551                           "(struct relocation_info) of LC_DYSYMTAB command " +
552                           Twine(LoadCommandIndex) + " extends past the end of "
553                           "the file");
554   if (Error Err = checkOverlappingElement(Elements, Dysymtab.extreloff,
555                                           Dysymtab.nextrel *
556                                               sizeof(MachO::relocation_info),
557                                           "external relocation table"))
558     return Err;
559   if (Dysymtab.locreloff > FileSize)
560     return malformedError("locreloff field of LC_DYSYMTAB command " +
561                           Twine(LoadCommandIndex) + " extends past the end of "
562                           "the file");
563   BigSize = Dysymtab.nlocrel;
564   BigSize *= sizeof(MachO::relocation_info);
565   BigSize += Dysymtab.locreloff;
566   if (BigSize > FileSize)
567     return malformedError("locreloff field plus nlocrel field times sizeof"
568                           "(struct relocation_info) of LC_DYSYMTAB command " +
569                           Twine(LoadCommandIndex) + " extends past the end of "
570                           "the file");
571   if (Error Err = checkOverlappingElement(Elements, Dysymtab.locreloff,
572                                           Dysymtab.nlocrel *
573                                               sizeof(MachO::relocation_info),
574                                           "local relocation table"))
575     return Err;
576   *DysymtabLoadCmd = Load.Ptr;
577   return Error::success();
578 }
579 
580 static Error checkLinkeditDataCommand(const MachOObjectFile &Obj,
581                                  const MachOObjectFile::LoadCommandInfo &Load,
582                                  uint32_t LoadCommandIndex,
583                                  const char **LoadCmd, const char *CmdName,
584                                  std::list<MachOElement> &Elements,
585                                  const char *ElementName) {
586   if (Load.C.cmdsize < sizeof(MachO::linkedit_data_command))
587     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
588                           CmdName + " cmdsize too small");
589   if (*LoadCmd != nullptr)
590     return malformedError("more than one " + Twine(CmdName) + " command");
591   MachO::linkedit_data_command LinkData =
592     getStruct<MachO::linkedit_data_command>(Obj, Load.Ptr);
593   if (LinkData.cmdsize != sizeof(MachO::linkedit_data_command))
594     return malformedError(Twine(CmdName) + " command " +
595                           Twine(LoadCommandIndex) + " has incorrect cmdsize");
596   uint64_t FileSize = Obj.getData().size();
597   if (LinkData.dataoff > FileSize)
598     return malformedError("dataoff field of " + Twine(CmdName) + " command " +
599                           Twine(LoadCommandIndex) + " extends past the end of "
600                           "the file");
601   uint64_t BigSize = LinkData.dataoff;
602   BigSize += LinkData.datasize;
603   if (BigSize > FileSize)
604     return malformedError("dataoff field plus datasize field of " +
605                           Twine(CmdName) + " command " +
606                           Twine(LoadCommandIndex) + " extends past the end of "
607                           "the file");
608   if (Error Err = checkOverlappingElement(Elements, LinkData.dataoff,
609                                           LinkData.datasize, ElementName))
610     return Err;
611   *LoadCmd = Load.Ptr;
612   return Error::success();
613 }
614 
615 static Error checkDyldInfoCommand(const MachOObjectFile &Obj,
616                                   const MachOObjectFile::LoadCommandInfo &Load,
617                                   uint32_t LoadCommandIndex,
618                                   const char **LoadCmd, const char *CmdName,
619                                   std::list<MachOElement> &Elements) {
620   if (Load.C.cmdsize < sizeof(MachO::dyld_info_command))
621     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
622                           CmdName + " cmdsize too small");
623   if (*LoadCmd != nullptr)
624     return malformedError("more than one LC_DYLD_INFO and or LC_DYLD_INFO_ONLY "
625                           "command");
626   MachO::dyld_info_command DyldInfo =
627     getStruct<MachO::dyld_info_command>(Obj, Load.Ptr);
628   if (DyldInfo.cmdsize != sizeof(MachO::dyld_info_command))
629     return malformedError(Twine(CmdName) + " command " +
630                           Twine(LoadCommandIndex) + " has incorrect cmdsize");
631   uint64_t FileSize = Obj.getData().size();
632   if (DyldInfo.rebase_off > FileSize)
633     return malformedError("rebase_off field of " + Twine(CmdName) +
634                           " command " + Twine(LoadCommandIndex) + " extends "
635                           "past the end of the file");
636   uint64_t BigSize = DyldInfo.rebase_off;
637   BigSize += DyldInfo.rebase_size;
638   if (BigSize > FileSize)
639     return malformedError("rebase_off field plus rebase_size field of " +
640                           Twine(CmdName) + " command " +
641                           Twine(LoadCommandIndex) + " extends past the end of "
642                           "the file");
643   if (Error Err = checkOverlappingElement(Elements, DyldInfo.rebase_off,
644                                           DyldInfo.rebase_size,
645                                           "dyld rebase info"))
646     return Err;
647   if (DyldInfo.bind_off > FileSize)
648     return malformedError("bind_off field of " + Twine(CmdName) +
649                           " command " + Twine(LoadCommandIndex) + " extends "
650                           "past the end of the file");
651   BigSize = DyldInfo.bind_off;
652   BigSize += DyldInfo.bind_size;
653   if (BigSize > FileSize)
654     return malformedError("bind_off field plus bind_size field of " +
655                           Twine(CmdName) + " command " +
656                           Twine(LoadCommandIndex) + " extends past the end of "
657                           "the file");
658   if (Error Err = checkOverlappingElement(Elements, DyldInfo.bind_off,
659                                           DyldInfo.bind_size,
660                                           "dyld bind info"))
661     return Err;
662   if (DyldInfo.weak_bind_off > FileSize)
663     return malformedError("weak_bind_off field of " + Twine(CmdName) +
664                           " command " + Twine(LoadCommandIndex) + " extends "
665                           "past the end of the file");
666   BigSize = DyldInfo.weak_bind_off;
667   BigSize += DyldInfo.weak_bind_size;
668   if (BigSize > FileSize)
669     return malformedError("weak_bind_off field plus weak_bind_size field of " +
670                           Twine(CmdName) + " command " +
671                           Twine(LoadCommandIndex) + " extends past the end of "
672                           "the file");
673   if (Error Err = checkOverlappingElement(Elements, DyldInfo.weak_bind_off,
674                                           DyldInfo.weak_bind_size,
675                                           "dyld weak bind info"))
676     return Err;
677   if (DyldInfo.lazy_bind_off > FileSize)
678     return malformedError("lazy_bind_off field of " + Twine(CmdName) +
679                           " command " + Twine(LoadCommandIndex) + " extends "
680                           "past the end of the file");
681   BigSize = DyldInfo.lazy_bind_off;
682   BigSize += DyldInfo.lazy_bind_size;
683   if (BigSize > FileSize)
684     return malformedError("lazy_bind_off field plus lazy_bind_size field of " +
685                           Twine(CmdName) + " command " +
686                           Twine(LoadCommandIndex) + " extends past the end of "
687                           "the file");
688   if (Error Err = checkOverlappingElement(Elements, DyldInfo.lazy_bind_off,
689                                           DyldInfo.lazy_bind_size,
690                                           "dyld lazy bind info"))
691     return Err;
692   if (DyldInfo.export_off > FileSize)
693     return malformedError("export_off field of " + Twine(CmdName) +
694                           " command " + Twine(LoadCommandIndex) + " extends "
695                           "past the end of the file");
696   BigSize = DyldInfo.export_off;
697   BigSize += DyldInfo.export_size;
698   if (BigSize > FileSize)
699     return malformedError("export_off field plus export_size field of " +
700                           Twine(CmdName) + " command " +
701                           Twine(LoadCommandIndex) + " extends past the end of "
702                           "the file");
703   if (Error Err = checkOverlappingElement(Elements, DyldInfo.export_off,
704                                           DyldInfo.export_size,
705                                           "dyld export info"))
706     return Err;
707   *LoadCmd = Load.Ptr;
708   return Error::success();
709 }
710 
711 static Error checkDylibCommand(const MachOObjectFile &Obj,
712                                const MachOObjectFile::LoadCommandInfo &Load,
713                                uint32_t LoadCommandIndex, const char *CmdName) {
714   if (Load.C.cmdsize < sizeof(MachO::dylib_command))
715     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
716                           CmdName + " cmdsize too small");
717   MachO::dylib_command D = getStruct<MachO::dylib_command>(Obj, Load.Ptr);
718   if (D.dylib.name < sizeof(MachO::dylib_command))
719     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
720                           CmdName + " name.offset field too small, not past "
721                           "the end of the dylib_command struct");
722   if (D.dylib.name >= D.cmdsize)
723     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
724                           CmdName + " name.offset field extends past the end "
725                           "of the load command");
726   // Make sure there is a null between the starting offset of the name and
727   // the end of the load command.
728   uint32_t i;
729   const char *P = (const char *)Load.Ptr;
730   for (i = D.dylib.name; i < D.cmdsize; i++)
731     if (P[i] == '\0')
732       break;
733   if (i >= D.cmdsize)
734     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
735                           CmdName + " library name extends past the end of the "
736                           "load command");
737   return Error::success();
738 }
739 
740 static Error checkDylibIdCommand(const MachOObjectFile &Obj,
741                                  const MachOObjectFile::LoadCommandInfo &Load,
742                                  uint32_t LoadCommandIndex,
743                                  const char **LoadCmd) {
744   if (Error Err = checkDylibCommand(Obj, Load, LoadCommandIndex,
745                                      "LC_ID_DYLIB"))
746     return Err;
747   if (*LoadCmd != nullptr)
748     return malformedError("more than one LC_ID_DYLIB command");
749   if (Obj.getHeader().filetype != MachO::MH_DYLIB &&
750       Obj.getHeader().filetype != MachO::MH_DYLIB_STUB)
751     return malformedError("LC_ID_DYLIB load command in non-dynamic library "
752                           "file type");
753   *LoadCmd = Load.Ptr;
754   return Error::success();
755 }
756 
757 static Error checkDyldCommand(const MachOObjectFile &Obj,
758                               const MachOObjectFile::LoadCommandInfo &Load,
759                               uint32_t LoadCommandIndex, const char *CmdName) {
760   if (Load.C.cmdsize < sizeof(MachO::dylinker_command))
761     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
762                           CmdName + " cmdsize too small");
763   MachO::dylinker_command D = getStruct<MachO::dylinker_command>(Obj, Load.Ptr);
764   if (D.name < sizeof(MachO::dylinker_command))
765     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
766                           CmdName + " name.offset field too small, not past "
767                           "the end of the dylinker_command struct");
768   if (D.name >= D.cmdsize)
769     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
770                           CmdName + " name.offset field extends past the end "
771                           "of the load command");
772   // Make sure there is a null between the starting offset of the name and
773   // the end of the load command.
774   uint32_t i;
775   const char *P = (const char *)Load.Ptr;
776   for (i = D.name; i < D.cmdsize; i++)
777     if (P[i] == '\0')
778       break;
779   if (i >= D.cmdsize)
780     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
781                           CmdName + " dyld name extends past the end of the "
782                           "load command");
783   return Error::success();
784 }
785 
786 static Error checkVersCommand(const MachOObjectFile &Obj,
787                               const MachOObjectFile::LoadCommandInfo &Load,
788                               uint32_t LoadCommandIndex,
789                               const char **LoadCmd, const char *CmdName) {
790   if (Load.C.cmdsize != sizeof(MachO::version_min_command))
791     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
792                           CmdName + " has incorrect cmdsize");
793   if (*LoadCmd != nullptr)
794     return malformedError("more than one LC_VERSION_MIN_MACOSX, "
795                           "LC_VERSION_MIN_IPHONEOS, LC_VERSION_MIN_TVOS or "
796                           "LC_VERSION_MIN_WATCHOS command");
797   *LoadCmd = Load.Ptr;
798   return Error::success();
799 }
800 
801 static Error checkNoteCommand(const MachOObjectFile &Obj,
802                               const MachOObjectFile::LoadCommandInfo &Load,
803                               uint32_t LoadCommandIndex,
804                               std::list<MachOElement> &Elements) {
805   if (Load.C.cmdsize != sizeof(MachO::note_command))
806     return malformedError("load command " + Twine(LoadCommandIndex) +
807                           " LC_NOTE has incorrect cmdsize");
808   MachO::note_command Nt = getStruct<MachO::note_command>(Obj, Load.Ptr);
809   uint64_t FileSize = Obj.getData().size();
810   if (Nt.offset > FileSize)
811     return malformedError("offset field of LC_NOTE command " +
812                           Twine(LoadCommandIndex) + " extends "
813                           "past the end of the file");
814   uint64_t BigSize = Nt.offset;
815   BigSize += Nt.size;
816   if (BigSize > FileSize)
817     return malformedError("size field plus offset field of LC_NOTE command " +
818                           Twine(LoadCommandIndex) + " extends past the end of "
819                           "the file");
820   if (Error Err = checkOverlappingElement(Elements, Nt.offset, Nt.size,
821                                           "LC_NOTE data"))
822     return Err;
823   return Error::success();
824 }
825 
826 static Error
827 parseBuildVersionCommand(const MachOObjectFile &Obj,
828                          const MachOObjectFile::LoadCommandInfo &Load,
829                          SmallVectorImpl<const char*> &BuildTools,
830                          uint32_t LoadCommandIndex) {
831   MachO::build_version_command BVC =
832       getStruct<MachO::build_version_command>(Obj, Load.Ptr);
833   if (Load.C.cmdsize !=
834       sizeof(MachO::build_version_command) +
835           BVC.ntools * sizeof(MachO::build_tool_version))
836     return malformedError("load command " + Twine(LoadCommandIndex) +
837                           " LC_BUILD_VERSION_COMMAND has incorrect cmdsize");
838 
839   auto Start = Load.Ptr + sizeof(MachO::build_version_command);
840   BuildTools.resize(BVC.ntools);
841   for (unsigned i = 0; i < BVC.ntools; ++i)
842     BuildTools[i] = Start + i * sizeof(MachO::build_tool_version);
843 
844   return Error::success();
845 }
846 
847 static Error checkRpathCommand(const MachOObjectFile &Obj,
848                                const MachOObjectFile::LoadCommandInfo &Load,
849                                uint32_t LoadCommandIndex) {
850   if (Load.C.cmdsize < sizeof(MachO::rpath_command))
851     return malformedError("load command " + Twine(LoadCommandIndex) +
852                           " LC_RPATH cmdsize too small");
853   MachO::rpath_command R = getStruct<MachO::rpath_command>(Obj, Load.Ptr);
854   if (R.path < sizeof(MachO::rpath_command))
855     return malformedError("load command " + Twine(LoadCommandIndex) +
856                           " LC_RPATH path.offset field too small, not past "
857                           "the end of the rpath_command struct");
858   if (R.path >= R.cmdsize)
859     return malformedError("load command " + Twine(LoadCommandIndex) +
860                           " LC_RPATH path.offset field extends past the end "
861                           "of the load command");
862   // Make sure there is a null between the starting offset of the path and
863   // the end of the load command.
864   uint32_t i;
865   const char *P = (const char *)Load.Ptr;
866   for (i = R.path; i < R.cmdsize; i++)
867     if (P[i] == '\0')
868       break;
869   if (i >= R.cmdsize)
870     return malformedError("load command " + Twine(LoadCommandIndex) +
871                           " LC_RPATH library name extends past the end of the "
872                           "load command");
873   return Error::success();
874 }
875 
876 static Error checkEncryptCommand(const MachOObjectFile &Obj,
877                                  const MachOObjectFile::LoadCommandInfo &Load,
878                                  uint32_t LoadCommandIndex,
879                                  uint64_t cryptoff, uint64_t cryptsize,
880                                  const char **LoadCmd, const char *CmdName) {
881   if (*LoadCmd != nullptr)
882     return malformedError("more than one LC_ENCRYPTION_INFO and or "
883                           "LC_ENCRYPTION_INFO_64 command");
884   uint64_t FileSize = Obj.getData().size();
885   if (cryptoff > FileSize)
886     return malformedError("cryptoff field of " + Twine(CmdName) +
887                           " command " + Twine(LoadCommandIndex) + " extends "
888                           "past the end of the file");
889   uint64_t BigSize = cryptoff;
890   BigSize += cryptsize;
891   if (BigSize > FileSize)
892     return malformedError("cryptoff field plus cryptsize field of " +
893                           Twine(CmdName) + " command " +
894                           Twine(LoadCommandIndex) + " extends past the end of "
895                           "the file");
896   *LoadCmd = Load.Ptr;
897   return Error::success();
898 }
899 
900 static Error checkLinkerOptCommand(const MachOObjectFile &Obj,
901                                    const MachOObjectFile::LoadCommandInfo &Load,
902                                    uint32_t LoadCommandIndex) {
903   if (Load.C.cmdsize < sizeof(MachO::linker_option_command))
904     return malformedError("load command " + Twine(LoadCommandIndex) +
905                           " LC_LINKER_OPTION cmdsize too small");
906   MachO::linker_option_command L =
907     getStruct<MachO::linker_option_command>(Obj, Load.Ptr);
908   // Make sure the count of strings is correct.
909   const char *string = (const char *)Load.Ptr +
910                        sizeof(struct MachO::linker_option_command);
911   uint32_t left = L.cmdsize - sizeof(struct MachO::linker_option_command);
912   uint32_t i = 0;
913   while (left > 0) {
914     while (*string == '\0' && left > 0) {
915       string++;
916       left--;
917     }
918     if (left > 0) {
919       i++;
920       uint32_t NullPos = StringRef(string, left).find('\0');
921       uint32_t len = std::min(NullPos, left) + 1;
922       string += len;
923       left -= len;
924     }
925   }
926   if (L.count != i)
927     return malformedError("load command " + Twine(LoadCommandIndex) +
928                           " LC_LINKER_OPTION string count " + Twine(L.count) +
929                           " does not match number of strings");
930   return Error::success();
931 }
932 
933 static Error checkSubCommand(const MachOObjectFile &Obj,
934                              const MachOObjectFile::LoadCommandInfo &Load,
935                              uint32_t LoadCommandIndex, const char *CmdName,
936                              size_t SizeOfCmd, const char *CmdStructName,
937                              uint32_t PathOffset, const char *PathFieldName) {
938   if (PathOffset < SizeOfCmd)
939     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
940                           CmdName + " " + PathFieldName + ".offset field too "
941                           "small, not past the end of the " + CmdStructName);
942   if (PathOffset >= Load.C.cmdsize)
943     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
944                           CmdName + " " + PathFieldName + ".offset field "
945                           "extends past the end of the load command");
946   // Make sure there is a null between the starting offset of the path and
947   // the end of the load command.
