xref: /freebsd/contrib/llvm-project/llvm/lib/Object/MachOObjectFile.cpp (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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/STLExtras.h"
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/ADT/StringSwitch.h"
19 #include "llvm/ADT/Twine.h"
20 #include "llvm/ADT/bit.h"
21 #include "llvm/BinaryFormat/MachO.h"
22 #include "llvm/BinaryFormat/Swift.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/Errc.h"
30 #include "llvm/Support/Error.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/FileSystem.h"
33 #include "llvm/Support/Format.h"
34 #include "llvm/Support/LEB128.h"
35 #include "llvm/Support/MemoryBufferRef.h"
36 #include "llvm/Support/Path.h"
37 #include "llvm/Support/SwapByteOrder.h"
38 #include "llvm/Support/raw_ostream.h"
39 #include "llvm/TargetParser/Host.h"
40 #include "llvm/TargetParser/Triple.h"
41 #include <algorithm>
42 #include <cassert>
43 #include <cstddef>
44 #include <cstdint>
45 #include <cstring>
46 #include <limits>
47 #include <list>
48 #include <memory>
49 #include <system_error>
50 
51 using namespace llvm;
52 using namespace object;
53 
54 namespace {
55 
56   struct section_base {
57     char sectname[16];
58     char segname[16];
59   };
60 
61 } // end anonymous namespace
62 
malformedError(const Twine & Msg)63 static Error malformedError(const Twine &Msg) {
64   return make_error<GenericBinaryError>("truncated or malformed object (" +
65                                             Msg + ")",
66                                         object_error::parse_failed);
67 }
68 
69 // FIXME: Replace all uses of this function with getStructOrErr.
70 template <typename T>
getStruct(const MachOObjectFile & O,const char * P)71 static T getStruct(const MachOObjectFile &O, const char *P) {
72   // Don't read before the beginning or past the end of the file
73   if (P < O.getData().begin() || P + sizeof(T) > O.getData().end())
74     report_fatal_error("Malformed MachO file.");
75 
76   T Cmd;
77   memcpy(&Cmd, P, sizeof(T));
78   if (O.isLittleEndian() != sys::IsLittleEndianHost)
79     MachO::swapStruct(Cmd);
80   return Cmd;
81 }
82 
83 template <typename T>
getStructOrErr(const MachOObjectFile & O,const char * P)84 static Expected<T> getStructOrErr(const MachOObjectFile &O, const char *P) {
85   // Don't read before the beginning or past the end of the file
86   if (P < O.getData().begin() || P + sizeof(T) > O.getData().end())
87     return malformedError("Structure read out-of-range");
88 
89   T Cmd;
90   memcpy(&Cmd, P, sizeof(T));
91   if (O.isLittleEndian() != sys::IsLittleEndianHost)
92     MachO::swapStruct(Cmd);
93   return Cmd;
94 }
95 
96 static const char *
getSectionPtr(const MachOObjectFile & O,MachOObjectFile::LoadCommandInfo L,unsigned Sec)97 getSectionPtr(const MachOObjectFile &O, MachOObjectFile::LoadCommandInfo L,
98               unsigned Sec) {
99   uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
100 
101   bool Is64 = O.is64Bit();
102   unsigned SegmentLoadSize = Is64 ? sizeof(MachO::segment_command_64) :
103                                     sizeof(MachO::segment_command);
104   unsigned SectionSize = Is64 ? sizeof(MachO::section_64) :
105                                 sizeof(MachO::section);
106 
107   uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
108   return reinterpret_cast<const char*>(SectionAddr);
109 }
110 
getPtr(const MachOObjectFile & O,size_t Offset,size_t MachOFilesetEntryOffset=0)111 static const char *getPtr(const MachOObjectFile &O, size_t Offset,
112                           size_t MachOFilesetEntryOffset = 0) {
113   assert(Offset <= O.getData().size() &&
114          MachOFilesetEntryOffset <= O.getData().size());
115   return O.getData().data() + Offset + MachOFilesetEntryOffset;
116 }
117 
118 static MachO::nlist_base
getSymbolTableEntryBase(const MachOObjectFile & O,DataRefImpl DRI)119 getSymbolTableEntryBase(const MachOObjectFile &O, DataRefImpl DRI) {
120   const char *P = reinterpret_cast<const char *>(DRI.p);
121   return getStruct<MachO::nlist_base>(O, P);
122 }
123 
parseSegmentOrSectionName(const char * P)124 static StringRef parseSegmentOrSectionName(const char *P) {
125   if (P[15] == 0)
126     // Null terminated.
127     return P;
128   // Not null terminated, so this is a 16 char string.
129   return StringRef(P, 16);
130 }
131 
getCPUType(const MachOObjectFile & O)132 static unsigned getCPUType(const MachOObjectFile &O) {
133   return O.getHeader().cputype;
134 }
135 
getCPUSubType(const MachOObjectFile & O)136 static unsigned getCPUSubType(const MachOObjectFile &O) {
137   return O.getHeader().cpusubtype;
138 }
139 
140 static uint32_t
getPlainRelocationAddress(const MachO::any_relocation_info & RE)141 getPlainRelocationAddress(const MachO::any_relocation_info &RE) {
142   return RE.r_word0;
143 }
144 
145 static unsigned
getScatteredRelocationAddress(const MachO::any_relocation_info & RE)146 getScatteredRelocationAddress(const MachO::any_relocation_info &RE) {
147   return RE.r_word0 & 0xffffff;
148 }
149 
getPlainRelocationPCRel(const MachOObjectFile & O,const MachO::any_relocation_info & RE)150 static bool getPlainRelocationPCRel(const MachOObjectFile &O,
151                                     const MachO::any_relocation_info &RE) {
152   if (O.isLittleEndian())
153     return (RE.r_word1 >> 24) & 1;
154   return (RE.r_word1 >> 7) & 1;
155 }
156 
157 static bool
getScatteredRelocationPCRel(const MachO::any_relocation_info & RE)158 getScatteredRelocationPCRel(const MachO::any_relocation_info &RE) {
159   return (RE.r_word0 >> 30) & 1;
160 }
161 
getPlainRelocationLength(const MachOObjectFile & O,const MachO::any_relocation_info & RE)162 static unsigned getPlainRelocationLength(const MachOObjectFile &O,
163                                          const MachO::any_relocation_info &RE) {
164   if (O.isLittleEndian())
165     return (RE.r_word1 >> 25) & 3;
166   return (RE.r_word1 >> 5) & 3;
167 }
168 
169 static unsigned
getScatteredRelocationLength(const MachO::any_relocation_info & RE)170 getScatteredRelocationLength(const MachO::any_relocation_info &RE) {
171   return (RE.r_word0 >> 28) & 3;
172 }
173 
getPlainRelocationType(const MachOObjectFile & O,const MachO::any_relocation_info & RE)174 static unsigned getPlainRelocationType(const MachOObjectFile &O,
175                                        const MachO::any_relocation_info &RE) {
176   if (O.isLittleEndian())
177     return RE.r_word1 >> 28;
178   return RE.r_word1 & 0xf;
179 }
180 
getSectionFlags(const MachOObjectFile & O,DataRefImpl Sec)181 static uint32_t getSectionFlags(const MachOObjectFile &O,
182                                 DataRefImpl Sec) {
183   if (O.is64Bit()) {
184     MachO::section_64 Sect = O.getSection64(Sec);
185     return Sect.flags;
186   }
187   MachO::section Sect = O.getSection(Sec);
188   return Sect.flags;
189 }
190 
191 static Expected<MachOObjectFile::LoadCommandInfo>
getLoadCommandInfo(const MachOObjectFile & Obj,const char * Ptr,uint32_t LoadCommandIndex)192 getLoadCommandInfo(const MachOObjectFile &Obj, const char *Ptr,
193                    uint32_t LoadCommandIndex) {
194   if (auto CmdOrErr = getStructOrErr<MachO::load_command>(Obj, Ptr)) {
195     if (CmdOrErr->cmdsize + Ptr > Obj.getData().end())
196       return malformedError("load command " + Twine(LoadCommandIndex) +
197                             " extends past end of file");
198     if (CmdOrErr->cmdsize < 8)
199       return malformedError("load command " + Twine(LoadCommandIndex) +
200                             " with size less than 8 bytes");
201     return MachOObjectFile::LoadCommandInfo({Ptr, *CmdOrErr});
202   } else
203     return CmdOrErr.takeError();
204 }
205 
206 static Expected<MachOObjectFile::LoadCommandInfo>
getFirstLoadCommandInfo(const MachOObjectFile & Obj)207 getFirstLoadCommandInfo(const MachOObjectFile &Obj) {
208   unsigned HeaderSize = Obj.is64Bit() ? sizeof(MachO::mach_header_64)
209                                       : sizeof(MachO::mach_header);
210   if (sizeof(MachO::load_command) > Obj.getHeader().sizeofcmds)
211     return malformedError("load command 0 extends past the end all load "
212                           "commands in the file");
213   return getLoadCommandInfo(
214       Obj, getPtr(Obj, HeaderSize, Obj.getMachOFilesetEntryOffset()), 0);
215 }
216 
217 static Expected<MachOObjectFile::LoadCommandInfo>
getNextLoadCommandInfo(const MachOObjectFile & Obj,uint32_t LoadCommandIndex,const MachOObjectFile::LoadCommandInfo & L)218 getNextLoadCommandInfo(const MachOObjectFile &Obj, uint32_t LoadCommandIndex,
219                        const MachOObjectFile::LoadCommandInfo &L) {
220   unsigned HeaderSize = Obj.is64Bit() ? sizeof(MachO::mach_header_64)
221                                       : sizeof(MachO::mach_header);
222   if (L.Ptr + L.C.cmdsize + sizeof(MachO::load_command) >
223       Obj.getData().data() + Obj.getMachOFilesetEntryOffset() + HeaderSize +
224           Obj.getHeader().sizeofcmds)
225     return malformedError("load command " + Twine(LoadCommandIndex + 1) +
226                           " extends past the end all load commands in the file");
227   return getLoadCommandInfo(Obj, L.Ptr + L.C.cmdsize, LoadCommandIndex + 1);
228 }
229 
230 template <typename T>
parseHeader(const MachOObjectFile & Obj,T & Header,Error & Err)231 static void parseHeader(const MachOObjectFile &Obj, T &Header,
232                         Error &Err) {
233   if (sizeof(T) > Obj.getData().size()) {
234     Err = malformedError("the mach header extends past the end of the "
235                          "file");
236     return;
237   }
238   if (auto HeaderOrErr = getStructOrErr<T>(
239           Obj, getPtr(Obj, 0, Obj.getMachOFilesetEntryOffset())))
240     Header = *HeaderOrErr;
241   else
242     Err = HeaderOrErr.takeError();
243 }
244 
245 // This is used to check for overlapping of Mach-O elements.
246 struct MachOElement {
247   uint64_t Offset;
248   uint64_t Size;
249   const char *Name;
250 };
251 
checkOverlappingElement(std::list<MachOElement> & Elements,uint64_t Offset,uint64_t Size,const char * Name)252 static Error checkOverlappingElement(std::list<MachOElement> &Elements,
253                                      uint64_t Offset, uint64_t Size,
254                                      const char *Name) {
255   if (Size == 0)
256     return Error::success();
257 
258   for (auto it = Elements.begin(); it != Elements.end(); ++it) {
259     const auto &E = *it;
260     if ((Offset >= E.Offset && Offset < E.Offset + E.Size) ||
261         (Offset + Size > E.Offset && Offset + Size < E.Offset + E.Size) ||
262         (Offset <= E.Offset && Offset + Size >= E.Offset + E.Size))
263       return malformedError(Twine(Name) + " at offset " + Twine(Offset) +
264                             " with a size of " + Twine(Size) + ", overlaps " +
265                             E.Name + " at offset " + Twine(E.Offset) + " with "
266                             "a size of " + Twine(E.Size));
267     auto nt = it;
268     nt++;
269     if (nt != Elements.end()) {
270       const auto &N = *nt;
271       if (Offset + Size <= N.Offset) {
272         Elements.insert(nt, {Offset, Size, Name});
273         return Error::success();
274       }
275     }
276   }
277   Elements.push_back({Offset, Size, Name});
278   return Error::success();
279 }
280 
281 // Parses LC_SEGMENT or LC_SEGMENT_64 load command, adds addresses of all
282 // sections to \param Sections, and optionally sets
283 // \param IsPageZeroSegment to true.
284 template <typename Segment, typename Section>
parseSegmentLoadCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,SmallVectorImpl<const char * > & Sections,bool & IsPageZeroSegment,uint32_t LoadCommandIndex,const char * CmdName,uint64_t SizeOfHeaders,std::list<MachOElement> & Elements)285 static Error parseSegmentLoadCommand(
286     const MachOObjectFile &Obj, const MachOObjectFile::LoadCommandInfo &Load,
287     SmallVectorImpl<const char *> &Sections, bool &IsPageZeroSegment,
288     uint32_t LoadCommandIndex, const char *CmdName, uint64_t SizeOfHeaders,
289     std::list<MachOElement> &Elements) {
290   const unsigned SegmentLoadSize = sizeof(Segment);
291   if (Load.C.cmdsize < SegmentLoadSize)
292     return malformedError("load command " + Twine(LoadCommandIndex) +
293                           " " + CmdName + " cmdsize too small");
294   if (auto SegOrErr = getStructOrErr<Segment>(Obj, Load.Ptr)) {
295     Segment S = SegOrErr.get();
296     const unsigned SectionSize = sizeof(Section);
297     uint64_t FileSize = Obj.getData().size();
298     if (S.nsects > std::numeric_limits<uint32_t>::max() / SectionSize ||
299         S.nsects * SectionSize > Load.C.cmdsize - SegmentLoadSize)
300       return malformedError("load command " + Twine(LoadCommandIndex) +
301                             " inconsistent cmdsize in " + CmdName +
302                             " for the number of sections");
303     for (unsigned J = 0; J < S.nsects; ++J) {
304       const char *Sec = getSectionPtr(Obj, Load, J);
305       Sections.push_back(Sec);
306       auto SectionOrErr = getStructOrErr<Section>(Obj, Sec);
307       if (!SectionOrErr)
308         return SectionOrErr.takeError();
309       Section s = SectionOrErr.get();
310       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
311           Obj.getHeader().filetype != MachO::MH_DSYM &&
312           s.flags != MachO::S_ZEROFILL &&
313           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
314           s.offset > FileSize)
315         return malformedError("offset field of section " + Twine(J) + " in " +
316                               CmdName + " command " + Twine(LoadCommandIndex) +
317                               " extends past the end of the file");
318       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
319           Obj.getHeader().filetype != MachO::MH_DSYM &&
320           s.flags != MachO::S_ZEROFILL &&
321           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL && S.fileoff == 0 &&
322           s.offset < SizeOfHeaders && s.size != 0)
323         return malformedError("offset field of section " + Twine(J) + " in " +
324                               CmdName + " command " + Twine(LoadCommandIndex) +
325                               " not past the headers of the file");
326       uint64_t BigSize = s.offset;
327       BigSize += s.size;
328       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
329           Obj.getHeader().filetype != MachO::MH_DSYM &&
330           s.flags != MachO::S_ZEROFILL &&
331           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
332           BigSize > FileSize)
333         return malformedError("offset field plus size field of section " +
334                               Twine(J) + " in " + CmdName + " command " +
335                               Twine(LoadCommandIndex) +
336                               " extends past the end of the file");
337       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
338           Obj.getHeader().filetype != MachO::MH_DSYM &&
339           s.flags != MachO::S_ZEROFILL &&
340           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
341           s.size > S.filesize)
342         return malformedError("size field of section " +
343                               Twine(J) + " in " + CmdName + " command " +
344                               Twine(LoadCommandIndex) +
345                               " greater than the segment");
346       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
347           Obj.getHeader().filetype != MachO::MH_DSYM && s.size != 0 &&
348           s.addr < S.vmaddr)
349         return malformedError("addr field of section " + Twine(J) + " in " +
350                               CmdName + " command " + Twine(LoadCommandIndex) +
351                               " less than the segment's vmaddr");
352       BigSize = s.addr;
353       BigSize += s.size;
354       uint64_t BigEnd = S.vmaddr;
355       BigEnd += S.vmsize;
356       if (S.vmsize != 0 && s.size != 0 && BigSize > BigEnd)
357         return malformedError("addr field plus size of section " + Twine(J) +
358                               " in " + CmdName + " command " +
359                               Twine(LoadCommandIndex) +
360                               " greater than than "
361                               "the segment's vmaddr plus vmsize");
362       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
363           Obj.getHeader().filetype != MachO::MH_DSYM &&
364           s.flags != MachO::S_ZEROFILL &&
365           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL)
366         if (Error Err = checkOverlappingElement(Elements, s.offset, s.size,
367                                                 "section contents"))
368           return Err;
369       if (s.reloff > FileSize)
370         return malformedError("reloff field of section " + Twine(J) + " in " +
371                               CmdName + " command " + Twine(LoadCommandIndex) +
372                               " extends past the end of the file");
373       BigSize = s.nreloc;
374       BigSize *= sizeof(struct MachO::relocation_info);
375       BigSize += s.reloff;
376       if (BigSize > FileSize)
377         return malformedError("reloff field plus nreloc field times sizeof("
378                               "struct relocation_info) of section " +
379                               Twine(J) + " in " + CmdName + " command " +
380                               Twine(LoadCommandIndex) +
381                               " extends past the end of the file");
382       if (Error Err = checkOverlappingElement(Elements, s.reloff, s.nreloc *
383                                               sizeof(struct
384                                               MachO::relocation_info),
385                                               "section relocation entries"))
386         return Err;
387     }
388     if (S.fileoff > FileSize)
389       return malformedError("load command " + Twine(LoadCommandIndex) +
390                             " fileoff field in " + CmdName +
391                             " extends past the end of the file");
392     uint64_t BigSize = S.fileoff;
393     BigSize += S.filesize;
394     if (BigSize > FileSize)
395       return malformedError("load command " + Twine(LoadCommandIndex) +
396                             " fileoff field plus filesize field in " +
397                             CmdName + " extends past the end of the file");
398     if (S.vmsize != 0 && S.filesize > S.vmsize)
399       return malformedError("load command " + Twine(LoadCommandIndex) +
400                             " filesize field in " + CmdName +
401                             " greater than vmsize field");
402     IsPageZeroSegment |= StringRef("__PAGEZERO") == S.segname;
403   } else
404     return SegOrErr.takeError();
405 
406   return Error::success();
407 }
408 
checkSymtabCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char ** SymtabLoadCmd,std::list<MachOElement> & Elements)409 static Error checkSymtabCommand(const MachOObjectFile &Obj,
410                                 const MachOObjectFile::LoadCommandInfo &Load,
411                                 uint32_t LoadCommandIndex,
412                                 const char **SymtabLoadCmd,
413                                 std::list<MachOElement> &Elements) {
414   if (Load.C.cmdsize < sizeof(MachO::symtab_command))
415     return malformedError("load command " + Twine(LoadCommandIndex) +
416                           " LC_SYMTAB cmdsize too small");
417   if (*SymtabLoadCmd != nullptr)
418     return malformedError("more than one LC_SYMTAB command");
419   auto SymtabOrErr = getStructOrErr<MachO::symtab_command>(Obj, Load.Ptr);
420   if (!SymtabOrErr)
421     return SymtabOrErr.takeError();
422   MachO::symtab_command Symtab = SymtabOrErr.get();
423   if (Symtab.cmdsize != sizeof(MachO::symtab_command))
424     return malformedError("LC_SYMTAB command " + Twine(LoadCommandIndex) +
425                           " has incorrect cmdsize");
426   uint64_t FileSize = Obj.getData().size();
427   if (Symtab.symoff > FileSize)
428     return malformedError("symoff field of LC_SYMTAB command " +
429                           Twine(LoadCommandIndex) + " extends past the end "
430                           "of the file");
431   uint64_t SymtabSize = Symtab.nsyms;
432   const char *struct_nlist_name;
433   if (Obj.is64Bit()) {
434     SymtabSize *= sizeof(MachO::nlist_64);
435     struct_nlist_name = "struct nlist_64";
436   } else {
437     SymtabSize *= sizeof(MachO::nlist);
438     struct_nlist_name = "struct nlist";
439   }
440   uint64_t BigSize = SymtabSize;
441   BigSize += Symtab.symoff;
442   if (BigSize > FileSize)
443     return malformedError("symoff field plus nsyms field times sizeof(" +
444                           Twine(struct_nlist_name) + ") of LC_SYMTAB command " +
445                           Twine(LoadCommandIndex) + " extends past the end "
446                           "of the file");
447   if (Error Err = checkOverlappingElement(Elements, Symtab.symoff, SymtabSize,
448                                           "symbol table"))
449     return Err;
450   if (Symtab.stroff > FileSize)
451     return malformedError("stroff field of LC_SYMTAB command " +
452                           Twine(LoadCommandIndex) + " extends past the end "
453                           "of the file");
454   BigSize = Symtab.stroff;
455   BigSize += Symtab.strsize;
456   if (BigSize > FileSize)
457     return malformedError("stroff field plus strsize field of LC_SYMTAB "
458                           "command " + Twine(LoadCommandIndex) + " extends "
459                           "past the end of the file");
460   if (Error Err = checkOverlappingElement(Elements, Symtab.stroff,
461                                           Symtab.strsize, "string table"))
462     return Err;
463   *SymtabLoadCmd = Load.Ptr;
464   return Error::success();
465 }
466 
checkDysymtabCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char ** DysymtabLoadCmd,std::list<MachOElement> & Elements)467 static Error checkDysymtabCommand(const MachOObjectFile &Obj,
468                                   const MachOObjectFile::LoadCommandInfo &Load,
469                                   uint32_t LoadCommandIndex,
470                                   const char **DysymtabLoadCmd,
471                                   std::list<MachOElement> &Elements) {
472   if (Load.C.cmdsize < sizeof(MachO::dysymtab_command))
473     return malformedError("load command " + Twine(LoadCommandIndex) +
474                           " LC_DYSYMTAB cmdsize too small");
475   if (*DysymtabLoadCmd != nullptr)
476     return malformedError("more than one LC_DYSYMTAB command");
477   auto DysymtabOrErr =
478     getStructOrErr<MachO::dysymtab_command>(Obj, Load.Ptr);
479   if (!DysymtabOrErr)
480     return DysymtabOrErr.takeError();
481   MachO::dysymtab_command Dysymtab = DysymtabOrErr.get();
482   if (Dysymtab.cmdsize != sizeof(MachO::dysymtab_command))
483     return malformedError("LC_DYSYMTAB command " + Twine(LoadCommandIndex) +
484                           " has incorrect cmdsize");
485   uint64_t FileSize = Obj.getData().size();
486   if (Dysymtab.tocoff > FileSize)
487     return malformedError("tocoff field of LC_DYSYMTAB command " +
488                           Twine(LoadCommandIndex) + " extends past the end of "
489                           "the file");
490   uint64_t BigSize = Dysymtab.ntoc;
491   BigSize *= sizeof(MachO::dylib_table_of_contents);
492   BigSize += Dysymtab.tocoff;
493   if (BigSize > FileSize)
494     return malformedError("tocoff field plus ntoc field times sizeof(struct "
495                           "dylib_table_of_contents) of LC_DYSYMTAB command " +
496                           Twine(LoadCommandIndex) + " extends past the end of "
497                           "the file");
498   if (Error Err = checkOverlappingElement(Elements, Dysymtab.tocoff,
499                                           Dysymtab.ntoc * sizeof(struct
500                                           MachO::dylib_table_of_contents),
501                                           "table of contents"))
502     return Err;
503   if (Dysymtab.modtaboff > FileSize)
504     return malformedError("modtaboff field of LC_DYSYMTAB command " +
505                           Twine(LoadCommandIndex) + " extends past the end of "
506                           "the file");
507   BigSize = Dysymtab.nmodtab;
508   const char *struct_dylib_module_name;
509   uint64_t sizeof_modtab;
510   if (Obj.is64Bit()) {
511     sizeof_modtab = sizeof(MachO::dylib_module_64);
512     struct_dylib_module_name = "struct dylib_module_64";
513   } else {
514     sizeof_modtab = sizeof(MachO::dylib_module);
515     struct_dylib_module_name = "struct dylib_module";
516   }
517   BigSize *= sizeof_modtab;
518   BigSize += Dysymtab.modtaboff;
519   if (BigSize > FileSize)
520     return malformedError("modtaboff field plus nmodtab field times sizeof(" +
521                           Twine(struct_dylib_module_name) + ") of LC_DYSYMTAB "
522                           "command " + Twine(LoadCommandIndex) + " extends "
523                           "past the end of the file");
524   if (Error Err = checkOverlappingElement(Elements, Dysymtab.modtaboff,
525                                           Dysymtab.nmodtab * sizeof_modtab,
526                                           "module table"))
527     return Err;
528   if (Dysymtab.extrefsymoff > FileSize)
529     return malformedError("extrefsymoff field of LC_DYSYMTAB command " +
530                           Twine(LoadCommandIndex) + " extends past the end of "
531                           "the file");
532   BigSize = Dysymtab.nextrefsyms;
533   BigSize *= sizeof(MachO::dylib_reference);
534   BigSize += Dysymtab.extrefsymoff;
535   if (BigSize > FileSize)
536     return malformedError("extrefsymoff field plus nextrefsyms field times "
537                           "sizeof(struct dylib_reference) of LC_DYSYMTAB "
538                           "command " + Twine(LoadCommandIndex) + " extends "
539                           "past the end of the file");
540   if (Error Err = checkOverlappingElement(Elements, Dysymtab.extrefsymoff,
541                                           Dysymtab.nextrefsyms *
542                                               sizeof(MachO::dylib_reference),
543                                           "reference table"))
544     return Err;
545   if (Dysymtab.indirectsymoff > FileSize)
546     return malformedError("indirectsymoff field of LC_DYSYMTAB command " +
547                           Twine(LoadCommandIndex) + " extends past the end of "
548                           "the file");
549   BigSize = Dysymtab.nindirectsyms;
550   BigSize *= sizeof(uint32_t);
551   BigSize += Dysymtab.indirectsymoff;
552   if (BigSize > FileSize)
553     return malformedError("indirectsymoff field plus nindirectsyms field times "
554                           "sizeof(uint32_t) of LC_DYSYMTAB command " +
555                           Twine(LoadCommandIndex) + " extends past the end of "
556                           "the file");
557   if (Error Err = checkOverlappingElement(Elements, Dysymtab.indirectsymoff,
558                                           Dysymtab.nindirectsyms *
559                                           sizeof(uint32_t),
560                                           "indirect table"))
561     return Err;
562   if (Dysymtab.extreloff > FileSize)
563     return malformedError("extreloff field of LC_DYSYMTAB command " +
564                           Twine(LoadCommandIndex) + " extends past the end of "
565                           "the file");
566   BigSize = Dysymtab.nextrel;
567   BigSize *= sizeof(MachO::relocation_info);
568   BigSize += Dysymtab.extreloff;
569   if (BigSize > FileSize)
570     return malformedError("extreloff field plus nextrel field times sizeof"
571                           "(struct relocation_info) of LC_DYSYMTAB command " +
572                           Twine(LoadCommandIndex) + " extends past the end of "
573                           "the file");
574   if (Error Err = checkOverlappingElement(Elements, Dysymtab.extreloff,
575                                           Dysymtab.nextrel *
576                                               sizeof(MachO::relocation_info),
577                                           "external relocation table"))
578     return Err;
579   if (Dysymtab.locreloff > FileSize)
580     return malformedError("locreloff field of LC_DYSYMTAB command " +
581                           Twine(LoadCommandIndex) + " extends past the end of "
582                           "the file");
583   BigSize = Dysymtab.nlocrel;
584   BigSize *= sizeof(MachO::relocation_info);
585   BigSize += Dysymtab.locreloff;
586   if (BigSize > FileSize)
587     return malformedError("locreloff field plus nlocrel field times sizeof"
588                           "(struct relocation_info) of LC_DYSYMTAB command " +
589                           Twine(LoadCommandIndex) + " extends past the end of "
590                           "the file");
591   if (Error Err = checkOverlappingElement(Elements, Dysymtab.locreloff,
592                                           Dysymtab.nlocrel *
593                                               sizeof(MachO::relocation_info),
594                                           "local relocation table"))
595     return Err;
596   *DysymtabLoadCmd = Load.Ptr;
597   return Error::success();
598 }
599 
checkLinkeditDataCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char ** LoadCmd,const char * CmdName,std::list<MachOElement> & Elements,const char * ElementName)600 static Error checkLinkeditDataCommand(const MachOObjectFile &Obj,
601                                  const MachOObjectFile::LoadCommandInfo &Load,
602                                  uint32_t LoadCommandIndex,
603                                  const char **LoadCmd, const char *CmdName,
604                                  std::list<MachOElement> &Elements,
605                                  const char *ElementName) {
606   if (Load.C.cmdsize < sizeof(MachO::linkedit_data_command))
607     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
608                           CmdName + " cmdsize too small");
609   if (*LoadCmd != nullptr)
610     return malformedError("more than one " + Twine(CmdName) + " command");
611   auto LinkDataOrError =
612     getStructOrErr<MachO::linkedit_data_command>(Obj, Load.Ptr);
613   if (!LinkDataOrError)
614     return LinkDataOrError.takeError();
615   MachO::linkedit_data_command LinkData = LinkDataOrError.get();
616   if (LinkData.cmdsize != sizeof(MachO::linkedit_data_command))
617     return malformedError(Twine(CmdName) + " command " +
618                           Twine(LoadCommandIndex) + " has incorrect cmdsize");
619   uint64_t FileSize = Obj.getData().size();
620   if (LinkData.dataoff > FileSize)
621     return malformedError("dataoff field of " + Twine(CmdName) + " command " +
622                           Twine(LoadCommandIndex) + " extends past the end of "
623                           "the file");
624   uint64_t BigSize = LinkData.dataoff;
625   BigSize += LinkData.datasize;
626   if (BigSize > FileSize)
627     return malformedError("dataoff field plus datasize field of " +
628                           Twine(CmdName) + " command " +
629                           Twine(LoadCommandIndex) + " extends past the end of "
630                           "the file");
631   if (Error Err = checkOverlappingElement(Elements, LinkData.dataoff,
632                                           LinkData.datasize, ElementName))
633     return Err;
634   *LoadCmd = Load.Ptr;
635   return Error::success();
636 }
637 
checkDyldInfoCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char ** LoadCmd,const char * CmdName,std::list<MachOElement> & Elements)638 static Error checkDyldInfoCommand(const MachOObjectFile &Obj,
639                                   const MachOObjectFile::LoadCommandInfo &Load,
640                                   uint32_t LoadCommandIndex,
641                                   const char **LoadCmd, const char *CmdName,
642                                   std::list<MachOElement> &Elements) {
643   if (Load.C.cmdsize < sizeof(MachO::dyld_info_command))
644     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
645                           CmdName + " cmdsize too small");
646   if (*LoadCmd != nullptr)
647     return malformedError("more than one LC_DYLD_INFO and or LC_DYLD_INFO_ONLY "
648                           "command");
649   auto DyldInfoOrErr =
650     getStructOrErr<MachO::dyld_info_command>(Obj, Load.Ptr);
651   if (!DyldInfoOrErr)
652     return DyldInfoOrErr.takeError();
653   MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
654   if (DyldInfo.cmdsize != sizeof(MachO::dyld_info_command))
655     return malformedError(Twine(CmdName) + " command " +
656                           Twine(LoadCommandIndex) + " has incorrect cmdsize");
657   uint64_t FileSize = Obj.getData().size();
658   if (DyldInfo.rebase_off > FileSize)
659     return malformedError("rebase_off field of " + Twine(CmdName) +
660                           " command " + Twine(LoadCommandIndex) + " extends "
661                           "past the end of the file");
662   uint64_t BigSize = DyldInfo.rebase_off;
663   BigSize += DyldInfo.rebase_size;
664   if (BigSize > FileSize)
665     return malformedError("rebase_off field plus rebase_size field of " +
666                           Twine(CmdName) + " command " +
667                           Twine(LoadCommandIndex) + " extends past the end of "
668                           "the file");
669   if (Error Err = checkOverlappingElement(Elements, DyldInfo.rebase_off,
670                                           DyldInfo.rebase_size,
671                                           "dyld rebase info"))
672     return Err;
673   if (DyldInfo.bind_off > FileSize)
674     return malformedError("bind_off field of " + Twine(CmdName) +
675                           " command " + Twine(LoadCommandIndex) + " extends "
676                           "past the end of the file");
677   BigSize = DyldInfo.bind_off;
678   BigSize += DyldInfo.bind_size;
679   if (BigSize > FileSize)
680     return malformedError("bind_off field plus bind_size field of " +
681                           Twine(CmdName) + " command " +
682                           Twine(LoadCommandIndex) + " extends past the end of "
683                           "the file");
684   if (Error Err = checkOverlappingElement(Elements, DyldInfo.bind_off,
685                                           DyldInfo.bind_size,
686                                           "dyld bind info"))
687     return Err;
688   if (DyldInfo.weak_bind_off > FileSize)
689     return malformedError("weak_bind_off field of " + Twine(CmdName) +
690                           " command " + Twine(LoadCommandIndex) + " extends "
691                           "past the end of the file");
692   BigSize = DyldInfo.weak_bind_off;
693   BigSize += DyldInfo.weak_bind_size;
694   if (BigSize > FileSize)
695     return malformedError("weak_bind_off field plus weak_bind_size field of " +
696                           Twine(CmdName) + " command " +
697                           Twine(LoadCommandIndex) + " extends past the end of "
698                           "the file");
699   if (Error Err = checkOverlappingElement(Elements, DyldInfo.weak_bind_off,
700                                           DyldInfo.weak_bind_size,
701                                           "dyld weak bind info"))
702     return Err;
703   if (DyldInfo.lazy_bind_off > FileSize)
704     return malformedError("lazy_bind_off field of " + Twine(CmdName) +
705                           " command " + Twine(LoadCommandIndex) + " extends "
706                           "past the end of the file");
707   BigSize = DyldInfo.lazy_bind_off;
708   BigSize += DyldInfo.lazy_bind_size;
709   if (BigSize > FileSize)
710     return malformedError("lazy_bind_off field plus lazy_bind_size field of " +
711                           Twine(CmdName) + " command " +
712                           Twine(LoadCommandIndex) + " extends past the end of "
713                           "the file");
714   if (Error Err = checkOverlappingElement(Elements, DyldInfo.lazy_bind_off,
715                                           DyldInfo.lazy_bind_size,
716                                           "dyld lazy bind info"))
717     return Err;
718   if (DyldInfo.export_off > FileSize)
719     return malformedError("export_off field of " + Twine(CmdName) +
720                           " command " + Twine(LoadCommandIndex) + " extends "
721                           "past the end of the file");
722   BigSize = DyldInfo.export_off;
723   BigSize += DyldInfo.export_size;
724   if (BigSize > FileSize)
725     return malformedError("export_off field plus export_size field of " +
726                           Twine(CmdName) + " command " +
727                           Twine(LoadCommandIndex) + " extends past the end of "
728                           "the file");
729   if (Error Err = checkOverlappingElement(Elements, DyldInfo.export_off,
730                                           DyldInfo.export_size,
731                                           "dyld export info"))
732     return Err;
733   *LoadCmd = Load.Ptr;
734   return Error::success();
735 }
736 
checkDylibCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char * CmdName)737 static Error checkDylibCommand(const MachOObjectFile &Obj,
738                                const MachOObjectFile::LoadCommandInfo &Load,
739                                uint32_t LoadCommandIndex, const char *CmdName) {
740   if (Load.C.cmdsize < sizeof(MachO::dylib_command))
741     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
742                           CmdName + " cmdsize too small");
743   auto CommandOrErr = getStructOrErr<MachO::dylib_command>(Obj, Load.Ptr);
744   if (!CommandOrErr)
745     return CommandOrErr.takeError();
746   MachO::dylib_command D = CommandOrErr.get();
747   if (D.dylib.name < sizeof(MachO::dylib_command))
748     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
749                           CmdName + " name.offset field too small, not past "
750                           "the end of the dylib_command struct");
751   if (D.dylib.name >= D.cmdsize)
752     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
753                           CmdName + " name.offset field extends past the end "
754                           "of the load command");
755   // Make sure there is a null between the starting offset of the name and
756   // the end of the load command.