948   uint32_t i;
949   const char *P = (const char *)Load.Ptr;
950   for (i = PathOffset; i < Load.C.cmdsize; i++)
951     if (P[i] == '\0')
952       break;
953   if (i >= Load.C.cmdsize)
954     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
955                           CmdName + " " + PathFieldName + " name extends past "
956                           "the end of the load command");
957   return Error::success();
958 }
959 
960 static Error checkThreadCommand(const MachOObjectFile &Obj,
961                                 const MachOObjectFile::LoadCommandInfo &Load,
962                                 uint32_t LoadCommandIndex,
963                                 const char *CmdName) {
964   if (Load.C.cmdsize < sizeof(MachO::thread_command))
965     return malformedError("load command " + Twine(LoadCommandIndex) +
966                           CmdName + " cmdsize too small");
967   MachO::thread_command T =
968     getStruct<MachO::thread_command>(Obj, Load.Ptr);
969   const char *state = Load.Ptr + sizeof(MachO::thread_command);
970   const char *end = Load.Ptr + T.cmdsize;
971   uint32_t nflavor = 0;
972   uint32_t cputype = getCPUType(Obj);
973   while (state < end) {
974     if(state + sizeof(uint32_t) > end)
975       return malformedError("load command " + Twine(LoadCommandIndex) +
976                             "flavor in " + CmdName + " extends past end of "
977                             "command");
978     uint32_t flavor;
979     memcpy(&flavor, state, sizeof(uint32_t));
980     if (Obj.isLittleEndian() != sys::IsLittleEndianHost)
981       sys::swapByteOrder(flavor);
982     state += sizeof(uint32_t);
983 
984     if(state + sizeof(uint32_t) > end)
985       return malformedError("load command " + Twine(LoadCommandIndex) +
986                             " count in " + CmdName + " extends past end of "
987                             "command");
988     uint32_t count;
989     memcpy(&count, state, sizeof(uint32_t));
990     if (Obj.isLittleEndian() != sys::IsLittleEndianHost)
991       sys::swapByteOrder(count);
992     state += sizeof(uint32_t);
993 
994     if (cputype == MachO::CPU_TYPE_I386) {
995       if (flavor == MachO::x86_THREAD_STATE32) {
996         if (count != MachO::x86_THREAD_STATE32_COUNT)
997           return malformedError("load command " + Twine(LoadCommandIndex) +
998                                 " count not x86_THREAD_STATE32_COUNT for "
999                                 "flavor number " + Twine(nflavor) + " which is "
1000                                 "a x86_THREAD_STATE32 flavor in " + CmdName +
1001                                 " command");
1002         if (state + sizeof(MachO::x86_thread_state32_t) > end)
1003           return malformedError("load command " + Twine(LoadCommandIndex) +
1004                                 " x86_THREAD_STATE32 extends past end of "
1005                                 "command in " + CmdName + " command");
1006         state += sizeof(MachO::x86_thread_state32_t);
1007       } else {
1008         return malformedError("load command " + Twine(LoadCommandIndex) +
1009                               " unknown flavor (" + Twine(flavor) + ") for "
1010                               "flavor number " + Twine(nflavor) + " in " +
1011                               CmdName + " command");
1012       }
1013     } else if (cputype == MachO::CPU_TYPE_X86_64) {
1014       if (flavor == MachO::x86_THREAD_STATE) {
1015         if (count != MachO::x86_THREAD_STATE_COUNT)
1016           return malformedError("load command " + Twine(LoadCommandIndex) +
1017                                 " count not x86_THREAD_STATE_COUNT for "
1018                                 "flavor number " + Twine(nflavor) + " which is "
1019                                 "a x86_THREAD_STATE flavor in " + CmdName +
1020                                 " command");
1021         if (state + sizeof(MachO::x86_thread_state_t) > end)
1022           return malformedError("load command " + Twine(LoadCommandIndex) +
1023                                 " x86_THREAD_STATE extends past end of "
1024                                 "command in " + CmdName + " command");
1025         state += sizeof(MachO::x86_thread_state_t);
1026       } else if (flavor == MachO::x86_FLOAT_STATE) {
1027         if (count != MachO::x86_FLOAT_STATE_COUNT)
1028           return malformedError("load command " + Twine(LoadCommandIndex) +
1029                                 " count not x86_FLOAT_STATE_COUNT for "
1030                                 "flavor number " + Twine(nflavor) + " which is "
1031                                 "a x86_FLOAT_STATE flavor in " + CmdName +
1032                                 " command");
1033         if (state + sizeof(MachO::x86_float_state_t) > end)
1034           return malformedError("load command " + Twine(LoadCommandIndex) +
1035                                 " x86_FLOAT_STATE extends past end of "
1036                                 "command in " + CmdName + " command");
1037         state += sizeof(MachO::x86_float_state_t);
1038       } else if (flavor == MachO::x86_EXCEPTION_STATE) {
1039         if (count != MachO::x86_EXCEPTION_STATE_COUNT)
1040           return malformedError("load command " + Twine(LoadCommandIndex) +
1041                                 " count not x86_EXCEPTION_STATE_COUNT for "
1042                                 "flavor number " + Twine(nflavor) + " which is "
1043                                 "a x86_EXCEPTION_STATE flavor in " + CmdName +
1044                                 " command");
1045         if (state + sizeof(MachO::x86_exception_state_t) > end)
1046           return malformedError("load command " + Twine(LoadCommandIndex) +
1047                                 " x86_EXCEPTION_STATE extends past end of "
1048                                 "command in " + CmdName + " command");
1049         state += sizeof(MachO::x86_exception_state_t);
1050       } else if (flavor == MachO::x86_THREAD_STATE64) {
1051         if (count != MachO::x86_THREAD_STATE64_COUNT)
1052           return malformedError("load command " + Twine(LoadCommandIndex) +
1053                                 " count not x86_THREAD_STATE64_COUNT for "
1054                                 "flavor number " + Twine(nflavor) + " which is "
1055                                 "a x86_THREAD_STATE64 flavor in " + CmdName +
1056                                 " command");
1057         if (state + sizeof(MachO::x86_thread_state64_t) > end)
1058           return malformedError("load command " + Twine(LoadCommandIndex) +
1059                                 " x86_THREAD_STATE64 extends past end of "
1060                                 "command in " + CmdName + " command");
1061         state += sizeof(MachO::x86_thread_state64_t);
1062       } else if (flavor == MachO::x86_EXCEPTION_STATE64) {
1063         if (count != MachO::x86_EXCEPTION_STATE64_COUNT)
1064           return malformedError("load command " + Twine(LoadCommandIndex) +
1065                                 " count not x86_EXCEPTION_STATE64_COUNT for "
1066                                 "flavor number " + Twine(nflavor) + " which is "
1067                                 "a x86_EXCEPTION_STATE64 flavor in " + CmdName +
1068                                 " command");
1069         if (state + sizeof(MachO::x86_exception_state64_t) > end)
1070           return malformedError("load command " + Twine(LoadCommandIndex) +
1071                                 " x86_EXCEPTION_STATE64 extends past end of "
1072                                 "command in " + CmdName + " command");
1073         state += sizeof(MachO::x86_exception_state64_t);
1074       } else {
1075         return malformedError("load command " + Twine(LoadCommandIndex) +
1076                               " unknown flavor (" + Twine(flavor) + ") for "
1077                               "flavor number " + Twine(nflavor) + " in " +
1078                               CmdName + " command");
1079       }
1080     } else if (cputype == MachO::CPU_TYPE_ARM) {
1081       if (flavor == MachO::ARM_THREAD_STATE) {
1082         if (count != MachO::ARM_THREAD_STATE_COUNT)
1083           return malformedError("load command " + Twine(LoadCommandIndex) +
1084                                 " count not ARM_THREAD_STATE_COUNT for "
1085                                 "flavor number " + Twine(nflavor) + " which is "
1086                                 "a ARM_THREAD_STATE flavor in " + CmdName +
1087                                 " command");
1088         if (state + sizeof(MachO::arm_thread_state32_t) > end)
1089           return malformedError("load command " + Twine(LoadCommandIndex) +
1090                                 " ARM_THREAD_STATE extends past end of "
1091                                 "command in " + CmdName + " command");
1092         state += sizeof(MachO::arm_thread_state32_t);
1093       } else {
1094         return malformedError("load command " + Twine(LoadCommandIndex) +
1095                               " unknown flavor (" + Twine(flavor) + ") for "
1096                               "flavor number " + Twine(nflavor) + " in " +
1097                               CmdName + " command");
1098       }
1099     } else if (cputype == MachO::CPU_TYPE_ARM64) {
1100       if (flavor == MachO::ARM_THREAD_STATE64) {
1101         if (count != MachO::ARM_THREAD_STATE64_COUNT)
1102           return malformedError("load command " + Twine(LoadCommandIndex) +
1103                                 " count not ARM_THREAD_STATE64_COUNT for "
1104                                 "flavor number " + Twine(nflavor) + " which is "
1105                                 "a ARM_THREAD_STATE64 flavor in " + CmdName +
1106                                 " command");
1107         if (state + sizeof(MachO::arm_thread_state64_t) > end)
1108           return malformedError("load command " + Twine(LoadCommandIndex) +
1109                                 " ARM_THREAD_STATE64 extends past end of "
1110                                 "command in " + CmdName + " command");
1111         state += sizeof(MachO::arm_thread_state64_t);
1112       } else {
1113         return malformedError("load command " + Twine(LoadCommandIndex) +
1114                               " unknown flavor (" + Twine(flavor) + ") for "
1115                               "flavor number " + Twine(nflavor) + " in " +
1116                               CmdName + " command");
1117       }
1118     } else if (cputype == MachO::CPU_TYPE_POWERPC) {
1119       if (flavor == MachO::PPC_THREAD_STATE) {
1120         if (count != MachO::PPC_THREAD_STATE_COUNT)
1121           return malformedError("load command " + Twine(LoadCommandIndex) +
1122                                 " count not PPC_THREAD_STATE_COUNT for "
1123                                 "flavor number " + Twine(nflavor) + " which is "
1124                                 "a PPC_THREAD_STATE flavor in " + CmdName +
1125                                 " command");
1126         if (state + sizeof(MachO::ppc_thread_state32_t) > end)
1127           return malformedError("load command " + Twine(LoadCommandIndex) +
1128                                 " PPC_THREAD_STATE extends past end of "
1129                                 "command in " + CmdName + " command");
1130         state += sizeof(MachO::ppc_thread_state32_t);
1131       } else {
1132         return malformedError("load command " + Twine(LoadCommandIndex) +
1133                               " unknown flavor (" + Twine(flavor) + ") for "
1134                               "flavor number " + Twine(nflavor) + " in " +
1135                               CmdName + " command");
1136       }
1137     } else {
1138       return malformedError("unknown cputype (" + Twine(cputype) + ") load "
1139                             "command " + Twine(LoadCommandIndex) + " for " +
1140                             CmdName + " command can't be checked");
1141     }
1142     nflavor++;
1143   }
1144   return Error::success();
1145 }
1146 
1147 static Error checkTwoLevelHintsCommand(const MachOObjectFile &Obj,
1148                                        const MachOObjectFile::LoadCommandInfo
1149                                          &Load,
1150                                        uint32_t LoadCommandIndex,
1151                                        const char **LoadCmd,
1152                                        std::list<MachOElement> &Elements) {
1153   if (Load.C.cmdsize != sizeof(MachO::twolevel_hints_command))
1154     return malformedError("load command " + Twine(LoadCommandIndex) +
1155                           " LC_TWOLEVEL_HINTS has incorrect cmdsize");
1156   if (*LoadCmd != nullptr)
1157     return malformedError("more than one LC_TWOLEVEL_HINTS command");
1158   MachO::twolevel_hints_command Hints =
1159     getStruct<MachO::twolevel_hints_command>(Obj, Load.Ptr);
1160   uint64_t FileSize = Obj.getData().size();
1161   if (Hints.offset > FileSize)
1162     return malformedError("offset field of LC_TWOLEVEL_HINTS command " +
1163                           Twine(LoadCommandIndex) + " extends past the end of "
1164                           "the file");
1165   uint64_t BigSize = Hints.nhints;
1166   BigSize *= sizeof(MachO::twolevel_hint);
1167   BigSize += Hints.offset;
1168   if (BigSize > FileSize)
1169     return malformedError("offset field plus nhints times sizeof(struct "
1170                           "twolevel_hint) field of LC_TWOLEVEL_HINTS command " +
1171                           Twine(LoadCommandIndex) + " extends past the end of "
1172                           "the file");
1173   if (Error Err = checkOverlappingElement(Elements, Hints.offset, Hints.nhints *
1174                                           sizeof(MachO::twolevel_hint),
1175                                           "two level hints"))
1176     return Err;
1177   *LoadCmd = Load.Ptr;
1178   return Error::success();
1179 }
1180 
1181 // Returns true if the libObject code does not support the load command and its
1182 // contents.  The cmd value it is treated as an unknown load command but with
1183 // an error message that says the cmd value is obsolete.
1184 static bool isLoadCommandObsolete(uint32_t cmd) {
1185   if (cmd == MachO::LC_SYMSEG ||
1186       cmd == MachO::LC_LOADFVMLIB ||
1187       cmd == MachO::LC_IDFVMLIB ||
1188       cmd == MachO::LC_IDENT ||
1189       cmd == MachO::LC_FVMFILE ||
1190       cmd == MachO::LC_PREPAGE ||
1191       cmd == MachO::LC_PREBOUND_DYLIB ||
1192       cmd == MachO::LC_TWOLEVEL_HINTS ||
1193       cmd == MachO::LC_PREBIND_CKSUM)
1194     return true;
1195   return false;
1196 }
1197 
1198 Expected<std::unique_ptr<MachOObjectFile>>
1199 MachOObjectFile::create(MemoryBufferRef Object, bool IsLittleEndian,
1200                         bool Is64Bits, uint32_t UniversalCputype,
1201                         uint32_t UniversalIndex) {
1202   Error Err = Error::success();
1203   std::unique_ptr<MachOObjectFile> Obj(
1204       new MachOObjectFile(std::move(Object), IsLittleEndian,
1205                           Is64Bits, Err, UniversalCputype,
1206                           UniversalIndex));
1207   if (Err)
1208     return std::move(Err);
1209   return std::move(Obj);
1210 }
1211 
1212 MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
1213                                  bool Is64bits, Error &Err,
1214                                  uint32_t UniversalCputype,
1215                                  uint32_t UniversalIndex)
1216     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object) {
1217   ErrorAsOutParameter ErrAsOutParam(&Err);
1218   uint64_t SizeOfHeaders;
1219   uint32_t cputype;
1220   if (is64Bit()) {
1221     parseHeader(*this, Header64, Err);
1222     SizeOfHeaders = sizeof(MachO::mach_header_64);
1223     cputype = Header64.cputype;
1224   } else {
1225     parseHeader(*this, Header, Err);
1226     SizeOfHeaders = sizeof(MachO::mach_header);
1227     cputype = Header.cputype;
1228   }
1229   if (Err)
1230     return;
1231   SizeOfHeaders += getHeader().sizeofcmds;
1232   if (getData().data() + SizeOfHeaders > getData().end()) {
1233     Err = malformedError("load commands extend past the end of the file");
1234     return;
1235   }
1236   if (UniversalCputype != 0 && cputype != UniversalCputype) {
1237     Err = malformedError("universal header architecture: " +
1238                          Twine(UniversalIndex) + "'s cputype does not match "
1239                          "object file's mach header");
1240     return;
1241   }
1242   std::list<MachOElement> Elements;
1243   Elements.push_back({0, SizeOfHeaders, "Mach-O headers"});
1244 
1245   uint32_t LoadCommandCount = getHeader().ncmds;
1246   LoadCommandInfo Load;
1247   if (LoadCommandCount != 0) {
1248     if (auto LoadOrErr = getFirstLoadCommandInfo(*this))
1249       Load = *LoadOrErr;
1250     else {
1251       Err = LoadOrErr.takeError();
1252       return;
1253     }
1254   }
1255 
1256   const char *DyldIdLoadCmd = nullptr;
1257   const char *FuncStartsLoadCmd = nullptr;
1258   const char *SplitInfoLoadCmd = nullptr;
1259   const char *CodeSignDrsLoadCmd = nullptr;
1260   const char *CodeSignLoadCmd = nullptr;
1261   const char *VersLoadCmd = nullptr;
1262   const char *SourceLoadCmd = nullptr;
1263   const char *EntryPointLoadCmd = nullptr;
1264   const char *EncryptLoadCmd = nullptr;
1265   const char *RoutinesLoadCmd = nullptr;
1266   const char *UnixThreadLoadCmd = nullptr;
1267   const char *TwoLevelHintsLoadCmd = nullptr;
1268   for (unsigned I = 0; I < LoadCommandCount; ++I) {
1269     if (is64Bit()) {
1270       if (Load.C.cmdsize % 8 != 0) {
1271         // We have a hack here to allow 64-bit Mach-O core files to have
1272         // LC_THREAD commands that are only a multiple of 4 and not 8 to be
1273         // allowed since the macOS kernel produces them.
1274         if (getHeader().filetype != MachO::MH_CORE ||
1275             Load.C.cmd != MachO::LC_THREAD || Load.C.cmdsize % 4) {
1276           Err = malformedError("load command " + Twine(I) + " cmdsize not a "
1277                                "multiple of 8");
1278           return;
1279         }
1280       }
1281     } else {
1282       if (Load.C.cmdsize % 4 != 0) {
1283         Err = malformedError("load command " + Twine(I) + " cmdsize not a "
1284                              "multiple of 4");
1285         return;
1286       }
1287     }
1288     LoadCommands.push_back(Load);
1289     if (Load.C.cmd == MachO::LC_SYMTAB) {
1290       if ((Err = checkSymtabCommand(*this, Load, I, &SymtabLoadCmd, Elements)))
1291         return;
1292     } else if (Load.C.cmd == MachO::LC_DYSYMTAB) {
1293       if ((Err = checkDysymtabCommand(*this, Load, I, &DysymtabLoadCmd,
1294                                       Elements)))
1295         return;
1296     } else if (Load.C.cmd == MachO::LC_DATA_IN_CODE) {
1297       if ((Err = checkLinkeditDataCommand(*this, Load, I, &DataInCodeLoadCmd,
1298                                           "LC_DATA_IN_CODE", Elements,
1299                                           "data in code info")))
1300         return;
1301     } else if (Load.C.cmd == MachO::LC_LINKER_OPTIMIZATION_HINT) {
1302       if ((Err = checkLinkeditDataCommand(*this, Load, I, &LinkOptHintsLoadCmd,
1303                                           "LC_LINKER_OPTIMIZATION_HINT",
1304                                           Elements, "linker optimization "
1305                                           "hints")))
1306         return;
1307     } else if (Load.C.cmd == MachO::LC_FUNCTION_STARTS) {
1308       if ((Err = checkLinkeditDataCommand(*this, Load, I, &FuncStartsLoadCmd,
1309                                           "LC_FUNCTION_STARTS", Elements,
1310                                           "function starts data")))
1311         return;
1312     } else if (Load.C.cmd == MachO::LC_SEGMENT_SPLIT_INFO) {
1313       if ((Err = checkLinkeditDataCommand(*this, Load, I, &SplitInfoLoadCmd,
1314                                           "LC_SEGMENT_SPLIT_INFO", Elements,
1315                                           "split info data")))
1316         return;
1317     } else if (Load.C.cmd == MachO::LC_DYLIB_CODE_SIGN_DRS) {
1318       if ((Err = checkLinkeditDataCommand(*this, Load, I, &CodeSignDrsLoadCmd,
1319                                           "LC_DYLIB_CODE_SIGN_DRS", Elements,
1320                                           "code signing RDs data")))
1321         return;
1322     } else if (Load.C.cmd == MachO::LC_CODE_SIGNATURE) {
1323       if ((Err = checkLinkeditDataCommand(*this, Load, I, &CodeSignLoadCmd,
1324                                           "LC_CODE_SIGNATURE", Elements,
1325                                           "code signature data")))
1326         return;
1327     } else if (Load.C.cmd == MachO::LC_DYLD_INFO) {
1328       if ((Err = checkDyldInfoCommand(*this, Load, I, &DyldInfoLoadCmd,
1329                                       "LC_DYLD_INFO", Elements)))
1330         return;
1331     } else if (Load.C.cmd == MachO::LC_DYLD_INFO_ONLY) {
1332       if ((Err = checkDyldInfoCommand(*this, Load, I, &DyldInfoLoadCmd,
1333                                       "LC_DYLD_INFO_ONLY", Elements)))
1334         return;
1335     } else if (Load.C.cmd == MachO::LC_UUID) {
1336       if (Load.C.cmdsize != sizeof(MachO::uuid_command)) {
1337         Err = malformedError("LC_UUID command " + Twine(I) + " has incorrect "
1338                              "cmdsize");
1339         return;
1340       }
1341       if (UuidLoadCmd) {
1342         Err = malformedError("more than one LC_UUID command");
1343         return;
1344       }
1345       UuidLoadCmd = Load.Ptr;
1346     } else if (Load.C.cmd == MachO::LC_SEGMENT_64) {
1347       if ((Err = parseSegmentLoadCommand<MachO::segment_command_64,
1348                                          MachO::section_64>(
1349                    *this, Load, Sections, HasPageZeroSegment, I,
1350                    "LC_SEGMENT_64", SizeOfHeaders, Elements)))
1351         return;
1352     } else if (Load.C.cmd == MachO::LC_SEGMENT) {
1353       if ((Err = parseSegmentLoadCommand<MachO::segment_command,
1354                                          MachO::section>(
1355                    *this, Load, Sections, HasPageZeroSegment, I,
1356                    "LC_SEGMENT", SizeOfHeaders, Elements)))
1357         return;
1358     } else if (Load.C.cmd == MachO::LC_ID_DYLIB) {
1359       if ((Err = checkDylibIdCommand(*this, Load, I, &DyldIdLoadCmd)))
1360         return;
1361     } else if (Load.C.cmd == MachO::LC_LOAD_DYLIB) {
1362       if ((Err = checkDylibCommand(*this, Load, I, "LC_LOAD_DYLIB")))
1363         return;
1364       Libraries.push_back(Load.Ptr);
1365     } else if (Load.C.cmd == MachO::LC_LOAD_WEAK_DYLIB) {
1366       if ((Err = checkDylibCommand(*this, Load, I, "LC_LOAD_WEAK_DYLIB")))
1367         return;
1368       Libraries.push_back(Load.Ptr);
1369     } else if (Load.C.cmd == MachO::LC_LAZY_LOAD_DYLIB) {
1370       if ((Err = checkDylibCommand(*this, Load, I, "LC_LAZY_LOAD_DYLIB")))
1371         return;
1372       Libraries.push_back(Load.Ptr);
1373     } else if (Load.C.cmd == MachO::LC_REEXPORT_DYLIB) {
1374       if ((Err = checkDylibCommand(*this, Load, I, "LC_REEXPORT_DYLIB")))
1375         return;
1376       Libraries.push_back(Load.Ptr);
1377     } else if (Load.C.cmd == MachO::LC_LOAD_UPWARD_DYLIB) {
1378       if ((Err = checkDylibCommand(*this, Load, I, "LC_LOAD_UPWARD_DYLIB")))
1379         return;
1380       Libraries.push_back(Load.Ptr);
1381     } else if (Load.C.cmd == MachO::LC_ID_DYLINKER) {
1382       if ((Err = checkDyldCommand(*this, Load, I, "LC_ID_DYLINKER")))
1383         return;
1384     } else if (Load.C.cmd == MachO::LC_LOAD_DYLINKER) {
1385       if ((Err = checkDyldCommand(*this, Load, I, "LC_LOAD_DYLINKER")))
1386         return;
1387     } else if (Load.C.cmd == MachO::LC_DYLD_ENVIRONMENT) {
1388       if ((Err = checkDyldCommand(*this, Load, I, "LC_DYLD_ENVIRONMENT")))
1389         return;
1390     } else if (Load.C.cmd == MachO::LC_VERSION_MIN_MACOSX) {
1391       if ((Err = checkVersCommand(*this, Load, I, &VersLoadCmd,
1392                                   "LC_VERSION_MIN_MACOSX")))
1393         return;
1394     } else if (Load.C.cmd == MachO::LC_VERSION_MIN_IPHONEOS) {
1395       if ((Err = checkVersCommand(*this, Load, I, &VersLoadCmd,
1396                                   "LC_VERSION_MIN_IPHONEOS")))
1397         return;
1398     } else if (Load.C.cmd == MachO::LC_VERSION_MIN_TVOS) {
1399       if ((Err = checkVersCommand(*this, Load, I, &VersLoadCmd,
1400                                   "LC_VERSION_MIN_TVOS")))
1401         return;
1402     } else if (Load.C.cmd == MachO::LC_VERSION_MIN_WATCHOS) {
1403       if ((Err = checkVersCommand(*this, Load, I, &VersLoadCmd,
1404                                   "LC_VERSION_MIN_WATCHOS")))
1405         return;
1406     } else if (Load.C.cmd == MachO::LC_NOTE) {
1407       if ((Err = checkNoteCommand(*this, Load, I, Elements)))
1408         return;
1409     } else if (Load.C.cmd == MachO::LC_BUILD_VERSION) {
1410       if ((Err = parseBuildVersionCommand(*this, Load, BuildTools, I)))
1411         return;
1412     } else if (Load.C.cmd == MachO::LC_RPATH) {
1413       if ((Err = checkRpathCommand(*this, Load, I)))
1414         return;
1415     } else if (Load.C.cmd == MachO::LC_SOURCE_VERSION) {
1416       if (Load.C.cmdsize != sizeof(MachO::source_version_command)) {
1417         Err = malformedError("LC_SOURCE_VERSION command " + Twine(I) +
1418                              " has incorrect cmdsize");
1419         return;
1420       }
1421       if (SourceLoadCmd) {
1422         Err = malformedError("more than one LC_SOURCE_VERSION command");
1423         return;
1424       }
1425       SourceLoadCmd = Load.Ptr;
1426     } else if (Load.C.cmd == MachO::LC_MAIN) {
1427       if (Load.C.cmdsize != sizeof(MachO::entry_point_command)) {
1428         Err = malformedError("LC_MAIN command " + Twine(I) +
1429                              " has incorrect cmdsize");
1430         return;
1431       }
1432       if (EntryPointLoadCmd) {
1433         Err = malformedError("more than one LC_MAIN command");
1434         return;
1435       }
1436       EntryPointLoadCmd = Load.Ptr;
1437     } else if (Load.C.cmd == MachO::LC_ENCRYPTION_INFO) {
1438       if (Load.C.cmdsize != sizeof(MachO::encryption_info_command)) {
1439         Err = malformedError("LC_ENCRYPTION_INFO command " + Twine(I) +
1440                              " has incorrect cmdsize");
1441         return;
1442       }
1443       MachO::encryption_info_command E =
1444         getStruct<MachO::encryption_info_command>(*this, Load.Ptr);
1445       if ((Err = checkEncryptCommand(*this, Load, I, E.cryptoff, E.cryptsize,
1446                                      &EncryptLoadCmd, "LC_ENCRYPTION_INFO")))
1447         return;
1448     } else if (Load.C.cmd == MachO::LC_ENCRYPTION_INFO_64) {
1449       if (Load.C.cmdsize != sizeof(MachO::encryption_info_command_64)) {
1450         Err = malformedError("LC_ENCRYPTION_INFO_64 command " + Twine(I) +
1451                              " has incorrect cmdsize");
1452         return;
1453       }
1454       MachO::encryption_info_command_64 E =
1455         getStruct<MachO::encryption_info_command_64>(*this, Load.Ptr);
1456       if ((Err = checkEncryptCommand(*this, Load, I, E.cryptoff, E.cryptsize,
1457                                      &EncryptLoadCmd, "LC_ENCRYPTION_INFO_64")))
1458         return;
1459     } else if (Load.C.cmd == MachO::LC_LINKER_OPTION) {
1460       if ((Err = checkLinkerOptCommand(*this, Load, I)))
1461         return;
1462     } else if (Load.C.cmd == MachO::LC_SUB_FRAMEWORK) {
1463       if (Load.C.cmdsize < sizeof(MachO::sub_framework_command)) {
1464         Err =  malformedError("load command " + Twine(I) +
1465                               " LC_SUB_FRAMEWORK cmdsize too small");
1466         return;
1467       }
1468       MachO::sub_framework_command S =
1469         getStruct<MachO::sub_framework_command>(*this, Load.Ptr);
1470       if ((Err = checkSubCommand(*this, Load, I, "LC_SUB_FRAMEWORK",
1471                                  sizeof(MachO::sub_framework_command),
1472                                  "sub_framework_command", S.umbrella,
1473                                  "umbrella")))
1474         return;
1475     } else if (Load.C.cmd == MachO::LC_SUB_UMBRELLA) {
1476       if (Load.C.cmdsize < sizeof(MachO::sub_umbrella_command)) {
1477         Err =  malformedError("load command " + Twine(I) +
1478                               " LC_SUB_UMBRELLA cmdsize too small");
1479         return;
1480       }
1481       MachO::sub_umbrella_command S =
1482         getStruct<MachO::sub_umbrella_command>(*this, Load.Ptr);
1483       if ((Err = checkSubCommand(*this, Load, I, "LC_SUB_UMBRELLA",
1484                                  sizeof(MachO::sub_umbrella_command),
1485                                  "sub_umbrella_command", S.sub_umbrella,
1486                                  "sub_umbrella")))
1487         return;
1488     } else if (Load.C.cmd == MachO::LC_SUB_LIBRARY) {
1489       if (Load.C.cmdsize < sizeof(MachO::sub_library_command)) {
1490         Err =  malformedError("load command " + Twine(I) +
1491                               " LC_SUB_LIBRARY cmdsize too small");
1492         return;
1493       }
1494       MachO::sub_library_command S =
1495         getStruct<MachO::sub_library_command>(*this, Load.Ptr);
1496       if ((Err = checkSubCommand(*this, Load, I, "LC_SUB_LIBRARY",
1497                                  sizeof(MachO::sub_library_command),
1498                                  "sub_library_command", S.sub_library,
1499                                  "sub_library")))
1500         return;
1501     } else if (Load.C.cmd == MachO::LC_SUB_CLIENT) {
1502       if (Load.C.cmdsize < sizeof(MachO::sub_client_command)) {
1503         Err =  malformedError("load command " + Twine(I) +
1504                               " LC_SUB_CLIENT cmdsize too small");
1505         return;
1506       }
1507       MachO::sub_client_command S =
1508         getStruct<MachO::sub_client_command>(*this, Load.Ptr);
1509       if ((Err = checkSubCommand(*this, Load, I, "LC_SUB_CLIENT",
1510                                  sizeof(MachO::sub_client_command),
1511                                  "sub_client_command", S.client, "client")))
1512         return;
1513     } else if (Load.C.cmd == MachO::LC_ROUTINES) {
1514       if (Load.C.cmdsize != sizeof(MachO::routines_command)) {
1515         Err = malformedError("LC_ROUTINES command " + Twine(I) +
1516                              " has incorrect cmdsize");
1517         return;
1518       }
1519       if (RoutinesLoadCmd) {
1520         Err = malformedError("more than one LC_ROUTINES and or LC_ROUTINES_64 "
1521                              "command");
1522         return;
1523       }
1524       RoutinesLoadCmd = Load.Ptr;
1525     } else if (Load.C.cmd == MachO::LC_ROUTINES_64) {
1526       if (Load.C.cmdsize != sizeof(MachO::routines_command_64)) {
1527         Err = malformedError("LC_ROUTINES_64 command " + Twine(I) +
1528                              " has incorrect cmdsize");
1529         return;
1530       }
1531       if (RoutinesLoadCmd) {
1532         Err = malformedError("more than one LC_ROUTINES_64 and or LC_ROUTINES "
1533                              "command");
1534         return;
1535       }
1536       RoutinesLoadCmd = Load.Ptr;
1537     } else if (Load.C.cmd == MachO::LC_UNIXTHREAD) {
1538       if ((Err = checkThreadCommand(*this, Load, I, "LC_UNIXTHREAD")))
1539         return;
1540       if (UnixThreadLoadCmd) {
1541         Err = malformedError("more than one LC_UNIXTHREAD command");
1542         return;
1543       }
1544       UnixThreadLoadCmd = Load.Ptr;
1545     } else if (Load.C.cmd == MachO::LC_THREAD) {
1546       if ((Err = checkThreadCommand(*this, Load, I, "LC_THREAD")))
1547         return;
1548     // Note: LC_TWOLEVEL_HINTS is really obsolete and is not supported.
1549     } else if (Load.C.cmd == MachO::LC_TWOLEVEL_HINTS) {
1550        if ((Err = checkTwoLevelHintsCommand(*this, Load, I,
1551                                             &TwoLevelHintsLoadCmd, Elements)))
1552          return;
1553     } else if (isLoadCommandObsolete(Load.C.cmd)) {
1554       Err = malformedError("load command " + Twine(I) + " for cmd value of: " +
1555                            Twine(Load.C.cmd) + " is obsolete and not "
1556                            "supported");
1557       return;
1558     }
1559     // TODO: generate a error for unknown load commands by default.  But still
1560     // need work out an approach to allow or not allow unknown values like this
1561     // as an option for some uses like lldb.
1562     if (I < LoadCommandCount - 1) {
1563       if (auto LoadOrErr = getNextLoadCommandInfo(*this, I, Load))
1564         Load = *LoadOrErr;
1565       else {
1566         Err = LoadOrErr.takeError();
1567         return;
1568       }
1569     }
1570   }
1571   if (!SymtabLoadCmd) {
1572     if (DysymtabLoadCmd) {
1573       Err = malformedError("contains LC_DYSYMTAB load command without a "
1574                            "LC_SYMTAB load command");
1575       return;
1576     }
1577   } else if (DysymtabLoadCmd) {
1578     MachO::symtab_command Symtab =
1579       getStruct<MachO::symtab_command>(*this, SymtabLoadCmd);
1580     MachO::dysymtab_command Dysymtab =
1581       getStruct<MachO::dysymtab_command>(*this, DysymtabLoadCmd);
1582     if (Dysymtab.nlocalsym != 0 && Dysymtab.ilocalsym > Symtab.nsyms) {
1583       Err = malformedError("ilocalsym in LC_DYSYMTAB load command "
1584                            "extends past the end of the symbol table");
1585       return;
1586     }
1587     uint64_t BigSize = Dysymtab.ilocalsym;
1588     BigSize += Dysymtab.nlocalsym;
1589     if (Dysymtab.nlocalsym != 0 && BigSize > Symtab.nsyms) {
1590       Err = malformedError("ilocalsym plus nlocalsym in LC_DYSYMTAB load "
1591                            "command extends past the end of the symbol table");
1592       return;
1593     }
1594     if (Dysymtab.nextdefsym != 0 && Dysymtab.iextdefsym > Symtab.nsyms) {
1595       Err = malformedError("iextdefsym in LC_DYSYMTAB load command "
1596                            "extends past the end of the symbol table");
1597       return;
1598     }
1599     BigSize = Dysymtab.iextdefsym;
1600     BigSize += Dysymtab.nextdefsym;
1601     if (Dysymtab.nextdefsym != 0 && BigSize > Symtab.nsyms) {
1602       Err = malformedError("iextdefsym plus nextdefsym in LC_DYSYMTAB "
1603                            "load command extends past the end of the symbol "
1604                            "table");
1605       return;
1606     }
1607     if (Dysymtab.nundefsym != 0 && Dysymtab.iundefsym > Symtab.nsyms) {
1608       Err = malformedError("iundefsym in LC_DYSYMTAB load command "
1609                            "extends past the end of the symbol table");
1610       return;
1611     }
1612     BigSize = Dysymtab.iundefsym;
1613     BigSize += Dysymtab.nundefsym;
1614     if (Dysymtab.nundefsym != 0 && BigSize > Symtab.nsyms) {
1615       Err = malformedError("iundefsym plus nundefsym in LC_DYSYMTAB load "
1616                            " command extends past the end of the symbol table");
1617       return;
1618     }
1619   }
1620   if ((getHeader().filetype == MachO::MH_DYLIB ||
1621        getHeader().filetype == MachO::MH_DYLIB_STUB) &&
1622        DyldIdLoadCmd == nullptr) {
1623     Err = malformedError("no LC_ID_DYLIB load command in dynamic library "
1624                          "filetype");
1625     return;
1626   }
1627   assert(LoadCommands.size() == LoadCommandCount);
1628 
1629   Err = Error::success();
1630 }
1631 
1632 Error MachOObjectFile::checkSymbolTable() const {
1633   uint32_t Flags = 0;
1634   if (is64Bit()) {
1635     MachO::mach_header_64 H_64 = MachOObjectFile::getHeader64();
1636     Flags = H_64.flags;
1637   } else {
1638     MachO::mach_header H = MachOObjectFile::getHeader();
1639     Flags = H.flags;
1640   }
1641   uint8_t NType = 0;
1642   uint8_t NSect = 0;
1643   uint16_t NDesc = 0;
1644   uint32_t NStrx = 0;
1645   uint64_t NValue = 0;
1646   uint32_t SymbolIndex = 0;
1647   MachO::symtab_command S = getSymtabLoadCommand();
1648   for (const SymbolRef &Symbol : symbols()) {
1649     DataRefImpl SymDRI = Symbol.getRawDataRefImpl();
1650     if (is64Bit()) {
1651       MachO::nlist_64 STE_64 = getSymbol64TableEntry(SymDRI);
1652       NType = STE_64.n_type;
1653       NSect = STE_64.n_sect;
1654       NDesc = STE_64.n_desc;
1655       NStrx = STE_64.n_strx;
1656       NValue = STE_64.n_value;
1657     } else {
1658       MachO::nlist STE = getSymbolTableEntry(SymDRI);
1659       NType = STE.n_type;
1660       NType = STE.n_type;
1661       NSect = STE.n_sect;
1662       NDesc = STE.n_desc;
1663       NStrx = STE.n_strx;
1664       NValue = STE.n_value;
1665     }
1666     if ((NType & MachO::N_STAB) == 0 &&
1667         (NType & MachO::N_TYPE) == MachO::N_SECT) {
1668       if (NSect == 0 || NSect > Sections.size())
1669         return malformedError("bad section index: " + Twine((int)NSect) +
1670                               " for symbol at index " + Twine(SymbolIndex));
1671     }
1672     if ((NType & MachO::N_STAB) == 0 &&
1673         (NType & MachO::N_TYPE) == MachO::N_INDR) {
1674       if (NValue >= S.strsize)
1675         return malformedError("bad n_value: " + Twine((int)NValue) + " past "
1676                               "the end of string table, for N_INDR symbol at "
1677                               "index " + Twine(SymbolIndex));
1678     }
1679     if ((Flags & MachO::MH_TWOLEVEL) == MachO::MH_TWOLEVEL &&
1680         (((NType & MachO::N_TYPE) == MachO::N_UNDF && NValue == 0) ||
1681          (NType & MachO::N_TYPE) == MachO::N_PBUD)) {
1682       uint32_t LibraryOrdinal = MachO::GET_LIBRARY_ORDINAL(NDesc);
1683       if (LibraryOrdinal != 0 &&
1684           LibraryOrdinal != MachO::EXECUTABLE_ORDINAL &&
1685           LibraryOrdinal != MachO::DYNAMIC_LOOKUP_ORDINAL &&
1686           LibraryOrdinal - 1 >= Libraries.size() ) {
1687         return malformedError("bad library ordinal: " + Twine(LibraryOrdinal) +
1688                             " for symbol at index " + Twine(SymbolIndex));
1689       }
1690     }
1691     if (NStrx >= S.strsize)
1692       return malformedError("bad string table index: " + Twine((int)NStrx) +
1693                             " past the end of string table, for symbol at "
1694                             "index " + Twine(SymbolIndex));
1695     SymbolIndex++;
1696   }
1697   return Error::success();
1698 }
1699 
1700 void MachOObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
1701   unsigned SymbolTableEntrySize = is64Bit() ?
1702     sizeof(MachO::nlist_64) :
1703     sizeof(MachO::nlist);
1704   Symb.p += SymbolTableEntrySize;
1705 }
1706 
1707 Expected<StringRef> MachOObjectFile::getSymbolName(DataRefImpl Symb) const {
1708   StringRef StringTable = getStringTableData();
1709   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, Symb);
1710   if (Entry.n_strx == 0)
1711     // A n_strx value of 0 indicates that no name is associated with a
1712     // particular symbol table entry.
1713     return StringRef();
1714   const char *Start = &StringTable.data()[Entry.n_strx];
1715   if (Start < getData().begin() || Start >= getData().end()) {
1716     return malformedError("bad string index: " + Twine(Entry.n_strx) +
1717                           " for symbol at index " + Twine(getSymbolIndex(Symb)));
1718   }
1719   return StringRef(Start);
1720 }
1721 
1722 unsigned MachOObjectFile::getSectionType(SectionRef Sec) const {
1723   DataRefImpl DRI = Sec.getRawDataRefImpl();
1724   uint32_t Flags = getSectionFlags(*this, DRI);
1725   return Flags & MachO::SECTION_TYPE;
1726 }
1727 
1728 uint64_t MachOObjectFile::getNValue(DataRefImpl Sym) const {
1729   if (is64Bit()) {
1730     MachO::nlist_64 Entry = getSymbol64TableEntry(Sym);
1731     return Entry.n_value;
1732   }
1733   MachO::nlist Entry = getSymbolTableEntry(Sym);
1734   return Entry.n_value;
1735 }
1736 
1737 // getIndirectName() returns the name of the alias'ed symbol who's string table
1738 // index is in the n_value field.
1739 std::error_code MachOObjectFile::getIndirectName(DataRefImpl Symb,
1740                                                  StringRef &Res) const {
1741   StringRef StringTable = getStringTableData();
1742   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, Symb);
1743   if ((Entry.n_type & MachO::N_TYPE) != MachO::N_INDR)
1744     return object_error::parse_failed;
1745   uint64_t NValue = getNValue(Symb);
1746   if (NValue >= StringTable.size())
1747     return object_error::parse_failed;
1748   const char *Start = &StringTable.data()[NValue];
1749   Res = StringRef(Start);
1750   return std::error_code();
1751 }
1752 
1753 uint64_t MachOObjectFile::getSymbolValueImpl(DataRefImpl Sym) const {
1754   return getNValue(Sym);
1755 }
1756 
1757 Expected<uint64_t> MachOObjectFile::getSymbolAddress(DataRefImpl Sym) const {
1758   return getSymbolValue(Sym);
1759 }
1760 
1761 uint32_t MachOObjectFile::getSymbolAlignment(DataRefImpl DRI) const {
1762   uint32_t flags = getSymbolFlags(DRI);
1763   if (flags & SymbolRef::SF_Common) {
1764     MachO::nlist_base Entry = getSymbolTableEntryBase(*this, DRI);
1765     return 1 << MachO::GET_COMM_ALIGN(Entry.n_desc);
1766   }
1767   return 0;
1768 }
1769 
1770 uint64_t MachOObjectFile::getCommonSymbolSizeImpl(DataRefImpl DRI) const {
1771   return getNValue(DRI);
1772 }
1773 
1774 Expected<SymbolRef::Type>
1775 MachOObjectFile::getSymbolType(DataRefImpl Symb) const {
1776   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, Symb);
1777   uint8_t n_type = Entry.n_type;
1778 
1779   // If this is a STAB debugging symbol, we can do nothing more.
1780   if (n_type & MachO::N_STAB)
1781     return SymbolRef::ST_Debug;
1782 
1783   switch (n_type & MachO::N_TYPE) {
1784     case MachO::N_UNDF :
1785       return SymbolRef::ST_Unknown;
1786     case MachO::N_SECT :
1787       Expected<section_iterator> SecOrError = getSymbolSection(Symb);
1788       if (!SecOrError)
1789         return SecOrError.takeError();
1790       section_iterator Sec = *SecOrError;
1791       if (Sec->isData() || Sec->isBSS())
1792         return SymbolRef::ST_Data;
1793       return SymbolRef::ST_Function;
1794   }
1795   return SymbolRef::ST_Other;
1796 }
1797 
1798 uint32_t MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
1799   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, DRI);
1800 
1801   uint8_t MachOType = Entry.n_type;
1802   uint16_t MachOFlags = Entry.n_desc;
1803 
1804   uint32_t Result = SymbolRef::SF_None;
1805 
1806   if ((MachOType & MachO::N_TYPE) == MachO::N_INDR)
1807     Result |= SymbolRef::SF_Indirect;
1808 
1809   if (MachOType & MachO::N_STAB)
1810     Result |= SymbolRef::SF_FormatSpecific;
1811 
1812   if (MachOType & MachO::N_EXT) {
1813     Result |= SymbolRef::SF_Global;
1814     if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF) {
1815       if (getNValue(DRI))
1816         Result |= SymbolRef::SF_Common;
1817       else
1818         Result |= SymbolRef::SF_Undefined;
1819     }
1820 
1821     if (!(MachOType & MachO::N_PEXT))
1822       Result |= SymbolRef::SF_Exported;
1823   }
1824 
1825   if (MachOFlags & (MachO::N_WEAK_REF | MachO::N_WEAK_DEF))
1826     Result |= SymbolRef::SF_Weak;
1827 
1828   if (MachOFlags & (MachO::N_ARM_THUMB_DEF))
1829     Result |= SymbolRef::SF_Thumb;
1830 
1831   if ((MachOType & MachO::N_TYPE) == MachO::N_ABS)
1832     Result |= SymbolRef::SF_Absolute;
1833 
1834   return Result;
1835 }
1836 
1837 Expected<section_iterator>
1838 MachOObjectFile::getSymbolSection(DataRefImpl Symb) const {
1839   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, Symb);
1840   uint8_t index = Entry.n_sect;
1841 
1842   if (index == 0)
1843     return section_end();
1844   DataRefImpl DRI;
1845   DRI.d.a = index - 1;
1846   if (DRI.d.a >= Sections.size()){
1847     return malformedError("bad section index: " + Twine((int)index) +
1848                           " for symbol at index " + Twine(getSymbolIndex(Symb)));
1849   }
1850   return section_iterator(SectionRef(DRI, this));
1851 }
1852 
1853 unsigned MachOObjectFile::getSymbolSectionID(SymbolRef Sym) const {
1854   MachO::nlist_base Entry =
1855       getSymbolTableEntryBase(*this, Sym.getRawDataRefImpl());
1856   return Entry.n_sect - 1;
1857 }
1858 
1859 void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
1860   Sec.d.a++;
1861 }
1862 
1863 std::error_code MachOObjectFile::getSectionName(DataRefImpl Sec,
1864                                                 StringRef &Result) const {
1865   ArrayRef<char> Raw = getSectionRawName(Sec);
1866   Result = parseSegmentOrSectionName(Raw.data());
1867   return std::error_code();
1868 }
1869 
1870 uint64_t MachOObjectFile::getSectionAddress(DataRefImpl Sec) const {
1871   if (is64Bit())
1872     return getSection64(Sec).addr;
1873   return getSection(Sec).addr;
1874 }
1875 
1876 uint64_t MachOObjectFile::getSectionIndex(DataRefImpl Sec) const {
1877   return Sec.d.a;
1878 }
1879 
1880 uint64_t MachOObjectFile::getSectionSize(DataRefImpl Sec) const {
1881   // In the case if a malformed Mach-O file where the section offset is past
1882   // the end of the file or some part of the section size is past the end of
1883   // the file return a size of zero or a size that covers the rest of the file
1884   // but does not extend past the end of the file.