757   uint32_t i;
758   const char *P = (const char *)Load.Ptr;
759   for (i = D.dylib.name; i < D.cmdsize; i++)
760     if (P[i] == '\0')
761       break;
762   if (i >= D.cmdsize)
763     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
764                           CmdName + " library name extends past the end of the "
765                           "load command");
766   return Error::success();
767 }
768 
checkDylibIdCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char ** LoadCmd)769 static Error checkDylibIdCommand(const MachOObjectFile &Obj,
770                                  const MachOObjectFile::LoadCommandInfo &Load,
771                                  uint32_t LoadCommandIndex,
772                                  const char **LoadCmd) {
773   if (Error Err = checkDylibCommand(Obj, Load, LoadCommandIndex,
774                                      "LC_ID_DYLIB"))
775     return Err;
776   if (*LoadCmd != nullptr)
777     return malformedError("more than one LC_ID_DYLIB command");
778   if (Obj.getHeader().filetype != MachO::MH_DYLIB &&
779       Obj.getHeader().filetype != MachO::MH_DYLIB_STUB)
780     return malformedError("LC_ID_DYLIB load command in non-dynamic library "
781                           "file type");
782   *LoadCmd = Load.Ptr;
783   return Error::success();
784 }
785 
checkDyldCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char * CmdName)786 static Error checkDyldCommand(const MachOObjectFile &Obj,
787                               const MachOObjectFile::LoadCommandInfo &Load,
788                               uint32_t LoadCommandIndex, const char *CmdName) {
789   if (Load.C.cmdsize < sizeof(MachO::dylinker_command))
790     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
791                           CmdName + " cmdsize too small");
792   auto CommandOrErr = getStructOrErr<MachO::dylinker_command>(Obj, Load.Ptr);
793   if (!CommandOrErr)
794     return CommandOrErr.takeError();
795   MachO::dylinker_command D = CommandOrErr.get();
796   if (D.name < sizeof(MachO::dylinker_command))
797     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
798                           CmdName + " name.offset field too small, not past "
799                           "the end of the dylinker_command struct");
800   if (D.name >= D.cmdsize)
801     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
802                           CmdName + " name.offset field extends past the end "
803                           "of the load command");
804   // Make sure there is a null between the starting offset of the name and
805   // the end of the load command.
806   uint32_t i;
807   const char *P = (const char *)Load.Ptr;
808   for (i = D.name; i < D.cmdsize; i++)
809     if (P[i] == '\0')
810       break;
811   if (i >= D.cmdsize)
812     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
813                           CmdName + " dyld name extends past the end of the "
814                           "load command");
815   return Error::success();
816 }
817 
checkVersCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char ** LoadCmd,const char * CmdName)818 static Error checkVersCommand(const MachOObjectFile &Obj,
819                               const MachOObjectFile::LoadCommandInfo &Load,
820                               uint32_t LoadCommandIndex,
821                               const char **LoadCmd, const char *CmdName) {
822   if (Load.C.cmdsize != sizeof(MachO::version_min_command))
823     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
824                           CmdName + " has incorrect cmdsize");
825   if (*LoadCmd != nullptr)
826     return malformedError("more than one LC_VERSION_MIN_MACOSX, "
827                           "LC_VERSION_MIN_IPHONEOS, LC_VERSION_MIN_TVOS or "
828                           "LC_VERSION_MIN_WATCHOS command");
829   *LoadCmd = Load.Ptr;
830   return Error::success();
831 }
832 
checkNoteCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,std::list<MachOElement> & Elements)833 static Error checkNoteCommand(const MachOObjectFile &Obj,
834                               const MachOObjectFile::LoadCommandInfo &Load,
835                               uint32_t LoadCommandIndex,
836                               std::list<MachOElement> &Elements) {
837   if (Load.C.cmdsize != sizeof(MachO::note_command))
838     return malformedError("load command " + Twine(LoadCommandIndex) +
839                           " LC_NOTE has incorrect cmdsize");
840   auto NoteCmdOrErr = getStructOrErr<MachO::note_command>(Obj, Load.Ptr);
841   if (!NoteCmdOrErr)
842     return NoteCmdOrErr.takeError();
843   MachO::note_command Nt = NoteCmdOrErr.get();
844   uint64_t FileSize = Obj.getData().size();
845   if (Nt.offset > FileSize)
846     return malformedError("offset field of LC_NOTE command " +
847                           Twine(LoadCommandIndex) + " extends "
848                           "past the end of the file");
849   uint64_t BigSize = Nt.offset;
850   BigSize += Nt.size;
851   if (BigSize > FileSize)
852     return malformedError("size field plus offset field of LC_NOTE command " +
853                           Twine(LoadCommandIndex) + " extends past the end of "
854                           "the file");
855   if (Error Err = checkOverlappingElement(Elements, Nt.offset, Nt.size,
856                                           "LC_NOTE data"))
857     return Err;
858   return Error::success();
859 }
860 
861 static Error
parseBuildVersionCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,SmallVectorImpl<const char * > & BuildTools,uint32_t LoadCommandIndex)862 parseBuildVersionCommand(const MachOObjectFile &Obj,
863                          const MachOObjectFile::LoadCommandInfo &Load,
864                          SmallVectorImpl<const char*> &BuildTools,
865                          uint32_t LoadCommandIndex) {
866   auto BVCOrErr =
867     getStructOrErr<MachO::build_version_command>(Obj, Load.Ptr);
868   if (!BVCOrErr)
869     return BVCOrErr.takeError();
870   MachO::build_version_command BVC = BVCOrErr.get();
871   if (Load.C.cmdsize !=
872       sizeof(MachO::build_version_command) +
873           BVC.ntools * sizeof(MachO::build_tool_version))
874     return malformedError("load command " + Twine(LoadCommandIndex) +
875                           " LC_BUILD_VERSION_COMMAND has incorrect cmdsize");
876 
877   auto Start = Load.Ptr + sizeof(MachO::build_version_command);
878   BuildTools.resize(BVC.ntools);
879   for (unsigned i = 0; i < BVC.ntools; ++i)
880     BuildTools[i] = Start + i * sizeof(MachO::build_tool_version);
881 
882   return Error::success();
883 }
884 
checkRpathCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex)885 static Error checkRpathCommand(const MachOObjectFile &Obj,
886                                const MachOObjectFile::LoadCommandInfo &Load,
887                                uint32_t LoadCommandIndex) {
888   if (Load.C.cmdsize < sizeof(MachO::rpath_command))
889     return malformedError("load command " + Twine(LoadCommandIndex) +
890                           " LC_RPATH cmdsize too small");
891   auto ROrErr = getStructOrErr<MachO::rpath_command>(Obj, Load.Ptr);
892   if (!ROrErr)
893     return ROrErr.takeError();
894   MachO::rpath_command R = ROrErr.get();
895   if (R.path < sizeof(MachO::rpath_command))
896     return malformedError("load command " + Twine(LoadCommandIndex) +
897                           " LC_RPATH path.offset field too small, not past "
898                           "the end of the rpath_command struct");
899   if (R.path >= R.cmdsize)
900     return malformedError("load command " + Twine(LoadCommandIndex) +
901                           " LC_RPATH path.offset field extends past the end "
902                           "of the load command");
903   // Make sure there is a null between the starting offset of the path and
904   // the end of the load command.
905   uint32_t i;
906   const char *P = (const char *)Load.Ptr;
907   for (i = R.path; i < R.cmdsize; i++)
908     if (P[i] == '\0')
909       break;
910   if (i >= R.cmdsize)
911     return malformedError("load command " + Twine(LoadCommandIndex) +
912                           " LC_RPATH library name extends past the end of the "
913                           "load command");
914   return Error::success();
915 }
916 
checkEncryptCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,uint64_t cryptoff,uint64_t cryptsize,const char ** LoadCmd,const char * CmdName)917 static Error checkEncryptCommand(const MachOObjectFile &Obj,
918                                  const MachOObjectFile::LoadCommandInfo &Load,
919                                  uint32_t LoadCommandIndex,
920                                  uint64_t cryptoff, uint64_t cryptsize,
921                                  const char **LoadCmd, const char *CmdName) {
922   if (*LoadCmd != nullptr)
923     return malformedError("more than one LC_ENCRYPTION_INFO and or "
924                           "LC_ENCRYPTION_INFO_64 command");
925   uint64_t FileSize = Obj.getData().size();
926   if (cryptoff > FileSize)
927     return malformedError("cryptoff field of " + Twine(CmdName) +
928                           " command " + Twine(LoadCommandIndex) + " extends "
929                           "past the end of the file");
930   uint64_t BigSize = cryptoff;
931   BigSize += cryptsize;
932   if (BigSize > FileSize)
933     return malformedError("cryptoff field plus cryptsize field of " +
934                           Twine(CmdName) + " command " +
935                           Twine(LoadCommandIndex) + " extends past the end of "
936                           "the file");
937   *LoadCmd = Load.Ptr;
938   return Error::success();
939 }
940 
checkLinkerOptCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex)941 static Error checkLinkerOptCommand(const MachOObjectFile &Obj,
942                                    const MachOObjectFile::LoadCommandInfo &Load,
943                                    uint32_t LoadCommandIndex) {
944   if (Load.C.cmdsize < sizeof(MachO::linker_option_command))
945     return malformedError("load command " + Twine(LoadCommandIndex) +
946                           " LC_LINKER_OPTION cmdsize too small");
947   auto LinkOptionOrErr =
948     getStructOrErr<MachO::linker_option_command>(Obj, Load.Ptr);
949   if (!LinkOptionOrErr)
950     return LinkOptionOrErr.takeError();
951   MachO::linker_option_command L = LinkOptionOrErr.get();
952   // Make sure the count of strings is correct.
953   const char *string = (const char *)Load.Ptr +
954                        sizeof(struct MachO::linker_option_command);
955   uint32_t left = L.cmdsize - sizeof(struct MachO::linker_option_command);
956   uint32_t i = 0;
957   while (left > 0) {
958     while (*string == '\0' && left > 0) {
959       string++;
960       left--;
961     }
962     if (left > 0) {
963       i++;
964       uint32_t NullPos = StringRef(string, left).find('\0');
965       if (0xffffffff == NullPos)
966         return malformedError("load command " + Twine(LoadCommandIndex) +
967                               " LC_LINKER_OPTION string #" + Twine(i) +
968                               " is not NULL terminated");
969       uint32_t len = std::min(NullPos, left) + 1;
970       string += len;
971       left -= len;
972     }
973   }
974   if (L.count != i)
975     return malformedError("load command " + Twine(LoadCommandIndex) +
976                           " LC_LINKER_OPTION string count " + Twine(L.count) +
977                           " does not match number of strings");
978   return Error::success();
979 }
980 
checkSubCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char * CmdName,size_t SizeOfCmd,const char * CmdStructName,uint32_t PathOffset,const char * PathFieldName)981 static Error checkSubCommand(const MachOObjectFile &Obj,
982                              const MachOObjectFile::LoadCommandInfo &Load,
983                              uint32_t LoadCommandIndex, const char *CmdName,
984                              size_t SizeOfCmd, const char *CmdStructName,
985                              uint32_t PathOffset, const char *PathFieldName) {
986   if (PathOffset < SizeOfCmd)
987     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
988                           CmdName + " " + PathFieldName + ".offset field too "
989                           "small, not past the end of the " + CmdStructName);
990   if (PathOffset >= Load.C.cmdsize)
991     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
992                           CmdName + " " + PathFieldName + ".offset field "
993                           "extends past the end of the load command");
994   // Make sure there is a null between the starting offset of the path and
995   // the end of the load command.
996   uint32_t i;
997   const char *P = (const char *)Load.Ptr;
998   for (i = PathOffset; i < Load.C.cmdsize; i++)
999     if (P[i] == '\0')
1000       break;
1001   if (i >= Load.C.cmdsize)
1002     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
1003                           CmdName + " " + PathFieldName + " name extends past "
1004                           "the end of the load command");
1005   return Error::success();
1006 }
1007 
checkThreadCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char * CmdName)1008 static Error checkThreadCommand(const MachOObjectFile &Obj,
1009                                 const MachOObjectFile::LoadCommandInfo &Load,
1010                                 uint32_t LoadCommandIndex,
1011                                 const char *CmdName) {
1012   if (Load.C.cmdsize < sizeof(MachO::thread_command))
1013     return malformedError("load command " + Twine(LoadCommandIndex) +
1014                           CmdName + " cmdsize too small");
1015   auto ThreadCommandOrErr =
1016     getStructOrErr<MachO::thread_command>(Obj, Load.Ptr);
1017   if (!ThreadCommandOrErr)
1018     return ThreadCommandOrErr.takeError();
1019   MachO::thread_command T = ThreadCommandOrErr.get();
1020   const char *state = Load.Ptr + sizeof(MachO::thread_command);
1021   const char *end = Load.Ptr + T.cmdsize;
1022   uint32_t nflavor = 0;
1023   uint32_t cputype = getCPUType(Obj);
1024   while (state < end) {
1025     if(state + sizeof(uint32_t) > end)
1026       return malformedError("load command " + Twine(LoadCommandIndex) +
1027                             "flavor in " + CmdName + " extends past end of "
1028                             "command");
1029     uint32_t flavor;
1030     memcpy(&flavor, state, sizeof(uint32_t));
1031     if (Obj.isLittleEndian() != sys::IsLittleEndianHost)
1032       sys::swapByteOrder(flavor);
1033     state += sizeof(uint32_t);
1034 
1035     if(state + sizeof(uint32_t) > end)
1036       return malformedError("load command " + Twine(LoadCommandIndex) +
1037                             " count in " + CmdName + " extends past end of "
1038                             "command");
1039     uint32_t count;
1040     memcpy(&count, state, sizeof(uint32_t));
1041     if (Obj.isLittleEndian() != sys::IsLittleEndianHost)
1042       sys::swapByteOrder(count);
1043     state += sizeof(uint32_t);
1044 
1045     if (cputype == MachO::CPU_TYPE_I386) {
1046       if (flavor == MachO::x86_THREAD_STATE32) {
1047         if (count != MachO::x86_THREAD_STATE32_COUNT)
1048           return malformedError("load command " + Twine(LoadCommandIndex) +
1049                                 " count not x86_THREAD_STATE32_COUNT for "
1050                                 "flavor number " + Twine(nflavor) + " which is "
1051                                 "a x86_THREAD_STATE32 flavor in " + CmdName +
1052                                 " command");
1053         if (state + sizeof(MachO::x86_thread_state32_t) > end)
1054           return malformedError("load command " + Twine(LoadCommandIndex) +
1055                                 " x86_THREAD_STATE32 extends past end of "
1056                                 "command in " + CmdName + " command");
1057         state += sizeof(MachO::x86_thread_state32_t);
1058       } else {
1059         return malformedError("load command " + Twine(LoadCommandIndex) +
1060                               " unknown flavor (" + Twine(flavor) + ") for "
1061                               "flavor number " + Twine(nflavor) + " in " +
1062                               CmdName + " command");
1063       }
1064     } else if (cputype == MachO::CPU_TYPE_X86_64) {
1065       if (flavor == MachO::x86_THREAD_STATE) {
1066         if (count != MachO::x86_THREAD_STATE_COUNT)
1067           return malformedError("load command " + Twine(LoadCommandIndex) +
1068                                 " count not x86_THREAD_STATE_COUNT for "
1069                                 "flavor number " + Twine(nflavor) + " which is "
1070                                 "a x86_THREAD_STATE flavor in " + CmdName +
1071                                 " command");
1072         if (state + sizeof(MachO::x86_thread_state_t) > end)
1073           return malformedError("load command " + Twine(LoadCommandIndex) +
1074                                 " x86_THREAD_STATE extends past end of "
1075                                 "command in " + CmdName + " command");
1076         state += sizeof(MachO::x86_thread_state_t);
1077       } else if (flavor == MachO::x86_FLOAT_STATE) {
1078         if (count != MachO::x86_FLOAT_STATE_COUNT)
1079           return malformedError("load command " + Twine(LoadCommandIndex) +
1080                                 " count not x86_FLOAT_STATE_COUNT for "
1081                                 "flavor number " + Twine(nflavor) + " which is "
1082                                 "a x86_FLOAT_STATE flavor in " + CmdName +
1083                                 " command");
1084         if (state + sizeof(MachO::x86_float_state_t) > end)
1085           return malformedError("load command " + Twine(LoadCommandIndex) +
1086                                 " x86_FLOAT_STATE extends past end of "
1087                                 "command in " + CmdName + " command");
1088         state += sizeof(MachO::x86_float_state_t);
1089       } else if (flavor == MachO::x86_EXCEPTION_STATE) {
1090         if (count != MachO::x86_EXCEPTION_STATE_COUNT)
1091           return malformedError("load command " + Twine(LoadCommandIndex) +
1092                                 " count not x86_EXCEPTION_STATE_COUNT for "
1093                                 "flavor number " + Twine(nflavor) + " which is "
1094                                 "a x86_EXCEPTION_STATE flavor in " + CmdName +
1095                                 " command");
1096         if (state + sizeof(MachO::x86_exception_state_t) > end)
1097           return malformedError("load command " + Twine(LoadCommandIndex) +
1098                                 " x86_EXCEPTION_STATE extends past end of "
1099                                 "command in " + CmdName + " command");
1100         state += sizeof(MachO::x86_exception_state_t);
1101       } else if (flavor == MachO::x86_THREAD_STATE64) {
1102         if (count != MachO::x86_THREAD_STATE64_COUNT)
1103           return malformedError("load command " + Twine(LoadCommandIndex) +
1104                                 " count not x86_THREAD_STATE64_COUNT for "
1105                                 "flavor number " + Twine(nflavor) + " which is "
1106                                 "a x86_THREAD_STATE64 flavor in " + CmdName +
1107                                 " command");
1108         if (state + sizeof(MachO::x86_thread_state64_t) > end)
1109           return malformedError("load command " + Twine(LoadCommandIndex) +
1110                                 " x86_THREAD_STATE64 extends past end of "
1111                                 "command in " + CmdName + " command");
1112         state += sizeof(MachO::x86_thread_state64_t);
1113       } else if (flavor == MachO::x86_EXCEPTION_STATE64) {
1114         if (count != MachO::x86_EXCEPTION_STATE64_COUNT)
1115           return malformedError("load command " + Twine(LoadCommandIndex) +
1116                                 " count not x86_EXCEPTION_STATE64_COUNT for "
1117                                 "flavor number " + Twine(nflavor) + " which is "
1118                                 "a x86_EXCEPTION_STATE64 flavor in " + CmdName +
1119                                 " command");
1120         if (state + sizeof(MachO::x86_exception_state64_t) > end)
1121           return malformedError("load command " + Twine(LoadCommandIndex) +
1122                                 " x86_EXCEPTION_STATE64 extends past end of "
1123                                 "command in " + CmdName + " command");
1124         state += sizeof(MachO::x86_exception_state64_t);
1125       } else {
1126         return malformedError("load command " + Twine(LoadCommandIndex) +
1127                               " unknown flavor (" + Twine(flavor) + ") for "
1128                               "flavor number " + Twine(nflavor) + " in " +
1129                               CmdName + " command");
1130       }
1131     } else if (cputype == MachO::CPU_TYPE_ARM) {
1132       if (flavor == MachO::ARM_THREAD_STATE) {
1133         if (count != MachO::ARM_THREAD_STATE_COUNT)
1134           return malformedError("load command " + Twine(LoadCommandIndex) +
1135                                 " count not ARM_THREAD_STATE_COUNT for "
1136                                 "flavor number " + Twine(nflavor) + " which is "
1137                                 "a ARM_THREAD_STATE flavor in " + CmdName +
1138                                 " command");
1139         if (state + sizeof(MachO::arm_thread_state32_t) > end)
1140           return malformedError("load command " + Twine(LoadCommandIndex) +
1141                                 " ARM_THREAD_STATE extends past end of "
1142                                 "command in " + CmdName + " command");
1143         state += sizeof(MachO::arm_thread_state32_t);
1144       } else {
1145         return malformedError("load command " + Twine(LoadCommandIndex) +
1146                               " unknown flavor (" + Twine(flavor) + ") for "
1147                               "flavor number " + Twine(nflavor) + " in " +
1148                               CmdName + " command");
1149       }
1150     } else if (cputype == MachO::CPU_TYPE_ARM64 ||
1151                cputype == MachO::CPU_TYPE_ARM64_32) {
1152       if (flavor == MachO::ARM_THREAD_STATE64) {
1153         if (count != MachO::ARM_THREAD_STATE64_COUNT)
1154           return malformedError("load command " + Twine(LoadCommandIndex) +
1155                                 " count not ARM_THREAD_STATE64_COUNT for "
1156                                 "flavor number " + Twine(nflavor) + " which is "
1157                                 "a ARM_THREAD_STATE64 flavor in " + CmdName +
1158                                 " command");
1159         if (state + sizeof(MachO::arm_thread_state64_t) > end)
1160           return malformedError("load command " + Twine(LoadCommandIndex) +
1161                                 " ARM_THREAD_STATE64 extends past end of "
1162                                 "command in " + CmdName + " command");
1163         state += sizeof(MachO::arm_thread_state64_t);
1164       } else {
1165         return malformedError("load command " + Twine(LoadCommandIndex) +
1166                               " unknown flavor (" + Twine(flavor) + ") for "
1167                               "flavor number " + Twine(nflavor) + " in " +
1168                               CmdName + " command");
1169       }
1170     } else if (cputype == MachO::CPU_TYPE_POWERPC) {
1171       if (flavor == MachO::PPC_THREAD_STATE) {
1172         if (count != MachO::PPC_THREAD_STATE_COUNT)
1173           return malformedError("load command " + Twine(LoadCommandIndex) +
1174                                 " count not PPC_THREAD_STATE_COUNT for "
1175                                 "flavor number " + Twine(nflavor) + " which is "
1176                                 "a PPC_THREAD_STATE flavor in " + CmdName +
1177                                 " command");
1178         if (state + sizeof(MachO::ppc_thread_state32_t) > end)
1179           return malformedError("load command " + Twine(LoadCommandIndex) +
1180                                 " PPC_THREAD_STATE extends past end of "
1181                                 "command in " + CmdName + " command");
1182         state += sizeof(MachO::ppc_thread_state32_t);
1183       } else {
1184         return malformedError("load command " + Twine(LoadCommandIndex) +
1185                               " unknown flavor (" + Twine(flavor) + ") for "
1186                               "flavor number " + Twine(nflavor) + " in " +
1187                               CmdName + " command");
1188       }
1189     } else {
1190       return malformedError("unknown cputype (" + Twine(cputype) + ") load "
1191                             "command " + Twine(LoadCommandIndex) + " for " +
1192                             CmdName + " command can't be checked");
1193     }
1194     nflavor++;
1195   }
1196   return Error::success();
1197 }
1198 
checkTwoLevelHintsCommand(const MachOObjectFile & Obj,const MachOObjectFile::LoadCommandInfo & Load,uint32_t LoadCommandIndex,const char ** LoadCmd,std::list<MachOElement> & Elements)1199 static Error checkTwoLevelHintsCommand(const MachOObjectFile &Obj,
1200                                        const MachOObjectFile::LoadCommandInfo
1201                                          &Load,
1202                                        uint32_t LoadCommandIndex,
1203                                        const char **LoadCmd,
1204                                        std::list<MachOElement> &Elements) {
1205   if (Load.C.cmdsize != sizeof(MachO::twolevel_hints_command))
1206     return malformedError("load command " + Twine(LoadCommandIndex) +
1207                           " LC_TWOLEVEL_HINTS has incorrect cmdsize");
1208   if (*LoadCmd != nullptr)
1209     return malformedError("more than one LC_TWOLEVEL_HINTS command");
1210   auto HintsOrErr = getStructOrErr<MachO::twolevel_hints_command>(Obj, Load.Ptr);
1211   if(!HintsOrErr)
1212     return HintsOrErr.takeError();
1213   MachO::twolevel_hints_command Hints = HintsOrErr.get();
1214   uint64_t FileSize = Obj.getData().size();
1215   if (Hints.offset > FileSize)
1216     return malformedError("offset field of LC_TWOLEVEL_HINTS command " +
1217                           Twine(LoadCommandIndex) + " extends past the end of "
1218                           "the file");
1219   uint64_t BigSize = Hints.nhints;
1220   BigSize *= sizeof(MachO::twolevel_hint);
1221   BigSize += Hints.offset;
1222   if (BigSize > FileSize)
1223     return malformedError("offset field plus nhints times sizeof(struct "
1224                           "twolevel_hint) field of LC_TWOLEVEL_HINTS command " +
1225                           Twine(LoadCommandIndex) + " extends past the end of "
1226                           "the file");
1227   if (Error Err = checkOverlappingElement(Elements, Hints.offset, Hints.nhints *
1228                                           sizeof(MachO::twolevel_hint),
1229                                           "two level hints"))
1230     return Err;
1231   *LoadCmd = Load.Ptr;
1232   return Error::success();
1233 }
1234 
1235 // Returns true if the libObject code does not support the load command and its
1236 // contents.  The cmd value it is treated as an unknown load command but with
1237 // an error message that says the cmd value is obsolete.
isLoadCommandObsolete(uint32_t cmd)1238 static bool isLoadCommandObsolete(uint32_t cmd) {
1239   if (cmd == MachO::LC_SYMSEG ||
1240       cmd == MachO::LC_LOADFVMLIB ||
1241       cmd == MachO::LC_IDFVMLIB ||
1242       cmd == MachO::LC_IDENT ||
1243       cmd == MachO::LC_FVMFILE ||
1244       cmd == MachO::LC_PREPAGE ||
1245       cmd == MachO::LC_PREBOUND_DYLIB ||
1246       cmd == MachO::LC_TWOLEVEL_HINTS ||
1247       cmd == MachO::LC_PREBIND_CKSUM)
1248     return true;
1249   return false;
1250 }
1251 
1252 Expected<std::unique_ptr<MachOObjectFile>>
create(MemoryBufferRef Object,bool IsLittleEndian,bool Is64Bits,uint32_t UniversalCputype,uint32_t UniversalIndex,size_t MachOFilesetEntryOffset)1253 MachOObjectFile::create(MemoryBufferRef Object, bool IsLittleEndian,
1254                         bool Is64Bits, uint32_t UniversalCputype,
1255                         uint32_t UniversalIndex,
1256                         size_t MachOFilesetEntryOffset) {
1257   Error Err = Error::success();
1258   std::unique_ptr<MachOObjectFile> Obj(new MachOObjectFile(
1259       std::move(Object), IsLittleEndian, Is64Bits, Err, UniversalCputype,
1260       UniversalIndex, MachOFilesetEntryOffset));
1261   if (Err)
1262     return std::move(Err);
1263   return std::move(Obj);
1264 }
1265 
MachOObjectFile(MemoryBufferRef Object,bool IsLittleEndian,bool Is64bits,Error & Err,uint32_t UniversalCputype,uint32_t UniversalIndex,size_t MachOFilesetEntryOffset)1266 MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
1267                                  bool Is64bits, Error &Err,
1268                                  uint32_t UniversalCputype,
1269                                  uint32_t UniversalIndex,
1270                                  size_t MachOFilesetEntryOffset)
1271     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object),
1272       MachOFilesetEntryOffset(MachOFilesetEntryOffset) {
1273   ErrorAsOutParameter ErrAsOutParam(&Err);
1274   uint64_t SizeOfHeaders;
1275   uint32_t cputype;
1276   if (is64Bit()) {
1277     parseHeader(*this, Header64, Err);
1278     SizeOfHeaders = sizeof(MachO::mach_header_64);
1279     cputype = Header64.cputype;
1280   } else {
1281     parseHeader(*this, Header, Err);
1282     SizeOfHeaders = sizeof(MachO::mach_header);
1283     cputype = Header.cputype;
1284   }
1285   if (Err)
1286     return;
1287   SizeOfHeaders += getHeader().sizeofcmds;
1288   if (getData().data() + SizeOfHeaders > getData().end()) {
1289     Err = malformedError("load commands extend past the end of the file");
1290     return;
1291   }
1292   if (UniversalCputype != 0 && cputype != UniversalCputype) {
1293     Err = malformedError("universal header architecture: " +
1294                          Twine(UniversalIndex) + "'s cputype does not match "
1295                          "object file's mach header");
1296     return;
1297   }
1298   std::list<MachOElement> Elements;
1299   Elements.push_back({0, SizeOfHeaders, "Mach-O headers"});
1300 
1301   uint32_t LoadCommandCount = getHeader().ncmds;
1302   LoadCommandInfo Load;
1303   if (LoadCommandCount != 0) {
1304     if (auto LoadOrErr = getFirstLoadCommandInfo(*this))
1305       Load = *LoadOrErr;
1306     else {
1307       Err = LoadOrErr.takeError();
1308       return;
1309     }
1310   }
1311 
1312   const char *DyldIdLoadCmd = nullptr;
1313   const char *SplitInfoLoadCmd = nullptr;
1314   const char *CodeSignDrsLoadCmd = nullptr;
1315   const char *CodeSignLoadCmd = nullptr;
1316   const char *VersLoadCmd = nullptr;
1317   const char *SourceLoadCmd = nullptr;
1318   const char *EntryPointLoadCmd = nullptr;
1319   const char *EncryptLoadCmd = nullptr;
1320   const char *RoutinesLoadCmd = nullptr;
1321   const char *UnixThreadLoadCmd = nullptr;
1322   const char *TwoLevelHintsLoadCmd = nullptr;
1323   for (unsigned I = 0; I < LoadCommandCount; ++I) {
1324     if (is64Bit()) {
1325       if (Load.C.cmdsize % 8 != 0) {
1326         // We have a hack here to allow 64-bit Mach-O core files to have
1327         // LC_THREAD commands that are only a multiple of 4 and not 8 to be
1328         // allowed since the macOS kernel produces them.
1329         if (getHeader().filetype != MachO::MH_CORE ||
1330             Load.C.cmd != MachO::LC_THREAD || Load.C.cmdsize % 4) {
1331           Err = malformedError("load command " + Twine(I) + " cmdsize not a "
1332                                "multiple of 8");
1333           return;
1334         }
1335       }
1336     } else {
1337       if (Load.C.cmdsize % 4 != 0) {
1338         Err = malformedError("load command " + Twine(I) + " cmdsize not a "
1339                              "multiple of 4");
1340         return;
1341       }
1342     }
1343     LoadCommands.push_back(Load);
1344     if (Load.C.cmd == MachO::LC_SYMTAB) {
1345       if ((Err = checkSymtabCommand(*this, Load, I, &SymtabLoadCmd, Elements)))
1346         return;
1347     } else if (Load.C.cmd == MachO::LC_DYSYMTAB) {
1348       if ((Err = checkDysymtabCommand(*this, Load, I, &DysymtabLoadCmd,
1349                                       Elements)))
1350         return;
1351     } else if (Load.C.cmd == MachO::LC_DATA_IN_CODE) {
1352       if ((Err = checkLinkeditDataCommand(*this, Load, I, &DataInCodeLoadCmd,
1353                                           "LC_DATA_IN_CODE", Elements,
1354                                           "data in code info")))
1355         return;
1356     } else if (Load.C.cmd == MachO::LC_LINKER_OPTIMIZATION_HINT) {
1357       if ((Err = checkLinkeditDataCommand(*this, Load, I, &LinkOptHintsLoadCmd,
1358                                           "LC_LINKER_OPTIMIZATION_HINT",
1359                                           Elements, "linker optimization "
1360                                           "hints")))
1361         return;
1362     } else if (Load.C.cmd == MachO::LC_FUNCTION_STARTS) {
1363       if ((Err = checkLinkeditDataCommand(*this, Load, I, &FuncStartsLoadCmd,
1364                                           "LC_FUNCTION_STARTS", Elements,
1365                                           "function starts data")))
1366         return;
1367     } else if (Load.C.cmd == MachO::LC_SEGMENT_SPLIT_INFO) {
1368       if ((Err = checkLinkeditDataCommand(*this, Load, I, &SplitInfoLoadCmd,
1369                                           "LC_SEGMENT_SPLIT_INFO", Elements,
1370                                           "split info data")))
1371         return;
1372     } else if (Load.C.cmd == MachO::LC_DYLIB_CODE_SIGN_DRS) {
1373       if ((Err = checkLinkeditDataCommand(*this, Load, I, &CodeSignDrsLoadCmd,
1374                                           "LC_DYLIB_CODE_SIGN_DRS", Elements,
1375                                           "code signing RDs data")))
1376         return;
1377     } else if (Load.C.cmd == MachO::LC_CODE_SIGNATURE) {
1378       if ((Err = checkLinkeditDataCommand(*this, Load, I, &CodeSignLoadCmd,
1379                                           "LC_CODE_SIGNATURE", Elements,
1380                                           "code signature data")))
1381         return;
1382     } else if (Load.C.cmd == MachO::LC_DYLD_INFO) {
1383       if ((Err = checkDyldInfoCommand(*this, Load, I, &DyldInfoLoadCmd,
1384                                       "LC_DYLD_INFO", Elements)))
1385         return;
1386     } else if (Load.C.cmd == MachO::LC_DYLD_INFO_ONLY) {
1387       if ((Err = checkDyldInfoCommand(*this, Load, I, &DyldInfoLoadCmd,
1388                                       "LC_DYLD_INFO_ONLY", Elements)))
1389         return;
1390     } else if (Load.C.cmd == MachO::LC_DYLD_CHAINED_FIXUPS) {
1391       if ((Err = checkLinkeditDataCommand(
1392                *this, Load, I, &DyldChainedFixupsLoadCmd,
1393                "LC_DYLD_CHAINED_FIXUPS", Elements, "chained fixups")))
1394         return;
1395     } else if (Load.C.cmd == MachO::LC_DYLD_EXPORTS_TRIE) {
1396       if ((Err = checkLinkeditDataCommand(
1397                *this, Load, I, &DyldExportsTrieLoadCmd, "LC_DYLD_EXPORTS_TRIE",
1398                Elements, "exports trie")))
1399         return;
1400     } else if (Load.C.cmd == MachO::LC_UUID) {
1401       if (Load.C.cmdsize != sizeof(MachO::uuid_command)) {
1402         Err = malformedError("LC_UUID command " + Twine(I) + " has incorrect "
1403                              "cmdsize");
1404         return;
1405       }
1406       if (UuidLoadCmd) {
1407         Err = malformedError("more than one LC_UUID command");
1408         return;
1409       }
1410       UuidLoadCmd = Load.Ptr;
1411     } else if (Load.C.cmd == MachO::LC_SEGMENT_64) {
1412       if ((Err = parseSegmentLoadCommand<MachO::segment_command_64,
1413                                          MachO::section_64>(
1414                    *this, Load, Sections, HasPageZeroSegment, I,
1415                    "LC_SEGMENT_64", SizeOfHeaders, Elements)))
1416         return;
1417     } else if (Load.C.cmd == MachO::LC_SEGMENT) {
1418       if ((Err = parseSegmentLoadCommand<MachO::segment_command,
1419                                          MachO::section>(
1420                    *this, Load, Sections, HasPageZeroSegment, I,
1421                    "LC_SEGMENT", SizeOfHeaders, Elements)))
1422         return;
1423     } else if (Load.C.cmd == MachO::LC_ID_DYLIB) {
1424       if ((Err = checkDylibIdCommand(*this, Load, I, &DyldIdLoadCmd)))
1425         return;
1426     } else if (Load.C.cmd == MachO::LC_LOAD_DYLIB) {
1427       if ((Err = checkDylibCommand(*this, Load, I, "LC_LOAD_DYLIB")))
1428         return;
1429       Libraries.push_back(Load.Ptr);
1430     } else if (Load.C.cmd == MachO::LC_LOAD_WEAK_DYLIB) {
1431       if ((Err = checkDylibCommand(*this, Load, I, "LC_LOAD_WEAK_DYLIB")))
1432         return;
1433       Libraries.push_back(Load.Ptr);
1434     } else if (Load.C.cmd == MachO::LC_LAZY_LOAD_DYLIB) {
1435       if ((Err = checkDylibCommand(*this, Load, I, "LC_LAZY_LOAD_DYLIB")))
1436         return;
1437       Libraries.push_back(Load.Ptr);
1438     } else if (Load.C.cmd == MachO::LC_REEXPORT_DYLIB) {
1439       if ((Err = checkDylibCommand(*this, Load, I, "LC_REEXPORT_DYLIB")))
1440         return;
1441       Libraries.push_back(Load.Ptr);
1442     } else if (Load.C.cmd == MachO::LC_LOAD_UPWARD_DYLIB) {
1443       if ((Err = checkDylibCommand(*this, Load, I, "LC_LOAD_UPWARD_DYLIB")))
1444         return;
1445       Libraries.push_back(Load.Ptr);
1446     } else if (Load.C.cmd == MachO::LC_ID_DYLINKER) {
1447       if ((Err = checkDyldCommand(*this, Load, I, "LC_ID_DYLINKER")))
1448         return;
1449     } else if (Load.C.cmd == MachO::LC_LOAD_DYLINKER) {
1450       if ((Err = checkDyldCommand(*this, Load, I, "LC_LOAD_DYLINKER")))
1451         return;
1452     } else if (Load.C.cmd == MachO::LC_DYLD_ENVIRONMENT) {
1453       if ((Err = checkDyldCommand(*this, Load, I, "LC_DYLD_ENVIRONMENT")))
1454         return;
1455     } else if (Load.C.cmd == MachO::LC_VERSION_MIN_MACOSX) {
1456       if ((Err = checkVersCommand(*this, Load, I, &VersLoadCmd,
1457                                   "LC_VERSION_MIN_MACOSX")))
1458         return;
1459     } else if (Load.C.cmd == MachO::LC_VERSION_MIN_IPHONEOS) {
1460       if ((Err = checkVersCommand(*this, Load, I, &VersLoadCmd,
1461                                   "LC_VERSION_MIN_IPHONEOS")))
1462         return;
1463     } else if (Load.C.cmd == MachO::LC_VERSION_MIN_TVOS) {
1464       if ((Err = checkVersCommand(*this, Load, I, &VersLoadCmd,
1465                                   "LC_VERSION_MIN_TVOS")))
1466         return;
1467     } else if (Load.C.cmd == MachO::LC_VERSION_MIN_WATCHOS) {
1468       if ((Err = checkVersCommand(*this, Load, I, &VersLoadCmd,
1469                                   "LC_VERSION_MIN_WATCHOS")))
1470         return;
1471     } else if (Load.C.cmd == MachO::LC_NOTE) {
1472       if ((Err = checkNoteCommand(*this, Load, I, Elements)))
1473         return;
1474     } else if (Load.C.cmd == MachO::LC_BUILD_VERSION) {
1475       if ((Err = parseBuildVersionCommand(*this, Load, BuildTools, I)))
1476         return;
1477     } else if (Load.C.cmd == MachO::LC_RPATH) {
1478       if ((Err = checkRpathCommand(*this, Load, I)))
1479         return;
1480     } else if (Load.C.cmd == MachO::LC_SOURCE_VERSION) {
1481       if (Load.C.cmdsize != sizeof(MachO::source_version_command)) {
1482         Err = malformedError("LC_SOURCE_VERSION command " + Twine(I) +
1483                              " has incorrect cmdsize");
1484         return;
1485       }
1486       if (SourceLoadCmd) {
1487         Err = malformedError("more than one LC_SOURCE_VERSION command");
1488         return;
1489       }
1490       SourceLoadCmd = Load.Ptr;
1491     } else if (Load.C.cmd == MachO::LC_MAIN) {
1492       if (Load.C.cmdsize != sizeof(MachO::entry_point_command)) {
1493         Err = malformedError("LC_MAIN command " + Twine(I) +
1494                              " has incorrect cmdsize");
1495         return;
1496       }
1497       if (EntryPointLoadCmd) {
1498         Err = malformedError("more than one LC_MAIN command");
1499         return;
1500       }
1501       EntryPointLoadCmd = Load.Ptr;
1502     } else if (Load.C.cmd == MachO::LC_ENCRYPTION_INFO) {
1503       if (Load.C.cmdsize != sizeof(MachO::encryption_info_command)) {
1504         Err = malformedError("LC_ENCRYPTION_INFO command " + Twine(I) +
1505                              " has incorrect cmdsize");
1506         return;
1507       }
1508       MachO::encryption_info_command E =
1509         getStruct<MachO::encryption_info_command>(*this, Load.Ptr);
1510       if ((Err = checkEncryptCommand(*this, Load, I, E.cryptoff, E.cryptsize,
1511                                      &EncryptLoadCmd, "LC_ENCRYPTION_INFO")))
1512         return;
1513     } else if (Load.C.cmd == MachO::LC_ENCRYPTION_INFO_64) {
1514       if (Load.C.cmdsize != sizeof(MachO::encryption_info_command_64)) {
1515         Err = malformedError("LC_ENCRYPTION_INFO_64 command " + Twine(I) +
1516                              " has incorrect cmdsize");
1517         return;
1518       }
1519       MachO::encryption_info_command_64 E =
1520         getStruct<MachO::encryption_info_command_64>(*this, Load.Ptr);
1521       if ((Err = checkEncryptCommand(*this, Load, I, E.cryptoff, E.cryptsize,
1522                                      &EncryptLoadCmd, "LC_ENCRYPTION_INFO_64")))
1523         return;
1524     } else if (Load.C.cmd == MachO::LC_LINKER_OPTION) {
1525       if ((Err = checkLinkerOptCommand(*this, Load, I)))
1526         return;
1527     } else if (Load.C.cmd == MachO::LC_SUB_FRAMEWORK) {
1528       if (Load.C.cmdsize < sizeof(MachO::sub_framework_command)) {
1529         Err =  malformedError("load command " + Twine(I) +
1530                               " LC_SUB_FRAMEWORK cmdsize too small");
1531         return;
1532       }
1533       MachO::sub_framework_command S =
1534         getStruct<MachO::sub_framework_command>(*this, Load.Ptr);
1535       if ((Err = checkSubCommand(*this, Load, I, "LC_SUB_FRAMEWORK",
1536                                  sizeof(MachO::sub_framework_command),
1537                                  "sub_framework_command", S.umbrella,
1538                                  "umbrella")))
1539         return;
1540     } else if (Load.C.cmd == MachO::LC_SUB_UMBRELLA) {
1541       if (Load.C.cmdsize < sizeof(MachO::sub_umbrella_command)) {
1542         Err =  malformedError("load command " + Twine(I) +
1543                               " LC_SUB_UMBRELLA cmdsize too small");
1544         return;
1545       }
1546       MachO::sub_umbrella_command S =
1547         getStruct<MachO::sub_umbrella_command>(*this, Load.Ptr);
1548       if ((Err = checkSubCommand(*this, Load, I, "LC_SUB_UMBRELLA",
1549                                  sizeof(MachO::sub_umbrella_command),
1550                                  "sub_umbrella_command", S.sub_umbrella,
1551                                  "sub_umbrella")))
1552         return;
1553     } else if (Load.C.cmd == MachO::LC_SUB_LIBRARY) {
1554       if (Load.C.cmdsize < sizeof(MachO::sub_library_command)) {
1555         Err =  malformedError("load command " + Twine(I) +
1556                               " LC_SUB_LIBRARY cmdsize too small");
1557         return;
1558       }
1559       MachO::sub_library_command S =
1560         getStruct<MachO::sub_library_command>(*this, Load.Ptr);
1561       if ((Err = checkSubCommand(*this, Load, I, "LC_SUB_LIBRARY",
1562                                  sizeof(MachO::sub_library_command),
1563                                  "sub_library_command", S.sub_library,
1564                                  "sub_library")))
1565         return;
1566     } else if (Load.C.cmd == MachO::LC_SUB_CLIENT) {
1567       if (Load.C.cmdsize < sizeof(MachO::sub_client_command)) {
1568         Err =  malformedError("load command " + Twine(I) +
1569                               " LC_SUB_CLIENT cmdsize too small");
1570         return;
1571       }
1572       MachO::sub_client_command S =
1573         getStruct<MachO::sub_client_command>(*this, Load.Ptr);
1574       if ((Err = checkSubCommand(*this, Load, I, "LC_SUB_CLIENT",
1575                                  sizeof(MachO::sub_client_command),
1576                                  "sub_client_command", S.client, "client")))
1577         return;
1578     } else if (Load.C.cmd == MachO::LC_ROUTINES) {
1579       if (Load.C.cmdsize != sizeof(MachO::routines_command)) {
1580         Err = malformedError("LC_ROUTINES command " + Twine(I) +
1581                              " has incorrect cmdsize");
1582         return;
1583       }
1584       if (RoutinesLoadCmd) {
1585         Err = malformedError("more than one LC_ROUTINES and or LC_ROUTINES_64 "
1586                              "command");
1587         return;
1588       }
1589       RoutinesLoadCmd = Load.Ptr;
1590     } else if (Load.C.cmd == MachO::LC_ROUTINES_64) {
1591       if (Load.C.cmdsize != sizeof(MachO::routines_command_64)) {
1592         Err = malformedError("LC_ROUTINES_64 command " + Twine(I) +
1593                              " has incorrect cmdsize");
1594         return;
1595       }
1596       if (RoutinesLoadCmd) {
1597         Err = malformedError("more than one LC_ROUTINES_64 and or LC_ROUTINES "
1598                              "command");
1599         return;
1600       }
1601       RoutinesLoadCmd = Load.Ptr;
1602     } else if (Load.C.cmd == MachO::LC_UNIXTHREAD) {
1603       if ((Err = checkThreadCommand(*this, Load, I, "LC_UNIXTHREAD")))
1604         return;
1605       if (UnixThreadLoadCmd) {
1606         Err = malformedError("more than one LC_UNIXTHREAD command");
1607         return;
1608       }
1609       UnixThreadLoadCmd = Load.Ptr;
1610     } else if (Load.C.cmd == MachO::LC_THREAD) {
1611       if ((Err = checkThreadCommand(*this, Load, I, "LC_THREAD")))
1612         return;
1613     // Note: LC_TWOLEVEL_HINTS is really obsolete and is not supported.
1614     } else if (Load.C.cmd == MachO::LC_TWOLEVEL_HINTS) {
1615       if ((Err = checkTwoLevelHintsCommand(*this, Load, I,
1616                                            &TwoLevelHintsLoadCmd, Elements)))
1617         return;
1618     } else if (Load.C.cmd == MachO::LC_IDENT) {
1619       // Note: LC_IDENT is ignored.
1620       continue;
1621     } else if (isLoadCommandObsolete(Load.C.cmd)) {
1622       Err = malformedError("load command " + Twine(I) + " for cmd value of: " +
1623                            Twine(Load.C.cmd) + " is obsolete and not "
1624                            "supported");
1625       return;
1626     }
1627     // TODO: generate a error for unknown load commands by default.  But still
1628     // need work out an approach to allow or not allow unknown values like this
1629     // as an option for some uses like lldb.
1630     if (I < LoadCommandCount - 1) {
1631       if (auto LoadOrErr = getNextLoadCommandInfo(*this, I, Load))
1632         Load = *LoadOrErr;
1633       else {
1634         Err = LoadOrErr.takeError();
1635         return;
1636       }
1637     }
1638   }
1639   if (!SymtabLoadCmd) {
1640     if (DysymtabLoadCmd) {
1641       Err = malformedError("contains LC_DYSYMTAB load command without a "
1642                            "LC_SYMTAB load command");
1643       return;
1644     }
1645   } else if (DysymtabLoadCmd) {
1646     MachO::symtab_command Symtab =
1647       getStruct<MachO::symtab_command>(*this, SymtabLoadCmd);
1648     MachO::dysymtab_command Dysymtab =
1649       getStruct<MachO::dysymtab_command>(*this, DysymtabLoadCmd);
1650     if (Dysymtab.nlocalsym != 0 && Dysymtab.ilocalsym > Symtab.nsyms) {
1651       Err = malformedError("ilocalsym in LC_DYSYMTAB load command "
1652                            "extends past the end of the symbol table");
1653       return;
1654     }
1655     uint64_t BigSize = Dysymtab.ilocalsym;
1656     BigSize += Dysymtab.nlocalsym;
1657     if (Dysymtab.nlocalsym != 0 && BigSize > Symtab.nsyms) {
1658       Err = malformedError("ilocalsym plus nlocalsym in LC_DYSYMTAB load "
1659                            "command extends past the end of the symbol table");
1660       return;
1661     }
1662     if (Dysymtab.nextdefsym != 0 && Dysymtab.iextdefsym > Symtab.nsyms) {
1663       Err = malformedError("iextdefsym in LC_DYSYMTAB load command "
1664                            "extends past the end of the symbol table");
1665       return;
1666     }
1667     BigSize = Dysymtab.iextdefsym;
1668     BigSize += Dysymtab.nextdefsym;
1669     if (Dysymtab.nextdefsym != 0 && BigSize > Symtab.nsyms) {
1670       Err = malformedError("iextdefsym plus nextdefsym in LC_DYSYMTAB "
1671                            "load command extends past the end of the symbol "
1672                            "table");
1673       return;
1674     }
1675     if (Dysymtab.nundefsym != 0 && Dysymtab.iundefsym > Symtab.nsyms) {
1676       Err = malformedError("iundefsym in LC_DYSYMTAB load command "
1677                            "extends past the end of the symbol table");
1678       return;
1679     }
1680     BigSize = Dysymtab.iundefsym;
1681     BigSize += Dysymtab.nundefsym;
1682     if (Dysymtab.nundefsym != 0 && BigSize > Symtab.nsyms) {
1683       Err = malformedError("iundefsym plus nundefsym in LC_DYSYMTAB load "
1684                            " command extends past the end of the symbol table");
1685       return;
1686     }
1687   }
1688   if ((getHeader().filetype == MachO::MH_DYLIB ||
1689        getHeader().filetype == MachO::MH_DYLIB_STUB) &&
1690        DyldIdLoadCmd == nullptr) {
1691     Err = malformedError("no LC_ID_DYLIB load command in dynamic library "
1692                          "filetype");
1693     return;
1694   }
1695   assert(LoadCommands.size() == LoadCommandCount);
1696 
1697   Err = Error::success();
1698 }
1699 
checkSymbolTable() const1700 Error MachOObjectFile::checkSymbolTable() const {
1701   uint32_t Flags = 0;
1702   if (is64Bit()) {
1703     MachO::mach_header_64 H_64 = MachOObjectFile::getHeader64();
1704     Flags = H_64.flags;
1705   } else {
1706     MachO::mach_header H = MachOObjectFile::getHeader();
1707     Flags = H.flags;
1708   }
1709   uint8_t NType = 0;
1710   uint8_t NSect = 0;
1711   uint16_t NDesc = 0;
1712   uint32_t NStrx = 0;
1713   uint64_t NValue = 0;
1714   uint32_t SymbolIndex = 0;
1715   MachO::symtab_command S = getSymtabLoadCommand();
1716   for (const SymbolRef &Symbol : symbols()) {
1717     DataRefImpl SymDRI = Symbol.getRawDataRefImpl();
1718     if (is64Bit()) {
1719       MachO::nlist_64 STE_64 = getSymbol64TableEntry(SymDRI);
1720       NType = STE_64.n_type;
1721       NSect = STE_64.n_sect;
1722       NDesc = STE_64.n_desc;
1723       NStrx = STE_64.n_strx;
1724       NValue = STE_64.n_value;
1725     } else {
1726       MachO::nlist STE = getSymbolTableEntry(SymDRI);
1727       NType = STE.n_type;
1728       NSect = STE.n_sect;
1729       NDesc = STE.n_desc;
1730       NStrx = STE.n_strx;
1731       NValue = STE.n_value;
1732     }
1733     if ((NType & MachO::N_STAB) == 0) {
1734       if ((NType & MachO::N_TYPE) == MachO::N_SECT) {
1735         if (NSect == 0 || NSect > Sections.size())
1736           return malformedError("bad section index: " + Twine((int)NSect) +
1737                                 " for symbol at index " + Twine(SymbolIndex));
1738       }
1739       if ((NType & MachO::N_TYPE) == MachO::N_INDR) {
1740         if (NValue >= S.strsize)
1741           return malformedError("bad n_value: " + Twine((int)NValue) + " past "
1742                                 "the end of string table, for N_INDR symbol at "
1743                                 "index " + Twine(SymbolIndex));
1744       }
1745       if ((Flags & MachO::MH_TWOLEVEL) == MachO::MH_TWOLEVEL &&
1746           (((NType & MachO::N_TYPE) == MachO::N_UNDF && NValue == 0) ||
1747            (NType & MachO::N_TYPE) == MachO::N_PBUD)) {
1748             uint32_t LibraryOrdinal = MachO::GET_LIBRARY_ORDINAL(NDesc);
1749             if (LibraryOrdinal != 0 &&
1750                 LibraryOrdinal != MachO::EXECUTABLE_ORDINAL &&
1751                 LibraryOrdinal != MachO::DYNAMIC_LOOKUP_ORDINAL &&
1752                 LibraryOrdinal - 1 >= Libraries.size() ) {
1753               return malformedError("bad library ordinal: " + Twine(LibraryOrdinal) +
1754                                     " for symbol at index " + Twine(SymbolIndex));
1755             }
1756           }
1757     }
1758     if (NStrx >= S.strsize)
1759       return malformedError("bad string table index: " + Twine((int)NStrx) +
1760                             " past the end of string table, for symbol at "
1761                             "index " + Twine(SymbolIndex));
1762     SymbolIndex++;
1763   }
1764   return Error::success();
1765 }
1766 
moveSymbolNext(DataRefImpl & Symb) const1767 void MachOObjectFile::moveSymbolNext(DataRefImpl &Symb) const {
1768   unsigned SymbolTableEntrySize = is64Bit() ?
1769     sizeof(MachO::nlist_64) :
1770     sizeof(MachO::nlist);
1771   Symb.p += SymbolTableEntrySize;
1772 }
1773 
getSymbolName(DataRefImpl Symb) const1774 Expected<StringRef> MachOObjectFile::getSymbolName(DataRefImpl Symb) const {
1775   StringRef StringTable = getStringTableData();
1776   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, Symb);
1777   if (Entry.n_strx == 0)
1778     // A n_strx value of 0 indicates that no name is associated with a
1779     // particular symbol table entry.