1885   uint32_t SectOffset, SectType;
1886   uint64_t SectSize;
1887 
1888   if (is64Bit()) {
1889     MachO::section_64 Sect = getSection64(Sec);
1890     SectOffset = Sect.offset;
1891     SectSize = Sect.size;
1892     SectType = Sect.flags & MachO::SECTION_TYPE;
1893   } else {
1894     MachO::section Sect = getSection(Sec);
1895     SectOffset = Sect.offset;
1896     SectSize = Sect.size;
1897     SectType = Sect.flags & MachO::SECTION_TYPE;
1898   }
1899   if (SectType == MachO::S_ZEROFILL || SectType == MachO::S_GB_ZEROFILL)
1900     return SectSize;
1901   uint64_t FileSize = getData().size();
1902   if (SectOffset > FileSize)
1903     return 0;
1904   if (FileSize - SectOffset < SectSize)
1905     return FileSize - SectOffset;
1906   return SectSize;
1907 }
1908 
1909 std::error_code MachOObjectFile::getSectionContents(DataRefImpl Sec,
1910                                                     StringRef &Res) const {
1911   uint32_t Offset;
1912   uint64_t Size;
1913 
1914   if (is64Bit()) {
1915     MachO::section_64 Sect = getSection64(Sec);
1916     Offset = Sect.offset;
1917     Size = Sect.size;
1918   } else {
1919     MachO::section Sect = getSection(Sec);
1920     Offset = Sect.offset;
1921     Size = Sect.size;
1922   }
1923 
1924   Res = this->getData().substr(Offset, Size);
1925   return std::error_code();
1926 }
1927 
1928 uint64_t MachOObjectFile::getSectionAlignment(DataRefImpl Sec) const {
1929   uint32_t Align;
1930   if (is64Bit()) {
1931     MachO::section_64 Sect = getSection64(Sec);
1932     Align = Sect.align;
1933   } else {
1934     MachO::section Sect = getSection(Sec);
1935     Align = Sect.align;
1936   }
1937 
1938   return uint64_t(1) << Align;
1939 }
1940 
1941 Expected<SectionRef> MachOObjectFile::getSection(unsigned SectionIndex) const {
1942   if (SectionIndex < 1 || SectionIndex > Sections.size())
1943     return malformedError("bad section index: " + Twine((int)SectionIndex));
1944 
1945   DataRefImpl DRI;
1946   DRI.d.a = SectionIndex - 1;
1947   return SectionRef(DRI, this);
1948 }
1949 
1950 Expected<SectionRef> MachOObjectFile::getSection(StringRef SectionName) const {
1951   StringRef SecName;
1952   for (const SectionRef &Section : sections()) {
1953     if (std::error_code E = Section.getName(SecName))
1954       return errorCodeToError(E);
1955     if (SecName == SectionName) {
1956       return Section;
1957     }
1958   }
1959   return errorCodeToError(object_error::parse_failed);
1960 }
1961 
1962 bool MachOObjectFile::isSectionCompressed(DataRefImpl Sec) const {
1963   return false;
1964 }
1965 
1966 bool MachOObjectFile::isSectionText(DataRefImpl Sec) const {
1967   uint32_t Flags = getSectionFlags(*this, Sec);
1968   return Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
1969 }
1970 
1971 bool MachOObjectFile::isSectionData(DataRefImpl Sec) const {
1972   uint32_t Flags = getSectionFlags(*this, Sec);
1973   unsigned SectionType = Flags & MachO::SECTION_TYPE;
1974   return !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
1975          !(SectionType == MachO::S_ZEROFILL ||
1976            SectionType == MachO::S_GB_ZEROFILL);
1977 }
1978 
1979 bool MachOObjectFile::isSectionBSS(DataRefImpl Sec) const {
1980   uint32_t Flags = getSectionFlags(*this, Sec);
1981   unsigned SectionType = Flags & MachO::SECTION_TYPE;
1982   return !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
1983          (SectionType == MachO::S_ZEROFILL ||
1984           SectionType == MachO::S_GB_ZEROFILL);
1985 }
1986 
1987 unsigned MachOObjectFile::getSectionID(SectionRef Sec) const {
1988   return Sec.getRawDataRefImpl().d.a;
1989 }
1990 
1991 bool MachOObjectFile::isSectionVirtual(DataRefImpl Sec) const {
1992   uint32_t Flags = getSectionFlags(*this, Sec);
1993   unsigned SectionType = Flags & MachO::SECTION_TYPE;
1994   return SectionType == MachO::S_ZEROFILL ||
1995          SectionType == MachO::S_GB_ZEROFILL;
1996 }
1997 
1998 bool MachOObjectFile::isSectionBitcode(DataRefImpl Sec) const {
1999   StringRef SegmentName = getSectionFinalSegmentName(Sec);
2000   StringRef SectName;
2001   if (!getSectionName(Sec, SectName))
2002     return (SegmentName == "__LLVM" && SectName == "__bitcode");
2003   return false;
2004 }
2005 
2006 bool MachOObjectFile::isSectionStripped(DataRefImpl Sec) const {
2007   if (is64Bit())
2008     return getSection64(Sec).offset == 0;
2009   return getSection(Sec).offset == 0;
2010 }
2011 
2012 relocation_iterator MachOObjectFile::section_rel_begin(DataRefImpl Sec) const {
2013   DataRefImpl Ret;
2014   Ret.d.a = Sec.d.a;
2015   Ret.d.b = 0;
2016   return relocation_iterator(RelocationRef(Ret, this));
2017 }
2018 
2019 relocation_iterator
2020 MachOObjectFile::section_rel_end(DataRefImpl Sec) const {
2021   uint32_t Num;
2022   if (is64Bit()) {
2023     MachO::section_64 Sect = getSection64(Sec);
2024     Num = Sect.nreloc;
2025   } else {
2026     MachO::section Sect = getSection(Sec);
2027     Num = Sect.nreloc;
2028   }
2029 
2030   DataRefImpl Ret;
2031   Ret.d.a = Sec.d.a;
2032   Ret.d.b = Num;
2033   return relocation_iterator(RelocationRef(Ret, this));
2034 }
2035 
2036 relocation_iterator MachOObjectFile::extrel_begin() const {
2037   DataRefImpl Ret;
2038   // for DYSYMTAB symbols, Ret.d.a == 0 for external relocations
2039   Ret.d.a = 0; // Would normally be a section index.
2040   Ret.d.b = 0; // Index into the external relocations
2041   return relocation_iterator(RelocationRef(Ret, this));
2042 }
2043 
2044 relocation_iterator MachOObjectFile::extrel_end() const {
2045   MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
2046   DataRefImpl Ret;
2047   // for DYSYMTAB symbols, Ret.d.a == 0 for external relocations
2048   Ret.d.a = 0; // Would normally be a section index.
2049   Ret.d.b = DysymtabLoadCmd.nextrel; // Index into the external relocations
2050   return relocation_iterator(RelocationRef(Ret, this));
2051 }
2052 
2053 relocation_iterator MachOObjectFile::locrel_begin() const {
2054   DataRefImpl Ret;
2055   // for DYSYMTAB symbols, Ret.d.a == 1 for local relocations
2056   Ret.d.a = 1; // Would normally be a section index.
2057   Ret.d.b = 0; // Index into the local relocations
2058   return relocation_iterator(RelocationRef(Ret, this));
2059 }
2060 
2061 relocation_iterator MachOObjectFile::locrel_end() const {
2062   MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
2063   DataRefImpl Ret;
2064   // for DYSYMTAB symbols, Ret.d.a == 1 for local relocations
2065   Ret.d.a = 1; // Would normally be a section index.
2066   Ret.d.b = DysymtabLoadCmd.nlocrel; // Index into the local relocations
2067   return relocation_iterator(RelocationRef(Ret, this));
2068 }
2069 
2070 void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
2071   ++Rel.d.b;
2072 }
2073 
2074 uint64_t MachOObjectFile::getRelocationOffset(DataRefImpl Rel) const {
2075   assert((getHeader().filetype == MachO::MH_OBJECT ||
2076           getHeader().filetype == MachO::MH_KEXT_BUNDLE) &&
2077          "Only implemented for MH_OBJECT && MH_KEXT_BUNDLE");
2078   MachO::any_relocation_info RE = getRelocation(Rel);
2079   return getAnyRelocationAddress(RE);
2080 }
2081 
2082 symbol_iterator
2083 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
2084   MachO::any_relocation_info RE = getRelocation(Rel);
2085   if (isRelocationScattered(RE))
2086     return symbol_end();
2087 
2088   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
2089   bool isExtern = getPlainRelocationExternal(RE);
2090   if (!isExtern)
2091     return symbol_end();
2092 
2093   MachO::symtab_command S = getSymtabLoadCommand();
2094   unsigned SymbolTableEntrySize = is64Bit() ?
2095     sizeof(MachO::nlist_64) :
2096     sizeof(MachO::nlist);
2097   uint64_t Offset = S.symoff + SymbolIdx * SymbolTableEntrySize;
2098   DataRefImpl Sym;
2099   Sym.p = reinterpret_cast<uintptr_t>(getPtr(*this, Offset));
2100   return symbol_iterator(SymbolRef(Sym, this));
2101 }
2102 
2103 section_iterator
2104 MachOObjectFile::getRelocationSection(DataRefImpl Rel) const {
2105   return section_iterator(getAnyRelocationSection(getRelocation(Rel)));
2106 }
2107 
2108 uint64_t MachOObjectFile::getRelocationType(DataRefImpl Rel) const {
2109   MachO::any_relocation_info RE = getRelocation(Rel);
2110   return getAnyRelocationType(RE);
2111 }
2112 
2113 void MachOObjectFile::getRelocationTypeName(
2114     DataRefImpl Rel, SmallVectorImpl<char> &Result) const {
2115   StringRef res;
2116   uint64_t RType = getRelocationType(Rel);
2117 
2118   unsigned Arch = this->getArch();
2119 
2120   switch (Arch) {
2121     case Triple::x86: {
2122       static const char *const Table[] =  {
2123         "GENERIC_RELOC_VANILLA",
2124         "GENERIC_RELOC_PAIR",
2125         "GENERIC_RELOC_SECTDIFF",
2126         "GENERIC_RELOC_PB_LA_PTR",
2127         "GENERIC_RELOC_LOCAL_SECTDIFF",
2128         "GENERIC_RELOC_TLV" };
2129 
2130       if (RType > 5)
2131         res = "Unknown";
2132       else
2133         res = Table[RType];
2134       break;
2135     }
2136     case Triple::x86_64: {
2137       static const char *const Table[] =  {
2138         "X86_64_RELOC_UNSIGNED",
2139         "X86_64_RELOC_SIGNED",
2140         "X86_64_RELOC_BRANCH",
2141         "X86_64_RELOC_GOT_LOAD",
2142         "X86_64_RELOC_GOT",
2143         "X86_64_RELOC_SUBTRACTOR",
2144         "X86_64_RELOC_SIGNED_1",
2145         "X86_64_RELOC_SIGNED_2",
2146         "X86_64_RELOC_SIGNED_4",
2147         "X86_64_RELOC_TLV" };
2148 
2149       if (RType > 9)
2150         res = "Unknown";
2151       else
2152         res = Table[RType];
2153       break;
2154     }
2155     case Triple::arm: {
2156       static const char *const Table[] =  {
2157         "ARM_RELOC_VANILLA",
2158         "ARM_RELOC_PAIR",
2159         "ARM_RELOC_SECTDIFF",
2160         "ARM_RELOC_LOCAL_SECTDIFF",
2161         "ARM_RELOC_PB_LA_PTR",
2162         "ARM_RELOC_BR24",
2163         "ARM_THUMB_RELOC_BR22",
2164         "ARM_THUMB_32BIT_BRANCH",
2165         "ARM_RELOC_HALF",
2166         "ARM_RELOC_HALF_SECTDIFF" };
2167 
2168       if (RType > 9)
2169         res = "Unknown";
2170       else
2171         res = Table[RType];
2172       break;
2173     }
2174     case Triple::aarch64: {
2175       static const char *const Table[] = {
2176         "ARM64_RELOC_UNSIGNED",           "ARM64_RELOC_SUBTRACTOR",
2177         "ARM64_RELOC_BRANCH26",           "ARM64_RELOC_PAGE21",
2178         "ARM64_RELOC_PAGEOFF12",          "ARM64_RELOC_GOT_LOAD_PAGE21",
2179         "ARM64_RELOC_GOT_LOAD_PAGEOFF12", "ARM64_RELOC_POINTER_TO_GOT",
2180         "ARM64_RELOC_TLVP_LOAD_PAGE21",   "ARM64_RELOC_TLVP_LOAD_PAGEOFF12",
2181         "ARM64_RELOC_ADDEND"
2182       };
2183 
2184       if (RType >= array_lengthof(Table))
2185         res = "Unknown";
2186       else
2187         res = Table[RType];
2188       break;
2189     }
2190     case Triple::ppc: {
2191       static const char *const Table[] =  {
2192         "PPC_RELOC_VANILLA",
2193         "PPC_RELOC_PAIR",
2194         "PPC_RELOC_BR14",
2195         "PPC_RELOC_BR24",
2196         "PPC_RELOC_HI16",
2197         "PPC_RELOC_LO16",
2198         "PPC_RELOC_HA16",
2199         "PPC_RELOC_LO14",
2200         "PPC_RELOC_SECTDIFF",
2201         "PPC_RELOC_PB_LA_PTR",
2202         "PPC_RELOC_HI16_SECTDIFF",
2203         "PPC_RELOC_LO16_SECTDIFF",
2204         "PPC_RELOC_HA16_SECTDIFF",
2205         "PPC_RELOC_JBSR",
2206         "PPC_RELOC_LO14_SECTDIFF",
2207         "PPC_RELOC_LOCAL_SECTDIFF" };
2208 
2209       if (RType > 15)
2210         res = "Unknown";
2211       else
2212         res = Table[RType];
2213       break;
2214     }
2215     case Triple::UnknownArch:
2216       res = "Unknown";
2217       break;
2218   }
2219   Result.append(res.begin(), res.end());
2220 }
2221 
2222 uint8_t MachOObjectFile::getRelocationLength(DataRefImpl Rel) const {
2223   MachO::any_relocation_info RE = getRelocation(Rel);
2224   return getAnyRelocationLength(RE);
2225 }
2226 
2227 //
2228 // guessLibraryShortName() is passed a name of a dynamic library and returns a
2229 // guess on what the short name is.  Then name is returned as a substring of the
2230 // StringRef Name passed in.  The name of the dynamic library is recognized as
2231 // a framework if it has one of the two following forms:
2232 //      Foo.framework/Versions/A/Foo
2233 //      Foo.framework/Foo
2234 // Where A and Foo can be any string.  And may contain a trailing suffix
2235 // starting with an underbar.  If the Name is recognized as a framework then
2236 // isFramework is set to true else it is set to false.  If the Name has a
2237 // suffix then Suffix is set to the substring in Name that contains the suffix
2238 // else it is set to a NULL StringRef.
2239 //
2240 // The Name of the dynamic library is recognized as a library name if it has
2241 // one of the two following forms:
2242 //      libFoo.A.dylib
2243 //      libFoo.dylib
2244 // The library may have a suffix trailing the name Foo of the form:
2245 //      libFoo_profile.A.dylib
2246 //      libFoo_profile.dylib
2247 //
2248 // The Name of the dynamic library is also recognized as a library name if it
2249 // has the following form:
2250 //      Foo.qtx
2251 //
2252 // If the Name of the dynamic library is none of the forms above then a NULL
2253 // StringRef is returned.
2254 //
2255 StringRef MachOObjectFile::guessLibraryShortName(StringRef Name,
2256                                                  bool &isFramework,
2257                                                  StringRef &Suffix) {
2258   StringRef Foo, F, DotFramework, V, Dylib, Lib, Dot, Qtx;
2259   size_t a, b, c, d, Idx;
2260 
2261   isFramework = false;
2262   Suffix = StringRef();
2263 
2264   // Pull off the last component and make Foo point to it
2265   a = Name.rfind('/');
2266   if (a == Name.npos || a == 0)
2267     goto guess_library;
2268   Foo = Name.slice(a+1, Name.npos);
2269 
2270   // Look for a suffix starting with a '_'
2271   Idx = Foo.rfind('_');
2272   if (Idx != Foo.npos && Foo.size() >= 2) {
2273     Suffix = Foo.slice(Idx, Foo.npos);
2274     Foo = Foo.slice(0, Idx);
2275   }
2276 
2277   // First look for the form Foo.framework/Foo
2278   b = Name.rfind('/', a);
2279   if (b == Name.npos)
2280     Idx = 0;
2281   else
2282     Idx = b+1;
2283   F = Name.slice(Idx, Idx + Foo.size());
2284   DotFramework = Name.slice(Idx + Foo.size(),
2285                             Idx + Foo.size() + sizeof(".framework/")-1);
2286   if (F == Foo && DotFramework == ".framework/") {
2287     isFramework = true;
2288     return Foo;
2289   }
2290 
2291   // Next look for the form Foo.framework/Versions/A/Foo
2292   if (b == Name.npos)
2293     goto guess_library;
2294   c =  Name.rfind('/', b);
2295   if (c == Name.npos || c == 0)
2296     goto guess_library;
2297   V = Name.slice(c+1, Name.npos);
2298   if (!V.startswith("Versions/"))
2299     goto guess_library;
2300   d =  Name.rfind('/', c);
2301   if (d == Name.npos)
2302     Idx = 0;
2303   else
2304     Idx = d+1;
2305   F = Name.slice(Idx, Idx + Foo.size());
2306   DotFramework = Name.slice(Idx + Foo.size(),
2307                             Idx + Foo.size() + sizeof(".framework/")-1);
2308   if (F == Foo && DotFramework == ".framework/") {
2309     isFramework = true;
2310     return Foo;
2311   }
2312 
2313 guess_library:
2314   // pull off the suffix after the "." and make a point to it
2315   a = Name.rfind('.');
2316   if (a == Name.npos || a == 0)
2317     return StringRef();
2318   Dylib = Name.slice(a, Name.npos);
2319   if (Dylib != ".dylib")
2320     goto guess_qtx;
2321 
2322   // First pull off the version letter for the form Foo.A.dylib if any.
2323   if (a >= 3) {
2324     Dot = Name.slice(a-2, a-1);
2325     if (Dot == ".")
2326       a = a - 2;
2327   }
2328 
2329   b = Name.rfind('/', a);
2330   if (b == Name.npos)
2331     b = 0;
2332   else
2333     b = b+1;
2334   // ignore any suffix after an underbar like Foo_profile.A.dylib
2335   Idx = Name.find('_', b);
2336   if (Idx != Name.npos && Idx != b) {
2337     Lib = Name.slice(b, Idx);
2338     Suffix = Name.slice(Idx, a);
2339   }
2340   else
2341     Lib = Name.slice(b, a);
2342   // There are incorrect library names of the form:
2343   // libATS.A_profile.dylib so check for these.
2344   if (Lib.size() >= 3) {
2345     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
2346     if (Dot == ".")
2347       Lib = Lib.slice(0, Lib.size()-2);
2348   }
2349   return Lib;
2350 
2351 guess_qtx:
2352   Qtx = Name.slice(a, Name.npos);
2353   if (Qtx != ".qtx")
2354     return StringRef();
2355   b = Name.rfind('/', a);
2356   if (b == Name.npos)
2357     Lib = Name.slice(0, a);
2358   else
2359     Lib = Name.slice(b+1, a);
2360   // There are library names of the form: QT.A.qtx so check for these.
2361   if (Lib.size() >= 3) {
2362     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
2363     if (Dot == ".")
2364       Lib = Lib.slice(0, Lib.size()-2);
2365   }
2366   return Lib;
2367 }
2368 
2369 // getLibraryShortNameByIndex() is used to get the short name of the library
2370 // for an undefined symbol in a linked Mach-O binary that was linked with the
2371 // normal two-level namespace default (that is MH_TWOLEVEL in the header).
2372 // It is passed the index (0 - based) of the library as translated from
2373 // GET_LIBRARY_ORDINAL (1 - based).
2374 std::error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
2375                                                          StringRef &Res) const {
2376   if (Index >= Libraries.size())
2377     return object_error::parse_failed;
2378 
2379   // If the cache of LibrariesShortNames is not built up do that first for
2380   // all the Libraries.
2381   if (LibrariesShortNames.size() == 0) {
2382     for (unsigned i = 0; i < Libraries.size(); i++) {
2383       MachO::dylib_command D =
2384         getStruct<MachO::dylib_command>(*this, Libraries[i]);
2385       if (D.dylib.name >= D.cmdsize)
2386         return object_error::parse_failed;
2387       const char *P = (const char *)(Libraries[i]) + D.dylib.name;
2388       StringRef Name = StringRef(P);
2389       if (D.dylib.name+Name.size() >= D.cmdsize)
2390         return object_error::parse_failed;
2391       StringRef Suffix;
2392       bool isFramework;
2393       StringRef shortName = guessLibraryShortName(Name, isFramework, Suffix);
2394       if (shortName.empty())
2395         LibrariesShortNames.push_back(Name);
2396       else
2397         LibrariesShortNames.push_back(shortName);
2398     }
2399   }
2400 
2401   Res = LibrariesShortNames[Index];
2402   return std::error_code();
2403 }
2404 
2405 uint32_t MachOObjectFile::getLibraryCount() const {
2406   return Libraries.size();
2407 }
2408 
2409 section_iterator
2410 MachOObjectFile::getRelocationRelocatedSection(relocation_iterator Rel) const {
2411   DataRefImpl Sec;
2412   Sec.d.a = Rel->getRawDataRefImpl().d.a;
2413   return section_iterator(SectionRef(Sec, this));
2414 }
2415 
2416 basic_symbol_iterator MachOObjectFile::symbol_begin() const {
2417   DataRefImpl DRI;
2418   MachO::symtab_command Symtab = getSymtabLoadCommand();
2419   if (!SymtabLoadCmd || Symtab.nsyms == 0)
2420     return basic_symbol_iterator(SymbolRef(DRI, this));
2421 
2422   return getSymbolByIndex(0);
2423 }
2424 
2425 basic_symbol_iterator MachOObjectFile::symbol_end() const {
2426   DataRefImpl DRI;
2427   MachO::symtab_command Symtab = getSymtabLoadCommand();
2428   if (!SymtabLoadCmd || Symtab.nsyms == 0)
2429     return basic_symbol_iterator(SymbolRef(DRI, this));
2430 
2431   unsigned SymbolTableEntrySize = is64Bit() ?