1780     return StringRef();
1781   const char *Start = &StringTable.data()[Entry.n_strx];
1782   if (Start < getData().begin() || Start >= getData().end()) {
1783     return malformedError("bad string index: " + Twine(Entry.n_strx) +
1784                           " for symbol at index " + Twine(getSymbolIndex(Symb)));
1785   }
1786   return StringRef(Start);
1787 }
1788 
getSectionType(SectionRef Sec) const1789 unsigned MachOObjectFile::getSectionType(SectionRef Sec) const {
1790   DataRefImpl DRI = Sec.getRawDataRefImpl();
1791   uint32_t Flags = getSectionFlags(*this, DRI);
1792   return Flags & MachO::SECTION_TYPE;
1793 }
1794 
getNValue(DataRefImpl Sym) const1795 uint64_t MachOObjectFile::getNValue(DataRefImpl Sym) const {
1796   if (is64Bit()) {
1797     MachO::nlist_64 Entry = getSymbol64TableEntry(Sym);
1798     return Entry.n_value;
1799   }
1800   MachO::nlist Entry = getSymbolTableEntry(Sym);
1801   return Entry.n_value;
1802 }
1803 
1804 // getIndirectName() returns the name of the alias'ed symbol who's string table
1805 // index is in the n_value field.
getIndirectName(DataRefImpl Symb,StringRef & Res) const1806 std::error_code MachOObjectFile::getIndirectName(DataRefImpl Symb,
1807                                                  StringRef &Res) const {
1808   StringRef StringTable = getStringTableData();
1809   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, Symb);
1810   if ((Entry.n_type & MachO::N_TYPE) != MachO::N_INDR)
1811     return object_error::parse_failed;
1812   uint64_t NValue = getNValue(Symb);
1813   if (NValue >= StringTable.size())
1814     return object_error::parse_failed;
1815   const char *Start = &StringTable.data()[NValue];
1816   Res = StringRef(Start);
1817   return std::error_code();
1818 }
1819 
getSymbolValueImpl(DataRefImpl Sym) const1820 uint64_t MachOObjectFile::getSymbolValueImpl(DataRefImpl Sym) const {
1821   return getNValue(Sym);
1822 }
1823 
getSymbolAddress(DataRefImpl Sym) const1824 Expected<uint64_t> MachOObjectFile::getSymbolAddress(DataRefImpl Sym) const {
1825   return getSymbolValue(Sym);
1826 }
1827 
getSymbolAlignment(DataRefImpl DRI) const1828 uint32_t MachOObjectFile::getSymbolAlignment(DataRefImpl DRI) const {
1829   uint32_t Flags = cantFail(getSymbolFlags(DRI));
1830   if (Flags & SymbolRef::SF_Common) {
1831     MachO::nlist_base Entry = getSymbolTableEntryBase(*this, DRI);
1832     return 1 << MachO::GET_COMM_ALIGN(Entry.n_desc);
1833   }
1834   return 0;
1835 }
1836 
getCommonSymbolSizeImpl(DataRefImpl DRI) const1837 uint64_t MachOObjectFile::getCommonSymbolSizeImpl(DataRefImpl DRI) const {
1838   return getNValue(DRI);
1839 }
1840 
1841 Expected<SymbolRef::Type>
getSymbolType(DataRefImpl Symb) const1842 MachOObjectFile::getSymbolType(DataRefImpl Symb) const {
1843   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, Symb);
1844   uint8_t n_type = Entry.n_type;
1845 
1846   // If this is a STAB debugging symbol, we can do nothing more.
1847   if (n_type & MachO::N_STAB)
1848     return SymbolRef::ST_Debug;
1849 
1850   switch (n_type & MachO::N_TYPE) {
1851     case MachO::N_UNDF :
1852       return SymbolRef::ST_Unknown;
1853     case MachO::N_SECT :
1854       Expected<section_iterator> SecOrError = getSymbolSection(Symb);
1855       if (!SecOrError)
1856         return SecOrError.takeError();
1857       section_iterator Sec = *SecOrError;
1858       if (Sec == section_end())
1859         return SymbolRef::ST_Other;
1860       if (Sec->isData() || Sec->isBSS())
1861         return SymbolRef::ST_Data;
1862       return SymbolRef::ST_Function;
1863   }
1864   return SymbolRef::ST_Other;
1865 }
1866 
getSymbolFlags(DataRefImpl DRI) const1867 Expected<uint32_t> MachOObjectFile::getSymbolFlags(DataRefImpl DRI) const {
1868   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, DRI);
1869 
1870   uint8_t MachOType = Entry.n_type;
1871   uint16_t MachOFlags = Entry.n_desc;
1872 
1873   uint32_t Result = SymbolRef::SF_None;
1874 
1875   if ((MachOType & MachO::N_TYPE) == MachO::N_INDR)
1876     Result |= SymbolRef::SF_Indirect;
1877 
1878   if (MachOType & MachO::N_STAB)
1879     Result |= SymbolRef::SF_FormatSpecific;
1880 
1881   if (MachOType & MachO::N_EXT) {
1882     Result |= SymbolRef::SF_Global;
1883     if ((MachOType & MachO::N_TYPE) == MachO::N_UNDF) {
1884       if (getNValue(DRI))
1885         Result |= SymbolRef::SF_Common;
1886       else
1887         Result |= SymbolRef::SF_Undefined;
1888     }
1889 
1890     if (MachOType & MachO::N_PEXT)
1891       Result |= SymbolRef::SF_Hidden;
1892     else
1893       Result |= SymbolRef::SF_Exported;
1894 
1895   } else if (MachOType & MachO::N_PEXT)
1896     Result |= SymbolRef::SF_Hidden;
1897 
1898   if (MachOFlags & (MachO::N_WEAK_REF | MachO::N_WEAK_DEF))
1899     Result |= SymbolRef::SF_Weak;
1900 
1901   if (MachOFlags & (MachO::N_ARM_THUMB_DEF))
1902     Result |= SymbolRef::SF_Thumb;
1903 
1904   if ((MachOType & MachO::N_TYPE) == MachO::N_ABS)
1905     Result |= SymbolRef::SF_Absolute;
1906 
1907   return Result;
1908 }
1909 
1910 Expected<section_iterator>
getSymbolSection(DataRefImpl Symb) const1911 MachOObjectFile::getSymbolSection(DataRefImpl Symb) const {
1912   MachO::nlist_base Entry = getSymbolTableEntryBase(*this, Symb);
1913   uint8_t index = Entry.n_sect;
1914 
1915   if (index == 0)
1916     return section_end();
1917   DataRefImpl DRI;
1918   DRI.d.a = index - 1;
1919   if (DRI.d.a >= Sections.size()){
1920     return malformedError("bad section index: " + Twine((int)index) +
1921                           " for symbol at index " + Twine(getSymbolIndex(Symb)));
1922   }
1923   return section_iterator(SectionRef(DRI, this));
1924 }
1925 
getSymbolSectionID(SymbolRef Sym) const1926 unsigned MachOObjectFile::getSymbolSectionID(SymbolRef Sym) const {
1927   MachO::nlist_base Entry =
1928       getSymbolTableEntryBase(*this, Sym.getRawDataRefImpl());
1929   return Entry.n_sect - 1;
1930 }
1931 
moveSectionNext(DataRefImpl & Sec) const1932 void MachOObjectFile::moveSectionNext(DataRefImpl &Sec) const {
1933   Sec.d.a++;
1934 }
1935 
getSectionName(DataRefImpl Sec) const1936 Expected<StringRef> MachOObjectFile::getSectionName(DataRefImpl Sec) const {
1937   ArrayRef<char> Raw = getSectionRawName(Sec);
1938   return parseSegmentOrSectionName(Raw.data());
1939 }
1940 
getSectionAddress(DataRefImpl Sec) const1941 uint64_t MachOObjectFile::getSectionAddress(DataRefImpl Sec) const {
1942   if (is64Bit())
1943     return getSection64(Sec).addr;
1944   return getSection(Sec).addr;
1945 }
1946 
getSectionIndex(DataRefImpl Sec) const1947 uint64_t MachOObjectFile::getSectionIndex(DataRefImpl Sec) const {
1948   return Sec.d.a;
1949 }
1950 
getSectionSize(DataRefImpl Sec) const1951 uint64_t MachOObjectFile::getSectionSize(DataRefImpl Sec) const {
1952   // In the case if a malformed Mach-O file where the section offset is past
1953   // the end of the file or some part of the section size is past the end of
1954   // the file return a size of zero or a size that covers the rest of the file
1955   // but does not extend past the end of the file.
1956   uint32_t SectOffset, SectType;
1957   uint64_t SectSize;
1958 
1959   if (is64Bit()) {
1960     MachO::section_64 Sect = getSection64(Sec);
1961     SectOffset = Sect.offset;
1962     SectSize = Sect.size;
1963     SectType = Sect.flags & MachO::SECTION_TYPE;
1964   } else {
1965     MachO::section Sect = getSection(Sec);
1966     SectOffset = Sect.offset;
1967     SectSize = Sect.size;
1968     SectType = Sect.flags & MachO::SECTION_TYPE;
1969   }
1970   if (SectType == MachO::S_ZEROFILL || SectType == MachO::S_GB_ZEROFILL)
1971     return SectSize;
1972   uint64_t FileSize = getData().size();
1973   if (SectOffset > FileSize)
1974     return 0;
1975   if (FileSize - SectOffset < SectSize)
1976     return FileSize - SectOffset;
1977   return SectSize;
1978 }
1979 
getSectionContents(uint32_t Offset,uint64_t Size) const1980 ArrayRef<uint8_t> MachOObjectFile::getSectionContents(uint32_t Offset,
1981                                                       uint64_t Size) const {
1982   return arrayRefFromStringRef(getData().substr(Offset, Size));
1983 }
1984 
1985 Expected<ArrayRef<uint8_t>>
getSectionContents(DataRefImpl Sec) const1986 MachOObjectFile::getSectionContents(DataRefImpl Sec) const {
1987   uint32_t Offset;
1988   uint64_t Size;
1989 
1990   if (is64Bit()) {
1991     MachO::section_64 Sect = getSection64(Sec);
1992     Offset = Sect.offset;
1993     Size = Sect.size;
1994   } else {
1995     MachO::section Sect = getSection(Sec);
1996     Offset = Sect.offset;
1997     Size = Sect.size;
1998   }
1999 
2000   return getSectionContents(Offset, Size);
2001 }
2002 
getSectionAlignment(DataRefImpl Sec) const2003 uint64_t MachOObjectFile::getSectionAlignment(DataRefImpl Sec) const {
2004   uint32_t Align;
2005   if (is64Bit()) {
2006     MachO::section_64 Sect = getSection64(Sec);
2007     Align = Sect.align;
2008   } else {
2009     MachO::section Sect = getSection(Sec);
2010     Align = Sect.align;
2011   }
2012 
2013   return uint64_t(1) << Align;
2014 }
2015 
getSection(unsigned SectionIndex) const2016 Expected<SectionRef> MachOObjectFile::getSection(unsigned SectionIndex) const {
2017   if (SectionIndex < 1 || SectionIndex > Sections.size())
2018     return malformedError("bad section index: " + Twine((int)SectionIndex));
2019 
2020   DataRefImpl DRI;
2021   DRI.d.a = SectionIndex - 1;
2022   return SectionRef(DRI, this);
2023 }
2024 
getSection(StringRef SectionName) const2025 Expected<SectionRef> MachOObjectFile::getSection(StringRef SectionName) const {
2026   for (const SectionRef &Section : sections()) {
2027     auto NameOrErr = Section.getName();
2028     if (!NameOrErr)
2029       return NameOrErr.takeError();
2030     if (*NameOrErr == SectionName)
2031       return Section;
2032   }
2033   return errorCodeToError(object_error::parse_failed);
2034 }
2035 
isSectionCompressed(DataRefImpl Sec) const2036 bool MachOObjectFile::isSectionCompressed(DataRefImpl Sec) const {
2037   return false;
2038 }
2039 
isSectionText(DataRefImpl Sec) const2040 bool MachOObjectFile::isSectionText(DataRefImpl Sec) const {
2041   uint32_t Flags = getSectionFlags(*this, Sec);
2042   return Flags & MachO::S_ATTR_PURE_INSTRUCTIONS;
2043 }
2044 
isSectionData(DataRefImpl Sec) const2045 bool MachOObjectFile::isSectionData(DataRefImpl Sec) const {
2046   uint32_t Flags = getSectionFlags(*this, Sec);
2047   unsigned SectionType = Flags & MachO::SECTION_TYPE;
2048   return !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
2049          !(SectionType == MachO::S_ZEROFILL ||
2050            SectionType == MachO::S_GB_ZEROFILL);
2051 }
2052 
isSectionBSS(DataRefImpl Sec) const2053 bool MachOObjectFile::isSectionBSS(DataRefImpl Sec) const {
2054   uint32_t Flags = getSectionFlags(*this, Sec);
2055   unsigned SectionType = Flags & MachO::SECTION_TYPE;
2056   return !(Flags & MachO::S_ATTR_PURE_INSTRUCTIONS) &&
2057          (SectionType == MachO::S_ZEROFILL ||
2058           SectionType == MachO::S_GB_ZEROFILL);
2059 }
2060 
isDebugSection(DataRefImpl Sec) const2061 bool MachOObjectFile::isDebugSection(DataRefImpl Sec) const {
2062   Expected<StringRef> SectionNameOrErr = getSectionName(Sec);
2063   if (!SectionNameOrErr) {
2064     // TODO: Report the error message properly.
2065     consumeError(SectionNameOrErr.takeError());
2066     return false;
2067   }
2068   StringRef SectionName = SectionNameOrErr.get();
2069   return SectionName.starts_with("__debug") ||
2070          SectionName.starts_with("__zdebug") ||
2071          SectionName.starts_with("__apple") || SectionName == "__gdb_index" ||
2072          SectionName == "__swift_ast";
2073 }
2074 
2075 namespace {
2076 template <typename LoadCommandType>
getSegmentContents(const MachOObjectFile & Obj,MachOObjectFile::LoadCommandInfo LoadCmd,StringRef SegmentName)2077 ArrayRef<uint8_t> getSegmentContents(const MachOObjectFile &Obj,
2078                                      MachOObjectFile::LoadCommandInfo LoadCmd,
2079                                      StringRef SegmentName) {
2080   auto SegmentOrErr = getStructOrErr<LoadCommandType>(Obj, LoadCmd.Ptr);
2081   if (!SegmentOrErr) {
2082     consumeError(SegmentOrErr.takeError());
2083     return {};
2084   }
2085   auto &Segment = SegmentOrErr.get();
2086   if (StringRef(Segment.segname, 16).starts_with(SegmentName))
2087     return arrayRefFromStringRef(Obj.getData().slice(
2088         Segment.fileoff, Segment.fileoff + Segment.filesize));
2089   return {};
2090 }
2091 
2092 template <typename LoadCommandType>
getSegmentContents(const MachOObjectFile & Obj,MachOObjectFile::LoadCommandInfo LoadCmd)2093 ArrayRef<uint8_t> getSegmentContents(const MachOObjectFile &Obj,
2094                                      MachOObjectFile::LoadCommandInfo LoadCmd) {
2095   auto SegmentOrErr = getStructOrErr<LoadCommandType>(Obj, LoadCmd.Ptr);
2096   if (!SegmentOrErr) {
2097     consumeError(SegmentOrErr.takeError());
2098     return {};
2099   }
2100   auto &Segment = SegmentOrErr.get();
2101   return arrayRefFromStringRef(
2102       Obj.getData().slice(Segment.fileoff, Segment.fileoff + Segment.filesize));
2103 }
2104 } // namespace
2105 
2106 ArrayRef<uint8_t>
getSegmentContents(StringRef SegmentName) const2107 MachOObjectFile::getSegmentContents(StringRef SegmentName) const {
2108   for (auto LoadCmd : load_commands()) {
2109     ArrayRef<uint8_t> Contents;
2110     switch (LoadCmd.C.cmd) {
2111     case MachO::LC_SEGMENT:
2112       Contents = ::getSegmentContents<MachO::segment_command>(*this, LoadCmd,
2113                                                               SegmentName);
2114       break;
2115     case MachO::LC_SEGMENT_64:
2116       Contents = ::getSegmentContents<MachO::segment_command_64>(*this, LoadCmd,
2117                                                                  SegmentName);
2118       break;
2119     default:
2120       continue;
2121     }
2122     if (!Contents.empty())
2123       return Contents;
2124   }
2125   return {};
2126 }
2127 
2128 ArrayRef<uint8_t>
getSegmentContents(size_t SegmentIndex) const2129 MachOObjectFile::getSegmentContents(size_t SegmentIndex) const {
2130   size_t Idx = 0;
2131   for (auto LoadCmd : load_commands()) {
2132     switch (LoadCmd.C.cmd) {
2133     case MachO::LC_SEGMENT:
2134       if (Idx == SegmentIndex)
2135         return ::getSegmentContents<MachO::segment_command>(*this, LoadCmd);
2136       ++Idx;
2137       break;
2138     case MachO::LC_SEGMENT_64:
2139       if (Idx == SegmentIndex)
2140         return ::getSegmentContents<MachO::segment_command_64>(*this, LoadCmd);
2141       ++Idx;
2142       break;
2143     default:
2144       continue;
2145     }
2146   }
2147   return {};
2148 }
2149 
getSectionID(SectionRef Sec) const2150 unsigned MachOObjectFile::getSectionID(SectionRef Sec) const {
2151   return Sec.getRawDataRefImpl().d.a;
2152 }
2153 
isSectionVirtual(DataRefImpl Sec) const2154 bool MachOObjectFile::isSectionVirtual(DataRefImpl Sec) const {
2155   uint32_t Flags = getSectionFlags(*this, Sec);
2156   unsigned SectionType = Flags & MachO::SECTION_TYPE;
2157   return SectionType == MachO::S_ZEROFILL ||
2158          SectionType == MachO::S_GB_ZEROFILL;
2159 }
2160 
isSectionBitcode(DataRefImpl Sec) const2161 bool MachOObjectFile::isSectionBitcode(DataRefImpl Sec) const {
2162   StringRef SegmentName = getSectionFinalSegmentName(Sec);
2163   if (Expected<StringRef> NameOrErr = getSectionName(Sec))
2164     return (SegmentName == "__LLVM" && *NameOrErr == "__bitcode");
2165   return false;
2166 }
2167 
isSectionStripped(DataRefImpl Sec) const2168 bool MachOObjectFile::isSectionStripped(DataRefImpl Sec) const {
2169   if (is64Bit())
2170     return getSection64(Sec).offset == 0;
2171   return getSection(Sec).offset == 0;
2172 }
2173 
section_rel_begin(DataRefImpl Sec) const2174 relocation_iterator MachOObjectFile::section_rel_begin(DataRefImpl Sec) const {
2175   DataRefImpl Ret;
2176   Ret.d.a = Sec.d.a;
2177   Ret.d.b = 0;
2178   return relocation_iterator(RelocationRef(Ret, this));
2179 }
2180 
2181 relocation_iterator
section_rel_end(DataRefImpl Sec) const2182 MachOObjectFile::section_rel_end(DataRefImpl Sec) const {
2183   uint32_t Num;
2184   if (is64Bit()) {
2185     MachO::section_64 Sect = getSection64(Sec);
2186     Num = Sect.nreloc;
2187   } else {
2188     MachO::section Sect = getSection(Sec);
2189     Num = Sect.nreloc;
2190   }
2191 
2192   DataRefImpl Ret;
2193   Ret.d.a = Sec.d.a;
2194   Ret.d.b = Num;
2195   return relocation_iterator(RelocationRef(Ret, this));
2196 }
2197 
extrel_begin() const2198 relocation_iterator MachOObjectFile::extrel_begin() const {
2199   DataRefImpl Ret;
2200   // for DYSYMTAB symbols, Ret.d.a == 0 for external relocations
2201   Ret.d.a = 0; // Would normally be a section index.
2202   Ret.d.b = 0; // Index into the external relocations
2203   return relocation_iterator(RelocationRef(Ret, this));
2204 }
2205 
extrel_end() const2206 relocation_iterator MachOObjectFile::extrel_end() const {
2207   MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
2208   DataRefImpl Ret;
2209   // for DYSYMTAB symbols, Ret.d.a == 0 for external relocations
2210   Ret.d.a = 0; // Would normally be a section index.
2211   Ret.d.b = DysymtabLoadCmd.nextrel; // Index into the external relocations
2212   return relocation_iterator(RelocationRef(Ret, this));
2213 }
2214 
locrel_begin() const2215 relocation_iterator MachOObjectFile::locrel_begin() const {
2216   DataRefImpl Ret;
2217   // for DYSYMTAB symbols, Ret.d.a == 1 for local relocations
2218   Ret.d.a = 1; // Would normally be a section index.
2219   Ret.d.b = 0; // Index into the local relocations
2220   return relocation_iterator(RelocationRef(Ret, this));
2221 }
2222 
locrel_end() const2223 relocation_iterator MachOObjectFile::locrel_end() const {
2224   MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
2225   DataRefImpl Ret;
2226   // for DYSYMTAB symbols, Ret.d.a == 1 for local relocations
2227   Ret.d.a = 1; // Would normally be a section index.
2228   Ret.d.b = DysymtabLoadCmd.nlocrel; // Index into the local relocations
2229   return relocation_iterator(RelocationRef(Ret, this));
2230 }
2231 
moveRelocationNext(DataRefImpl & Rel) const2232 void MachOObjectFile::moveRelocationNext(DataRefImpl &Rel) const {
2233   ++Rel.d.b;
2234 }
2235 
getRelocationOffset(DataRefImpl Rel) const2236 uint64_t MachOObjectFile::getRelocationOffset(DataRefImpl Rel) const {
2237   assert((getHeader().filetype == MachO::MH_OBJECT ||
2238           getHeader().filetype == MachO::MH_KEXT_BUNDLE) &&
2239          "Only implemented for MH_OBJECT && MH_KEXT_BUNDLE");
2240   MachO::any_relocation_info RE = getRelocation(Rel);
2241   return getAnyRelocationAddress(RE);
2242 }
2243 
2244 symbol_iterator
getRelocationSymbol(DataRefImpl Rel) const2245 MachOObjectFile::getRelocationSymbol(DataRefImpl Rel) const {
2246   MachO::any_relocation_info RE = getRelocation(Rel);
2247   if (isRelocationScattered(RE))
2248     return symbol_end();
2249 
2250   uint32_t SymbolIdx = getPlainRelocationSymbolNum(RE);
2251   bool isExtern = getPlainRelocationExternal(RE);
2252   if (!isExtern)
2253     return symbol_end();
2254 
2255   MachO::symtab_command S = getSymtabLoadCommand();
2256   unsigned SymbolTableEntrySize = is64Bit() ?
2257     sizeof(MachO::nlist_64) :
2258     sizeof(MachO::nlist);
2259   uint64_t Offset = S.symoff + SymbolIdx * SymbolTableEntrySize;
2260   DataRefImpl Sym;
2261   Sym.p = reinterpret_cast<uintptr_t>(getPtr(*this, Offset));
2262   return symbol_iterator(SymbolRef(Sym, this));
2263 }
2264 
2265 section_iterator
getRelocationSection(DataRefImpl Rel) const2266 MachOObjectFile::getRelocationSection(DataRefImpl Rel) const {
2267   return section_iterator(getAnyRelocationSection(getRelocation(Rel)));
2268 }
2269 
getRelocationType(DataRefImpl Rel) const2270 uint64_t MachOObjectFile::getRelocationType(DataRefImpl Rel) const {
2271   MachO::any_relocation_info RE = getRelocation(Rel);
2272   return getAnyRelocationType(RE);
2273 }
2274 
getRelocationTypeName(DataRefImpl Rel,SmallVectorImpl<char> & Result) const2275 void MachOObjectFile::getRelocationTypeName(
2276     DataRefImpl Rel, SmallVectorImpl<char> &Result) const {
2277   StringRef res;
2278   uint64_t RType = getRelocationType(Rel);
2279 
2280   unsigned Arch = this->getArch();
2281 
2282   switch (Arch) {
2283     case Triple::x86: {
2284       static const char *const Table[] =  {
2285         "GENERIC_RELOC_VANILLA",
2286         "GENERIC_RELOC_PAIR",
2287         "GENERIC_RELOC_SECTDIFF",
2288         "GENERIC_RELOC_PB_LA_PTR",
2289         "GENERIC_RELOC_LOCAL_SECTDIFF",
2290         "GENERIC_RELOC_TLV" };
2291 
2292       if (RType > 5)
2293         res = "Unknown";
2294       else
2295         res = Table[RType];
2296       break;
2297     }
2298     case Triple::x86_64: {
2299       static const char *const Table[] =  {
2300         "X86_64_RELOC_UNSIGNED",
2301         "X86_64_RELOC_SIGNED",
2302         "X86_64_RELOC_BRANCH",
2303         "X86_64_RELOC_GOT_LOAD",
2304         "X86_64_RELOC_GOT",
2305         "X86_64_RELOC_SUBTRACTOR",
2306         "X86_64_RELOC_SIGNED_1",
2307         "X86_64_RELOC_SIGNED_2",
2308         "X86_64_RELOC_SIGNED_4",
2309         "X86_64_RELOC_TLV" };
2310 
2311       if (RType > 9)
2312         res = "Unknown";
2313       else
2314         res = Table[RType];
2315       break;
2316     }
2317     case Triple::arm: {
2318       static const char *const Table[] =  {
2319         "ARM_RELOC_VANILLA",
2320         "ARM_RELOC_PAIR",
2321         "ARM_RELOC_SECTDIFF",
2322         "ARM_RELOC_LOCAL_SECTDIFF",
2323         "ARM_RELOC_PB_LA_PTR",
2324         "ARM_RELOC_BR24",
2325         "ARM_THUMB_RELOC_BR22",
2326         "ARM_THUMB_32BIT_BRANCH",
2327         "ARM_RELOC_HALF",
2328         "ARM_RELOC_HALF_SECTDIFF" };
2329 
2330       if (RType > 9)
2331         res = "Unknown";
2332       else
2333         res = Table[RType];
2334       break;
2335     }
2336     case Triple::aarch64:
2337     case Triple::aarch64_32: {
2338       static const char *const Table[] = {
2339         "ARM64_RELOC_UNSIGNED",           "ARM64_RELOC_SUBTRACTOR",
2340         "ARM64_RELOC_BRANCH26",           "ARM64_RELOC_PAGE21",
2341         "ARM64_RELOC_PAGEOFF12",          "ARM64_RELOC_GOT_LOAD_PAGE21",
2342         "ARM64_RELOC_GOT_LOAD_PAGEOFF12", "ARM64_RELOC_POINTER_TO_GOT",
2343         "ARM64_RELOC_TLVP_LOAD_PAGE21",   "ARM64_RELOC_TLVP_LOAD_PAGEOFF12",
2344         "ARM64_RELOC_ADDEND"
2345       };
2346 
2347       if (RType >= std::size(Table))
2348         res = "Unknown";
2349       else
2350         res = Table[RType];
2351       break;
2352     }
2353     case Triple::ppc: {
2354       static const char *const Table[] =  {
2355         "PPC_RELOC_VANILLA",
2356         "PPC_RELOC_PAIR",
2357         "PPC_RELOC_BR14",
2358         "PPC_RELOC_BR24",
2359         "PPC_RELOC_HI16",
2360         "PPC_RELOC_LO16",
2361         "PPC_RELOC_HA16",
2362         "PPC_RELOC_LO14",
2363         "PPC_RELOC_SECTDIFF",
2364         "PPC_RELOC_PB_LA_PTR",
2365         "PPC_RELOC_HI16_SECTDIFF",
2366         "PPC_RELOC_LO16_SECTDIFF",
2367         "PPC_RELOC_HA16_SECTDIFF",
2368         "PPC_RELOC_JBSR",
2369         "PPC_RELOC_LO14_SECTDIFF",
2370         "PPC_RELOC_LOCAL_SECTDIFF" };
2371 
2372       if (RType > 15)
2373         res = "Unknown";
2374       else
2375         res = Table[RType];
2376       break;
2377     }
2378     case Triple::UnknownArch:
2379       res = "Unknown";
2380       break;
2381   }
2382   Result.append(res.begin(), res.end());
2383 }
2384 
getRelocationLength(DataRefImpl Rel) const2385 uint8_t MachOObjectFile::getRelocationLength(DataRefImpl Rel) const {
2386   MachO::any_relocation_info RE = getRelocation(Rel);
2387   return getAnyRelocationLength(RE);
2388 }
2389 
2390 //
2391 // guessLibraryShortName() is passed a name of a dynamic library and returns a
2392 // guess on what the short name is.  Then name is returned as a substring of the
2393 // StringRef Name passed in.  The name of the dynamic library is recognized as
2394 // a framework if it has one of the two following forms:
2395 //      Foo.framework/Versions/A/Foo
2396 //      Foo.framework/Foo
2397 // Where A and Foo can be any string.  And may contain a trailing suffix
2398 // starting with an underbar.  If the Name is recognized as a framework then
2399 // isFramework is set to true else it is set to false.  If the Name has a
2400 // suffix then Suffix is set to the substring in Name that contains the suffix
2401 // else it is set to a NULL StringRef.
2402 //
2403 // The Name of the dynamic library is recognized as a library name if it has
2404 // one of the two following forms:
2405 //      libFoo.A.dylib
2406 //      libFoo.dylib
2407 //
2408 // The library may have a suffix trailing the name Foo of the form:
2409 //      libFoo_profile.A.dylib
2410 //      libFoo_profile.dylib
2411 // These dyld image suffixes are separated from the short name by a '_'
2412 // character. Because the '_' character is commonly used to separate words in
2413 // filenames guessLibraryShortName() cannot reliably separate a dylib's short
2414 // name from an arbitrary image suffix; imagine if both the short name and the
2415 // suffix contains an '_' character! To better deal with this ambiguity,
2416 // guessLibraryShortName() will recognize only "_debug" and "_profile" as valid
2417 // Suffix values. Calling code needs to be tolerant of guessLibraryShortName()
2418 // guessing incorrectly.