2432     sizeof(MachO::nlist_64) :
2433     sizeof(MachO::nlist);
2434   unsigned Offset = Symtab.symoff +
2435     Symtab.nsyms * SymbolTableEntrySize;
2436   DRI.p = reinterpret_cast<uintptr_t>(getPtr(*this, Offset));
2437   return basic_symbol_iterator(SymbolRef(DRI, this));
2438 }
2439 
2440 symbol_iterator MachOObjectFile::getSymbolByIndex(unsigned Index) const {
2441   MachO::symtab_command Symtab = getSymtabLoadCommand();
2442   if (!SymtabLoadCmd || Index >= Symtab.nsyms)
2443     report_fatal_error("Requested symbol index is out of range.");
2444   unsigned SymbolTableEntrySize =
2445     is64Bit() ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
2446   DataRefImpl DRI;
2447   DRI.p = reinterpret_cast<uintptr_t>(getPtr(*this, Symtab.symoff));
2448   DRI.p += Index * SymbolTableEntrySize;
2449   return basic_symbol_iterator(SymbolRef(DRI, this));
2450 }
2451 
2452 uint64_t MachOObjectFile::getSymbolIndex(DataRefImpl Symb) const {
2453   MachO::symtab_command Symtab = getSymtabLoadCommand();
2454   if (!SymtabLoadCmd)
2455     report_fatal_error("getSymbolIndex() called with no symbol table symbol");
2456   unsigned SymbolTableEntrySize =
2457     is64Bit() ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
2458   DataRefImpl DRIstart;
2459   DRIstart.p = reinterpret_cast<uintptr_t>(getPtr(*this, Symtab.symoff));
2460   uint64_t Index = (Symb.p - DRIstart.p) / SymbolTableEntrySize;
2461   return Index;
2462 }
2463 
2464 section_iterator MachOObjectFile::section_begin() const {
2465   DataRefImpl DRI;
2466   return section_iterator(SectionRef(DRI, this));
2467 }
2468 
2469 section_iterator MachOObjectFile::section_end() const {
2470   DataRefImpl DRI;
2471   DRI.d.a = Sections.size();
2472   return section_iterator(SectionRef(DRI, this));
2473 }
2474 
2475 uint8_t MachOObjectFile::getBytesInAddress() const {
2476   return is64Bit() ? 8 : 4;
2477 }
2478 
2479 StringRef MachOObjectFile::getFileFormatName() const {
2480   unsigned CPUType = getCPUType(*this);
2481   if (!is64Bit()) {
2482     switch (CPUType) {
2483     case MachO::CPU_TYPE_I386:
2484       return "Mach-O 32-bit i386";
2485     case MachO::CPU_TYPE_ARM:
2486       return "Mach-O arm";
2487     case MachO::CPU_TYPE_POWERPC:
2488       return "Mach-O 32-bit ppc";
2489     default:
2490       return "Mach-O 32-bit unknown";
2491     }
2492   }
2493 
2494   switch (CPUType) {
2495   case MachO::CPU_TYPE_X86_64:
2496     return "Mach-O 64-bit x86-64";
2497   case MachO::CPU_TYPE_ARM64:
2498     return "Mach-O arm64";
2499   case MachO::CPU_TYPE_POWERPC64:
2500     return "Mach-O 64-bit ppc64";
2501   default:
2502     return "Mach-O 64-bit unknown";
2503   }
2504 }
2505 
2506 Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType) {
2507   switch (CPUType) {
2508   case MachO::CPU_TYPE_I386:
2509     return Triple::x86;
2510   case MachO::CPU_TYPE_X86_64:
2511     return Triple::x86_64;
2512   case MachO::CPU_TYPE_ARM:
2513     return Triple::arm;
2514   case MachO::CPU_TYPE_ARM64:
2515     return Triple::aarch64;
2516   case MachO::CPU_TYPE_POWERPC:
2517     return Triple::ppc;
2518   case MachO::CPU_TYPE_POWERPC64:
2519     return Triple::ppc64;
2520   default:
2521     return Triple::UnknownArch;
2522   }
2523 }
2524 
2525 Triple MachOObjectFile::getArchTriple(uint32_t CPUType, uint32_t CPUSubType,
2526                                       const char **McpuDefault,
2527                                       const char **ArchFlag) {
2528   if (McpuDefault)
2529     *McpuDefault = nullptr;
2530   if (ArchFlag)
2531     *ArchFlag = nullptr;
2532 
2533   switch (CPUType) {
2534   case MachO::CPU_TYPE_I386:
2535     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2536     case MachO::CPU_SUBTYPE_I386_ALL:
2537       if (ArchFlag)
2538         *ArchFlag = "i386";
2539       return Triple("i386-apple-darwin");
2540     default:
2541       return Triple();
2542     }
2543   case MachO::CPU_TYPE_X86_64:
2544     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2545     case MachO::CPU_SUBTYPE_X86_64_ALL:
2546       if (ArchFlag)
2547         *ArchFlag = "x86_64";
2548       return Triple("x86_64-apple-darwin");
2549     case MachO::CPU_SUBTYPE_X86_64_H:
2550       if (ArchFlag)
2551         *ArchFlag = "x86_64h";
2552       return Triple("x86_64h-apple-darwin");
2553     default:
2554       return Triple();
2555     }
2556   case MachO::CPU_TYPE_ARM:
2557     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2558     case MachO::CPU_SUBTYPE_ARM_V4T:
2559       if (ArchFlag)
2560         *ArchFlag = "armv4t";
2561       return Triple("armv4t-apple-darwin");
2562     case MachO::CPU_SUBTYPE_ARM_V5TEJ:
2563       if (ArchFlag)
2564         *ArchFlag = "armv5e";
2565       return Triple("armv5e-apple-darwin");
2566     case MachO::CPU_SUBTYPE_ARM_XSCALE:
2567       if (ArchFlag)
2568         *ArchFlag = "xscale";
2569       return Triple("xscale-apple-darwin");
2570     case MachO::CPU_SUBTYPE_ARM_V6:
2571       if (ArchFlag)
2572         *ArchFlag = "armv6";
2573       return Triple("armv6-apple-darwin");
2574     case MachO::CPU_SUBTYPE_ARM_V6M:
2575       if (McpuDefault)
2576         *McpuDefault = "cortex-m0";
2577       if (ArchFlag)
2578         *ArchFlag = "armv6m";
2579       return Triple("armv6m-apple-darwin");
2580     case MachO::CPU_SUBTYPE_ARM_V7:
2581       if (ArchFlag)
2582         *ArchFlag = "armv7";
2583       return Triple("armv7-apple-darwin");
2584     case MachO::CPU_SUBTYPE_ARM_V7EM:
2585       if (McpuDefault)
2586         *McpuDefault = "cortex-m4";
2587       if (ArchFlag)
2588         *ArchFlag = "armv7em";
2589       return Triple("thumbv7em-apple-darwin");
2590     case MachO::CPU_SUBTYPE_ARM_V7K:
2591       if (McpuDefault)
2592         *McpuDefault = "cortex-a7";
2593       if (ArchFlag)
2594         *ArchFlag = "armv7k";
2595       return Triple("armv7k-apple-darwin");
2596     case MachO::CPU_SUBTYPE_ARM_V7M:
2597       if (McpuDefault)
2598         *McpuDefault = "cortex-m3";
2599       if (ArchFlag)
2600         *ArchFlag = "armv7m";
2601       return Triple("thumbv7m-apple-darwin");
2602     case MachO::CPU_SUBTYPE_ARM_V7S:
2603       if (McpuDefault)
2604         *McpuDefault = "cortex-a7";
2605       if (ArchFlag)
2606         *ArchFlag = "armv7s";
2607       return Triple("armv7s-apple-darwin");
2608     default:
2609       return Triple();
2610     }
2611   case MachO::CPU_TYPE_ARM64:
2612     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2613     case MachO::CPU_SUBTYPE_ARM64_ALL:
2614       if (McpuDefault)
2615         *McpuDefault = "cyclone";
2616       if (ArchFlag)
2617         *ArchFlag = "arm64";
2618       return Triple("arm64-apple-darwin");
2619     default:
2620       return Triple();
2621     }
2622   case MachO::CPU_TYPE_POWERPC:
2623     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2624     case MachO::CPU_SUBTYPE_POWERPC_ALL:
2625       if (ArchFlag)
2626         *ArchFlag = "ppc";
2627       return Triple("ppc-apple-darwin");
2628     default:
2629       return Triple();
2630     }
2631   case MachO::CPU_TYPE_POWERPC64:
2632     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2633     case MachO::CPU_SUBTYPE_POWERPC_ALL:
2634       if (ArchFlag)
2635         *ArchFlag = "ppc64";
2636       return Triple("ppc64-apple-darwin");
2637     default:
2638       return Triple();
2639     }
2640   default:
2641     return Triple();
2642   }
2643 }
2644 
2645 Triple MachOObjectFile::getHostArch() {
2646   return Triple(sys::getDefaultTargetTriple());
2647 }
2648 
2649 bool MachOObjectFile::isValidArch(StringRef ArchFlag) {
2650   return StringSwitch<bool>(ArchFlag)
2651       .Case("i386", true)
2652       .Case("x86_64", true)
2653       .Case("x86_64h", true)
2654       .Case("armv4t", true)
2655       .Case("arm", true)
2656       .Case("armv5e", true)
2657       .Case("armv6", true)
2658       .Case("armv6m", true)
2659       .Case("armv7", true)
2660       .Case("armv7em", true)
2661       .Case("armv7k", true)
2662       .Case("armv7m", true)
2663       .Case("armv7s", true)
2664       .Case("arm64", true)
2665       .Case("ppc", true)
2666       .Case("ppc64", true)
2667       .Default(false);
2668 }
2669 
2670 Triple::ArchType MachOObjectFile::getArch() const {
2671   return getArch(getCPUType(*this));
2672 }
2673 
2674 Triple MachOObjectFile::getArchTriple(const char **McpuDefault) const {
2675   return getArchTriple(Header.cputype, Header.cpusubtype, McpuDefault);
2676 }
2677 
2678 relocation_iterator MachOObjectFile::section_rel_begin(unsigned Index) const {
2679   DataRefImpl DRI;
2680   DRI.d.a = Index;
2681   return section_rel_begin(DRI);
2682 }
2683 
2684 relocation_iterator MachOObjectFile::section_rel_end(unsigned Index) const {
2685   DataRefImpl DRI;
2686   DRI.d.a = Index;
2687   return section_rel_end(DRI);
2688 }
2689 
2690 dice_iterator MachOObjectFile::begin_dices() const {
2691   DataRefImpl DRI;
2692   if (!DataInCodeLoadCmd)
2693     return dice_iterator(DiceRef(DRI, this));
2694 
2695   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
2696   DRI.p = reinterpret_cast<uintptr_t>(getPtr(*this, DicLC.dataoff));
2697   return dice_iterator(DiceRef(DRI, this));
2698 }
2699 
2700 dice_iterator MachOObjectFile::end_dices() const {
2701   DataRefImpl DRI;
2702   if (!DataInCodeLoadCmd)
2703     return dice_iterator(DiceRef(DRI, this));
2704 
2705   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
2706   unsigned Offset = DicLC.dataoff + DicLC.datasize;
2707   DRI.p = reinterpret_cast<uintptr_t>(getPtr(*this, Offset));
2708   return dice_iterator(DiceRef(DRI, this));
2709 }
2710 
2711 ExportEntry::ExportEntry(Error *E, const MachOObjectFile *O,
2712                          ArrayRef<uint8_t> T) : E(E), O(O), Trie(T) {}
2713 
2714 void ExportEntry::moveToFirst() {
2715   ErrorAsOutParameter ErrAsOutParam(E);
2716   pushNode(0);
2717   if (*E)
2718     return;
2719   pushDownUntilBottom();
2720 }
2721 
2722 void ExportEntry::moveToEnd() {
2723   Stack.clear();
2724   Done = true;
2725 }
2726 
2727 bool ExportEntry::operator==(const ExportEntry &Other) const {
2728   // Common case, one at end, other iterating from begin.
2729   if (Done || Other.Done)
2730     return (Done == Other.Done);
2731   // Not equal if different stack sizes.
2732   if (Stack.size() != Other.Stack.size())
2733     return false;
2734   // Not equal if different cumulative strings.
2735   if (!CumulativeString.equals(Other.CumulativeString))
2736     return false;
2737   // Equal if all nodes in both stacks match.
2738   for (unsigned i=0; i < Stack.size(); ++i) {
2739     if (Stack[i].Start != Other.Stack[i].Start)
2740       return false;
2741   }
2742   return true;
2743 }
2744 
2745 uint64_t ExportEntry::readULEB128(const uint8_t *&Ptr, const char **error) {
2746   unsigned Count;
2747   uint64_t Result = decodeULEB128(Ptr, &Count, Trie.end(), error);
2748   Ptr += Count;
2749   if (Ptr > Trie.end())
2750     Ptr = Trie.end();
2751   return Result;
2752 }
2753 
2754 StringRef ExportEntry::name() const {
2755   return CumulativeString;
2756 }
2757 
2758 uint64_t ExportEntry::flags() const {
2759   return Stack.back().Flags;
2760 }
2761 
2762 uint64_t ExportEntry::address() const {
2763   return Stack.back().Address;
2764 }
2765 
2766 uint64_t ExportEntry::other() const {
2767   return Stack.back().Other;
2768 }
2769 
2770 StringRef ExportEntry::otherName() const {
2771   const char* ImportName = Stack.back().ImportName;
2772   if (ImportName)
2773     return StringRef(ImportName);
2774   return StringRef();
2775 }
2776 
2777 uint32_t ExportEntry::nodeOffset() const {
2778   return Stack.back().Start - Trie.begin();
2779 }
2780 
2781 ExportEntry::NodeState::NodeState(const uint8_t *Ptr)
2782     : Start(Ptr), Current(Ptr) {}
2783 
2784 void ExportEntry::pushNode(uint64_t offset) {
2785   ErrorAsOutParameter ErrAsOutParam(E);
2786   const uint8_t *Ptr = Trie.begin() + offset;
2787   NodeState State(Ptr);
2788   const char *error;
2789   uint64_t ExportInfoSize = readULEB128(State.Current, &error);
2790   if (error) {
2791     *E = malformedError("export info size " + Twine(error) +
2792                         " in export trie data at node: 0x" +
2793                         Twine::utohexstr(offset));
2794     moveToEnd();
2795     return;
2796   }
2797   State.IsExportNode = (ExportInfoSize != 0);
2798   const uint8_t* Children = State.Current + ExportInfoSize;
2799   if (Children > Trie.end()) {
2800     *E = malformedError(
2801         "export info size: 0x" + Twine::utohexstr(ExportInfoSize) +
2802         " in export trie data at node: 0x" + Twine::utohexstr(offset) +
2803         " too big and extends past end of trie data");
2804     moveToEnd();
2805     return;
2806   }
2807   if (State.IsExportNode) {
2808     const uint8_t *ExportStart = State.Current;
2809     State.Flags = readULEB128(State.Current, &error);
2810     if (error) {
2811       *E = malformedError("flags " + Twine(error) +
2812                           " in export trie data at node: 0x" +
2813                           Twine::utohexstr(offset));
2814       moveToEnd();
2815       return;
2816     }
2817     uint64_t Kind = State.Flags & MachO::EXPORT_SYMBOL_FLAGS_KIND_MASK;
2818     if (State.Flags != 0 &&
2819         (Kind != MachO::EXPORT_SYMBOL_FLAGS_KIND_REGULAR &&
2820          Kind != MachO::EXPORT_SYMBOL_FLAGS_KIND_ABSOLUTE &&
2821          Kind != MachO::EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL)) {
2822       *E = malformedError(
2823           "unsupported exported symbol kind: " + Twine((int)Kind) +
2824           " in flags: 0x" + Twine::utohexstr(State.Flags) +
2825           " in export trie data at node: 0x" + Twine::utohexstr(offset));
2826       moveToEnd();
2827       return;
2828     }
2829     if (State.Flags & MachO::EXPORT_SYMBOL_FLAGS_REEXPORT) {
2830       State.Address = 0;
2831       State.Other = readULEB128(State.Current, &error); // dylib ordinal
2832       if (error) {
2833         *E = malformedError("dylib ordinal of re-export " + Twine(error) +
2834                             " in export trie data at node: 0x" +
2835                             Twine::utohexstr(offset));
2836         moveToEnd();
2837         return;
2838       }
2839       if (O != nullptr) {
2840         if (State.Other > O->getLibraryCount()) {
2841           *E = malformedError(
2842               "bad library ordinal: " + Twine((int)State.Other) + " (max " +
2843               Twine((int)O->getLibraryCount()) +
2844               ") in export trie data at node: 0x" + Twine::utohexstr(offset));
2845           moveToEnd();
2846           return;
2847         }
2848       }
2849       State.ImportName = reinterpret_cast<const char*>(State.Current);
2850       if (*State.ImportName == '\0') {
2851         State.Current++;
2852       } else {
2853         const uint8_t *End = State.Current + 1;
2854         if (End >= Trie.end()) {
2855           *E = malformedError("import name of re-export in export trie data at "
2856                               "node: 0x" +
2857                               Twine::utohexstr(offset) +
2858                               " starts past end of trie data");
2859           moveToEnd();
2860           return;
2861         }
2862         while(*End != '\0' && End < Trie.end())
2863           End++;
2864         if (*End != '\0') {
2865           *E = malformedError("import name of re-export in export trie data at "
2866                               "node: 0x" +
2867                               Twine::utohexstr(offset) +
2868                               " extends past end of trie data");
2869           moveToEnd();
2870           return;
2871         }
2872         State.Current = End + 1;
2873       }
2874     } else {
2875       State.Address = readULEB128(State.Current, &error);
2876       if (error) {
2877         *E = malformedError("address " + Twine(error) +
2878                             " in export trie data at node: 0x" +
2879                             Twine::utohexstr(offset));
2880         moveToEnd();
2881         return;
2882       }
2883       if (State.Flags & MachO::EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER) {
2884         State.Other = readULEB128(State.Current, &error);
2885         if (error) {
2886           *E = malformedError("resolver of stub and resolver " + Twine(error) +
2887                               " in export trie data at node: 0x" +
2888                               Twine::utohexstr(offset));
2889           moveToEnd();
2890           return;
2891         }
2892       }
2893     }
2894     if(ExportStart + ExportInfoSize != State.Current) {
2895       *E = malformedError(
2896           "inconsistant export info size: 0x" +
2897           Twine::utohexstr(ExportInfoSize) + " where actual size was: 0x" +
2898           Twine::utohexstr(State.Current - ExportStart) +
2899           " in export trie data at node: 0x" + Twine::utohexstr(offset));
2900       moveToEnd();
2901       return;
2902     }
2903   }
2904   State.ChildCount = *Children;
2905   if (State.ChildCount != 0 && Children + 1 >= Trie.end()) {
2906     *E = malformedError("byte for count of childern in export trie data at "
2907                         "node: 0x" +
2908                         Twine::utohexstr(offset) +
2909                         " extends past end of trie data");
2910     moveToEnd();
2911     return;
2912   }
2913   State.Current = Children + 1;
2914   State.NextChildIndex = 0;
2915   State.ParentStringLength = CumulativeString.size();
2916   Stack.push_back(State);
2917 }
2918 
2919 void ExportEntry::pushDownUntilBottom() {
2920   ErrorAsOutParameter ErrAsOutParam(E);
2921   const char *error;
2922   while (Stack.back().NextChildIndex < Stack.back().ChildCount) {
2923     NodeState &Top = Stack.back();
2924     CumulativeString.resize(Top.ParentStringLength);
2925     for (;*Top.Current != 0 && Top.Current < Trie.end(); Top.Current++) {
2926       char C = *Top.Current;
2927       CumulativeString.push_back(C);
2928     }
2929     if (Top.Current >= Trie.end()) {
2930       *E = malformedError("edge sub-string in export trie data at node: 0x" +
2931                           Twine::utohexstr(Top.Start - Trie.begin()) +
2932                           " for child #" + Twine((int)Top.NextChildIndex) +
2933                           " extends past end of trie data");
2934       moveToEnd();
2935       return;
2936     }
2937     Top.Current += 1;
2938     uint64_t childNodeIndex = readULEB128(Top.Current, &error);
2939     if (error) {
2940       *E = malformedError("child node offset " + Twine(error) +
2941                           " in export trie data at node: 0x" +
2942                           Twine::utohexstr(Top.Start - Trie.begin()));
2943       moveToEnd();
2944       return;
2945     }
2946     for (const NodeState &node : nodes()) {
2947       if (node.Start == Trie.begin() + childNodeIndex){
2948         *E = malformedError("loop in childern in export trie data at node: 0x" +
2949                             Twine::utohexstr(Top.Start - Trie.begin()) +
2950                             " back to node: 0x" +
2951                             Twine::utohexstr(childNodeIndex));
2952         moveToEnd();
2953         return;
2954       }
2955     }
2956     Top.NextChildIndex += 1;
2957     pushNode(childNodeIndex);
2958     if (*E)
2959       return;
2960   }
2961   if (!Stack.back().IsExportNode) {
2962     *E = malformedError("node is not an export node in export trie data at "
2963                         "node: 0x" +
2964                         Twine::utohexstr(Stack.back().Start - Trie.begin()));
2965     moveToEnd();
2966     return;
2967   }
2968 }
2969 
2970 // We have a trie data structure and need a way to walk it that is compatible
2971 // with the C++ iterator model. The solution is a non-recursive depth first
2972 // traversal where the iterator contains a stack of parent nodes along with a
2973 // string that is the accumulation of all edge strings along the parent chain
2974 // to this point.
2975 //
2976 // There is one "export" node for each exported symbol.  But because some
2977 // symbols may be a prefix of another symbol (e.g. _dup and _dup2), an export
2978 // node may have child nodes too.
2979 //
2980 // The algorithm for moveNext() is to keep moving down the leftmost unvisited
2981 // child until hitting a node with no children (which is an export node or
2982 // else the trie is malformed). On the way down, each node is pushed on the
2983 // stack ivar.  If there is no more ways down, it pops up one and tries to go
2984 // down a sibling path until a childless node is reached.
2985 void ExportEntry::moveNext() {
2986   assert(!Stack.empty() && "ExportEntry::moveNext() with empty node stack");
2987   if (!Stack.back().IsExportNode) {
2988     *E = malformedError("node is not an export node in export trie data at "
2989                         "node: 0x" +
2990                         Twine::utohexstr(Stack.back().Start - Trie.begin()));
2991     moveToEnd();
2992     return;
2993   }
2994 
2995   Stack.pop_back();
2996   while (!Stack.empty()) {
2997     NodeState &Top = Stack.back();
2998     if (Top.NextChildIndex < Top.ChildCount) {
2999       pushDownUntilBottom();
3000       // Now at the next export node.
3001       return;
3002     } else {
3003       if (Top.IsExportNode) {
3004         // This node has no children but is itself an export node.
3005         CumulativeString.resize(Top.ParentStringLength);
3006         return;
3007       }
3008       Stack.pop_back();
3009     }
3010   }
3011   Done = true;
3012 }
3013 
3014 iterator_range<export_iterator>
3015 MachOObjectFile::exports(Error &E, ArrayRef<uint8_t> Trie,
3016                          const MachOObjectFile *O) {
3017   ExportEntry Start(&E, O, Trie);
3018   if (Trie.empty())
3019     Start.moveToEnd();
3020   else
3021     Start.moveToFirst();
3022 
3023   ExportEntry Finish(&E, O, Trie);
3024   Finish.moveToEnd();
3025 
3026   return make_range(export_iterator(Start), export_iterator(Finish));
3027 }
3028 
3029 iterator_range<export_iterator> MachOObjectFile::exports(Error &Err) const {
3030   return exports(Err, getDyldInfoExportsTrie(), this);
3031 }
3032 
3033 MachORebaseEntry::MachORebaseEntry(Error *E, const MachOObjectFile *O,
3034                                    ArrayRef<uint8_t> Bytes, bool is64Bit)
3035     : E(E), O(O), Opcodes(Bytes), Ptr(Bytes.begin()),
3036       PointerSize(is64Bit ? 8 : 4) {}
3037 
3038 void MachORebaseEntry::moveToFirst() {
3039   Ptr = Opcodes.begin();
3040   moveNext();
3041 }
3042 
3043 void MachORebaseEntry::moveToEnd() {
3044   Ptr = Opcodes.end();
3045   RemainingLoopCount = 0;
3046   Done = true;
3047 }
3048 
3049 void MachORebaseEntry::moveNext() {
3050   ErrorAsOutParameter ErrAsOutParam(E);
3051   // If in the middle of some loop, move to next rebasing in loop.
3052   SegmentOffset += AdvanceAmount;
3053   if (RemainingLoopCount) {
3054     --RemainingLoopCount;
3055     return;
3056   }
3057   // REBASE_OPCODE_DONE is only used for padding if we are not aligned to
3058   // pointer size. Therefore it is possible to reach the end without ever having
3059   // seen REBASE_OPCODE_DONE.
3060   if (Ptr == Opcodes.end()) {
3061     Done = true;
3062     return;
3063   }
3064   bool More = true;
3065   while (More) {
3066     // Parse next opcode and set up next loop.
3067     const uint8_t *OpcodeStart = Ptr;
3068     uint8_t Byte = *Ptr++;
3069     uint8_t ImmValue = Byte & MachO::REBASE_IMMEDIATE_MASK;
3070     uint8_t Opcode = Byte & MachO::REBASE_OPCODE_MASK;
3071     uint32_t Count, Skip;
3072     const char *error = nullptr;
3073     switch (Opcode) {
3074     case MachO::REBASE_OPCODE_DONE:
3075       More = false;
3076       Done = true;
3077       moveToEnd();
3078       DEBUG_WITH_TYPE("mach-o-rebase", dbgs() << "REBASE_OPCODE_DONE\n");
3079       break;
3080     case MachO::REBASE_OPCODE_SET_TYPE_IMM:
3081       RebaseType = ImmValue;
3082       if (RebaseType > MachO::REBASE_TYPE_TEXT_PCREL32) {
3083         *E = malformedError("for REBASE_OPCODE_SET_TYPE_IMM bad bind type: " +
3084                             Twine((int)RebaseType) + " for opcode at: 0x" +
3085                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3086         moveToEnd();
3087         return;
3088       }
3089       DEBUG_WITH_TYPE(
3090           "mach-o-rebase",
3091           dbgs() << "REBASE_OPCODE_SET_TYPE_IMM: "
3092                  << "RebaseType=" << (int) RebaseType << "\n");
3093       break;
3094     case MachO::REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
3095       SegmentIndex = ImmValue;
3096       SegmentOffset = readULEB128(&error);
3097       if (error) {
3098         *E = malformedError("for REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB " +
3099                             Twine(error) + " for opcode at: 0x" +
3100                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3101         moveToEnd();
3102         return;
3103       }
3104       error = O->RebaseEntryCheckSegAndOffset(SegmentIndex, SegmentOffset,
3105                                               true);
3106       if (error) {
3107         *E = malformedError("for REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB " +
3108                             Twine(error) + " for opcode at: 0x" +
3109                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3110         moveToEnd();
3111         return;
3112       }
3113       DEBUG_WITH_TYPE(
3114           "mach-o-rebase",
3115           dbgs() << "REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: "
3116                  << "SegmentIndex=" << SegmentIndex << ", "
3117                  << format("SegmentOffset=0x%06X", SegmentOffset)
3118                  << "\n");
3119       break;
3120     case MachO::REBASE_OPCODE_ADD_ADDR_ULEB:
3121       SegmentOffset += readULEB128(&error);
3122       if (error) {
3123         *E = malformedError("for REBASE_OPCODE_ADD_ADDR_ULEB " + Twine(error) +
3124                             " for opcode at: 0x" +
3125                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3126         moveToEnd();
3127         return;
3128       }
3129       error = O->RebaseEntryCheckSegAndOffset(SegmentIndex, SegmentOffset,
3130                                               true);
3131       if (error) {
3132         *E = malformedError("for REBASE_OPCODE_ADD_ADDR_ULEB " + Twine(error) +
3133                             " for opcode at: 0x" +
3134                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3135         moveToEnd();
3136         return;
3137       }
3138       DEBUG_WITH_TYPE("mach-o-rebase",
3139                       dbgs() << "REBASE_OPCODE_ADD_ADDR_ULEB: "
3140                              << format("SegmentOffset=0x%06X",
3141                                        SegmentOffset) << "\n");
3142       break;
3143     case MachO::REBASE_OPCODE_ADD_ADDR_IMM_SCALED:
3144       error = O->RebaseEntryCheckSegAndOffset(SegmentIndex, SegmentOffset,
3145                                               true);
3146       if (error) {
3147         *E = malformedError("for REBASE_OPCODE_ADD_ADDR_IMM_SCALED " +
3148                             Twine(error) + " for opcode at: 0x" +
3149                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3150         moveToEnd();
3151         return;
3152       }
3153       SegmentOffset += ImmValue * PointerSize;
3154       error = O->RebaseEntryCheckSegAndOffset(SegmentIndex, SegmentOffset,
3155                                               false);
3156       if (error) {
3157         *E =
3158             malformedError("for REBASE_OPCODE_ADD_ADDR_IMM_SCALED "
3159                            " (after adding immediate times the pointer size) " +
3160                            Twine(error) + " for opcode at: 0x" +
3161                            Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3162         moveToEnd();
3163         return;
3164       }
3165       DEBUG_WITH_TYPE("mach-o-rebase",
3166                       dbgs() << "REBASE_OPCODE_ADD_ADDR_IMM_SCALED: "
3167                              << format("SegmentOffset=0x%06X",
3168                                        SegmentOffset) << "\n");
3169       break;
3170     case MachO::REBASE_OPCODE_DO_REBASE_IMM_TIMES:
3171       error = O->RebaseEntryCheckSegAndOffset(SegmentIndex, SegmentOffset,
3172                                               true);
3173       if (error) {
3174         *E = malformedError("for REBASE_OPCODE_DO_REBASE_IMM_TIMES " +
3175                             Twine(error) + " for opcode at: 0x" +
3176                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3177         moveToEnd();
3178         return;
3179       }
3180       AdvanceAmount = PointerSize;
3181       Skip = 0;
3182       Count = ImmValue;
3183       if (ImmValue != 0)
3184         RemainingLoopCount = ImmValue - 1;
3185       else
3186         RemainingLoopCount = 0;
3187       error = O->RebaseEntryCheckCountAndSkip(Count, Skip, PointerSize,
3188                                               SegmentIndex, SegmentOffset);
3189       if (error) {
3190         *E = malformedError("for REBASE_OPCODE_DO_REBASE_IMM_TIMES " +
3191                             Twine(error) + " for opcode at: 0x" +
3192                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3193         moveToEnd();
3194         return;
3195       }
3196       DEBUG_WITH_TYPE(
3197           "mach-o-rebase",
3198           dbgs() << "REBASE_OPCODE_DO_REBASE_IMM_TIMES: "
3199                  << format("SegmentOffset=0x%06X", SegmentOffset)
3200                  << ", AdvanceAmount=" << AdvanceAmount
3201                  << ", RemainingLoopCount=" << RemainingLoopCount
3202                  << "\n");
3203       return;
3204     case MachO::REBASE_OPCODE_DO_REBASE_ULEB_TIMES:
3205       error = O->RebaseEntryCheckSegAndOffset(SegmentIndex, SegmentOffset,
3206                                               true);
3207       if (error) {
3208         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES " +
3209                             Twine(error) + " for opcode at: 0x" +
3210                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3211         moveToEnd();
3212         return;
3213       }
3214       AdvanceAmount = PointerSize;
3215       Skip = 0;
3216       Count = readULEB128(&error);
3217       if (error) {
3218         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES " +
3219                             Twine(error) + " for opcode at: 0x" +
3220                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3221         moveToEnd();
3222         return;
3223       }
3224       if (Count != 0)
3225         RemainingLoopCount = Count - 1;
3226       else
3227         RemainingLoopCount = 0;
3228       error = O->RebaseEntryCheckCountAndSkip(Count, Skip, PointerSize,
3229                                               SegmentIndex, SegmentOffset);
3230       if (error) {
3231         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES " +
3232                             Twine(error) + " for opcode at: 0x" +
3233                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3234         moveToEnd();
3235         return;
3236       }
3237       DEBUG_WITH_TYPE(
3238           "mach-o-rebase",
3239           dbgs() << "REBASE_OPCODE_DO_REBASE_ULEB_TIMES: "
3240                  << format("SegmentOffset=0x%06X", SegmentOffset)
3241                  << ", AdvanceAmount=" << AdvanceAmount
3242                  << ", RemainingLoopCount=" << RemainingLoopCount
3243                  << "\n");
3244       return;
3245     case MachO::REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB:
3246       error = O->RebaseEntryCheckSegAndOffset(SegmentIndex, SegmentOffset,
3247                                               true);
3248       if (error) {
3249         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB " +
3250                             Twine(error) + " for opcode at: 0x" +
3251                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3252         moveToEnd();
3253         return;
3254       }
3255       Skip = readULEB128(&error);
3256       if (error) {
3257         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB " +
3258                             Twine(error) + " for opcode at: 0x" +
3259                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3260         moveToEnd();
3261         return;
3262       }
3263       AdvanceAmount = Skip + PointerSize;
3264       Count = 1;
3265       RemainingLoopCount = 0;
3266       error = O->RebaseEntryCheckCountAndSkip(Count, Skip, PointerSize,
3267                                               SegmentIndex, SegmentOffset);
3268       if (error) {
3269         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB " +
3270                             Twine(error) + " for opcode at: 0x" +
3271                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3272         moveToEnd();
3273         return;
3274       }
3275       DEBUG_WITH_TYPE(
3276           "mach-o-rebase",
3277           dbgs() << "REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB: "
3278                  << format("SegmentOffset=0x%06X", SegmentOffset)
3279                  << ", AdvanceAmount=" << AdvanceAmount
3280                  << ", RemainingLoopCount=" << RemainingLoopCount
3281                  << "\n");
3282       return;
3283     case MachO::REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB:
3284       error = O->RebaseEntryCheckSegAndOffset(SegmentIndex, SegmentOffset,
3285                                               true);
3286       if (error) {
3287         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_"
3288                             "ULEB " +
3289                             Twine(error) + " for opcode at: 0x" +
3290                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3291         moveToEnd();
3292         return;
3293       }
3294       Count = readULEB128(&error);
3295       if (error) {
3296         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_"
3297                             "ULEB " +
3298                             Twine(error) + " for opcode at: 0x" +
3299                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3300         moveToEnd();
3301         return;
3302       }
3303       if (Count != 0)
3304         RemainingLoopCount = Count - 1;
3305       else
3306         RemainingLoopCount = 0;
3307       Skip = readULEB128(&error);
3308       if (error) {
3309         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_"
3310                             "ULEB " +
3311                             Twine(error) + " for opcode at: 0x" +
3312                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3313         moveToEnd();
3314         return;
3315       }
3316       AdvanceAmount = Skip + PointerSize;
3317 
3318       error = O->RebaseEntryCheckCountAndSkip(Count, Skip, PointerSize,
3319                                               SegmentIndex, SegmentOffset);
3320       if (error) {
3321         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_"
3322                             "ULEB " +
3323                             Twine(error) + " for opcode at: 0x" +
3324                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3325         moveToEnd();
3326         return;
3327       }
3328       DEBUG_WITH_TYPE(
3329           "mach-o-rebase",
3330           dbgs() << "REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB: "
3331                  << format("SegmentOffset=0x%06X", SegmentOffset)
3332                  << ", AdvanceAmount=" << AdvanceAmount
3333                  << ", RemainingLoopCount=" << RemainingLoopCount
3334                  << "\n");
3335       return;
3336     default:
3337       *E = malformedError("bad rebase info (bad opcode value 0x" +
3338                           Twine::utohexstr(Opcode) + " for opcode at: 0x" +
3339                           Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3340       moveToEnd();
3341       return;
3342     }
3343   }
3344 }
3345 
3346 uint64_t MachORebaseEntry::readULEB128(const char **error) {
3347   unsigned Count;
3348   uint64_t Result = decodeULEB128(Ptr, &Count, Opcodes.end(), error);
3349   Ptr += Count;
3350   if (Ptr > Opcodes.end())
3351     Ptr = Opcodes.end();
3352   return Result;
3353 }
3354 
3355 int32_t MachORebaseEntry::segmentIndex() const { return SegmentIndex; }
3356 
3357 uint64_t MachORebaseEntry::segmentOffset() const { return SegmentOffset; }
3358 
3359 StringRef MachORebaseEntry::typeName() const {
3360   switch (RebaseType) {
3361   case MachO::REBASE_TYPE_POINTER:
3362     return "pointer";
3363   case MachO::REBASE_TYPE_TEXT_ABSOLUTE32:
3364     return "text abs32";
3365   case MachO::REBASE_TYPE_TEXT_PCREL32:
3366     return "text rel32";
3367   }
3368   return "unknown";
3369 }
3370 
3371 // For use with the SegIndex of a checked Mach-O Rebase entry
3372 // to get the segment name.
3373 StringRef MachORebaseEntry::segmentName() const {
3374   return O->BindRebaseSegmentName(SegmentIndex);
3375 }
3376 
3377 // For use with a SegIndex,SegOffset pair from a checked Mach-O Rebase entry
3378 // to get the section name.
3379 StringRef MachORebaseEntry::sectionName() const {
3380   return O->BindRebaseSectionName(SegmentIndex, SegmentOffset);
3381 }
3382 
3383 // For use with a SegIndex,SegOffset pair from a checked Mach-O Rebase entry
3384 // to get the address.
3385 uint64_t MachORebaseEntry::address() const {
3386   return O->BindRebaseAddress(SegmentIndex, SegmentOffset);
3387 }
3388 
3389 bool MachORebaseEntry::operator==(const MachORebaseEntry &Other) const {
3390 #ifdef EXPENSIVE_CHECKS
3391   assert(Opcodes == Other.Opcodes && "compare iterators of different files");
3392 #else
3393   assert(Opcodes.data() == Other.Opcodes.data() && "compare iterators of different files");
3394 #endif
3395   return (Ptr == Other.Ptr) &&
3396          (RemainingLoopCount == Other.RemainingLoopCount) &&
3397          (Done == Other.Done);
3398 }
3399 
3400 iterator_range<rebase_iterator>
3401 MachOObjectFile::rebaseTable(Error &Err, MachOObjectFile *O,
3402                              ArrayRef<uint8_t> Opcodes, bool is64) {
3403   if (O->BindRebaseSectionTable == nullptr)
3404     O->BindRebaseSectionTable = llvm::make_unique<BindRebaseSegInfo>(O);
3405   MachORebaseEntry Start(&Err, O, Opcodes, is64);
3406   Start.moveToFirst();
3407 
3408   MachORebaseEntry Finish(&Err, O, Opcodes, is64);
3409   Finish.moveToEnd();
3410 
3411   return make_range(rebase_iterator(Start), rebase_iterator(Finish));
3412 }
3413 
3414 iterator_range<rebase_iterator> MachOObjectFile::rebaseTable(Error &Err) {
3415   return rebaseTable(Err, this, getDyldInfoRebaseOpcodes(), is64Bit());
3416 }
3417 
3418 MachOBindEntry::MachOBindEntry(Error *E, const MachOObjectFile *O,
3419                                ArrayRef<uint8_t> Bytes, bool is64Bit, Kind BK)
3420     : E(E), O(O), Opcodes(Bytes), Ptr(Bytes.begin()),
3421       PointerSize(is64Bit ? 8 : 4), TableKind(BK) {}
3422 
3423 void MachOBindEntry::moveToFirst() {
3424   Ptr = Opcodes.begin();
3425   moveNext();
3426 }
3427 
3428 void MachOBindEntry::moveToEnd() {
3429   Ptr = Opcodes.end();
3430   RemainingLoopCount = 0;
3431   Done = true;
3432 }
3433 
3434 void MachOBindEntry::moveNext() {
3435   ErrorAsOutParameter ErrAsOutParam(E);
3436   // If in the middle of some loop, move to next binding in loop.
3437   SegmentOffset += AdvanceAmount;
3438   if (RemainingLoopCount) {
3439     --RemainingLoopCount;
3440     return;
3441   }
3442   // BIND_OPCODE_DONE is only used for padding if we are not aligned to
3443   // pointer size. Therefore it is possible to reach the end without ever having
3444   // seen BIND_OPCODE_DONE.
3445   if (Ptr == Opcodes.end()) {
3446     Done = true;
3447     return;
3448   }
3449   bool More = true;
3450   while (More) {
3451     // Parse next opcode and set up next loop.
3452     const uint8_t *OpcodeStart = Ptr;
3453     uint8_t Byte = *Ptr++;
3454     uint8_t ImmValue = Byte & MachO::BIND_IMMEDIATE_MASK;
3455     uint8_t Opcode = Byte & MachO::BIND_OPCODE_MASK;
3456     int8_t SignExtended;
3457     const uint8_t *SymStart;
3458     uint32_t Count, Skip;
3459     const char *error = nullptr;
3460     switch (Opcode) {
3461     case MachO::BIND_OPCODE_DONE:
3462       if (TableKind == Kind::Lazy) {
3463         // Lazying bindings have a DONE opcode between entries.  Need to ignore
3464         // it to advance to next entry.  But need not if this is last entry.