2419 //
2420 // The Name of the dynamic library is also recognized as a library name if it
2421 // has the following form:
2422 //      Foo.qtx
2423 //
2424 // If the Name of the dynamic library is none of the forms above then a NULL
2425 // StringRef is returned.
guessLibraryShortName(StringRef Name,bool & isFramework,StringRef & Suffix)2426 StringRef MachOObjectFile::guessLibraryShortName(StringRef Name,
2427                                                  bool &isFramework,
2428                                                  StringRef &Suffix) {
2429   StringRef Foo, F, DotFramework, V, Dylib, Lib, Dot, Qtx;
2430   size_t a, b, c, d, Idx;
2431 
2432   isFramework = false;
2433   Suffix = StringRef();
2434 
2435   // Pull off the last component and make Foo point to it
2436   a = Name.rfind('/');
2437   if (a == Name.npos || a == 0)
2438     goto guess_library;
2439   Foo = Name.slice(a+1, Name.npos);
2440 
2441   // Look for a suffix starting with a '_'
2442   Idx = Foo.rfind('_');
2443   if (Idx != Foo.npos && Foo.size() >= 2) {
2444     Suffix = Foo.slice(Idx, Foo.npos);
2445     if (Suffix != "_debug" && Suffix != "_profile")
2446       Suffix = StringRef();
2447     else
2448       Foo = Foo.slice(0, Idx);
2449   }
2450 
2451   // First look for the form Foo.framework/Foo
2452   b = Name.rfind('/', a);
2453   if (b == Name.npos)
2454     Idx = 0;
2455   else
2456     Idx = b+1;
2457   F = Name.slice(Idx, Idx + Foo.size());
2458   DotFramework = Name.slice(Idx + Foo.size(),
2459                             Idx + Foo.size() + sizeof(".framework/")-1);
2460   if (F == Foo && DotFramework == ".framework/") {
2461     isFramework = true;
2462     return Foo;
2463   }
2464 
2465   // Next look for the form Foo.framework/Versions/A/Foo
2466   if (b == Name.npos)
2467     goto guess_library;
2468   c =  Name.rfind('/', b);
2469   if (c == Name.npos || c == 0)
2470     goto guess_library;
2471   V = Name.slice(c+1, Name.npos);
2472   if (!V.starts_with("Versions/"))
2473     goto guess_library;
2474   d =  Name.rfind('/', c);
2475   if (d == Name.npos)
2476     Idx = 0;
2477   else
2478     Idx = d+1;
2479   F = Name.slice(Idx, Idx + Foo.size());
2480   DotFramework = Name.slice(Idx + Foo.size(),
2481                             Idx + Foo.size() + sizeof(".framework/")-1);
2482   if (F == Foo && DotFramework == ".framework/") {
2483     isFramework = true;
2484     return Foo;
2485   }
2486 
2487 guess_library:
2488   // pull off the suffix after the "." and make a point to it
2489   a = Name.rfind('.');
2490   if (a == Name.npos || a == 0)
2491     return StringRef();
2492   Dylib = Name.slice(a, Name.npos);
2493   if (Dylib != ".dylib")
2494     goto guess_qtx;
2495 
2496   // First pull off the version letter for the form Foo.A.dylib if any.
2497   if (a >= 3) {
2498     Dot = Name.slice(a-2, a-1);
2499     if (Dot == ".")
2500       a = a - 2;
2501   }
2502 
2503   b = Name.rfind('/', a);
2504   if (b == Name.npos)
2505     b = 0;
2506   else
2507     b = b+1;
2508   // ignore any suffix after an underbar like Foo_profile.A.dylib
2509   Idx = Name.rfind('_');
2510   if (Idx != Name.npos && Idx != b) {
2511     Lib = Name.slice(b, Idx);
2512     Suffix = Name.slice(Idx, a);
2513     if (Suffix != "_debug" && Suffix != "_profile") {
2514       Suffix = StringRef();
2515       Lib = Name.slice(b, a);
2516     }
2517   }
2518   else
2519     Lib = Name.slice(b, a);
2520   // There are incorrect library names of the form:
2521   // libATS.A_profile.dylib so check for these.
2522   if (Lib.size() >= 3) {
2523     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
2524     if (Dot == ".")
2525       Lib = Lib.slice(0, Lib.size()-2);
2526   }
2527   return Lib;
2528 
2529 guess_qtx:
2530   Qtx = Name.slice(a, Name.npos);
2531   if (Qtx != ".qtx")
2532     return StringRef();
2533   b = Name.rfind('/', a);
2534   if (b == Name.npos)
2535     Lib = Name.slice(0, a);
2536   else
2537     Lib = Name.slice(b+1, a);
2538   // There are library names of the form: QT.A.qtx so check for these.
2539   if (Lib.size() >= 3) {
2540     Dot = Lib.slice(Lib.size()-2, Lib.size()-1);
2541     if (Dot == ".")
2542       Lib = Lib.slice(0, Lib.size()-2);
2543   }
2544   return Lib;
2545 }
2546 
2547 // getLibraryShortNameByIndex() is used to get the short name of the library
2548 // for an undefined symbol in a linked Mach-O binary that was linked with the
2549 // normal two-level namespace default (that is MH_TWOLEVEL in the header).
2550 // It is passed the index (0 - based) of the library as translated from
2551 // GET_LIBRARY_ORDINAL (1 - based).
getLibraryShortNameByIndex(unsigned Index,StringRef & Res) const2552 std::error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
2553                                                          StringRef &Res) const {
2554   if (Index >= Libraries.size())
2555     return object_error::parse_failed;
2556 
2557   // If the cache of LibrariesShortNames is not built up do that first for
2558   // all the Libraries.
2559   if (LibrariesShortNames.size() == 0) {
2560     for (unsigned i = 0; i < Libraries.size(); i++) {
2561       auto CommandOrErr =
2562         getStructOrErr<MachO::dylib_command>(*this, Libraries[i]);
2563       if (!CommandOrErr)
2564         return object_error::parse_failed;
2565       MachO::dylib_command D = CommandOrErr.get();
2566       if (D.dylib.name >= D.cmdsize)
2567         return object_error::parse_failed;
2568       const char *P = (const char *)(Libraries[i]) + D.dylib.name;
2569       StringRef Name = StringRef(P);
2570       if (D.dylib.name+Name.size() >= D.cmdsize)
2571         return object_error::parse_failed;
2572       StringRef Suffix;
2573       bool isFramework;
2574       StringRef shortName = guessLibraryShortName(Name, isFramework, Suffix);
2575       if (shortName.empty())
2576         LibrariesShortNames.push_back(Name);
2577       else
2578         LibrariesShortNames.push_back(shortName);
2579     }
2580   }
2581 
2582   Res = LibrariesShortNames[Index];
2583   return std::error_code();
2584 }
2585 
getLibraryCount() const2586 uint32_t MachOObjectFile::getLibraryCount() const {
2587   return Libraries.size();
2588 }
2589 
2590 section_iterator
getRelocationRelocatedSection(relocation_iterator Rel) const2591 MachOObjectFile::getRelocationRelocatedSection(relocation_iterator Rel) const {
2592   DataRefImpl Sec;
2593   Sec.d.a = Rel->getRawDataRefImpl().d.a;
2594   return section_iterator(SectionRef(Sec, this));
2595 }
2596 
symbol_begin() const2597 basic_symbol_iterator MachOObjectFile::symbol_begin() const {
2598   DataRefImpl DRI;
2599   MachO::symtab_command Symtab = getSymtabLoadCommand();
2600   if (!SymtabLoadCmd || Symtab.nsyms == 0)
2601     return basic_symbol_iterator(SymbolRef(DRI, this));
2602 
2603   return getSymbolByIndex(0);
2604 }
2605 
symbol_end() const2606 basic_symbol_iterator MachOObjectFile::symbol_end() const {
2607   DataRefImpl DRI;
2608   MachO::symtab_command Symtab = getSymtabLoadCommand();
2609   if (!SymtabLoadCmd || Symtab.nsyms == 0)
2610     return basic_symbol_iterator(SymbolRef(DRI, this));
2611 
2612   unsigned SymbolTableEntrySize = is64Bit() ?
2613     sizeof(MachO::nlist_64) :
2614     sizeof(MachO::nlist);
2615   unsigned Offset = Symtab.symoff +
2616     Symtab.nsyms * SymbolTableEntrySize;
2617   DRI.p = reinterpret_cast<uintptr_t>(getPtr(*this, Offset));
2618   return basic_symbol_iterator(SymbolRef(DRI, this));
2619 }
2620 
getSymbolByIndex(unsigned Index) const2621 symbol_iterator MachOObjectFile::getSymbolByIndex(unsigned Index) const {
2622   MachO::symtab_command Symtab = getSymtabLoadCommand();
2623   if (!SymtabLoadCmd || Index >= Symtab.nsyms)
2624     report_fatal_error("Requested symbol index is out of range.");
2625   unsigned SymbolTableEntrySize =
2626     is64Bit() ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
2627   DataRefImpl DRI;
2628   DRI.p = reinterpret_cast<uintptr_t>(getPtr(*this, Symtab.symoff));
2629   DRI.p += Index * SymbolTableEntrySize;
2630   return basic_symbol_iterator(SymbolRef(DRI, this));
2631 }
2632 
getSymbolIndex(DataRefImpl Symb) const2633 uint64_t MachOObjectFile::getSymbolIndex(DataRefImpl Symb) const {
2634   MachO::symtab_command Symtab = getSymtabLoadCommand();
2635   if (!SymtabLoadCmd)
2636     report_fatal_error("getSymbolIndex() called with no symbol table symbol");
2637   unsigned SymbolTableEntrySize =
2638     is64Bit() ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
2639   DataRefImpl DRIstart;
2640   DRIstart.p = reinterpret_cast<uintptr_t>(getPtr(*this, Symtab.symoff));
2641   uint64_t Index = (Symb.p - DRIstart.p) / SymbolTableEntrySize;
2642   return Index;
2643 }
2644 
section_begin() const2645 section_iterator MachOObjectFile::section_begin() const {
2646   DataRefImpl DRI;
2647   return section_iterator(SectionRef(DRI, this));
2648 }
2649 
section_end() const2650 section_iterator MachOObjectFile::section_end() const {
2651   DataRefImpl DRI;
2652   DRI.d.a = Sections.size();
2653   return section_iterator(SectionRef(DRI, this));
2654 }
2655 
getBytesInAddress() const2656 uint8_t MachOObjectFile::getBytesInAddress() const {
2657   return is64Bit() ? 8 : 4;
2658 }
2659 
getFileFormatName() const2660 StringRef MachOObjectFile::getFileFormatName() const {
2661   unsigned CPUType = getCPUType(*this);
2662   if (!is64Bit()) {
2663     switch (CPUType) {
2664     case MachO::CPU_TYPE_I386:
2665       return "Mach-O 32-bit i386";
2666     case MachO::CPU_TYPE_ARM:
2667       return "Mach-O arm";
2668     case MachO::CPU_TYPE_ARM64_32:
2669       return "Mach-O arm64 (ILP32)";
2670     case MachO::CPU_TYPE_POWERPC:
2671       return "Mach-O 32-bit ppc";
2672     default:
2673       return "Mach-O 32-bit unknown";
2674     }
2675   }
2676 
2677   switch (CPUType) {
2678   case MachO::CPU_TYPE_X86_64:
2679     return "Mach-O 64-bit x86-64";
2680   case MachO::CPU_TYPE_ARM64:
2681     return "Mach-O arm64";
2682   case MachO::CPU_TYPE_POWERPC64:
2683     return "Mach-O 64-bit ppc64";
2684   default:
2685     return "Mach-O 64-bit unknown";
2686   }
2687 }
2688 
getArch(uint32_t CPUType,uint32_t CPUSubType)2689 Triple::ArchType MachOObjectFile::getArch(uint32_t CPUType, uint32_t CPUSubType) {
2690   switch (CPUType) {
2691   case MachO::CPU_TYPE_I386:
2692     return Triple::x86;
2693   case MachO::CPU_TYPE_X86_64:
2694     return Triple::x86_64;
2695   case MachO::CPU_TYPE_ARM:
2696     return Triple::arm;
2697   case MachO::CPU_TYPE_ARM64:
2698     return Triple::aarch64;
2699   case MachO::CPU_TYPE_ARM64_32:
2700     return Triple::aarch64_32;
2701   case MachO::CPU_TYPE_POWERPC:
2702     return Triple::ppc;
2703   case MachO::CPU_TYPE_POWERPC64:
2704     return Triple::ppc64;
2705   default:
2706     return Triple::UnknownArch;
2707   }
2708 }
2709 
getArchTriple(uint32_t CPUType,uint32_t CPUSubType,const char ** McpuDefault,const char ** ArchFlag)2710 Triple MachOObjectFile::getArchTriple(uint32_t CPUType, uint32_t CPUSubType,
2711                                       const char **McpuDefault,
2712                                       const char **ArchFlag) {
2713   if (McpuDefault)
2714     *McpuDefault = nullptr;
2715   if (ArchFlag)
2716     *ArchFlag = nullptr;
2717 
2718   switch (CPUType) {
2719   case MachO::CPU_TYPE_I386:
2720     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2721     case MachO::CPU_SUBTYPE_I386_ALL:
2722       if (ArchFlag)
2723         *ArchFlag = "i386";
2724       return Triple("i386-apple-darwin");
2725     default:
2726       return Triple();
2727     }
2728   case MachO::CPU_TYPE_X86_64:
2729     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2730     case MachO::CPU_SUBTYPE_X86_64_ALL:
2731       if (ArchFlag)
2732         *ArchFlag = "x86_64";
2733       return Triple("x86_64-apple-darwin");
2734     case MachO::CPU_SUBTYPE_X86_64_H:
2735       if (ArchFlag)
2736         *ArchFlag = "x86_64h";
2737       return Triple("x86_64h-apple-darwin");
2738     default:
2739       return Triple();
2740     }
2741   case MachO::CPU_TYPE_ARM:
2742     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2743     case MachO::CPU_SUBTYPE_ARM_V4T:
2744       if (ArchFlag)
2745         *ArchFlag = "armv4t";
2746       return Triple("armv4t-apple-darwin");
2747     case MachO::CPU_SUBTYPE_ARM_V5TEJ:
2748       if (ArchFlag)
2749         *ArchFlag = "armv5e";
2750       return Triple("armv5e-apple-darwin");
2751     case MachO::CPU_SUBTYPE_ARM_XSCALE:
2752       if (ArchFlag)
2753         *ArchFlag = "xscale";
2754       return Triple("xscale-apple-darwin");
2755     case MachO::CPU_SUBTYPE_ARM_V6:
2756       if (ArchFlag)
2757         *ArchFlag = "armv6";
2758       return Triple("armv6-apple-darwin");
2759     case MachO::CPU_SUBTYPE_ARM_V6M:
2760       if (McpuDefault)
2761         *McpuDefault = "cortex-m0";
2762       if (ArchFlag)
2763         *ArchFlag = "armv6m";
2764       return Triple("armv6m-apple-darwin");
2765     case MachO::CPU_SUBTYPE_ARM_V7:
2766       if (ArchFlag)
2767         *ArchFlag = "armv7";
2768       return Triple("armv7-apple-darwin");
2769     case MachO::CPU_SUBTYPE_ARM_V7EM:
2770       if (McpuDefault)
2771         *McpuDefault = "cortex-m4";
2772       if (ArchFlag)
2773         *ArchFlag = "armv7em";
2774       return Triple("thumbv7em-apple-darwin");
2775     case MachO::CPU_SUBTYPE_ARM_V7K:
2776       if (McpuDefault)
2777         *McpuDefault = "cortex-a7";
2778       if (ArchFlag)
2779         *ArchFlag = "armv7k";
2780       return Triple("armv7k-apple-darwin");
2781     case MachO::CPU_SUBTYPE_ARM_V7M:
2782       if (McpuDefault)
2783         *McpuDefault = "cortex-m3";
2784       if (ArchFlag)
2785         *ArchFlag = "armv7m";
2786       return Triple("thumbv7m-apple-darwin");
2787     case MachO::CPU_SUBTYPE_ARM_V7S:
2788       if (McpuDefault)
2789         *McpuDefault = "cortex-a7";
2790       if (ArchFlag)
2791         *ArchFlag = "armv7s";
2792       return Triple("armv7s-apple-darwin");
2793     default:
2794       return Triple();
2795     }
2796   case MachO::CPU_TYPE_ARM64:
2797     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2798     case MachO::CPU_SUBTYPE_ARM64_ALL:
2799       if (McpuDefault)
2800         *McpuDefault = "cyclone";
2801       if (ArchFlag)
2802         *ArchFlag = "arm64";
2803       return Triple("arm64-apple-darwin");
2804     case MachO::CPU_SUBTYPE_ARM64E:
2805       if (McpuDefault)
2806         *McpuDefault = "apple-a12";
2807       if (ArchFlag)
2808         *ArchFlag = "arm64e";
2809       return Triple("arm64e-apple-darwin");
2810     default:
2811       return Triple();
2812     }
2813   case MachO::CPU_TYPE_ARM64_32:
2814     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2815     case MachO::CPU_SUBTYPE_ARM64_32_V8:
2816       if (McpuDefault)
2817         *McpuDefault = "cyclone";
2818       if (ArchFlag)
2819         *ArchFlag = "arm64_32";
2820       return Triple("arm64_32-apple-darwin");
2821     default:
2822       return Triple();
2823     }
2824   case MachO::CPU_TYPE_POWERPC:
2825     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2826     case MachO::CPU_SUBTYPE_POWERPC_ALL:
2827       if (ArchFlag)
2828         *ArchFlag = "ppc";
2829       return Triple("ppc-apple-darwin");
2830     default:
2831       return Triple();
2832     }
2833   case MachO::CPU_TYPE_POWERPC64:
2834     switch (CPUSubType & ~MachO::CPU_SUBTYPE_MASK) {
2835     case MachO::CPU_SUBTYPE_POWERPC_ALL:
2836       if (ArchFlag)
2837         *ArchFlag = "ppc64";
2838       return Triple("ppc64-apple-darwin");
2839     default:
2840       return Triple();
2841     }
2842   default:
2843     return Triple();
2844   }
2845 }
2846 
getHostArch()2847 Triple MachOObjectFile::getHostArch() {
2848   return Triple(sys::getDefaultTargetTriple());
2849 }
2850 
isValidArch(StringRef ArchFlag)2851 bool MachOObjectFile::isValidArch(StringRef ArchFlag) {
2852   auto validArchs = getValidArchs();
2853   return llvm::is_contained(validArchs, ArchFlag);
2854 }
2855 
getValidArchs()2856 ArrayRef<StringRef> MachOObjectFile::getValidArchs() {
2857   static const std::array<StringRef, 18> ValidArchs = {{
2858       "i386",
2859       "x86_64",
2860       "x86_64h",
2861       "armv4t",
2862       "arm",
2863       "armv5e",
2864       "armv6",
2865       "armv6m",
2866       "armv7",
2867       "armv7em",
2868       "armv7k",
2869       "armv7m",
2870       "armv7s",
2871       "arm64",
2872       "arm64e",
2873       "arm64_32",
2874       "ppc",
2875       "ppc64",
2876   }};
2877 
2878   return ValidArchs;
2879 }
2880 
getArch() const2881 Triple::ArchType MachOObjectFile::getArch() const {
2882   return getArch(getCPUType(*this), getCPUSubType(*this));
2883 }
2884 
getArchTriple(const char ** McpuDefault) const2885 Triple MachOObjectFile::getArchTriple(const char **McpuDefault) const {
2886   return getArchTriple(Header.cputype, Header.cpusubtype, McpuDefault);
2887 }
2888 
section_rel_begin(unsigned Index) const2889 relocation_iterator MachOObjectFile::section_rel_begin(unsigned Index) const {
2890   DataRefImpl DRI;
2891   DRI.d.a = Index;
2892   return section_rel_begin(DRI);
2893 }
2894 
section_rel_end(unsigned Index) const2895 relocation_iterator MachOObjectFile::section_rel_end(unsigned Index) const {
2896   DataRefImpl DRI;
2897   DRI.d.a = Index;
2898   return section_rel_end(DRI);
2899 }
2900 
begin_dices() const2901 dice_iterator MachOObjectFile::begin_dices() const {
2902   DataRefImpl DRI;
2903   if (!DataInCodeLoadCmd)
2904     return dice_iterator(DiceRef(DRI, this));
2905 
2906   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
2907   DRI.p = reinterpret_cast<uintptr_t>(getPtr(*this, DicLC.dataoff));
2908   return dice_iterator(DiceRef(DRI, this));
2909 }
2910 
end_dices() const2911 dice_iterator MachOObjectFile::end_dices() const {
2912   DataRefImpl DRI;
2913   if (!DataInCodeLoadCmd)
2914     return dice_iterator(DiceRef(DRI, this));
2915 
2916   MachO::linkedit_data_command DicLC = getDataInCodeLoadCommand();
2917   unsigned Offset = DicLC.dataoff + DicLC.datasize;
2918   DRI.p = reinterpret_cast<uintptr_t>(getPtr(*this, Offset));
2919   return dice_iterator(DiceRef(DRI, this));
2920 }
2921 
ExportEntry(Error * E,const MachOObjectFile * O,ArrayRef<uint8_t> T)2922 ExportEntry::ExportEntry(Error *E, const MachOObjectFile *O,
2923                          ArrayRef<uint8_t> T) : E(E), O(O), Trie(T) {}
2924 
moveToFirst()2925 void ExportEntry::moveToFirst() {
2926   ErrorAsOutParameter ErrAsOutParam(E);
2927   pushNode(0);
2928   if (*E)
2929     return;
2930   pushDownUntilBottom();
2931 }
2932 
moveToEnd()2933 void ExportEntry::moveToEnd() {
2934   Stack.clear();
2935   Done = true;
2936 }
2937 
operator ==(const ExportEntry & Other) const2938 bool ExportEntry::operator==(const ExportEntry &Other) const {
2939   // Common case, one at end, other iterating from begin.
2940   if (Done || Other.Done)
2941     return (Done == Other.Done);
2942   // Not equal if different stack sizes.
2943   if (Stack.size() != Other.Stack.size())
2944     return false;
2945   // Not equal if different cumulative strings.
2946   if (!CumulativeString.equals(Other.CumulativeString))
2947     return false;
2948   // Equal if all nodes in both stacks match.
2949   for (unsigned i=0; i < Stack.size(); ++i) {
2950     if (Stack[i].Start != Other.Stack[i].Start)
2951       return false;
2952   }
2953   return true;
2954 }
2955 
readULEB128(const uint8_t * & Ptr,const char ** error)2956 uint64_t ExportEntry::readULEB128(const uint8_t *&Ptr, const char **error) {
2957   unsigned Count;
2958   uint64_t Result = decodeULEB128(Ptr, &Count, Trie.end(), error);
2959   Ptr += Count;
2960   if (Ptr > Trie.end())
2961     Ptr = Trie.end();
2962   return Result;
2963 }
2964 
name() const2965 StringRef ExportEntry::name() const {
2966   return CumulativeString;
2967 }
2968 
flags() const2969 uint64_t ExportEntry::flags() const {
2970   return Stack.back().Flags;
2971 }
2972 
address() const2973 uint64_t ExportEntry::address() const {
2974   return Stack.back().Address;
2975 }
2976 
other() const2977 uint64_t ExportEntry::other() const {
2978   return Stack.back().Other;
2979 }
2980 
otherName() const2981 StringRef ExportEntry::otherName() const {
2982   const char* ImportName = Stack.back().ImportName;
2983   if (ImportName)
2984     return StringRef(ImportName);
2985   return StringRef();
2986 }
2987 
nodeOffset() const2988 uint32_t ExportEntry::nodeOffset() const {
2989   return Stack.back().Start - Trie.begin();
2990 }
2991 
NodeState(const uint8_t * Ptr)2992 ExportEntry::NodeState::NodeState(const uint8_t *Ptr)
2993     : Start(Ptr), Current(Ptr) {}
2994 
pushNode(uint64_t offset)2995 void ExportEntry::pushNode(uint64_t offset) {
2996   ErrorAsOutParameter ErrAsOutParam(E);
2997   const uint8_t *Ptr = Trie.begin() + offset;
2998   NodeState State(Ptr);
2999   const char *error = nullptr;
3000   uint64_t ExportInfoSize = readULEB128(State.Current, &error);
3001   if (error) {
3002     *E = malformedError("export info size " + Twine(error) +
3003                         " in export trie data at node: 0x" +
3004                         Twine::utohexstr(offset));
3005     moveToEnd();
3006     return;
3007   }
3008   State.IsExportNode = (ExportInfoSize != 0);
3009   const uint8_t* Children = State.Current + ExportInfoSize;
3010   if (Children > Trie.end()) {
3011     *E = malformedError(
3012         "export info size: 0x" + Twine::utohexstr(ExportInfoSize) +
3013         " in export trie data at node: 0x" + Twine::utohexstr(offset) +
3014         " too big and extends past end of trie data");
3015     moveToEnd();
3016     return;
3017   }
3018   if (State.IsExportNode) {
3019     const uint8_t *ExportStart = State.Current;
3020     State.Flags = readULEB128(State.Current, &error);
3021     if (error) {
3022       *E = malformedError("flags " + Twine(error) +
3023                           " in export trie data at node: 0x" +
3024                           Twine::utohexstr(offset));
3025       moveToEnd();
3026       return;
3027     }
3028     uint64_t Kind = State.Flags & MachO::EXPORT_SYMBOL_FLAGS_KIND_MASK;
3029     if (State.Flags != 0 &&
3030         (Kind != MachO::EXPORT_SYMBOL_FLAGS_KIND_REGULAR &&
3031          Kind != MachO::EXPORT_SYMBOL_FLAGS_KIND_ABSOLUTE &&
3032          Kind != MachO::EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL)) {
3033       *E = malformedError(
3034           "unsupported exported symbol kind: " + Twine((int)Kind) +
3035           " in flags: 0x" + Twine::utohexstr(State.Flags) +
3036           " in export trie data at node: 0x" + Twine::utohexstr(offset));
3037       moveToEnd();
3038       return;
3039     }
3040     if (State.Flags & MachO::EXPORT_SYMBOL_FLAGS_REEXPORT) {
3041       State.Address = 0;
3042       State.Other = readULEB128(State.Current, &error); // dylib ordinal
3043       if (error) {
3044         *E = malformedError("dylib ordinal of re-export " + Twine(error) +
3045                             " in export trie data at node: 0x" +
3046                             Twine::utohexstr(offset));
3047         moveToEnd();
3048         return;
3049       }
3050       if (O != nullptr) {
3051         // Only positive numbers represent library ordinals. Zero and negative
3052         // numbers have special meaning (see BindSpecialDylib).
3053         if ((int64_t)State.Other > 0 && State.Other > O->getLibraryCount()) {
3054           *E = malformedError(
3055               "bad library ordinal: " + Twine((int)State.Other) + " (max " +
3056               Twine((int)O->getLibraryCount()) +
3057               ") in export trie data at node: 0x" + Twine::utohexstr(offset));
3058           moveToEnd();
3059           return;
3060         }
3061       }
3062       State.ImportName = reinterpret_cast<const char*>(State.Current);
3063       if (*State.ImportName == '\0') {
3064         State.Current++;
3065       } else {
3066         const uint8_t *End = State.Current + 1;
3067         if (End >= Trie.end()) {
3068           *E = malformedError("import name of re-export in export trie data at "
3069                               "node: 0x" +
3070                               Twine::utohexstr(offset) +
3071                               " starts past end of trie data");
3072           moveToEnd();
3073           return;
3074         }
3075         while(*End != '\0' && End < Trie.end())
3076           End++;
3077         if (*End != '\0') {
3078           *E = malformedError("import name of re-export in export trie data at "
3079                               "node: 0x" +
3080                               Twine::utohexstr(offset) +
3081                               " extends past end of trie data");
3082           moveToEnd();
3083           return;
3084         }
3085         State.Current = End + 1;
3086       }
3087     } else {
3088       State.Address = readULEB128(State.Current, &error);
3089       if (error) {
3090         *E = malformedError("address " + Twine(error) +
3091                             " in export trie data at node: 0x" +
3092                             Twine::utohexstr(offset));
3093         moveToEnd();
3094         return;
3095       }
3096       if (State.Flags & MachO::EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER) {
3097         State.Other = readULEB128(State.Current, &error);
3098         if (error) {
3099           *E = malformedError("resolver of stub and resolver " + Twine(error) +
3100                               " in export trie data at node: 0x" +
3101                               Twine::utohexstr(offset));
3102           moveToEnd();
3103           return;
3104         }
3105       }
3106     }
3107     if (ExportStart + ExportInfoSize < State.Current) {
3108       *E = malformedError(
3109           "inconsistent export info size: 0x" +
3110           Twine::utohexstr(ExportInfoSize) + " where actual size was: 0x" +
3111           Twine::utohexstr(State.Current - ExportStart) +
3112           " in export trie data at node: 0x" + Twine::utohexstr(offset));
3113       moveToEnd();
3114       return;
3115     }
3116   }
3117   State.ChildCount = *Children;
3118   if (State.ChildCount != 0 && Children + 1 >= Trie.end()) {
3119     *E = malformedError("byte for count of childern in export trie data at "
3120                         "node: 0x" +
3121                         Twine::utohexstr(offset) +
3122                         " extends past end of trie data");
3123     moveToEnd();
3124     return;
3125   }
3126   State.Current = Children + 1;
3127   State.NextChildIndex = 0;
3128   State.ParentStringLength = CumulativeString.size();
3129   Stack.push_back(State);
3130 }
3131 
pushDownUntilBottom()3132 void ExportEntry::pushDownUntilBottom() {
3133   ErrorAsOutParameter ErrAsOutParam(E);
3134   const char *error = nullptr;
3135   while (Stack.back().NextChildIndex < Stack.back().ChildCount) {
3136     NodeState &Top = Stack.back();
3137     CumulativeString.resize(Top.ParentStringLength);
3138     for (;*Top.Current != 0 && Top.Current < Trie.end(); Top.Current++) {
3139       char C = *Top.Current;
3140       CumulativeString.push_back(C);
3141     }
3142     if (Top.Current >= Trie.end()) {
3143       *E = malformedError("edge sub-string in export trie data at node: 0x" +
3144                           Twine::utohexstr(Top.Start - Trie.begin()) +
3145                           " for child #" + Twine((int)Top.NextChildIndex) +
3146                           " extends past end of trie data");
3147       moveToEnd();
3148       return;
3149     }
3150     Top.Current += 1;
3151     uint64_t childNodeIndex = readULEB128(Top.Current, &error);
3152     if (error) {
3153       *E = malformedError("child node offset " + Twine(error) +
3154                           " in export trie data at node: 0x" +
3155                           Twine::utohexstr(Top.Start - Trie.begin()));
3156       moveToEnd();
3157       return;
3158     }
3159     for (const NodeState &node : nodes()) {
3160       if (node.Start == Trie.begin() + childNodeIndex){
3161         *E = malformedError("loop in childern in export trie data at node: 0x" +
3162                             Twine::utohexstr(Top.Start - Trie.begin()) +
3163                             " back to node: 0x" +
3164                             Twine::utohexstr(childNodeIndex));
3165         moveToEnd();
3166         return;
3167       }
3168     }
3169     Top.NextChildIndex += 1;
3170     pushNode(childNodeIndex);
3171     if (*E)
3172       return;
3173   }
3174   if (!Stack.back().IsExportNode) {
3175     *E = malformedError("node is not an export node in export trie data at "
3176                         "node: 0x" +
3177                         Twine::utohexstr(Stack.back().Start - Trie.begin()));
3178     moveToEnd();
3179     return;
3180   }
3181 }
3182 
3183 // We have a trie data structure and need a way to walk it that is compatible
3184 // with the C++ iterator model. The solution is a non-recursive depth first
3185 // traversal where the iterator contains a stack of parent nodes along with a
3186 // string that is the accumulation of all edge strings along the parent chain
3187 // to this point.
3188 //
3189 // There is one "export" node for each exported symbol.  But because some
3190 // symbols may be a prefix of another symbol (e.g. _dup and _dup2), an export
3191 // node may have child nodes too.
3192 //
3193 // The algorithm for moveNext() is to keep moving down the leftmost unvisited
3194 // child until hitting a node with no children (which is an export node or
3195 // else the trie is malformed). On the way down, each node is pushed on the
3196 // stack ivar.  If there is no more ways down, it pops up one and tries to go
3197 // down a sibling path until a childless node is reached.
moveNext()3198 void ExportEntry::moveNext() {
3199   assert(!Stack.empty() && "ExportEntry::moveNext() with empty node stack");
3200   if (!Stack.back().IsExportNode) {
3201     *E = malformedError("node is not an export node in export trie data at "
3202                         "node: 0x" +
3203                         Twine::utohexstr(Stack.back().Start - Trie.begin()));
3204     moveToEnd();
3205     return;
3206   }
3207 
3208   Stack.pop_back();
3209   while (!Stack.empty()) {
3210     NodeState &Top = Stack.back();
3211     if (Top.NextChildIndex < Top.ChildCount) {
3212       pushDownUntilBottom();
3213       // Now at the next export node.
3214       return;
3215     } else {
3216       if (Top.IsExportNode) {
3217         // This node has no children but is itself an export node.
3218         CumulativeString.resize(Top.ParentStringLength);
3219         return;
3220       }
3221       Stack.pop_back();
3222     }
3223   }
3224   Done = true;
3225 }
3226 
3227 iterator_range<export_iterator>
exports(Error & E,ArrayRef<uint8_t> Trie,const MachOObjectFile * O)3228 MachOObjectFile::exports(Error &E, ArrayRef<uint8_t> Trie,
3229                          const MachOObjectFile *O) {
3230   ExportEntry Start(&E, O, Trie);
3231   if (Trie.empty())
3232     Start.moveToEnd();
3233   else
3234     Start.moveToFirst();
3235 
3236   ExportEntry Finish(&E, O, Trie);
3237   Finish.moveToEnd();
3238 
3239   return make_range(export_iterator(Start), export_iterator(Finish));
3240 }
3241 
exports(Error & Err) const3242 iterator_range<export_iterator> MachOObjectFile::exports(Error &Err) const {
3243   ArrayRef<uint8_t> Trie;
3244   if (DyldInfoLoadCmd)
3245     Trie = getDyldInfoExportsTrie();
3246   else if (DyldExportsTrieLoadCmd)
3247     Trie = getDyldExportsTrie();
3248 
3249   return exports(Err, Trie, this);
3250 }
3251 
MachOAbstractFixupEntry(Error * E,const MachOObjectFile * O)3252 MachOAbstractFixupEntry::MachOAbstractFixupEntry(Error *E,
3253                                                  const MachOObjectFile *O)
3254     : E(E), O(O) {
3255   // Cache the vmaddress of __TEXT
3256   for (const auto &Command : O->load_commands()) {
3257     if (Command.C.cmd == MachO::LC_SEGMENT) {
3258       MachO::segment_command SLC = O->getSegmentLoadCommand(Command);
3259       if (StringRef(SLC.segname) == "__TEXT") {
3260         TextAddress = SLC.vmaddr;
3261         break;
3262       }
3263     } else if (Command.C.cmd == MachO::LC_SEGMENT_64) {
3264       MachO::segment_command_64 SLC_64 = O->getSegment64LoadCommand(Command);
3265       if (StringRef(SLC_64.segname) == "__TEXT") {
3266         TextAddress = SLC_64.vmaddr;
3267         break;
3268       }
3269     }
3270   }
3271 }
3272 
segmentIndex() const3273 int32_t MachOAbstractFixupEntry::segmentIndex() const { return SegmentIndex; }
3274 
segmentOffset() const3275 uint64_t MachOAbstractFixupEntry::segmentOffset() const {
3276   return SegmentOffset;
3277 }
3278 
segmentAddress() const3279 uint64_t MachOAbstractFixupEntry::segmentAddress() const {
3280   return O->BindRebaseAddress(SegmentIndex, 0);
3281 }
3282 
segmentName() const3283 StringRef MachOAbstractFixupEntry::segmentName() const {
3284   return O->BindRebaseSegmentName(SegmentIndex);
3285 }
3286 
sectionName() const3287 StringRef MachOAbstractFixupEntry::sectionName() const {
3288   return O->BindRebaseSectionName(SegmentIndex, SegmentOffset);
3289 }
3290 
address() const3291 uint64_t MachOAbstractFixupEntry::address() const {
3292   return O->BindRebaseAddress(SegmentIndex, SegmentOffset);
3293 }
3294 
symbolName() const3295 StringRef MachOAbstractFixupEntry::symbolName() const { return SymbolName; }
3296 
addend() const3297 int64_t MachOAbstractFixupEntry::addend() const { return Addend; }
3298 
flags() const3299 uint32_t MachOAbstractFixupEntry::flags() const { return Flags; }
3300 
ordinal() const3301 int MachOAbstractFixupEntry::ordinal() const { return Ordinal; }
3302 
typeName() const3303 StringRef MachOAbstractFixupEntry::typeName() const { return "unknown"; }
3304 
moveToFirst()3305 void MachOAbstractFixupEntry::moveToFirst() {
3306   SegmentOffset = 0;
3307   SegmentIndex = -1;
3308   Ordinal = 0;
3309   Flags = 0;
3310   Addend = 0;
3311   Done = false;
3312 }
3313 
moveToEnd()3314 void MachOAbstractFixupEntry::moveToEnd() { Done = true; }
3315 
moveNext()3316 void MachOAbstractFixupEntry::moveNext() {}
3317 
MachOChainedFixupEntry(Error * E,const MachOObjectFile * O,bool Parse)3318 MachOChainedFixupEntry::MachOChainedFixupEntry(Error *E,
3319                                                const MachOObjectFile *O,
3320                                                bool Parse)
3321     : MachOAbstractFixupEntry(E, O) {
3322   ErrorAsOutParameter e(E);
3323   if (!Parse)
3324     return;
3325 
3326   if (auto FixupTargetsOrErr = O->getDyldChainedFixupTargets()) {
3327     FixupTargets = *FixupTargetsOrErr;
3328   } else {
3329     *E = FixupTargetsOrErr.takeError();
3330     return;
3331   }
3332 
3333   if (auto SegmentsOrErr = O->getChainedFixupsSegments()) {
3334     Segments = std::move(SegmentsOrErr->second);
3335   } else {
3336     *E = SegmentsOrErr.takeError();
3337     return;
3338   }
3339 }
3340 
findNextPageWithFixups()3341 void MachOChainedFixupEntry::findNextPageWithFixups() {
3342   auto FindInSegment = [this]() {
3343     const ChainedFixupsSegment &SegInfo = Segments[InfoSegIndex];
3344     while (PageIndex < SegInfo.PageStarts.size() &&
3345            SegInfo.PageStarts[PageIndex] == MachO::DYLD_CHAINED_PTR_START_NONE)
3346       ++PageIndex;
3347     return PageIndex < SegInfo.PageStarts.size();
3348   };
3349 
3350   while (InfoSegIndex < Segments.size()) {
3351     if (FindInSegment()) {
3352       PageOffset = Segments[InfoSegIndex].PageStarts[PageIndex];
3353       SegmentData = O->getSegmentContents(Segments[InfoSegIndex].SegIdx);
3354       return;
3355     }
3356 
3357     InfoSegIndex++;
3358     PageIndex = 0;
3359   }
3360 }
3361 
moveToFirst()3362 void MachOChainedFixupEntry::moveToFirst() {
3363   MachOAbstractFixupEntry::moveToFirst();
3364   if (Segments.empty()) {
3365     Done = true;
3366     return;
3367   }
3368 
3369   InfoSegIndex = 0;
3370   PageIndex = 0;
3371 
3372   findNextPageWithFixups();
3373   moveNext();
3374 }
3375 
moveToEnd()3376 void MachOChainedFixupEntry::moveToEnd() {
3377   MachOAbstractFixupEntry::moveToEnd();
3378 }
3379 
moveNext()3380 void MachOChainedFixupEntry::moveNext() {
3381   ErrorAsOutParameter ErrAsOutParam(E);
3382 
3383   if (InfoSegIndex == Segments.size()) {
3384     Done = true;
3385     return;
3386   }
3387 
3388   const ChainedFixupsSegment &SegInfo = Segments[InfoSegIndex];
3389   SegmentIndex = SegInfo.SegIdx;
3390   SegmentOffset = SegInfo.Header.page_size * PageIndex + PageOffset;
3391 
3392   // FIXME: Handle other pointer formats.
3393   uint16_t PointerFormat = SegInfo.Header.pointer_format;
3394   if (PointerFormat != MachO::DYLD_CHAINED_PTR_64 &&
3395       PointerFormat != MachO::DYLD_CHAINED_PTR_64_OFFSET) {
3396     *E = createError("segment " + Twine(SegmentIndex) +
3397                      " has unsupported chained fixup pointer_format " +
3398                      Twine(PointerFormat));
3399     moveToEnd();
3400     return;
3401   }
3402 
3403   Ordinal = 0;
3404   Flags = 0;
3405   Addend = 0;
3406   PointerValue = 0;
3407   SymbolName = {};
3408 
3409   if (SegmentOffset + sizeof(RawValue) > SegmentData.size()) {
3410     *E = malformedError("fixup in segment " + Twine(SegmentIndex) +
3411                         " at offset " + Twine(SegmentOffset) +
3412                         " extends past segment's end");
3413     moveToEnd();
3414     return;
3415   }
3416 
3417   static_assert(sizeof(RawValue) == sizeof(MachO::dyld_chained_import_addend));
3418   memcpy(&RawValue, SegmentData.data() + SegmentOffset, sizeof(RawValue));
3419   if (O->isLittleEndian() != sys::IsLittleEndianHost)
3420     sys::swapByteOrder(RawValue);
3421 
3422   // The bit extraction below assumes little-endian fixup entries.
3423   assert(O->isLittleEndian() && "big-endian object should have been rejected "
3424                                 "by getDyldChainedFixupTargets()");
3425   auto Field = [this](uint8_t Right, uint8_t Count) {
3426     return (RawValue >> Right) & ((1ULL << Count) - 1);
3427   };
3428 
3429   // The `bind` field (most significant bit) of the encoded fixup determines
3430   // whether it is dyld_chained_ptr_64_bind or dyld_chained_ptr_64_rebase.
3431   bool IsBind = Field(63, 1);
3432   Kind = IsBind ? FixupKind::Bind : FixupKind::Rebase;
3433   uint32_t Next = Field(51, 12);
3434   if (IsBind) {
3435     uint32_t ImportOrdinal = Field(0, 24);
3436     uint8_t InlineAddend = Field(24, 8);
3437 
3438     if (ImportOrdinal >= FixupTargets.size()) {
3439       *E = malformedError("fixup in segment " + Twine(SegmentIndex) +
3440                           " at offset " + Twine(SegmentOffset) +
3441                           "  has out-of range import ordinal " +
3442                           Twine(ImportOrdinal));
3443       moveToEnd();
3444       return;
3445     }
3446 
3447     ChainedFixupTarget &Target = FixupTargets[ImportOrdinal];
3448     Ordinal = Target.libOrdinal();
3449     Addend = InlineAddend ? InlineAddend : Target.addend();
3450     Flags = Target.weakImport() ? MachO::BIND_SYMBOL_FLAGS_WEAK_IMPORT : 0;
3451     SymbolName = Target.symbolName();
3452   } else {
3453     uint64_t Target = Field(0, 36);
3454     uint64_t High8 = Field(36, 8);
3455 
3456     PointerValue = Target | (High8 << 56);
3457     if (PointerFormat == MachO::DYLD_CHAINED_PTR_64_OFFSET)
3458       PointerValue += textAddress();
3459   }
3460 
3461   // The stride is 4 bytes for DYLD_CHAINED_PTR_64(_OFFSET).
3462   if (Next != 0) {
3463     PageOffset += 4 * Next;
3464   } else {
3465     ++PageIndex;
3466     findNextPageWithFixups();
3467   }
3468 }
3469 
operator ==(const MachOChainedFixupEntry & Other) const3470 bool MachOChainedFixupEntry::operator==(
3471     const MachOChainedFixupEntry &Other) const {
3472   if (Done && Other.Done)
3473     return true;
3474   if (Done != Other.Done)
3475     return false;
3476   return InfoSegIndex == Other.InfoSegIndex && PageIndex == Other.PageIndex &&
3477          PageOffset == Other.PageOffset;
3478 }
3479 
MachORebaseEntry(Error * E,const MachOObjectFile * O,ArrayRef<uint8_t> Bytes,bool is64Bit)3480 MachORebaseEntry::MachORebaseEntry(Error *E, const MachOObjectFile *O,
3481                                    ArrayRef<uint8_t> Bytes, bool is64Bit)
3482     : E(E), O(O), Opcodes(Bytes), Ptr(Bytes.begin()),
3483       PointerSize(is64Bit ? 8 : 4) {}
3484 
moveToFirst()3485 void MachORebaseEntry::moveToFirst() {
3486   Ptr = Opcodes.begin();
3487   moveNext();
3488 }
3489 
moveToEnd()3490 void MachORebaseEntry::moveToEnd() {
3491   Ptr = Opcodes.end();
3492   RemainingLoopCount = 0;
3493   Done = true;
3494 }
3495 
moveNext()3496 void MachORebaseEntry::moveNext() {
3497   ErrorAsOutParameter ErrAsOutParam(E);
3498   // If in the middle of some loop, move to next rebasing in loop.
3499   SegmentOffset += AdvanceAmount;
3500   if (RemainingLoopCount) {
3501     --RemainingLoopCount;
3502     return;
3503   }
3504 
3505   bool More = true;
3506   while (More) {
3507     // REBASE_OPCODE_DONE is only used for padding if we are not aligned to
3508     // pointer size. Therefore it is possible to reach the end without ever
3509     // having seen REBASE_OPCODE_DONE.
3510     if (Ptr == Opcodes.end()) {
3511       Done = true;
3512       return;
3513     }
3514 
3515     // Parse next opcode and set up next loop.
3516     const uint8_t *OpcodeStart = Ptr;
3517     uint8_t Byte = *Ptr++;
3518     uint8_t ImmValue = Byte & MachO::REBASE_IMMEDIATE_MASK;
3519     uint8_t Opcode = Byte & MachO::REBASE_OPCODE_MASK;
3520     uint64_t Count, Skip;
3521     const char *error = nullptr;
3522     switch (Opcode) {
3523     case MachO::REBASE_OPCODE_DONE:
3524       More = false;
3525       Done = true;
3526       moveToEnd();
3527       DEBUG_WITH_TYPE("mach-o-rebase", dbgs() << "REBASE_OPCODE_DONE\n");
3528       break;
3529     case MachO::REBASE_OPCODE_SET_TYPE_IMM:
3530       RebaseType = ImmValue;
3531       if (RebaseType > MachO::REBASE_TYPE_TEXT_PCREL32) {
3532         *E = malformedError("for REBASE_OPCODE_SET_TYPE_IMM bad bind type: " +
3533                             Twine((int)RebaseType) + " for opcode at: 0x" +
3534                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3535         moveToEnd();
3536         return;
3537       }
3538       DEBUG_WITH_TYPE(
3539           "mach-o-rebase",
3540           dbgs() << "REBASE_OPCODE_SET_TYPE_IMM: "
3541                  << "RebaseType=" << (int) RebaseType << "\n");
3542       break;
3543     case MachO::REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
3544       SegmentIndex = ImmValue;
3545       SegmentOffset = readULEB128(&error);
3546       if (error) {
3547         *E = malformedError("for REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB " +
3548                             Twine(error) + " for opcode at: 0x" +
3549                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3550         moveToEnd();
3551         return;
3552       }
3553       error = O->RebaseEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
3554                                                PointerSize);
3555       if (error) {
3556         *E = malformedError("for REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB " +
3557                             Twine(error) + " for opcode at: 0x" +
3558                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3559         moveToEnd();
3560         return;
3561       }
3562       DEBUG_WITH_TYPE(
3563           "mach-o-rebase",
3564           dbgs() << "REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: "
3565                  << "SegmentIndex=" << SegmentIndex << ", "
3566                  << format("SegmentOffset=0x%06X", SegmentOffset)
3567                  << "\n");
3568       break;
3569     case MachO::REBASE_OPCODE_ADD_ADDR_ULEB:
3570       SegmentOffset += readULEB128(&error);
3571       if (error) {
3572         *E = malformedError("for REBASE_OPCODE_ADD_ADDR_ULEB " + Twine(error) +
3573                             " for opcode at: 0x" +
3574                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3575         moveToEnd();
3576         return;
3577       }
3578       error = O->RebaseEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
3579                                                PointerSize);
3580       if (error) {
3581         *E = malformedError("for REBASE_OPCODE_ADD_ADDR_ULEB " + Twine(error) +
3582                             " for opcode at: 0x" +
3583                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3584         moveToEnd();
3585         return;
3586       }
3587       DEBUG_WITH_TYPE("mach-o-rebase",
3588                       dbgs() << "REBASE_OPCODE_ADD_ADDR_ULEB: "
3589                              << format("SegmentOffset=0x%06X",
3590                                        SegmentOffset) << "\n");
3591       break;
3592     case MachO::REBASE_OPCODE_ADD_ADDR_IMM_SCALED:
3593       SegmentOffset += ImmValue * PointerSize;
3594       error = O->RebaseEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
3595                                                PointerSize);
3596       if (error) {
3597         *E = malformedError("for REBASE_OPCODE_ADD_ADDR_IMM_SCALED " +
3598                             Twine(error) + " for opcode at: 0x" +
3599                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3600         moveToEnd();
3601         return;
3602       }
3603       DEBUG_WITH_TYPE("mach-o-rebase",
3604                       dbgs() << "REBASE_OPCODE_ADD_ADDR_IMM_SCALED: "
3605                              << format("SegmentOffset=0x%06X",
3606                                        SegmentOffset) << "\n");
3607       break;
3608     case MachO::REBASE_OPCODE_DO_REBASE_IMM_TIMES:
3609       AdvanceAmount = PointerSize;
3610       Skip = 0;
3611       Count = ImmValue;
3612       if (ImmValue != 0)
3613         RemainingLoopCount = ImmValue - 1;
3614       else
3615         RemainingLoopCount = 0;
3616       error = O->RebaseEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
3617                                                PointerSize, Count, Skip);
3618       if (error) {
3619         *E = malformedError("for REBASE_OPCODE_DO_REBASE_IMM_TIMES " +
3620                             Twine(error) + " for opcode at: 0x" +
3621                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3622         moveToEnd();
3623         return;
3624       }
3625       DEBUG_WITH_TYPE(
3626           "mach-o-rebase",
3627           dbgs() << "REBASE_OPCODE_DO_REBASE_IMM_TIMES: "
3628                  << format("SegmentOffset=0x%06X", SegmentOffset)
3629                  << ", AdvanceAmount=" << AdvanceAmount
3630                  << ", RemainingLoopCount=" << RemainingLoopCount
3631                  << "\n");
3632       return;
3633     case MachO::REBASE_OPCODE_DO_REBASE_ULEB_TIMES:
3634       AdvanceAmount = PointerSize;
3635       Skip = 0;
3636       Count = readULEB128(&error);
3637       if (error) {
3638         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES " +
3639                             Twine(error) + " for opcode at: 0x" +
3640                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3641         moveToEnd();
3642         return;
3643       }
3644       if (Count != 0)
3645         RemainingLoopCount = Count - 1;
3646       else
3647         RemainingLoopCount = 0;
3648       error = O->RebaseEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
3649                                                PointerSize, Count, Skip);
3650       if (error) {
3651         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES " +
3652                             Twine(error) + " for opcode at: 0x" +
3653                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3654         moveToEnd();
3655         return;
3656       }
3657       DEBUG_WITH_TYPE(
3658           "mach-o-rebase",
3659           dbgs() << "REBASE_OPCODE_DO_REBASE_ULEB_TIMES: "
3660                  << format("SegmentOffset=0x%06X", SegmentOffset)
3661                  << ", AdvanceAmount=" << AdvanceAmount
3662                  << ", RemainingLoopCount=" << RemainingLoopCount
3663                  << "\n");
3664       return;
3665     case MachO::REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB:
3666       Skip = readULEB128(&error);
3667       if (error) {
3668         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB " +
3669                             Twine(error) + " for opcode at: 0x" +
3670                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3671         moveToEnd();
3672         return;
3673       }
3674       AdvanceAmount = Skip + PointerSize;
3675       Count = 1;
3676       RemainingLoopCount = 0;
3677       error = O->RebaseEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
3678                                                PointerSize, Count, Skip);
3679       if (error) {
3680         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB " +
3681                             Twine(error) + " for opcode at: 0x" +
3682                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3683         moveToEnd();
3684         return;
3685       }
3686       DEBUG_WITH_TYPE(
3687           "mach-o-rebase",
3688           dbgs() << "REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB: "
3689                  << format("SegmentOffset=0x%06X", SegmentOffset)
3690                  << ", AdvanceAmount=" << AdvanceAmount
3691                  << ", RemainingLoopCount=" << RemainingLoopCount
3692                  << "\n");
3693       return;
3694     case MachO::REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB:
3695       Count = readULEB128(&error);
3696       if (error) {
3697         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_"
3698                             "ULEB " +
3699                             Twine(error) + " for opcode at: 0x" +
3700                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3701         moveToEnd();
3702         return;
3703       }
3704       if (Count != 0)
3705         RemainingLoopCount = Count - 1;
3706       else
3707         RemainingLoopCount = 0;
3708       Skip = readULEB128(&error);
3709       if (error) {
3710         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_"
3711                             "ULEB " +
3712                             Twine(error) + " for opcode at: 0x" +
3713                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3714         moveToEnd();
3715         return;
3716       }
3717       AdvanceAmount = Skip + PointerSize;
3718 
3719       error = O->RebaseEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
3720                                                PointerSize, Count, Skip);
3721       if (error) {
3722         *E = malformedError("for REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_"
3723                             "ULEB " +
3724                             Twine(error) + " for opcode at: 0x" +
3725                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3726         moveToEnd();
3727         return;
3728       }
3729       DEBUG_WITH_TYPE(
3730           "mach-o-rebase",
3731           dbgs() << "REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB: "
3732                  << format("SegmentOffset=0x%06X", SegmentOffset)
3733                  << ", AdvanceAmount=" << AdvanceAmount
3734                  << ", RemainingLoopCount=" << RemainingLoopCount
3735                  << "\n");
3736       return;
3737     default:
3738       *E = malformedError("bad rebase info (bad opcode value 0x" +
3739                           Twine::utohexstr(Opcode) + " for opcode at: 0x" +
3740                           Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3741       moveToEnd();
3742       return;
3743     }
3744   }
3745 }
3746 
readULEB128(const char ** error)3747 uint64_t MachORebaseEntry::readULEB128(const char **error) {
3748   unsigned Count;
3749   uint64_t Result = decodeULEB128(Ptr, &Count, Opcodes.end(), error);
3750   Ptr += Count;
3751   if (Ptr > Opcodes.end())
3752     Ptr = Opcodes.end();
3753   return Result;
3754 }
3755 
segmentIndex() const3756 int32_t MachORebaseEntry::segmentIndex() const { return SegmentIndex; }
3757 
segmentOffset() const3758 uint64_t MachORebaseEntry::segmentOffset() const { return SegmentOffset; }
3759 
typeName() const3760 StringRef MachORebaseEntry::typeName() const {
3761   switch (RebaseType) {
3762   case MachO::REBASE_TYPE_POINTER:
3763     return "pointer";
3764   case MachO::REBASE_TYPE_TEXT_ABSOLUTE32:
3765     return "text abs32";
3766   case MachO::REBASE_TYPE_TEXT_PCREL32:
3767     return "text rel32";
3768   }
3769   return "unknown";
3770 }
3771 
3772 // For use with the SegIndex of a checked Mach-O Rebase entry
3773 // to get the segment name.
segmentName() const3774 StringRef MachORebaseEntry::segmentName() const {
3775   return O->BindRebaseSegmentName(SegmentIndex);
3776 }
3777 
3778 // For use with a SegIndex,SegOffset pair from a checked Mach-O Rebase entry
3779 // to get the section name.
sectionName() const3780 StringRef MachORebaseEntry::sectionName() const {
3781   return O->BindRebaseSectionName(SegmentIndex, SegmentOffset);
3782 }
3783 
3784 // For use with a SegIndex,SegOffset pair from a checked Mach-O Rebase entry
3785 // to get the address.
address() const3786 uint64_t MachORebaseEntry::address() const {
3787   return O->BindRebaseAddress(SegmentIndex, SegmentOffset);
3788 }
3789 
operator ==(const MachORebaseEntry & Other) const3790 bool MachORebaseEntry::operator==(const MachORebaseEntry &Other) const {
3791 #ifdef EXPENSIVE_CHECKS
3792   assert(Opcodes == Other.Opcodes && "compare iterators of different files");
3793 #else
3794   assert(Opcodes.data() == Other.Opcodes.data() && "compare iterators of different files");
3795 #endif
3796   return (Ptr == Other.Ptr) &&
3797          (RemainingLoopCount == Other.RemainingLoopCount) &&
3798          (Done == Other.Done);
3799 }
3800 
3801 iterator_range<rebase_iterator>
rebaseTable(Error & Err,MachOObjectFile * O,ArrayRef<uint8_t> Opcodes,bool is64)3802 MachOObjectFile::rebaseTable(Error &Err, MachOObjectFile *O,
3803                              ArrayRef<uint8_t> Opcodes, bool is64) {
3804   if (O->BindRebaseSectionTable == nullptr)
3805     O->BindRebaseSectionTable = std::make_unique<BindRebaseSegInfo>(O);
3806   MachORebaseEntry Start(&Err, O, Opcodes, is64);
3807   Start.moveToFirst();
3808 
3809   MachORebaseEntry Finish(&Err, O, Opcodes, is64);
3810   Finish.moveToEnd();
3811 
3812   return make_range(rebase_iterator(Start), rebase_iterator(Finish));
3813 }
3814 
rebaseTable(Error & Err)3815 iterator_range<rebase_iterator> MachOObjectFile::rebaseTable(Error &Err) {
3816   return rebaseTable(Err, this, getDyldInfoRebaseOpcodes(), is64Bit());
3817 }
3818 
MachOBindEntry(Error * E,const MachOObjectFile * O,ArrayRef<uint8_t> Bytes,bool is64Bit,Kind BK)3819 MachOBindEntry::MachOBindEntry(Error *E, const MachOObjectFile *O,
3820                                ArrayRef<uint8_t> Bytes, bool is64Bit, Kind BK)
3821     : E(E), O(O), Opcodes(Bytes), Ptr(Bytes.begin()),
3822       PointerSize(is64Bit ? 8 : 4), TableKind(BK) {}
3823 
moveToFirst()3824 void MachOBindEntry::moveToFirst() {
3825   Ptr = Opcodes.begin();
3826   moveNext();
3827 }
3828 
moveToEnd()3829 void MachOBindEntry::moveToEnd() {
3830   Ptr = Opcodes.end();
3831   RemainingLoopCount = 0;
3832   Done = true;
3833 }
3834 
moveNext()3835 void MachOBindEntry::moveNext() {
3836   ErrorAsOutParameter ErrAsOutParam(E);
3837   // If in the middle of some loop, move to next binding in loop.
3838   SegmentOffset += AdvanceAmount;
3839   if (RemainingLoopCount) {
3840     --RemainingLoopCount;
3841     return;
3842   }
3843 
3844   bool More = true;
3845   while (More) {
3846     // BIND_OPCODE_DONE is only used for padding if we are not aligned to
3847     // pointer size. Therefore it is possible to reach the end without ever
3848     // having seen BIND_OPCODE_DONE.
3849     if (Ptr == Opcodes.end()) {
3850       Done = true;
3851       return;
3852     }
3853 
3854     // Parse next opcode and set up next loop.
3855     const uint8_t *OpcodeStart = Ptr;
3856     uint8_t Byte = *Ptr++;
3857     uint8_t ImmValue = Byte & MachO::BIND_IMMEDIATE_MASK;
3858     uint8_t Opcode = Byte & MachO::BIND_OPCODE_MASK;
3859     int8_t SignExtended;
3860     const uint8_t *SymStart;
3861     uint64_t Count, Skip;
3862     const char *error = nullptr;
3863     switch (Opcode) {
3864     case MachO::BIND_OPCODE_DONE:
3865       if (TableKind == Kind::Lazy) {
3866         // Lazying bindings have a DONE opcode between entries.  Need to ignore
3867         // it to advance to next entry.  But need not if this is last entry.