3465         bool NotLastEntry = false;
3466         for (const uint8_t *P = Ptr; P < Opcodes.end(); ++P) {
3467           if (*P) {
3468             NotLastEntry = true;
3469           }
3470         }
3471         if (NotLastEntry)
3472           break;
3473       }
3474       More = false;
3475       moveToEnd();
3476       DEBUG_WITH_TYPE("mach-o-bind", dbgs() << "BIND_OPCODE_DONE\n");
3477       break;
3478     case MachO::BIND_OPCODE_SET_DYLIB_ORDINAL_IMM:
3479       if (TableKind == Kind::Weak) {
3480         *E = malformedError("BIND_OPCODE_SET_DYLIB_ORDINAL_IMM not allowed in "
3481                             "weak bind table for opcode at: 0x" +
3482                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3483         moveToEnd();
3484         return;
3485       }
3486       Ordinal = ImmValue;
3487       LibraryOrdinalSet = true;
3488       if (ImmValue > O->getLibraryCount()) {
3489         *E = malformedError("for BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB bad "
3490                             "library ordinal: " +
3491                             Twine((int)ImmValue) + " (max " +
3492                             Twine((int)O->getLibraryCount()) +
3493                             ") for opcode at: 0x" +
3494                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3495         moveToEnd();
3496         return;
3497       }
3498       DEBUG_WITH_TYPE(
3499           "mach-o-bind",
3500           dbgs() << "BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: "
3501                  << "Ordinal=" << Ordinal << "\n");
3502       break;
3503     case MachO::BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:
3504       if (TableKind == Kind::Weak) {
3505         *E = malformedError("BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB not allowed in "
3506                             "weak bind table for opcode at: 0x" +
3507                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3508         moveToEnd();
3509         return;
3510       }
3511       Ordinal = readULEB128(&error);
3512       LibraryOrdinalSet = true;
3513       if (error) {
3514         *E = malformedError("for BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB " +
3515                             Twine(error) + " for opcode at: 0x" +
3516                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3517         moveToEnd();
3518         return;
3519       }
3520       if (Ordinal > (int)O->getLibraryCount()) {
3521         *E = malformedError("for BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB bad "
3522                             "library ordinal: " +
3523                             Twine((int)Ordinal) + " (max " +
3524                             Twine((int)O->getLibraryCount()) +
3525                             ") for opcode at: 0x" +
3526                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3527         moveToEnd();
3528         return;
3529       }
3530       DEBUG_WITH_TYPE(
3531           "mach-o-bind",
3532           dbgs() << "BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: "
3533                  << "Ordinal=" << Ordinal << "\n");
3534       break;
3535     case MachO::BIND_OPCODE_SET_DYLIB_SPECIAL_IMM:
3536       if (TableKind == Kind::Weak) {
3537         *E = malformedError("BIND_OPCODE_SET_DYLIB_SPECIAL_IMM not allowed in "
3538                             "weak bind table for opcode at: 0x" +
3539                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3540         moveToEnd();
3541         return;
3542       }
3543       if (ImmValue) {
3544         SignExtended = MachO::BIND_OPCODE_MASK | ImmValue;
3545         Ordinal = SignExtended;
3546         if (Ordinal < MachO::BIND_SPECIAL_DYLIB_FLAT_LOOKUP) {
3547           *E = malformedError("for BIND_OPCODE_SET_DYLIB_SPECIAL_IMM unknown "
3548                               "special ordinal: " +
3549                               Twine((int)Ordinal) + " for opcode at: 0x" +
3550                               Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3551           moveToEnd();
3552           return;
3553         }
3554       } else
3555         Ordinal = 0;
3556       LibraryOrdinalSet = true;
3557       DEBUG_WITH_TYPE(
3558           "mach-o-bind",
3559           dbgs() << "BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: "
3560                  << "Ordinal=" << Ordinal << "\n");
3561       break;
3562     case MachO::BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
3563       Flags = ImmValue;
3564       SymStart = Ptr;
3565       while (*Ptr && (Ptr < Opcodes.end())) {
3566         ++Ptr;
3567       }
3568       if (Ptr == Opcodes.end()) {
3569         *E = malformedError(
3570             "for BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM "
3571             "symbol name extends past opcodes for opcode at: 0x" +
3572             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3573         moveToEnd();
3574         return;
3575       }
3576       SymbolName = StringRef(reinterpret_cast<const char*>(SymStart),
3577                              Ptr-SymStart);
3578       ++Ptr;
3579       DEBUG_WITH_TYPE(
3580           "mach-o-bind",
3581           dbgs() << "BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: "
3582                  << "SymbolName=" << SymbolName << "\n");
3583       if (TableKind == Kind::Weak) {
3584         if (ImmValue & MachO::BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION)
3585           return;
3586       }
3587       break;
3588     case MachO::BIND_OPCODE_SET_TYPE_IMM:
3589       BindType = ImmValue;
3590       if (ImmValue > MachO::BIND_TYPE_TEXT_PCREL32) {
3591         *E = malformedError("for BIND_OPCODE_SET_TYPE_IMM bad bind type: " +
3592                             Twine((int)ImmValue) + " for opcode at: 0x" +
3593                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3594         moveToEnd();
3595         return;
3596       }
3597       DEBUG_WITH_TYPE(
3598           "mach-o-bind",
3599           dbgs() << "BIND_OPCODE_SET_TYPE_IMM: "
3600                  << "BindType=" << (int)BindType << "\n");
3601       break;
3602     case MachO::BIND_OPCODE_SET_ADDEND_SLEB:
3603       Addend = readSLEB128(&error);
3604       if (error) {
3605         *E = malformedError("for BIND_OPCODE_SET_ADDEND_SLEB " + Twine(error) +
3606                             " for opcode at: 0x" +
3607                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3608         moveToEnd();
3609         return;
3610       }
3611       DEBUG_WITH_TYPE(
3612           "mach-o-bind",
3613           dbgs() << "BIND_OPCODE_SET_ADDEND_SLEB: "
3614                  << "Addend=" << Addend << "\n");
3615       break;
3616     case MachO::BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
3617       SegmentIndex = ImmValue;
3618       SegmentOffset = readULEB128(&error);
3619       if (error) {
3620         *E = malformedError("for BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB " +
3621                             Twine(error) + " for opcode at: 0x" +
3622                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3623         moveToEnd();
3624         return;
3625       }
3626       error = O->BindEntryCheckSegAndOffset(SegmentIndex, SegmentOffset, true);
3627       if (error) {
3628         *E = malformedError("for BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB " +
3629                             Twine(error) + " for opcode at: 0x" +
3630                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3631         moveToEnd();
3632         return;
3633       }
3634       DEBUG_WITH_TYPE(
3635           "mach-o-bind",
3636           dbgs() << "BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: "
3637                  << "SegmentIndex=" << SegmentIndex << ", "
3638                  << format("SegmentOffset=0x%06X", SegmentOffset)
3639                  << "\n");
3640       break;
3641     case MachO::BIND_OPCODE_ADD_ADDR_ULEB:
3642       SegmentOffset += readULEB128(&error);
3643       if (error) {
3644         *E = malformedError("for BIND_OPCODE_ADD_ADDR_ULEB " + Twine(error) +
3645                             " for opcode at: 0x" +
3646                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3647         moveToEnd();
3648         return;
3649       }
3650       error = O->BindEntryCheckSegAndOffset(SegmentIndex, SegmentOffset, true);
3651       if (error) {
3652         *E = malformedError("for BIND_OPCODE_ADD_ADDR_ULEB " + Twine(error) +
3653                             " for opcode at: 0x" +
3654                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3655         moveToEnd();
3656         return;
3657       }
3658       DEBUG_WITH_TYPE("mach-o-bind",
3659                       dbgs() << "BIND_OPCODE_ADD_ADDR_ULEB: "
3660                              << format("SegmentOffset=0x%06X",
3661                                        SegmentOffset) << "\n");
3662       break;
3663     case MachO::BIND_OPCODE_DO_BIND:
3664       AdvanceAmount = PointerSize;
3665       RemainingLoopCount = 0;
3666       error = O->BindEntryCheckSegAndOffset(SegmentIndex, SegmentOffset, true);
3667       if (error) {
3668         *E = malformedError("for BIND_OPCODE_DO_BIND " + Twine(error) +
3669                             " for opcode at: 0x" +
3670                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3671         moveToEnd();
3672         return;
3673       }
3674       if (SymbolName == StringRef()) {
3675         *E = malformedError(
3676             "for BIND_OPCODE_DO_BIND missing preceding "
3677             "BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM for opcode at: 0x" +
3678             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3679         moveToEnd();
3680         return;
3681       }
3682       if (!LibraryOrdinalSet && TableKind != Kind::Weak) {
3683         *E =
3684             malformedError("for BIND_OPCODE_DO_BIND missing preceding "
3685                            "BIND_OPCODE_SET_DYLIB_ORDINAL_* for opcode at: 0x" +
3686                            Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3687         moveToEnd();
3688         return;
3689       }
3690       DEBUG_WITH_TYPE("mach-o-bind",
3691                       dbgs() << "BIND_OPCODE_DO_BIND: "
3692                              << format("SegmentOffset=0x%06X",
3693                                        SegmentOffset) << "\n");
3694       return;
3695      case MachO::BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
3696       if (TableKind == Kind::Lazy) {
3697         *E = malformedError("BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB not allowed in "
3698                             "lazy bind table for opcode at: 0x" +
3699                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3700         moveToEnd();
3701         return;
3702       }
3703       error = O->BindEntryCheckSegAndOffset(SegmentIndex, SegmentOffset, true);
3704       if (error) {
3705         *E = malformedError("for BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB " +
3706                             Twine(error) + " for opcode at: 0x" +
3707                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3708         moveToEnd();
3709         return;
3710       }
3711       if (SymbolName == StringRef()) {
3712         *E = malformedError(
3713             "for BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB missing "
3714             "preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM for opcode "
3715             "at: 0x" +
3716             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3717         moveToEnd();
3718         return;
3719       }
3720       if (!LibraryOrdinalSet && TableKind != Kind::Weak) {
3721         *E = malformedError(
3722             "for BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB missing "
3723             "preceding BIND_OPCODE_SET_DYLIB_ORDINAL_* for opcode at: 0x" +
3724             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3725         moveToEnd();
3726         return;
3727       }
3728       AdvanceAmount = readULEB128(&error) + PointerSize;
3729       if (error) {
3730         *E = malformedError("for BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB " +
3731                             Twine(error) + " for opcode at: 0x" +
3732                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3733         moveToEnd();
3734         return;
3735       }
3736       // Note, this is not really an error until the next bind but make no sense
3737       // for a BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB to not be followed by another
3738       // bind operation.
3739       error = O->BindEntryCheckSegAndOffset(SegmentIndex, SegmentOffset +
3740                                             AdvanceAmount, false);
3741       if (error) {
3742         *E = malformedError("for BIND_OPCODE_ADD_ADDR_ULEB (after adding "
3743                             "ULEB) " +
3744                             Twine(error) + " for opcode at: 0x" +
3745                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3746         moveToEnd();
3747         return;
3748       }
3749       RemainingLoopCount = 0;
3750       DEBUG_WITH_TYPE(
3751           "mach-o-bind",
3752           dbgs() << "BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB: "
3753                  << format("SegmentOffset=0x%06X", SegmentOffset)
3754                  << ", AdvanceAmount=" << AdvanceAmount
3755                  << ", RemainingLoopCount=" << RemainingLoopCount
3756                  << "\n");
3757       return;
3758     case MachO::BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
3759       if (TableKind == Kind::Lazy) {
3760         *E = malformedError("BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED not "
3761                             "allowed in lazy bind table for opcode at: 0x" +
3762                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3763         moveToEnd();
3764         return;
3765       }
3766       error = O->BindEntryCheckSegAndOffset(SegmentIndex, SegmentOffset, true);
3767       if (error) {
3768         *E = malformedError("for BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED " +
3769                             Twine(error) + " for opcode at: 0x" +
3770                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3771         moveToEnd();
3772         return;
3773       }
3774       if (SymbolName == StringRef()) {
3775         *E = malformedError(
3776             "for BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED "
3777             "missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM for "
3778             "opcode at: 0x" +
3779             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3780         moveToEnd();
3781         return;
3782       }
3783       if (!LibraryOrdinalSet && TableKind != Kind::Weak) {
3784         *E = malformedError(
3785             "for BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED "
3786             "missing preceding BIND_OPCODE_SET_DYLIB_ORDINAL_* for opcode "
3787             "at: 0x" +
3788             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3789         moveToEnd();
3790         return;
3791       }
3792       AdvanceAmount = ImmValue * PointerSize + PointerSize;
3793       RemainingLoopCount = 0;
3794       error = O->BindEntryCheckSegAndOffset(SegmentIndex, SegmentOffset +
3795                                             AdvanceAmount, false);
3796       if (error) {
3797         *E =
3798             malformedError("for BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED "
3799                            " (after adding immediate times the pointer size) " +
3800                            Twine(error) + " for opcode at: 0x" +
3801                            Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3802         moveToEnd();
3803         return;
3804       }
3805       DEBUG_WITH_TYPE("mach-o-bind",
3806                       dbgs()
3807                       << "BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: "
3808                       << format("SegmentOffset=0x%06X", SegmentOffset) << "\n");
3809       return;
3810     case MachO::BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
3811       if (TableKind == Kind::Lazy) {
3812         *E = malformedError("BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB not "
3813                             "allowed in lazy bind table for opcode at: 0x" +
3814                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3815         moveToEnd();
3816         return;
3817       }
3818       Count = readULEB128(&error);
3819       if (Count != 0)
3820         RemainingLoopCount = Count - 1;
3821       else
3822         RemainingLoopCount = 0;
3823       if (error) {
3824         *E = malformedError("for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB "
3825                             " (count value) " +
3826                             Twine(error) + " for opcode at: 0x" +
3827                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3828         moveToEnd();
3829         return;
3830       }
3831       Skip = readULEB128(&error);
3832       AdvanceAmount = Skip + PointerSize;
3833       if (error) {
3834         *E = malformedError("for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB "
3835                             " (skip value) " +
3836                             Twine(error) + " for opcode at: 0x" +
3837                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3838         moveToEnd();
3839         return;
3840       }
3841       error = O->BindEntryCheckSegAndOffset(SegmentIndex, SegmentOffset, true);
3842       if (error) {
3843         *E =
3844             malformedError("for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB " +
3845                            Twine(error) + " for opcode at: 0x" +
3846                            Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3847         moveToEnd();
3848         return;
3849       }
3850       if (SymbolName == StringRef()) {
3851         *E = malformedError(
3852             "for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB "
3853             "missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM for "
3854             "opcode at: 0x" +
3855             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3856         moveToEnd();
3857         return;
3858       }
3859       if (!LibraryOrdinalSet && TableKind != Kind::Weak) {
3860         *E = malformedError(
3861             "for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB "
3862             "missing preceding BIND_OPCODE_SET_DYLIB_ORDINAL_* for opcode "
3863             "at: 0x" +
3864             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3865         moveToEnd();
3866         return;
3867       }
3868       error = O->BindEntryCheckCountAndSkip(Count, Skip, PointerSize,
3869                                             SegmentIndex, SegmentOffset);
3870       if (error) {
3871         *E =
3872             malformedError("for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB " +
3873                            Twine(error) + " for opcode at: 0x" +
3874                            Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3875         moveToEnd();
3876         return;
3877       }
3878       DEBUG_WITH_TYPE(
3879           "mach-o-bind",
3880           dbgs() << "BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: "
3881                  << format("SegmentOffset=0x%06X", SegmentOffset)
3882                  << ", AdvanceAmount=" << AdvanceAmount
3883                  << ", RemainingLoopCount=" << RemainingLoopCount
3884                  << "\n");
3885       return;
3886     default:
3887       *E = malformedError("bad bind info (bad opcode value 0x" +
3888                           Twine::utohexstr(Opcode) + " for opcode at: 0x" +
3889                           Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3890       moveToEnd();
3891       return;
3892     }
3893   }
3894 }
3895 
3896 uint64_t MachOBindEntry::readULEB128(const char **error) {
3897   unsigned Count;
3898   uint64_t Result = decodeULEB128(Ptr, &Count, Opcodes.end(), error);
3899   Ptr += Count;
3900   if (Ptr > Opcodes.end())
3901     Ptr = Opcodes.end();
3902   return Result;
3903 }
3904 
3905 int64_t MachOBindEntry::readSLEB128(const char **error) {
3906   unsigned Count;
3907   int64_t Result = decodeSLEB128(Ptr, &Count, Opcodes.end(), error);
3908   Ptr += Count;
3909   if (Ptr > Opcodes.end())
3910     Ptr = Opcodes.end();
3911   return Result;
3912 }
3913 
3914 int32_t MachOBindEntry::segmentIndex() const { return SegmentIndex; }
3915 
3916 uint64_t MachOBindEntry::segmentOffset() const { return SegmentOffset; }
3917 
3918 StringRef MachOBindEntry::typeName() const {
3919   switch (BindType) {
3920   case MachO::BIND_TYPE_POINTER:
3921     return "pointer";
3922   case MachO::BIND_TYPE_TEXT_ABSOLUTE32:
3923     return "text abs32";
3924   case MachO::BIND_TYPE_TEXT_PCREL32:
3925     return "text rel32";
3926   }
3927   return "unknown";
3928 }
3929 
3930 StringRef MachOBindEntry::symbolName() const { return SymbolName; }
3931 
3932 int64_t MachOBindEntry::addend() const { return Addend; }
3933 
3934 uint32_t MachOBindEntry::flags() const { return Flags; }
3935 
3936 int MachOBindEntry::ordinal() const { return Ordinal; }
3937 
3938 // For use with the SegIndex of a checked Mach-O Bind entry
3939 // to get the segment name.
3940 StringRef MachOBindEntry::segmentName() const {
3941   return O->BindRebaseSegmentName(SegmentIndex);
3942 }
3943 
3944 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind entry
3945 // to get the section name.
3946 StringRef MachOBindEntry::sectionName() const {
3947   return O->BindRebaseSectionName(SegmentIndex, SegmentOffset);
3948 }
3949 
3950 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind entry
3951 // to get the address.
3952 uint64_t MachOBindEntry::address() const {
3953   return O->BindRebaseAddress(SegmentIndex, SegmentOffset);
3954 }
3955 
3956 bool MachOBindEntry::operator==(const MachOBindEntry &Other) const {
3957 #ifdef EXPENSIVE_CHECKS
3958   assert(Opcodes == Other.Opcodes && "compare iterators of different files");
3959 #else
3960   assert(Opcodes.data() == Other.Opcodes.data() && "compare iterators of different files");
3961 #endif
3962   return (Ptr == Other.Ptr) &&
3963          (RemainingLoopCount == Other.RemainingLoopCount) &&
3964          (Done == Other.Done);
3965 }
3966 
3967 // Build table of sections so SegIndex/SegOffset pairs can be translated.
3968 BindRebaseSegInfo::BindRebaseSegInfo(const object::MachOObjectFile *Obj) {
3969   uint32_t CurSegIndex = Obj->hasPageZeroSegment() ? 1 : 0;
3970   StringRef CurSegName;
3971   uint64_t CurSegAddress;
3972   for (const SectionRef &Section : Obj->sections()) {
3973     SectionInfo Info;
3974     Section.getName(Info.SectionName);
3975     Info.Address = Section.getAddress();
3976     Info.Size = Section.getSize();
3977     Info.SegmentName =
3978         Obj->getSectionFinalSegmentName(Section.getRawDataRefImpl());
3979     if (!Info.SegmentName.equals(CurSegName)) {
3980       ++CurSegIndex;
3981       CurSegName = Info.SegmentName;
3982       CurSegAddress = Info.Address;
3983     }
3984     Info.SegmentIndex = CurSegIndex - 1;
3985     Info.OffsetInSegment = Info.Address - CurSegAddress;
3986     Info.SegmentStartAddress = CurSegAddress;
3987     Sections.push_back(Info);
3988   }
3989   MaxSegIndex = CurSegIndex;
3990 }
3991 
3992 // For use with a SegIndex,SegOffset pair in MachOBindEntry::moveNext() to
3993 // validate a MachOBindEntry or MachORebaseEntry.
3994 const char * BindRebaseSegInfo::checkSegAndOffset(int32_t SegIndex,
3995                                                   uint64_t SegOffset,
3996                                                   bool endInvalid) {
3997   if (SegIndex == -1)
3998     return "missing preceding *_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB";
3999   if (SegIndex >= MaxSegIndex)
4000     return "bad segIndex (too large)";
4001   for (const SectionInfo &SI : Sections) {
4002     if (SI.SegmentIndex != SegIndex)
4003       continue;
4004     if (SI.OffsetInSegment > SegOffset)
4005       continue;
4006     if (SegOffset > (SI.OffsetInSegment + SI.Size))
4007       continue;
4008     if (endInvalid && SegOffset >= (SI.OffsetInSegment + SI.Size))
4009       continue;
4010     return nullptr;
4011   }
4012   return "bad segOffset, too large";
4013 }
4014 
4015 // For use in MachOBindEntry::moveNext() to validate a MachOBindEntry for
4016 // the BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB opcode and for use in
4017 // MachORebaseEntry::moveNext() to validate a MachORebaseEntry for
4018 // REBASE_OPCODE_DO_*_TIMES* opcodes.  The SegIndex and SegOffset must have
4019 // been already checked.
4020 const char * BindRebaseSegInfo::checkCountAndSkip(uint32_t Count, uint32_t Skip,
4021                                                   uint8_t PointerSize,
4022                                                   int32_t SegIndex,
4023                                                   uint64_t SegOffset) {
4024   const SectionInfo &SI = findSection(SegIndex, SegOffset);
4025   uint64_t addr = SI.SegmentStartAddress + SegOffset;
4026   if (addr >= SI.Address + SI.Size)
4027     return "bad segOffset, too large";
4028   uint64_t i = 0;
4029   if (Count > 1)
4030     i = (Skip + PointerSize) * (Count - 1);
4031   else if (Count == 1)
4032     i = Skip + PointerSize;
4033   if (addr + i >= SI.Address + SI.Size) {
4034     // For rebase opcodes they can step from one section to another.
4035     uint64_t TrailingSegOffset = (addr + i) - SI.SegmentStartAddress;
4036     const char *error = checkSegAndOffset(SegIndex, TrailingSegOffset, false);
4037     if (error)
4038       return "bad count and skip, too large";
4039   }
4040   return nullptr;
4041 }
4042 
4043 // For use with the SegIndex of a checked Mach-O Bind or Rebase entry
4044 // to get the segment name.
4045 StringRef BindRebaseSegInfo::segmentName(int32_t SegIndex) {
4046   for (const SectionInfo &SI : Sections) {
4047     if (SI.SegmentIndex == SegIndex)
4048       return SI.SegmentName;
4049   }
4050   llvm_unreachable("invalid SegIndex");
4051 }
4052 
4053 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind or Rebase
4054 // to get the SectionInfo.
4055 const BindRebaseSegInfo::SectionInfo &BindRebaseSegInfo::findSection(
4056                                      int32_t SegIndex, uint64_t SegOffset) {
4057   for (const SectionInfo &SI : Sections) {
4058     if (SI.SegmentIndex != SegIndex)
4059       continue;
4060     if (SI.OffsetInSegment > SegOffset)
4061       continue;
4062     if (SegOffset >= (SI.OffsetInSegment + SI.Size))
4063       continue;
4064     return SI;
4065   }
4066   llvm_unreachable("SegIndex and SegOffset not in any section");
4067 }
4068 
4069 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind or Rebase
4070 // entry to get the section name.
4071 StringRef BindRebaseSegInfo::sectionName(int32_t SegIndex,
4072                                          uint64_t SegOffset) {
4073   return findSection(SegIndex, SegOffset).SectionName;
4074 }
4075 
4076 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind or Rebase
4077 // entry to get the address.