3868         bool NotLastEntry = false;
3869         for (const uint8_t *P = Ptr; P < Opcodes.end(); ++P) {
3870           if (*P) {
3871             NotLastEntry = true;
3872           }
3873         }
3874         if (NotLastEntry)
3875           break;
3876       }
3877       More = false;
3878       moveToEnd();
3879       DEBUG_WITH_TYPE("mach-o-bind", dbgs() << "BIND_OPCODE_DONE\n");
3880       break;
3881     case MachO::BIND_OPCODE_SET_DYLIB_ORDINAL_IMM:
3882       if (TableKind == Kind::Weak) {
3883         *E = malformedError("BIND_OPCODE_SET_DYLIB_ORDINAL_IMM not allowed in "
3884                             "weak bind table for opcode at: 0x" +
3885                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3886         moveToEnd();
3887         return;
3888       }
3889       Ordinal = ImmValue;
3890       LibraryOrdinalSet = true;
3891       if (ImmValue > O->getLibraryCount()) {
3892         *E = malformedError("for BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB bad "
3893                             "library ordinal: " +
3894                             Twine((int)ImmValue) + " (max " +
3895                             Twine((int)O->getLibraryCount()) +
3896                             ") for opcode at: 0x" +
3897                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3898         moveToEnd();
3899         return;
3900       }
3901       DEBUG_WITH_TYPE(
3902           "mach-o-bind",
3903           dbgs() << "BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: "
3904                  << "Ordinal=" << Ordinal << "\n");
3905       break;
3906     case MachO::BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:
3907       if (TableKind == Kind::Weak) {
3908         *E = malformedError("BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB not allowed in "
3909                             "weak bind table for opcode at: 0x" +
3910                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3911         moveToEnd();
3912         return;
3913       }
3914       Ordinal = readULEB128(&error);
3915       LibraryOrdinalSet = true;
3916       if (error) {
3917         *E = malformedError("for BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB " +
3918                             Twine(error) + " for opcode at: 0x" +
3919                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3920         moveToEnd();
3921         return;
3922       }
3923       if (Ordinal > (int)O->getLibraryCount()) {
3924         *E = malformedError("for BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB bad "
3925                             "library ordinal: " +
3926                             Twine((int)Ordinal) + " (max " +
3927                             Twine((int)O->getLibraryCount()) +
3928                             ") for opcode at: 0x" +
3929                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3930         moveToEnd();
3931         return;
3932       }
3933       DEBUG_WITH_TYPE(
3934           "mach-o-bind",
3935           dbgs() << "BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: "
3936                  << "Ordinal=" << Ordinal << "\n");
3937       break;
3938     case MachO::BIND_OPCODE_SET_DYLIB_SPECIAL_IMM:
3939       if (TableKind == Kind::Weak) {
3940         *E = malformedError("BIND_OPCODE_SET_DYLIB_SPECIAL_IMM not allowed in "
3941                             "weak bind table for opcode at: 0x" +
3942                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3943         moveToEnd();
3944         return;
3945       }
3946       if (ImmValue) {
3947         SignExtended = MachO::BIND_OPCODE_MASK | ImmValue;
3948         Ordinal = SignExtended;
3949         if (Ordinal < MachO::BIND_SPECIAL_DYLIB_FLAT_LOOKUP) {
3950           *E = malformedError("for BIND_OPCODE_SET_DYLIB_SPECIAL_IMM unknown "
3951                               "special ordinal: " +
3952                               Twine((int)Ordinal) + " for opcode at: 0x" +
3953                               Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3954           moveToEnd();
3955           return;
3956         }
3957       } else
3958         Ordinal = 0;
3959       LibraryOrdinalSet = true;
3960       DEBUG_WITH_TYPE(
3961           "mach-o-bind",
3962           dbgs() << "BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: "
3963                  << "Ordinal=" << Ordinal << "\n");
3964       break;
3965     case MachO::BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
3966       Flags = ImmValue;
3967       SymStart = Ptr;
3968       while (*Ptr && (Ptr < Opcodes.end())) {
3969         ++Ptr;
3970       }
3971       if (Ptr == Opcodes.end()) {
3972         *E = malformedError(
3973             "for BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM "
3974             "symbol name extends past opcodes for opcode at: 0x" +
3975             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3976         moveToEnd();
3977         return;
3978       }
3979       SymbolName = StringRef(reinterpret_cast<const char*>(SymStart),
3980                              Ptr-SymStart);
3981       ++Ptr;
3982       DEBUG_WITH_TYPE(
3983           "mach-o-bind",
3984           dbgs() << "BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: "
3985                  << "SymbolName=" << SymbolName << "\n");
3986       if (TableKind == Kind::Weak) {
3987         if (ImmValue & MachO::BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION)
3988           return;
3989       }
3990       break;
3991     case MachO::BIND_OPCODE_SET_TYPE_IMM:
3992       BindType = ImmValue;
3993       if (ImmValue > MachO::BIND_TYPE_TEXT_PCREL32) {
3994         *E = malformedError("for BIND_OPCODE_SET_TYPE_IMM bad bind type: " +
3995                             Twine((int)ImmValue) + " for opcode at: 0x" +
3996                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
3997         moveToEnd();
3998         return;
3999       }
4000       DEBUG_WITH_TYPE(
4001           "mach-o-bind",
4002           dbgs() << "BIND_OPCODE_SET_TYPE_IMM: "
4003                  << "BindType=" << (int)BindType << "\n");
4004       break;
4005     case MachO::BIND_OPCODE_SET_ADDEND_SLEB:
4006       Addend = readSLEB128(&error);
4007       if (error) {
4008         *E = malformedError("for BIND_OPCODE_SET_ADDEND_SLEB " + Twine(error) +
4009                             " for opcode at: 0x" +
4010                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4011         moveToEnd();
4012         return;
4013       }
4014       DEBUG_WITH_TYPE(
4015           "mach-o-bind",
4016           dbgs() << "BIND_OPCODE_SET_ADDEND_SLEB: "
4017                  << "Addend=" << Addend << "\n");
4018       break;
4019     case MachO::BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
4020       SegmentIndex = ImmValue;
4021       SegmentOffset = readULEB128(&error);
4022       if (error) {
4023         *E = malformedError("for BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB " +
4024                             Twine(error) + " for opcode at: 0x" +
4025                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4026         moveToEnd();
4027         return;
4028       }
4029       error = O->BindEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
4030                                              PointerSize);
4031       if (error) {
4032         *E = malformedError("for BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB " +
4033                             Twine(error) + " for opcode at: 0x" +
4034                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4035         moveToEnd();
4036         return;
4037       }
4038       DEBUG_WITH_TYPE(
4039           "mach-o-bind",
4040           dbgs() << "BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: "
4041                  << "SegmentIndex=" << SegmentIndex << ", "
4042                  << format("SegmentOffset=0x%06X", SegmentOffset)
4043                  << "\n");
4044       break;
4045     case MachO::BIND_OPCODE_ADD_ADDR_ULEB:
4046       SegmentOffset += readULEB128(&error);
4047       if (error) {
4048         *E = malformedError("for BIND_OPCODE_ADD_ADDR_ULEB " + Twine(error) +
4049                             " for opcode at: 0x" +
4050                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4051         moveToEnd();
4052         return;
4053       }
4054       error = O->BindEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
4055                                              PointerSize);
4056       if (error) {
4057         *E = malformedError("for BIND_OPCODE_ADD_ADDR_ULEB " + Twine(error) +
4058                             " for opcode at: 0x" +
4059                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4060         moveToEnd();
4061         return;
4062       }
4063       DEBUG_WITH_TYPE("mach-o-bind",
4064                       dbgs() << "BIND_OPCODE_ADD_ADDR_ULEB: "
4065                              << format("SegmentOffset=0x%06X",
4066                                        SegmentOffset) << "\n");
4067       break;
4068     case MachO::BIND_OPCODE_DO_BIND:
4069       AdvanceAmount = PointerSize;
4070       RemainingLoopCount = 0;
4071       error = O->BindEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
4072                                              PointerSize);
4073       if (error) {
4074         *E = malformedError("for BIND_OPCODE_DO_BIND " + Twine(error) +
4075                             " for opcode at: 0x" +
4076                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4077         moveToEnd();
4078         return;
4079       }
4080       if (SymbolName == StringRef()) {
4081         *E = malformedError(
4082             "for BIND_OPCODE_DO_BIND missing preceding "
4083             "BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM for opcode at: 0x" +
4084             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4085         moveToEnd();
4086         return;
4087       }
4088       if (!LibraryOrdinalSet && TableKind != Kind::Weak) {
4089         *E =
4090             malformedError("for BIND_OPCODE_DO_BIND missing preceding "
4091                            "BIND_OPCODE_SET_DYLIB_ORDINAL_* for opcode at: 0x" +
4092                            Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4093         moveToEnd();
4094         return;
4095       }
4096       DEBUG_WITH_TYPE("mach-o-bind",
4097                       dbgs() << "BIND_OPCODE_DO_BIND: "
4098                              << format("SegmentOffset=0x%06X",
4099                                        SegmentOffset) << "\n");
4100       return;
4101      case MachO::BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
4102       if (TableKind == Kind::Lazy) {
4103         *E = malformedError("BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB not allowed in "
4104                             "lazy bind table for opcode at: 0x" +
4105                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4106         moveToEnd();
4107         return;
4108       }
4109       error = O->BindEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
4110                                              PointerSize);
4111       if (error) {
4112         *E = malformedError("for BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB " +
4113                             Twine(error) + " for opcode at: 0x" +
4114                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4115         moveToEnd();
4116         return;
4117       }
4118       if (SymbolName == StringRef()) {
4119         *E = malformedError(
4120             "for BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB missing "
4121             "preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM for opcode "
4122             "at: 0x" +
4123             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4124         moveToEnd();
4125         return;
4126       }
4127       if (!LibraryOrdinalSet && TableKind != Kind::Weak) {
4128         *E = malformedError(
4129             "for BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB missing "
4130             "preceding BIND_OPCODE_SET_DYLIB_ORDINAL_* for opcode at: 0x" +
4131             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4132         moveToEnd();
4133         return;
4134       }
4135       AdvanceAmount = readULEB128(&error) + PointerSize;
4136       if (error) {
4137         *E = malformedError("for BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB " +
4138                             Twine(error) + " for opcode at: 0x" +
4139                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4140         moveToEnd();
4141         return;
4142       }
4143       // Note, this is not really an error until the next bind but make no sense
4144       // for a BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB to not be followed by another
4145       // bind operation.
4146       error = O->BindEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset +
4147                                             AdvanceAmount, PointerSize);
4148       if (error) {
4149         *E = malformedError("for BIND_OPCODE_ADD_ADDR_ULEB (after adding "
4150                             "ULEB) " +
4151                             Twine(error) + " for opcode at: 0x" +
4152                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4153         moveToEnd();
4154         return;
4155       }
4156       RemainingLoopCount = 0;
4157       DEBUG_WITH_TYPE(
4158           "mach-o-bind",
4159           dbgs() << "BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB: "
4160                  << format("SegmentOffset=0x%06X", SegmentOffset)
4161                  << ", AdvanceAmount=" << AdvanceAmount
4162                  << ", RemainingLoopCount=" << RemainingLoopCount
4163                  << "\n");
4164       return;
4165     case MachO::BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
4166       if (TableKind == Kind::Lazy) {
4167         *E = malformedError("BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED not "
4168                             "allowed in lazy bind table for opcode at: 0x" +
4169                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4170         moveToEnd();
4171         return;
4172       }
4173       if (SymbolName == StringRef()) {
4174         *E = malformedError(
4175             "for BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED "
4176             "missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM for "
4177             "opcode at: 0x" +
4178             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4179         moveToEnd();
4180         return;
4181       }
4182       if (!LibraryOrdinalSet && TableKind != Kind::Weak) {
4183         *E = malformedError(
4184             "for BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED "
4185             "missing preceding BIND_OPCODE_SET_DYLIB_ORDINAL_* for opcode "
4186             "at: 0x" +
4187             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4188         moveToEnd();
4189         return;
4190       }
4191       AdvanceAmount = ImmValue * PointerSize + PointerSize;
4192       RemainingLoopCount = 0;
4193       error = O->BindEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset +
4194                                              AdvanceAmount, PointerSize);
4195       if (error) {
4196         *E = malformedError("for BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED " +
4197                             Twine(error) + " for opcode at: 0x" +
4198                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4199         moveToEnd();
4200         return;
4201       }
4202       DEBUG_WITH_TYPE("mach-o-bind",
4203                       dbgs()
4204                       << "BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: "
4205                       << format("SegmentOffset=0x%06X", SegmentOffset) << "\n");
4206       return;
4207     case MachO::BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
4208       if (TableKind == Kind::Lazy) {
4209         *E = malformedError("BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB not "
4210                             "allowed in lazy bind table for opcode at: 0x" +
4211                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4212         moveToEnd();
4213         return;
4214       }
4215       Count = readULEB128(&error);
4216       if (Count != 0)
4217         RemainingLoopCount = Count - 1;
4218       else
4219         RemainingLoopCount = 0;
4220       if (error) {
4221         *E = malformedError("for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB "
4222                             " (count value) " +
4223                             Twine(error) + " for opcode at: 0x" +
4224                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4225         moveToEnd();
4226         return;
4227       }
4228       Skip = readULEB128(&error);
4229       AdvanceAmount = Skip + PointerSize;
4230       if (error) {
4231         *E = malformedError("for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB "
4232                             " (skip value) " +
4233                             Twine(error) + " for opcode at: 0x" +
4234                             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4235         moveToEnd();
4236         return;
4237       }
4238       if (SymbolName == StringRef()) {
4239         *E = malformedError(
4240             "for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB "
4241             "missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM for "
4242             "opcode at: 0x" +
4243             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4244         moveToEnd();
4245         return;
4246       }
4247       if (!LibraryOrdinalSet && TableKind != Kind::Weak) {
4248         *E = malformedError(
4249             "for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB "
4250             "missing preceding BIND_OPCODE_SET_DYLIB_ORDINAL_* for opcode "
4251             "at: 0x" +
4252             Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4253         moveToEnd();
4254         return;
4255       }
4256       error = O->BindEntryCheckSegAndOffsets(SegmentIndex, SegmentOffset,
4257                                              PointerSize, Count, Skip);
4258       if (error) {
4259         *E =
4260             malformedError("for BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB " +
4261                            Twine(error) + " for opcode at: 0x" +
4262                            Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4263         moveToEnd();
4264         return;
4265       }
4266       DEBUG_WITH_TYPE(
4267           "mach-o-bind",
4268           dbgs() << "BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: "
4269                  << format("SegmentOffset=0x%06X", SegmentOffset)
4270                  << ", AdvanceAmount=" << AdvanceAmount
4271                  << ", RemainingLoopCount=" << RemainingLoopCount
4272                  << "\n");
4273       return;
4274     default:
4275       *E = malformedError("bad bind info (bad opcode value 0x" +
4276                           Twine::utohexstr(Opcode) + " for opcode at: 0x" +
4277                           Twine::utohexstr(OpcodeStart - Opcodes.begin()));
4278       moveToEnd();
4279       return;
4280     }
4281   }
4282 }
4283 
readULEB128(const char ** error)4284 uint64_t MachOBindEntry::readULEB128(const char **error) {
4285   unsigned Count;
4286   uint64_t Result = decodeULEB128(Ptr, &Count, Opcodes.end(), error);
4287   Ptr += Count;
4288   if (Ptr > Opcodes.end())
4289     Ptr = Opcodes.end();
4290   return Result;
4291 }
4292 
readSLEB128(const char ** error)4293 int64_t MachOBindEntry::readSLEB128(const char **error) {
4294   unsigned Count;
4295   int64_t Result = decodeSLEB128(Ptr, &Count, Opcodes.end(), error);
4296   Ptr += Count;
4297   if (Ptr > Opcodes.end())
4298     Ptr = Opcodes.end();
4299   return Result;
4300 }
4301 
segmentIndex() const4302 int32_t MachOBindEntry::segmentIndex() const { return SegmentIndex; }
4303 
segmentOffset() const4304 uint64_t MachOBindEntry::segmentOffset() const { return SegmentOffset; }
4305 
typeName() const4306 StringRef MachOBindEntry::typeName() const {
4307   switch (BindType) {
4308   case MachO::BIND_TYPE_POINTER:
4309     return "pointer";
4310   case MachO::BIND_TYPE_TEXT_ABSOLUTE32:
4311     return "text abs32";
4312   case MachO::BIND_TYPE_TEXT_PCREL32:
4313     return "text rel32";
4314   }
4315   return "unknown";
4316 }
4317 
symbolName() const4318 StringRef MachOBindEntry::symbolName() const { return SymbolName; }
4319 
addend() const4320 int64_t MachOBindEntry::addend() const { return Addend; }
4321 
flags() const4322 uint32_t MachOBindEntry::flags() const { return Flags; }
4323 
ordinal() const4324 int MachOBindEntry::ordinal() const { return Ordinal; }
4325 
4326 // For use with the SegIndex of a checked Mach-O Bind entry
4327 // to get the segment name.
segmentName() const4328 StringRef MachOBindEntry::segmentName() const {
4329   return O->BindRebaseSegmentName(SegmentIndex);
4330 }
4331 
4332 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind entry
4333 // to get the section name.
sectionName() const4334 StringRef MachOBindEntry::sectionName() const {
4335   return O->BindRebaseSectionName(SegmentIndex, SegmentOffset);
4336 }
4337 
4338 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind entry
4339 // to get the address.
address() const4340 uint64_t MachOBindEntry::address() const {
4341   return O->BindRebaseAddress(SegmentIndex, SegmentOffset);
4342 }
4343 
operator ==(const MachOBindEntry & Other) const4344 bool MachOBindEntry::operator==(const MachOBindEntry &Other) const {
4345 #ifdef EXPENSIVE_CHECKS
4346   assert(Opcodes == Other.Opcodes && "compare iterators of different files");
4347 #else
4348   assert(Opcodes.data() == Other.Opcodes.data() && "compare iterators of different files");
4349 #endif
4350   return (Ptr == Other.Ptr) &&
4351          (RemainingLoopCount == Other.RemainingLoopCount) &&
4352          (Done == Other.Done);
4353 }
4354 
4355 // Build table of sections so SegIndex/SegOffset pairs can be translated.
BindRebaseSegInfo(const object::MachOObjectFile * Obj)4356 BindRebaseSegInfo::BindRebaseSegInfo(const object::MachOObjectFile *Obj) {
4357   uint32_t CurSegIndex = Obj->hasPageZeroSegment() ? 1 : 0;
4358   StringRef CurSegName;
4359   uint64_t CurSegAddress;
4360   for (const SectionRef &Section : Obj->sections()) {
4361     SectionInfo Info;
4362     Expected<StringRef> NameOrErr = Section.getName();
4363     if (!NameOrErr)
4364       consumeError(NameOrErr.takeError());
4365     else
4366       Info.SectionName = *NameOrErr;
4367     Info.Address = Section.getAddress();
4368     Info.Size = Section.getSize();
4369     Info.SegmentName =
4370         Obj->getSectionFinalSegmentName(Section.getRawDataRefImpl());
4371     if (Info.SegmentName != CurSegName) {
4372       ++CurSegIndex;
4373       CurSegName = Info.SegmentName;
4374       CurSegAddress = Info.Address;
4375     }
4376     Info.SegmentIndex = CurSegIndex - 1;
4377     Info.OffsetInSegment = Info.Address - CurSegAddress;
4378     Info.SegmentStartAddress = CurSegAddress;
4379     Sections.push_back(Info);
4380   }
4381   MaxSegIndex = CurSegIndex;
4382 }
4383 
4384 // For use with a SegIndex, SegOffset, and PointerSize triple in
4385 // MachOBindEntry::moveNext() to validate a MachOBindEntry or MachORebaseEntry.
4386 //
4387 // Given a SegIndex, SegOffset, and PointerSize, verify a valid section exists
4388 // that fully contains a pointer at that location. Multiple fixups in a bind
4389 // (such as with the BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB opcode) can
4390 // be tested via the Count and Skip parameters.
checkSegAndOffsets(int32_t SegIndex,uint64_t SegOffset,uint8_t PointerSize,uint64_t Count,uint64_t Skip)4391 const char *BindRebaseSegInfo::checkSegAndOffsets(int32_t SegIndex,
4392                                                   uint64_t SegOffset,
4393                                                   uint8_t PointerSize,
4394                                                   uint64_t Count,
4395                                                   uint64_t Skip) {
4396   if (SegIndex == -1)
4397     return "missing preceding *_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB";
4398   if (SegIndex >= MaxSegIndex)
4399     return "bad segIndex (too large)";
4400   for (uint64_t i = 0; i < Count; ++i) {
4401     uint64_t Start = SegOffset + i * (PointerSize + Skip);
4402     uint64_t End = Start + PointerSize;
4403     bool Found = false;
4404     for (const SectionInfo &SI : Sections) {
4405       if (SI.SegmentIndex != SegIndex)
4406         continue;
4407       if ((SI.OffsetInSegment<=Start) && (Start<(SI.OffsetInSegment+SI.Size))) {
4408         if (End <= SI.OffsetInSegment + SI.Size) {
4409           Found = true;
4410           break;
4411         }
4412         else
4413           return "bad offset, extends beyond section boundary";
4414       }
4415     }
4416     if (!Found)
4417       return "bad offset, not in section";
4418   }
4419   return nullptr;
4420 }
4421 
4422 // For use with the SegIndex of a checked Mach-O Bind or Rebase entry
4423 // to get the segment name.
segmentName(int32_t SegIndex)4424 StringRef BindRebaseSegInfo::segmentName(int32_t SegIndex) {
4425   for (const SectionInfo &SI : Sections) {
4426     if (SI.SegmentIndex == SegIndex)
4427       return SI.SegmentName;
4428   }
4429   llvm_unreachable("invalid SegIndex");
4430 }
4431 
4432 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind or Rebase
4433 // to get the SectionInfo.
findSection(int32_t SegIndex,uint64_t SegOffset)4434 const BindRebaseSegInfo::SectionInfo &BindRebaseSegInfo::findSection(
4435                                      int32_t SegIndex, uint64_t SegOffset) {
4436   for (const SectionInfo &SI : Sections) {
4437     if (SI.SegmentIndex != SegIndex)
4438       continue;
4439     if (SI.OffsetInSegment > SegOffset)
4440       continue;
4441     if (SegOffset >= (SI.OffsetInSegment + SI.Size))
4442       continue;
4443     return SI;
4444   }
4445   llvm_unreachable("SegIndex and SegOffset not in any section");
4446 }
4447 
4448 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind or Rebase
4449 // entry to get the section name.
sectionName(int32_t SegIndex,uint64_t SegOffset)4450 StringRef BindRebaseSegInfo::sectionName(int32_t SegIndex,
4451                                          uint64_t SegOffset) {
4452   return findSection(SegIndex, SegOffset).SectionName;
4453 }
4454 
4455 // For use with a SegIndex,SegOffset pair from a checked Mach-O Bind or Rebase
4456 // entry to get the address.