4078 uint64_t BindRebaseSegInfo::address(uint32_t SegIndex, uint64_t OffsetInSeg) {
4079   const SectionInfo &SI = findSection(SegIndex, OffsetInSeg);
4080   return SI.SegmentStartAddress + OffsetInSeg;
4081 }
4082 
4083 iterator_range<bind_iterator>
4084 MachOObjectFile::bindTable(Error &Err, MachOObjectFile *O,
4085                            ArrayRef<uint8_t> Opcodes, bool is64,
4086                            MachOBindEntry::Kind BKind) {
4087   if (O->BindRebaseSectionTable == nullptr)
4088     O->BindRebaseSectionTable = llvm::make_unique<BindRebaseSegInfo>(O);
4089   MachOBindEntry Start(&Err, O, Opcodes, is64, BKind);
4090   Start.moveToFirst();
4091 
4092   MachOBindEntry Finish(&Err, O, Opcodes, is64, BKind);
4093   Finish.moveToEnd();
4094 
4095   return make_range(bind_iterator(Start), bind_iterator(Finish));
4096 }
4097 
4098 iterator_range<bind_iterator> MachOObjectFile::bindTable(Error &Err) {
4099   return bindTable(Err, this, getDyldInfoBindOpcodes(), is64Bit(),
4100                    MachOBindEntry::Kind::Regular);
4101 }
4102 
4103 iterator_range<bind_iterator> MachOObjectFile::lazyBindTable(Error &Err) {
4104   return bindTable(Err, this, getDyldInfoLazyBindOpcodes(), is64Bit(),
4105                    MachOBindEntry::Kind::Lazy);
4106 }
4107 
4108 iterator_range<bind_iterator> MachOObjectFile::weakBindTable(Error &Err) {
4109   return bindTable(Err, this, getDyldInfoWeakBindOpcodes(), is64Bit(),
4110                    MachOBindEntry::Kind::Weak);
4111 }
4112 
4113 MachOObjectFile::load_command_iterator
4114 MachOObjectFile::begin_load_commands() const {
4115   return LoadCommands.begin();
4116 }
4117 
4118 MachOObjectFile::load_command_iterator
4119 MachOObjectFile::end_load_commands() const {
4120   return LoadCommands.end();
4121 }
4122 
4123 iterator_range<MachOObjectFile::load_command_iterator>
4124 MachOObjectFile::load_commands() const {
4125   return make_range(begin_load_commands(), end_load_commands());
4126 }
4127 
4128 StringRef
4129 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
4130   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
4131   return parseSegmentOrSectionName(Raw.data());
4132 }
4133 
4134 ArrayRef<char>
4135 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
4136   assert(Sec.d.a < Sections.size() && "Should have detected this earlier");
4137   const section_base *Base =
4138     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
4139   return makeArrayRef(Base->sectname);
4140 }
4141 
4142 ArrayRef<char>
4143 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
4144   assert(Sec.d.a < Sections.size() && "Should have detected this earlier");
4145   const section_base *Base =
4146     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
4147   return makeArrayRef(Base->segname);
4148 }
4149 
4150 bool
4151 MachOObjectFile::isRelocationScattered(const MachO::any_relocation_info &RE)
4152   const {
4153   if (getCPUType(*this) == MachO::CPU_TYPE_X86_64)
4154     return false;
4155   return getPlainRelocationAddress(RE) & MachO::R_SCATTERED;
4156 }
4157 
4158 unsigned MachOObjectFile::getPlainRelocationSymbolNum(
4159     const MachO::any_relocation_info &RE) const {
4160   if (isLittleEndian())
4161     return RE.r_word1 & 0xffffff;
4162   return RE.r_word1 >> 8;
4163 }
4164 
4165 bool MachOObjectFile::getPlainRelocationExternal(
4166     const MachO::any_relocation_info &RE) const {
4167   if (isLittleEndian())
4168     return (RE.r_word1 >> 27) & 1;
4169   return (RE.r_word1 >> 4) & 1;
4170 }
4171 
4172 bool MachOObjectFile::getScatteredRelocationScattered(
4173     const MachO::any_relocation_info &RE) const {
4174   return RE.r_word0 >> 31;
4175 }
4176 
4177 uint32_t MachOObjectFile::getScatteredRelocationValue(
4178     const MachO::any_relocation_info &RE) const {
4179   return RE.r_word1;
4180 }
4181 
4182 uint32_t MachOObjectFile::getScatteredRelocationType(
4183     const MachO::any_relocation_info &RE) const {
4184   return (RE.r_word0 >> 24) & 0xf;
4185 }
4186 
4187 unsigned MachOObjectFile::getAnyRelocationAddress(
4188     const MachO::any_relocation_info &RE) const {
4189   if (isRelocationScattered(RE))
4190     return getScatteredRelocationAddress(RE);
4191   return getPlainRelocationAddress(RE);
4192 }
4193 
4194 unsigned MachOObjectFile::getAnyRelocationPCRel(
4195     const MachO::any_relocation_info &RE) const {
4196   if (isRelocationScattered(RE))
4197     return getScatteredRelocationPCRel(RE);
4198   return getPlainRelocationPCRel(*this, RE);
4199 }
4200 
4201 unsigned MachOObjectFile::getAnyRelocationLength(
4202     const MachO::any_relocation_info &RE) const {
4203   if (isRelocationScattered(RE))
4204     return getScatteredRelocationLength(RE);
4205   return getPlainRelocationLength(*this, RE);
4206 }
4207 
4208 unsigned
4209 MachOObjectFile::getAnyRelocationType(
4210                                    const MachO::any_relocation_info &RE) const {
4211   if (isRelocationScattered(RE))
4212     return getScatteredRelocationType(RE);
4213   return getPlainRelocationType(*this, RE);
4214 }
4215 
4216 SectionRef
4217 MachOObjectFile::getAnyRelocationSection(
4218                                    const MachO::any_relocation_info &RE) const {
4219   if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
4220     return *section_end();
4221   unsigned SecNum = getPlainRelocationSymbolNum(RE);
4222   if (SecNum == MachO::R_ABS || SecNum > Sections.size())
4223     return *section_end();
4224   DataRefImpl DRI;
4225   DRI.d.a = SecNum - 1;
4226   return SectionRef(DRI, this);
4227 }
4228 
4229 MachO::section MachOObjectFile::getSection(DataRefImpl DRI) const {
4230   assert(DRI.d.a < Sections.size() && "Should have detected this earlier");
4231   return getStruct<MachO::section>(*this, Sections[DRI.d.a]);
4232 }
4233 
4234 MachO::section_64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
4235   assert(DRI.d.a < Sections.size() && "Should have detected this earlier");
4236   return getStruct<MachO::section_64>(*this, Sections[DRI.d.a]);
4237 }
4238 
4239 MachO::section MachOObjectFile::getSection(const LoadCommandInfo &L,
4240                                            unsigned Index) const {
4241   const char *Sec = getSectionPtr(*this, L, Index);
4242   return getStruct<MachO::section>(*this, Sec);
4243 }
4244 
4245 MachO::section_64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
4246                                                 unsigned Index) const {
4247   const char *Sec = getSectionPtr(*this, L, Index);
4248   return getStruct<MachO::section_64>(*this, Sec);
4249 }
4250 
4251 MachO::nlist
4252 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
4253   const char *P = reinterpret_cast<const char *>(DRI.p);
4254   return getStruct<MachO::nlist>(*this, P);
4255 }
4256 
4257 MachO::nlist_64
4258 MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI) const {
4259   const char *P = reinterpret_cast<const char *>(DRI.p);
4260   return getStruct<MachO::nlist_64>(*this, P);
4261 }
4262 
4263 MachO::linkedit_data_command
4264 MachOObjectFile::getLinkeditDataLoadCommand(const LoadCommandInfo &L) const {
4265   return getStruct<MachO::linkedit_data_command>(*this, L.Ptr);
4266 }
4267 
4268 MachO::segment_command
4269 MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
4270   return getStruct<MachO::segment_command>(*this, L.Ptr);
4271 }
4272 
4273 MachO::segment_command_64
4274 MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
4275   return getStruct<MachO::segment_command_64>(*this, L.Ptr);
4276 }
4277 
4278 MachO::linker_option_command
4279 MachOObjectFile::getLinkerOptionLoadCommand(const LoadCommandInfo &L) const {
4280   return getStruct<MachO::linker_option_command>(*this, L.Ptr);
4281 }
4282 
4283 MachO::version_min_command
4284 MachOObjectFile::getVersionMinLoadCommand(const LoadCommandInfo &L) const {
4285   return getStruct<MachO::version_min_command>(*this, L.Ptr);
4286 }
4287 
4288 MachO::note_command
4289 MachOObjectFile::getNoteLoadCommand(const LoadCommandInfo &L) const {
4290   return getStruct<MachO::note_command>(*this, L.Ptr);
4291 }
4292 
4293 MachO::build_version_command
4294 MachOObjectFile::getBuildVersionLoadCommand(const LoadCommandInfo &L) const {
4295   return getStruct<MachO::build_version_command>(*this, L.Ptr);
4296 }
4297 
4298 MachO::build_tool_version
4299 MachOObjectFile::getBuildToolVersion(unsigned index) const {
4300   return getStruct<MachO::build_tool_version>(*this, BuildTools[index]);
4301 }
4302 
4303 MachO::dylib_command
4304 MachOObjectFile::getDylibIDLoadCommand(const LoadCommandInfo &L) const {
4305   return getStruct<MachO::dylib_command>(*this, L.Ptr);
4306 }
4307 
4308 MachO::dyld_info_command
4309 MachOObjectFile::getDyldInfoLoadCommand(const LoadCommandInfo &L) const {
4310   return getStruct<MachO::dyld_info_command>(*this, L.Ptr);
4311 }
4312 
4313 MachO::dylinker_command
4314 MachOObjectFile::getDylinkerCommand(const LoadCommandInfo &L) const {
4315   return getStruct<MachO::dylinker_command>(*this, L.Ptr);
4316 }
4317 
4318 MachO::uuid_command
4319 MachOObjectFile::getUuidCommand(const LoadCommandInfo &L) const {
4320   return getStruct<MachO::uuid_command>(*this, L.Ptr);
4321 }
4322 
4323 MachO::rpath_command
4324 MachOObjectFile::getRpathCommand(const LoadCommandInfo &L) const {
4325   return getStruct<MachO::rpath_command>(*this, L.Ptr);
4326 }
4327 
4328 MachO::source_version_command
4329 MachOObjectFile::getSourceVersionCommand(const LoadCommandInfo &L) const {
4330   return getStruct<MachO::source_version_command>(*this, L.Ptr);
4331 }
4332 
4333 MachO::entry_point_command
4334 MachOObjectFile::getEntryPointCommand(const LoadCommandInfo &L) const {
4335   return getStruct<MachO::entry_point_command>(*this, L.Ptr);
4336 }
4337 
4338 MachO::encryption_info_command
4339 MachOObjectFile::getEncryptionInfoCommand(const LoadCommandInfo &L) const {
4340   return getStruct<MachO::encryption_info_command>(*this, L.Ptr);
4341 }
4342 
4343 MachO::encryption_info_command_64
4344 MachOObjectFile::getEncryptionInfoCommand64(const LoadCommandInfo &L) const {
4345   return getStruct<MachO::encryption_info_command_64>(*this, L.Ptr);
4346 }
4347 
4348 MachO::sub_framework_command
4349 MachOObjectFile::getSubFrameworkCommand(const LoadCommandInfo &L) const {
4350   return getStruct<MachO::sub_framework_command>(*this, L.Ptr);
4351 }
4352 
4353 MachO::sub_umbrella_command
4354 MachOObjectFile::getSubUmbrellaCommand(const LoadCommandInfo &L) const {
4355   return getStruct<MachO::sub_umbrella_command>(*this, L.Ptr);
4356 }
4357 
4358 MachO::sub_library_command
4359 MachOObjectFile::getSubLibraryCommand(const LoadCommandInfo &L) const {
4360   return getStruct<MachO::sub_library_command>(*this, L.Ptr);
4361 }
4362 
4363 MachO::sub_client_command
4364 MachOObjectFile::getSubClientCommand(const LoadCommandInfo &L) const {
4365   return getStruct<MachO::sub_client_command>(*this, L.Ptr);
4366 }
4367 
4368 MachO::routines_command
4369 MachOObjectFile::getRoutinesCommand(const LoadCommandInfo &L) const {
4370   return getStruct<MachO::routines_command>(*this, L.Ptr);
4371 }
4372 
4373 MachO::routines_command_64
4374 MachOObjectFile::getRoutinesCommand64(const LoadCommandInfo &L) const {
4375   return getStruct<MachO::routines_command_64>(*this, L.Ptr);
4376 }
4377 
4378 MachO::thread_command
4379 MachOObjectFile::getThreadCommand(const LoadCommandInfo &L) const {
4380   return getStruct<MachO::thread_command>(*this, L.Ptr);
4381 }
4382 
4383 MachO::any_relocation_info
4384 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
4385   uint32_t Offset;
4386   if (getHeader().filetype == MachO::MH_OBJECT) {
4387     DataRefImpl Sec;
4388     Sec.d.a = Rel.d.a;
4389     if (is64Bit()) {
4390       MachO::section_64 Sect = getSection64(Sec);
4391       Offset = Sect.reloff;
4392     } else {
4393       MachO::section Sect = getSection(Sec);
4394       Offset = Sect.reloff;
4395     }
4396   } else {
4397     MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
4398     if (Rel.d.a == 0)
4399       Offset = DysymtabLoadCmd.extreloff; // Offset to the external relocations
4400     else
4401       Offset = DysymtabLoadCmd.locreloff; // Offset to the local relocations
4402   }
4403 
4404   auto P = reinterpret_cast<const MachO::any_relocation_info *>(
4405       getPtr(*this, Offset)) + Rel.d.b;
4406   return getStruct<MachO::any_relocation_info>(
4407       *this, reinterpret_cast<const char *>(P));
4408 }
4409 
4410 MachO::data_in_code_entry
4411 MachOObjectFile::getDice(DataRefImpl Rel) const {
4412   const char *P = reinterpret_cast<const char *>(Rel.p);
4413   return getStruct<MachO::data_in_code_entry>(*this, P);
4414 }
4415 
4416 const MachO::mach_header &MachOObjectFile::getHeader() const {
4417   return Header;
4418 }
4419 
4420 const MachO::mach_header_64 &MachOObjectFile::getHeader64() const {
4421   assert(is64Bit());
4422   return Header64;
4423 }
4424 
4425 uint32_t MachOObjectFile::getIndirectSymbolTableEntry(
4426                                              const MachO::dysymtab_command &DLC,
4427                                              unsigned Index) const {
4428   uint64_t Offset = DLC.indirectsymoff + Index * sizeof(uint32_t);
4429   return getStruct<uint32_t>(*this, getPtr(*this, Offset));
4430 }
4431 
4432 MachO::data_in_code_entry
4433 MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
4434                                          unsigned Index) const {
4435   uint64_t Offset = DataOffset + Index * sizeof(MachO::data_in_code_entry);
4436   return getStruct<MachO::data_in_code_entry>(*this, getPtr(*this, Offset));
4437 }
4438 
4439 MachO::symtab_command MachOObjectFile::getSymtabLoadCommand() const {
4440   if (SymtabLoadCmd)
4441     return getStruct<MachO::symtab_command>(*this, SymtabLoadCmd);
4442 
4443   // If there is no SymtabLoadCmd return a load command with zero'ed fields.
4444   MachO::symtab_command Cmd;
4445   Cmd.cmd = MachO::LC_SYMTAB;
4446   Cmd.cmdsize = sizeof(MachO::symtab_command);
4447   Cmd.symoff = 0;
4448   Cmd.nsyms = 0;
4449   Cmd.stroff = 0;
4450   Cmd.strsize = 0;
4451   return Cmd;
4452 }
4453 
4454 MachO::dysymtab_command MachOObjectFile::getDysymtabLoadCommand() const {
4455   if (DysymtabLoadCmd)
4456     return getStruct<MachO::dysymtab_command>(*this, DysymtabLoadCmd);
4457 
4458   // If there is no DysymtabLoadCmd return a load command with zero'ed fields.
4459   MachO::dysymtab_command Cmd;
4460   Cmd.cmd = MachO::LC_DYSYMTAB;
4461   Cmd.cmdsize = sizeof(MachO::dysymtab_command);
4462   Cmd.ilocalsym = 0;
4463   Cmd.nlocalsym = 0;
4464   Cmd.iextdefsym = 0;
4465   Cmd.nextdefsym = 0;
4466   Cmd.iundefsym = 0;
4467   Cmd.nundefsym = 0;
4468   Cmd.tocoff = 0;
4469   Cmd.ntoc = 0;
4470   Cmd.modtaboff = 0;
4471   Cmd.nmodtab = 0;
4472   Cmd.extrefsymoff = 0;
4473   Cmd.nextrefsyms = 0;
4474   Cmd.indirectsymoff = 0;
4475   Cmd.nindirectsyms = 0;
4476   Cmd.extreloff = 0;
4477   Cmd.nextrel = 0;
4478   Cmd.locreloff = 0;
4479   Cmd.nlocrel = 0;
4480   return Cmd;
4481 }
4482 
4483 MachO::linkedit_data_command
4484 MachOObjectFile::getDataInCodeLoadCommand() const {
4485   if (DataInCodeLoadCmd)
4486     return getStruct<MachO::linkedit_data_command>(*this, DataInCodeLoadCmd);
4487 
4488   // If there is no DataInCodeLoadCmd return a load command with zero'ed fields.
4489   MachO::linkedit_data_command Cmd;
4490   Cmd.cmd = MachO::LC_DATA_IN_CODE;
4491   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
4492   Cmd.dataoff = 0;
4493   Cmd.datasize = 0;
4494   return Cmd;
4495 }
4496 
4497 MachO::linkedit_data_command
4498 MachOObjectFile::getLinkOptHintsLoadCommand() const {
4499   if (LinkOptHintsLoadCmd)
4500     return getStruct<MachO::linkedit_data_command>(*this, LinkOptHintsLoadCmd);
4501 
4502   // If there is no LinkOptHintsLoadCmd return a load command with zero'ed
4503   // fields.
4504   MachO::linkedit_data_command Cmd;
4505   Cmd.cmd = MachO::LC_LINKER_OPTIMIZATION_HINT;
4506   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
4507   Cmd.dataoff = 0;
4508   Cmd.datasize = 0;
4509   return Cmd;
4510 }
4511 
4512 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoRebaseOpcodes() const {
4513   if (!DyldInfoLoadCmd)
4514     return None;
4515 
4516   MachO::dyld_info_command DyldInfo =
4517       getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4518   const uint8_t *Ptr =
4519       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.rebase_off));
4520   return makeArrayRef(Ptr, DyldInfo.rebase_size);
4521 }
4522 
4523 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoBindOpcodes() const {
4524   if (!DyldInfoLoadCmd)
4525     return None;
4526 
4527   MachO::dyld_info_command DyldInfo =
4528       getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4529   const uint8_t *Ptr =
4530       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.bind_off));
4531   return makeArrayRef(Ptr, DyldInfo.bind_size);
4532 }
4533 
4534 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoWeakBindOpcodes() const {
4535   if (!DyldInfoLoadCmd)
4536     return None;
4537 
4538   MachO::dyld_info_command DyldInfo =
4539       getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4540   const uint8_t *Ptr =
4541       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.weak_bind_off));
4542   return makeArrayRef(Ptr, DyldInfo.weak_bind_size);
4543 }
4544 
4545 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoLazyBindOpcodes() const {
4546   if (!DyldInfoLoadCmd)
4547     return None;
4548 
4549   MachO::dyld_info_command DyldInfo =
4550       getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4551   const uint8_t *Ptr =
4552       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.lazy_bind_off));
4553   return makeArrayRef(Ptr, DyldInfo.lazy_bind_size);
4554 }
4555 
4556 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoExportsTrie() const {
4557   if (!DyldInfoLoadCmd)
4558     return None;
4559 
4560   MachO::dyld_info_command DyldInfo =
4561       getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4562   const uint8_t *Ptr =
4563       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.export_off));
4564   return makeArrayRef(Ptr, DyldInfo.export_size);
4565 }
4566 
4567 ArrayRef<uint8_t> MachOObjectFile::getUuid() const {
4568   if (!UuidLoadCmd)
4569     return None;
4570   // Returning a pointer is fine as uuid doesn't need endian swapping.
4571   const char *Ptr = UuidLoadCmd + offsetof(MachO::uuid_command, uuid);
4572   return makeArrayRef(reinterpret_cast<const uint8_t *>(Ptr), 16);
4573 }
4574 
4575 StringRef MachOObjectFile::getStringTableData() const {
4576   MachO::symtab_command S = getSymtabLoadCommand();
4577   return getData().substr(S.stroff, S.strsize);
4578 }
4579 
4580 bool MachOObjectFile::is64Bit() const {
4581   return getType() == getMachOType(false, true) ||
4582     getType() == getMachOType(true, true);
4583 }
4584 
4585 void MachOObjectFile::ReadULEB128s(uint64_t Index,
4586                                    SmallVectorImpl<uint64_t> &Out) const {
4587   DataExtractor extractor(ObjectFile::getData(), true, 0);
4588 
4589   uint32_t offset = Index;
4590   uint64_t data = 0;
4591   while (uint64_t delta = extractor.getULEB128(&offset)) {
4592     data += delta;
4593     Out.push_back(data);
4594   }
4595 }
4596 
4597 bool MachOObjectFile::isRelocatableObject() const {
4598   return getHeader().filetype == MachO::MH_OBJECT;
4599 }
4600 
4601 Expected<std::unique_ptr<MachOObjectFile>>
4602 ObjectFile::createMachOObjectFile(MemoryBufferRef Buffer,
4603                                   uint32_t UniversalCputype,
4604                                   uint32_t UniversalIndex) {
4605   StringRef Magic = Buffer.getBuffer().slice(0, 4);
4606   if (Magic == "\xFE\xED\xFA\xCE")
4607     return MachOObjectFile::create(Buffer, false, false,
4608                                    UniversalCputype, UniversalIndex);
4609   if (Magic == "\xCE\xFA\xED\xFE")
4610     return MachOObjectFile::create(Buffer, true, false,
4611                                    UniversalCputype, UniversalIndex);
4612   if (Magic == "\xFE\xED\xFA\xCF")
4613     return MachOObjectFile::create(Buffer, false, true,
4614                                    UniversalCputype, UniversalIndex);
4615   if (Magic == "\xCF\xFA\xED\xFE")
4616     return MachOObjectFile::create(Buffer, true, true,
4617                                    UniversalCputype, UniversalIndex);
4618   return make_error<GenericBinaryError>("Unrecognized MachO magic number",
4619                                         object_error::invalid_file_type);
4620 }
4621 
4622 StringRef MachOObjectFile::mapDebugSectionName(StringRef Name) const {
4623   return StringSwitch<StringRef>(Name)
4624       .Case("debug_str_offs", "debug_str_offsets")
4625       .Default(Name);
4626 }
4627