address(uint32_t SegIndex,uint64_t OffsetInSeg)4457 uint64_t BindRebaseSegInfo::address(uint32_t SegIndex, uint64_t OffsetInSeg) {
4458   const SectionInfo &SI = findSection(SegIndex, OffsetInSeg);
4459   return SI.SegmentStartAddress + OffsetInSeg;
4460 }
4461 
4462 iterator_range<bind_iterator>
bindTable(Error & Err,MachOObjectFile * O,ArrayRef<uint8_t> Opcodes,bool is64,MachOBindEntry::Kind BKind)4463 MachOObjectFile::bindTable(Error &Err, MachOObjectFile *O,
4464                            ArrayRef<uint8_t> Opcodes, bool is64,
4465                            MachOBindEntry::Kind BKind) {
4466   if (O->BindRebaseSectionTable == nullptr)
4467     O->BindRebaseSectionTable = std::make_unique<BindRebaseSegInfo>(O);
4468   MachOBindEntry Start(&Err, O, Opcodes, is64, BKind);
4469   Start.moveToFirst();
4470 
4471   MachOBindEntry Finish(&Err, O, Opcodes, is64, BKind);
4472   Finish.moveToEnd();
4473 
4474   return make_range(bind_iterator(Start), bind_iterator(Finish));
4475 }
4476 
bindTable(Error & Err)4477 iterator_range<bind_iterator> MachOObjectFile::bindTable(Error &Err) {
4478   return bindTable(Err, this, getDyldInfoBindOpcodes(), is64Bit(),
4479                    MachOBindEntry::Kind::Regular);
4480 }
4481 
lazyBindTable(Error & Err)4482 iterator_range<bind_iterator> MachOObjectFile::lazyBindTable(Error &Err) {
4483   return bindTable(Err, this, getDyldInfoLazyBindOpcodes(), is64Bit(),
4484                    MachOBindEntry::Kind::Lazy);
4485 }
4486 
weakBindTable(Error & Err)4487 iterator_range<bind_iterator> MachOObjectFile::weakBindTable(Error &Err) {
4488   return bindTable(Err, this, getDyldInfoWeakBindOpcodes(), is64Bit(),
4489                    MachOBindEntry::Kind::Weak);
4490 }
4491 
fixupTable(Error & Err)4492 iterator_range<fixup_iterator> MachOObjectFile::fixupTable(Error &Err) {
4493   if (BindRebaseSectionTable == nullptr)
4494     BindRebaseSectionTable = std::make_unique<BindRebaseSegInfo>(this);
4495 
4496   MachOChainedFixupEntry Start(&Err, this, true);
4497   Start.moveToFirst();
4498 
4499   MachOChainedFixupEntry Finish(&Err, this, false);
4500   Finish.moveToEnd();
4501 
4502   return make_range(fixup_iterator(Start), fixup_iterator(Finish));
4503 }
4504 
4505 MachOObjectFile::load_command_iterator
begin_load_commands() const4506 MachOObjectFile::begin_load_commands() const {
4507   return LoadCommands.begin();
4508 }
4509 
4510 MachOObjectFile::load_command_iterator
end_load_commands() const4511 MachOObjectFile::end_load_commands() const {
4512   return LoadCommands.end();
4513 }
4514 
4515 iterator_range<MachOObjectFile::load_command_iterator>
load_commands() const4516 MachOObjectFile::load_commands() const {
4517   return make_range(begin_load_commands(), end_load_commands());
4518 }
4519 
4520 StringRef
getSectionFinalSegmentName(DataRefImpl Sec) const4521 MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const {
4522   ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec);
4523   return parseSegmentOrSectionName(Raw.data());
4524 }
4525 
4526 ArrayRef<char>
getSectionRawName(DataRefImpl Sec) const4527 MachOObjectFile::getSectionRawName(DataRefImpl Sec) const {
4528   assert(Sec.d.a < Sections.size() && "Should have detected this earlier");
4529   const section_base *Base =
4530     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
4531   return ArrayRef(Base->sectname);
4532 }
4533 
4534 ArrayRef<char>
getSectionRawFinalSegmentName(DataRefImpl Sec) const4535 MachOObjectFile::getSectionRawFinalSegmentName(DataRefImpl Sec) const {
4536   assert(Sec.d.a < Sections.size() && "Should have detected this earlier");
4537   const section_base *Base =
4538     reinterpret_cast<const section_base *>(Sections[Sec.d.a]);
4539   return ArrayRef(Base->segname);
4540 }
4541 
4542 bool
isRelocationScattered(const MachO::any_relocation_info & RE) const4543 MachOObjectFile::isRelocationScattered(const MachO::any_relocation_info &RE)
4544   const {
4545   if (getCPUType(*this) == MachO::CPU_TYPE_X86_64)
4546     return false;
4547   return getPlainRelocationAddress(RE) & MachO::R_SCATTERED;
4548 }
4549 
getPlainRelocationSymbolNum(const MachO::any_relocation_info & RE) const4550 unsigned MachOObjectFile::getPlainRelocationSymbolNum(
4551     const MachO::any_relocation_info &RE) const {
4552   if (isLittleEndian())
4553     return RE.r_word1 & 0xffffff;
4554   return RE.r_word1 >> 8;
4555 }
4556 
getPlainRelocationExternal(const MachO::any_relocation_info & RE) const4557 bool MachOObjectFile::getPlainRelocationExternal(
4558     const MachO::any_relocation_info &RE) const {
4559   if (isLittleEndian())
4560     return (RE.r_word1 >> 27) & 1;
4561   return (RE.r_word1 >> 4) & 1;
4562 }
4563 
getScatteredRelocationScattered(const MachO::any_relocation_info & RE) const4564 bool MachOObjectFile::getScatteredRelocationScattered(
4565     const MachO::any_relocation_info &RE) const {
4566   return RE.r_word0 >> 31;
4567 }
4568 
getScatteredRelocationValue(const MachO::any_relocation_info & RE) const4569 uint32_t MachOObjectFile::getScatteredRelocationValue(
4570     const MachO::any_relocation_info &RE) const {
4571   return RE.r_word1;
4572 }
4573 
getScatteredRelocationType(const MachO::any_relocation_info & RE) const4574 uint32_t MachOObjectFile::getScatteredRelocationType(
4575     const MachO::any_relocation_info &RE) const {
4576   return (RE.r_word0 >> 24) & 0xf;
4577 }
4578 
getAnyRelocationAddress(const MachO::any_relocation_info & RE) const4579 unsigned MachOObjectFile::getAnyRelocationAddress(
4580     const MachO::any_relocation_info &RE) const {
4581   if (isRelocationScattered(RE))
4582     return getScatteredRelocationAddress(RE);
4583   return getPlainRelocationAddress(RE);
4584 }
4585 
getAnyRelocationPCRel(const MachO::any_relocation_info & RE) const4586 unsigned MachOObjectFile::getAnyRelocationPCRel(
4587     const MachO::any_relocation_info &RE) const {
4588   if (isRelocationScattered(RE))
4589     return getScatteredRelocationPCRel(RE);
4590   return getPlainRelocationPCRel(*this, RE);
4591 }
4592 
getAnyRelocationLength(const MachO::any_relocation_info & RE) const4593 unsigned MachOObjectFile::getAnyRelocationLength(
4594     const MachO::any_relocation_info &RE) const {
4595   if (isRelocationScattered(RE))
4596     return getScatteredRelocationLength(RE);
4597   return getPlainRelocationLength(*this, RE);
4598 }
4599 
4600 unsigned
getAnyRelocationType(const MachO::any_relocation_info & RE) const4601 MachOObjectFile::getAnyRelocationType(
4602                                    const MachO::any_relocation_info &RE) const {
4603   if (isRelocationScattered(RE))
4604     return getScatteredRelocationType(RE);
4605   return getPlainRelocationType(*this, RE);
4606 }
4607 
4608 SectionRef
getAnyRelocationSection(const MachO::any_relocation_info & RE) const4609 MachOObjectFile::getAnyRelocationSection(
4610                                    const MachO::any_relocation_info &RE) const {
4611   if (isRelocationScattered(RE) || getPlainRelocationExternal(RE))
4612     return *section_end();
4613   unsigned SecNum = getPlainRelocationSymbolNum(RE);
4614   if (SecNum == MachO::R_ABS || SecNum > Sections.size())
4615     return *section_end();
4616   DataRefImpl DRI;
4617   DRI.d.a = SecNum - 1;
4618   return SectionRef(DRI, this);
4619 }
4620 
getSection(DataRefImpl DRI) const4621 MachO::section MachOObjectFile::getSection(DataRefImpl DRI) const {
4622   assert(DRI.d.a < Sections.size() && "Should have detected this earlier");
4623   return getStruct<MachO::section>(*this, Sections[DRI.d.a]);
4624 }
4625 
getSection64(DataRefImpl DRI) const4626 MachO::section_64 MachOObjectFile::getSection64(DataRefImpl DRI) const {
4627   assert(DRI.d.a < Sections.size() && "Should have detected this earlier");
4628   return getStruct<MachO::section_64>(*this, Sections[DRI.d.a]);
4629 }
4630 
getSection(const LoadCommandInfo & L,unsigned Index) const4631 MachO::section MachOObjectFile::getSection(const LoadCommandInfo &L,
4632                                            unsigned Index) const {
4633   const char *Sec = getSectionPtr(*this, L, Index);
4634   return getStruct<MachO::section>(*this, Sec);
4635 }
4636 
getSection64(const LoadCommandInfo & L,unsigned Index) const4637 MachO::section_64 MachOObjectFile::getSection64(const LoadCommandInfo &L,
4638                                                 unsigned Index) const {
4639   const char *Sec = getSectionPtr(*this, L, Index);
4640   return getStruct<MachO::section_64>(*this, Sec);
4641 }
4642 
4643 MachO::nlist
getSymbolTableEntry(DataRefImpl DRI) const4644 MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI) const {
4645   const char *P = reinterpret_cast<const char *>(DRI.p);
4646   return getStruct<MachO::nlist>(*this, P);
4647 }
4648 
4649 MachO::nlist_64
getSymbol64TableEntry(DataRefImpl DRI) const4650 MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI) const {
4651   const char *P = reinterpret_cast<const char *>(DRI.p);
4652   return getStruct<MachO::nlist_64>(*this, P);
4653 }
4654 
4655 MachO::linkedit_data_command
getLinkeditDataLoadCommand(const LoadCommandInfo & L) const4656 MachOObjectFile::getLinkeditDataLoadCommand(const LoadCommandInfo &L) const {
4657   return getStruct<MachO::linkedit_data_command>(*this, L.Ptr);
4658 }
4659 
4660 MachO::segment_command
getSegmentLoadCommand(const LoadCommandInfo & L) const4661 MachOObjectFile::getSegmentLoadCommand(const LoadCommandInfo &L) const {
4662   return getStruct<MachO::segment_command>(*this, L.Ptr);
4663 }
4664 
4665 MachO::segment_command_64
getSegment64LoadCommand(const LoadCommandInfo & L) const4666 MachOObjectFile::getSegment64LoadCommand(const LoadCommandInfo &L) const {
4667   return getStruct<MachO::segment_command_64>(*this, L.Ptr);
4668 }
4669 
4670 MachO::linker_option_command
getLinkerOptionLoadCommand(const LoadCommandInfo & L) const4671 MachOObjectFile::getLinkerOptionLoadCommand(const LoadCommandInfo &L) const {
4672   return getStruct<MachO::linker_option_command>(*this, L.Ptr);
4673 }
4674 
4675 MachO::version_min_command
getVersionMinLoadCommand(const LoadCommandInfo & L) const4676 MachOObjectFile::getVersionMinLoadCommand(const LoadCommandInfo &L) const {
4677   return getStruct<MachO::version_min_command>(*this, L.Ptr);
4678 }
4679 
4680 MachO::note_command
getNoteLoadCommand(const LoadCommandInfo & L) const4681 MachOObjectFile::getNoteLoadCommand(const LoadCommandInfo &L) const {
4682   return getStruct<MachO::note_command>(*this, L.Ptr);
4683 }
4684 
4685 MachO::build_version_command
getBuildVersionLoadCommand(const LoadCommandInfo & L) const4686 MachOObjectFile::getBuildVersionLoadCommand(const LoadCommandInfo &L) const {
4687   return getStruct<MachO::build_version_command>(*this, L.Ptr);
4688 }
4689 
4690 MachO::build_tool_version
getBuildToolVersion(unsigned index) const4691 MachOObjectFile::getBuildToolVersion(unsigned index) const {
4692   return getStruct<MachO::build_tool_version>(*this, BuildTools[index]);
4693 }
4694 
4695 MachO::dylib_command
getDylibIDLoadCommand(const LoadCommandInfo & L) const4696 MachOObjectFile::getDylibIDLoadCommand(const LoadCommandInfo &L) const {
4697   return getStruct<MachO::dylib_command>(*this, L.Ptr);
4698 }
4699 
4700 MachO::dyld_info_command
getDyldInfoLoadCommand(const LoadCommandInfo & L) const4701 MachOObjectFile::getDyldInfoLoadCommand(const LoadCommandInfo &L) const {
4702   return getStruct<MachO::dyld_info_command>(*this, L.Ptr);
4703 }
4704 
4705 MachO::dylinker_command
getDylinkerCommand(const LoadCommandInfo & L) const4706 MachOObjectFile::getDylinkerCommand(const LoadCommandInfo &L) const {
4707   return getStruct<MachO::dylinker_command>(*this, L.Ptr);
4708 }
4709 
4710 MachO::uuid_command
getUuidCommand(const LoadCommandInfo & L) const4711 MachOObjectFile::getUuidCommand(const LoadCommandInfo &L) const {
4712   return getStruct<MachO::uuid_command>(*this, L.Ptr);
4713 }
4714 
4715 MachO::rpath_command
getRpathCommand(const LoadCommandInfo & L) const4716 MachOObjectFile::getRpathCommand(const LoadCommandInfo &L) const {
4717   return getStruct<MachO::rpath_command>(*this, L.Ptr);
4718 }
4719 
4720 MachO::source_version_command
getSourceVersionCommand(const LoadCommandInfo & L) const4721 MachOObjectFile::getSourceVersionCommand(const LoadCommandInfo &L) const {
4722   return getStruct<MachO::source_version_command>(*this, L.Ptr);
4723 }
4724 
4725 MachO::entry_point_command
getEntryPointCommand(const LoadCommandInfo & L) const4726 MachOObjectFile::getEntryPointCommand(const LoadCommandInfo &L) const {
4727   return getStruct<MachO::entry_point_command>(*this, L.Ptr);
4728 }
4729 
4730 MachO::encryption_info_command
getEncryptionInfoCommand(const LoadCommandInfo & L) const4731 MachOObjectFile::getEncryptionInfoCommand(const LoadCommandInfo &L) const {
4732   return getStruct<MachO::encryption_info_command>(*this, L.Ptr);
4733 }
4734 
4735 MachO::encryption_info_command_64
getEncryptionInfoCommand64(const LoadCommandInfo & L) const4736 MachOObjectFile::getEncryptionInfoCommand64(const LoadCommandInfo &L) const {
4737   return getStruct<MachO::encryption_info_command_64>(*this, L.Ptr);
4738 }
4739 
4740 MachO::sub_framework_command
getSubFrameworkCommand(const LoadCommandInfo & L) const4741 MachOObjectFile::getSubFrameworkCommand(const LoadCommandInfo &L) const {
4742   return getStruct<MachO::sub_framework_command>(*this, L.Ptr);
4743 }
4744 
4745 MachO::sub_umbrella_command
getSubUmbrellaCommand(const LoadCommandInfo & L) const4746 MachOObjectFile::getSubUmbrellaCommand(const LoadCommandInfo &L) const {
4747   return getStruct<MachO::sub_umbrella_command>(*this, L.Ptr);
4748 }
4749 
4750 MachO::sub_library_command
getSubLibraryCommand(const LoadCommandInfo & L) const4751 MachOObjectFile::getSubLibraryCommand(const LoadCommandInfo &L) const {
4752   return getStruct<MachO::sub_library_command>(*this, L.Ptr);
4753 }
4754 
4755 MachO::sub_client_command
getSubClientCommand(const LoadCommandInfo & L) const4756 MachOObjectFile::getSubClientCommand(const LoadCommandInfo &L) const {
4757   return getStruct<MachO::sub_client_command>(*this, L.Ptr);
4758 }
4759 
4760 MachO::routines_command
getRoutinesCommand(const LoadCommandInfo & L) const4761 MachOObjectFile::getRoutinesCommand(const LoadCommandInfo &L) const {
4762   return getStruct<MachO::routines_command>(*this, L.Ptr);
4763 }
4764 
4765 MachO::routines_command_64
getRoutinesCommand64(const LoadCommandInfo & L) const4766 MachOObjectFile::getRoutinesCommand64(const LoadCommandInfo &L) const {
4767   return getStruct<MachO::routines_command_64>(*this, L.Ptr);
4768 }
4769 
4770 MachO::thread_command
getThreadCommand(const LoadCommandInfo & L) const4771 MachOObjectFile::getThreadCommand(const LoadCommandInfo &L) const {
4772   return getStruct<MachO::thread_command>(*this, L.Ptr);
4773 }
4774 
4775 MachO::fileset_entry_command
getFilesetEntryLoadCommand(const LoadCommandInfo & L) const4776 MachOObjectFile::getFilesetEntryLoadCommand(const LoadCommandInfo &L) const {
4777   return getStruct<MachO::fileset_entry_command>(*this, L.Ptr);
4778 }
4779 
4780 MachO::any_relocation_info
getRelocation(DataRefImpl Rel) const4781 MachOObjectFile::getRelocation(DataRefImpl Rel) const {
4782   uint32_t Offset;
4783   if (getHeader().filetype == MachO::MH_OBJECT) {
4784     DataRefImpl Sec;
4785     Sec.d.a = Rel.d.a;
4786     if (is64Bit()) {
4787       MachO::section_64 Sect = getSection64(Sec);
4788       Offset = Sect.reloff;
4789     } else {
4790       MachO::section Sect = getSection(Sec);
4791       Offset = Sect.reloff;
4792     }
4793   } else {
4794     MachO::dysymtab_command DysymtabLoadCmd = getDysymtabLoadCommand();
4795     if (Rel.d.a == 0)
4796       Offset = DysymtabLoadCmd.extreloff; // Offset to the external relocations
4797     else
4798       Offset = DysymtabLoadCmd.locreloff; // Offset to the local relocations
4799   }
4800 
4801   auto P = reinterpret_cast<const MachO::any_relocation_info *>(
4802       getPtr(*this, Offset)) + Rel.d.b;
4803   return getStruct<MachO::any_relocation_info>(
4804       *this, reinterpret_cast<const char *>(P));
4805 }
4806 
4807 MachO::data_in_code_entry
getDice(DataRefImpl Rel) const4808 MachOObjectFile::getDice(DataRefImpl Rel) const {
4809   const char *P = reinterpret_cast<const char *>(Rel.p);
4810   return getStruct<MachO::data_in_code_entry>(*this, P);
4811 }
4812 
getHeader() const4813 const MachO::mach_header &MachOObjectFile::getHeader() const {
4814   return Header;
4815 }
4816 
getHeader64() const4817 const MachO::mach_header_64 &MachOObjectFile::getHeader64() const {
4818   assert(is64Bit());
4819   return Header64;
4820 }
4821 
getIndirectSymbolTableEntry(const MachO::dysymtab_command & DLC,unsigned Index) const4822 uint32_t MachOObjectFile::getIndirectSymbolTableEntry(
4823                                              const MachO::dysymtab_command &DLC,
4824                                              unsigned Index) const {
4825   uint64_t Offset = DLC.indirectsymoff + Index * sizeof(uint32_t);
4826   return getStruct<uint32_t>(*this, getPtr(*this, Offset));
4827 }
4828 
4829 MachO::data_in_code_entry
getDataInCodeTableEntry(uint32_t DataOffset,unsigned Index) const4830 MachOObjectFile::getDataInCodeTableEntry(uint32_t DataOffset,
4831                                          unsigned Index) const {
4832   uint64_t Offset = DataOffset + Index * sizeof(MachO::data_in_code_entry);
4833   return getStruct<MachO::data_in_code_entry>(*this, getPtr(*this, Offset));
4834 }
4835 
getSymtabLoadCommand() const4836 MachO::symtab_command MachOObjectFile::getSymtabLoadCommand() const {
4837   if (SymtabLoadCmd)
4838     return getStruct<MachO::symtab_command>(*this, SymtabLoadCmd);
4839 
4840   // If there is no SymtabLoadCmd return a load command with zero'ed fields.
4841   MachO::symtab_command Cmd;
4842   Cmd.cmd = MachO::LC_SYMTAB;
4843   Cmd.cmdsize = sizeof(MachO::symtab_command);
4844   Cmd.symoff = 0;
4845   Cmd.nsyms = 0;
4846   Cmd.stroff = 0;
4847   Cmd.strsize = 0;
4848   return Cmd;
4849 }
4850 
getDysymtabLoadCommand() const4851 MachO::dysymtab_command MachOObjectFile::getDysymtabLoadCommand() const {
4852   if (DysymtabLoadCmd)
4853     return getStruct<MachO::dysymtab_command>(*this, DysymtabLoadCmd);
4854 
4855   // If there is no DysymtabLoadCmd return a load command with zero'ed fields.
4856   MachO::dysymtab_command Cmd;
4857   Cmd.cmd = MachO::LC_DYSYMTAB;
4858   Cmd.cmdsize = sizeof(MachO::dysymtab_command);
4859   Cmd.ilocalsym = 0;
4860   Cmd.nlocalsym = 0;
4861   Cmd.iextdefsym = 0;
4862   Cmd.nextdefsym = 0;
4863   Cmd.iundefsym = 0;
4864   Cmd.nundefsym = 0;
4865   Cmd.tocoff = 0;
4866   Cmd.ntoc = 0;
4867   Cmd.modtaboff = 0;
4868   Cmd.nmodtab = 0;
4869   Cmd.extrefsymoff = 0;
4870   Cmd.nextrefsyms = 0;
4871   Cmd.indirectsymoff = 0;
4872   Cmd.nindirectsyms = 0;
4873   Cmd.extreloff = 0;
4874   Cmd.nextrel = 0;
4875   Cmd.locreloff = 0;
4876   Cmd.nlocrel = 0;
4877   return Cmd;
4878 }
4879 
4880 MachO::linkedit_data_command
getDataInCodeLoadCommand() const4881 MachOObjectFile::getDataInCodeLoadCommand() const {
4882   if (DataInCodeLoadCmd)
4883     return getStruct<MachO::linkedit_data_command>(*this, DataInCodeLoadCmd);
4884 
4885   // If there is no DataInCodeLoadCmd return a load command with zero'ed fields.
4886   MachO::linkedit_data_command Cmd;
4887   Cmd.cmd = MachO::LC_DATA_IN_CODE;
4888   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
4889   Cmd.dataoff = 0;
4890   Cmd.datasize = 0;
4891   return Cmd;
4892 }
4893 
4894 MachO::linkedit_data_command
getLinkOptHintsLoadCommand() const4895 MachOObjectFile::getLinkOptHintsLoadCommand() const {
4896   if (LinkOptHintsLoadCmd)
4897     return getStruct<MachO::linkedit_data_command>(*this, LinkOptHintsLoadCmd);
4898 
4899   // If there is no LinkOptHintsLoadCmd return a load command with zero'ed
4900   // fields.
4901   MachO::linkedit_data_command Cmd;
4902   Cmd.cmd = MachO::LC_LINKER_OPTIMIZATION_HINT;
4903   Cmd.cmdsize = sizeof(MachO::linkedit_data_command);
4904   Cmd.dataoff = 0;
4905   Cmd.datasize = 0;
4906   return Cmd;
4907 }
4908 
getDyldInfoRebaseOpcodes() const4909 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoRebaseOpcodes() const {
4910   if (!DyldInfoLoadCmd)
4911     return std::nullopt;
4912 
4913   auto DyldInfoOrErr =
4914     getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4915   if (!DyldInfoOrErr)
4916     return std::nullopt;
4917   MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
4918   const uint8_t *Ptr =
4919       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.rebase_off));
4920   return ArrayRef(Ptr, DyldInfo.rebase_size);
4921 }
4922 
getDyldInfoBindOpcodes() const4923 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoBindOpcodes() const {
4924   if (!DyldInfoLoadCmd)
4925     return std::nullopt;
4926 
4927   auto DyldInfoOrErr =
4928     getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4929   if (!DyldInfoOrErr)
4930     return std::nullopt;
4931   MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
4932   const uint8_t *Ptr =
4933       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.bind_off));
4934   return ArrayRef(Ptr, DyldInfo.bind_size);
4935 }
4936 
getDyldInfoWeakBindOpcodes() const4937 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoWeakBindOpcodes() const {
4938   if (!DyldInfoLoadCmd)
4939     return std::nullopt;
4940 
4941   auto DyldInfoOrErr =
4942     getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4943   if (!DyldInfoOrErr)
4944     return std::nullopt;
4945   MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
4946   const uint8_t *Ptr =
4947       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.weak_bind_off));
4948   return ArrayRef(Ptr, DyldInfo.weak_bind_size);
4949 }
4950 
getDyldInfoLazyBindOpcodes() const4951 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoLazyBindOpcodes() const {
4952   if (!DyldInfoLoadCmd)
4953     return std::nullopt;
4954 
4955   auto DyldInfoOrErr =
4956       getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4957   if (!DyldInfoOrErr)
4958     return std::nullopt;
4959   MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
4960   const uint8_t *Ptr =
4961       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.lazy_bind_off));
4962   return ArrayRef(Ptr, DyldInfo.lazy_bind_size);
4963 }
4964 
getDyldInfoExportsTrie() const4965 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoExportsTrie() const {
4966   if (!DyldInfoLoadCmd)
4967     return std::nullopt;
4968 
4969   auto DyldInfoOrErr =
4970       getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
4971   if (!DyldInfoOrErr)
4972     return std::nullopt;
4973   MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
4974   const uint8_t *Ptr =
4975       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.export_off));
4976   return ArrayRef(Ptr, DyldInfo.export_size);
4977 }
4978 
4979 Expected<std::optional<MachO::linkedit_data_command>>
getChainedFixupsLoadCommand() const4980 MachOObjectFile::getChainedFixupsLoadCommand() const {
4981   // Load the dyld chained fixups load command.
4982   if (!DyldChainedFixupsLoadCmd)
4983     return std::nullopt;
4984   auto DyldChainedFixupsOrErr = getStructOrErr<MachO::linkedit_data_command>(
4985       *this, DyldChainedFixupsLoadCmd);
4986   if (!DyldChainedFixupsOrErr)
4987     return DyldChainedFixupsOrErr.takeError();
4988   const MachO::linkedit_data_command &DyldChainedFixups =
4989       *DyldChainedFixupsOrErr;
4990 
4991   // If the load command is present but the data offset has been zeroed out,
4992   // as is the case for dylib stubs, return std::nullopt (no error).
4993   if (!DyldChainedFixups.dataoff)
4994     return std::nullopt;
4995   return DyldChainedFixups;
4996 }
4997 
4998 Expected<std::optional<MachO::dyld_chained_fixups_header>>
getChainedFixupsHeader() const4999 MachOObjectFile::getChainedFixupsHeader() const {
5000   auto CFOrErr = getChainedFixupsLoadCommand();
5001   if (!CFOrErr)
5002     return CFOrErr.takeError();
5003   if (!CFOrErr->has_value())
5004     return std::nullopt;
5005 
5006   const MachO::linkedit_data_command &DyldChainedFixups = **CFOrErr;
5007 
5008   uint64_t CFHeaderOffset = DyldChainedFixups.dataoff;
5009   uint64_t CFSize = DyldChainedFixups.datasize;
5010 
5011   // Load the dyld chained fixups header.
5012   const char *CFHeaderPtr = getPtr(*this, CFHeaderOffset);
5013   auto CFHeaderOrErr =
5014       getStructOrErr<MachO::dyld_chained_fixups_header>(*this, CFHeaderPtr);
5015   if (!CFHeaderOrErr)
5016     return CFHeaderOrErr.takeError();
5017   MachO::dyld_chained_fixups_header CFHeader = CFHeaderOrErr.get();
5018 
5019   // Reject unknown chained fixup formats.
5020   if (CFHeader.fixups_version != 0)
5021     return malformedError(Twine("bad chained fixups: unknown version: ") +
5022                           Twine(CFHeader.fixups_version));
5023   if (CFHeader.imports_format < 1 || CFHeader.imports_format > 3)
5024     return malformedError(
5025         Twine("bad chained fixups: unknown imports format: ") +
5026         Twine(CFHeader.imports_format));
5027 
5028   // Validate the image format.
5029   //
5030   // Load the image starts.
5031   uint64_t CFImageStartsOffset = (CFHeaderOffset + CFHeader.starts_offset);
5032   if (CFHeader.starts_offset < sizeof(MachO::dyld_chained_fixups_header)) {
5033     return malformedError(Twine("bad chained fixups: image starts offset ") +
5034                           Twine(CFHeader.starts_offset) +
5035                           " overlaps with chained fixups header");
5036   }
5037   uint32_t EndOffset = CFHeaderOffset + CFSize;
5038   if (CFImageStartsOffset + sizeof(MachO::dyld_chained_starts_in_image) >
5039       EndOffset) {
5040     return malformedError(Twine("bad chained fixups: image starts end ") +
5041                           Twine(CFImageStartsOffset +
5042                                 sizeof(MachO::dyld_chained_starts_in_image)) +
5043                           " extends past end " + Twine(EndOffset));
5044   }
5045 
5046   return CFHeader;
5047 }
5048 
5049 Expected<std::pair<size_t, std::vector<ChainedFixupsSegment>>>
getChainedFixupsSegments() const5050 MachOObjectFile::getChainedFixupsSegments() const {
5051   auto CFOrErr = getChainedFixupsLoadCommand();
5052   if (!CFOrErr)
5053     return CFOrErr.takeError();
5054 
5055   std::vector<ChainedFixupsSegment> Segments;
5056   if (!CFOrErr->has_value())
5057     return std::make_pair(0, Segments);
5058 
5059   const MachO::linkedit_data_command &DyldChainedFixups = **CFOrErr;
5060 
5061   auto HeaderOrErr = getChainedFixupsHeader();
5062   if (!HeaderOrErr)
5063     return HeaderOrErr.takeError();
5064   if (!HeaderOrErr->has_value())
5065     return std::make_pair(0, Segments);
5066   const MachO::dyld_chained_fixups_header &Header = **HeaderOrErr;
5067 
5068   const char *Contents = getPtr(*this, DyldChainedFixups.dataoff);
5069 
5070   auto ImageStartsOrErr = getStructOrErr<MachO::dyld_chained_starts_in_image>(
5071       *this, Contents + Header.starts_offset);
5072   if (!ImageStartsOrErr)
5073     return ImageStartsOrErr.takeError();
5074   const MachO::dyld_chained_starts_in_image &ImageStarts = *ImageStartsOrErr;
5075 
5076   const char *SegOffsPtr =
5077       Contents + Header.starts_offset +
5078       offsetof(MachO::dyld_chained_starts_in_image, seg_info_offset);
5079   const char *SegOffsEnd =
5080       SegOffsPtr + ImageStarts.seg_count * sizeof(uint32_t);
5081   if (SegOffsEnd > Contents + DyldChainedFixups.datasize)
5082     return malformedError(
5083         "bad chained fixups: seg_info_offset extends past end");
5084 
5085   const char *LastSegEnd = nullptr;
5086   for (size_t I = 0, N = ImageStarts.seg_count; I < N; ++I) {
5087     auto OffOrErr =
5088         getStructOrErr<uint32_t>(*this, SegOffsPtr + I * sizeof(uint32_t));
5089     if (!OffOrErr)
5090       return OffOrErr.takeError();
5091     // seg_info_offset == 0 means there is no associated starts_in_segment
5092     // entry.
5093     if (!*OffOrErr)
5094       continue;
5095 
5096     auto Fail = [&](Twine Message) {
5097       return malformedError("bad chained fixups: segment info" + Twine(I) +
5098                             " at offset " + Twine(*OffOrErr) + Message);
5099     };
5100 
5101     const char *SegPtr = Contents + Header.starts_offset + *OffOrErr;
5102     if (LastSegEnd && SegPtr < LastSegEnd)
5103       return Fail(" overlaps with previous segment info");
5104 
5105     auto SegOrErr =
5106         getStructOrErr<MachO::dyld_chained_starts_in_segment>(*this, SegPtr);
5107     if (!SegOrErr)
5108       return SegOrErr.takeError();
5109     const MachO::dyld_chained_starts_in_segment &Seg = *SegOrErr;
5110 
5111     LastSegEnd = SegPtr + Seg.size;
5112     if (Seg.pointer_format < 1 || Seg.pointer_format > 12)
5113       return Fail(" has unknown pointer format: " + Twine(Seg.pointer_format));
5114 
5115     const char *PageStart =
5116         SegPtr + offsetof(MachO::dyld_chained_starts_in_segment, page_start);
5117     const char *PageEnd = PageStart + Seg.page_count * sizeof(uint16_t);
5118     if (PageEnd > SegPtr + Seg.size)
5119       return Fail(" : page_starts extend past seg_info size");
5120 
5121     // FIXME: This does not account for multiple offsets on a single page
5122     //        (DYLD_CHAINED_PTR_START_MULTI; 32-bit only).
5123     std::vector<uint16_t> PageStarts;
5124     for (size_t PageIdx = 0; PageIdx < Seg.page_count; ++PageIdx) {
5125       uint16_t Start;
5126       memcpy(&Start, PageStart + PageIdx * sizeof(uint16_t), sizeof(uint16_t));
5127       if (isLittleEndian() != sys::IsLittleEndianHost)
5128         sys::swapByteOrder(Start);
5129       PageStarts.push_back(Start);
5130     }
5131 
5132     Segments.emplace_back(I, *OffOrErr, Seg, std::move(PageStarts));
5133   }
5134 
5135   return std::make_pair(ImageStarts.seg_count, Segments);
5136 }
5137 
5138 // The special library ordinals have a negative value, but they are encoded in
5139 // an unsigned bitfield, so we need to sign extend the value.
getEncodedOrdinal(T Value)5140 template <typename T> static int getEncodedOrdinal(T Value) {
5141   if (Value == static_cast<T>(MachO::BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE) ||
5142       Value == static_cast<T>(MachO::BIND_SPECIAL_DYLIB_FLAT_LOOKUP) ||
5143       Value == static_cast<T>(MachO::BIND_SPECIAL_DYLIB_WEAK_LOOKUP))
5144     return SignExtend32<sizeof(T) * CHAR_BIT>(Value);
5145   return Value;
5146 }
5147 
5148 template <typename T, unsigned N>
getArray(const MachOObjectFile & O,const void * Ptr)5149 static std::array<T, N> getArray(const MachOObjectFile &O, const void *Ptr) {
5150   std::array<T, N> RawValue;
5151   memcpy(RawValue.data(), Ptr, N * sizeof(T));
5152   if (O.isLittleEndian() != sys::IsLittleEndianHost)
5153     for (auto &Element : RawValue)
5154       sys::swapByteOrder(Element);
5155   return RawValue;
5156 }
5157 
5158 Expected<std::vector<ChainedFixupTarget>>
getDyldChainedFixupTargets() const5159 MachOObjectFile::getDyldChainedFixupTargets() const {
5160   auto CFOrErr = getChainedFixupsLoadCommand();
5161   if (!CFOrErr)
5162     return CFOrErr.takeError();
5163 
5164   std::vector<ChainedFixupTarget> Targets;
5165   if (!CFOrErr->has_value())
5166     return Targets;
5167 
5168   const MachO::linkedit_data_command &DyldChainedFixups = **CFOrErr;
5169 
5170   auto CFHeaderOrErr = getChainedFixupsHeader();
5171   if (!CFHeaderOrErr)
5172     return CFHeaderOrErr.takeError();
5173   if (!(*CFHeaderOrErr))
5174     return Targets;
5175   const MachO::dyld_chained_fixups_header &Header = **CFHeaderOrErr;
5176 
5177   size_t ImportSize = 0;
5178   if (Header.imports_format == MachO::DYLD_CHAINED_IMPORT)
5179     ImportSize = sizeof(MachO::dyld_chained_import);
5180   else if (Header.imports_format == MachO::DYLD_CHAINED_IMPORT_ADDEND)
5181     ImportSize = sizeof(MachO::dyld_chained_import_addend);
5182   else if (Header.imports_format == MachO::DYLD_CHAINED_IMPORT_ADDEND64)
5183     ImportSize = sizeof(MachO::dyld_chained_import_addend64);
5184   else
5185     return malformedError("bad chained fixups: unknown imports format: " +
5186                           Twine(Header.imports_format));
5187 
5188   const char *Contents = getPtr(*this, DyldChainedFixups.dataoff);
5189   const char *Imports = Contents + Header.imports_offset;
5190   size_t ImportsEndOffset =
5191       Header.imports_offset + ImportSize * Header.imports_count;
5192   const char *ImportsEnd = Contents + ImportsEndOffset;
5193   const char *Symbols = Contents + Header.symbols_offset;
5194   const char *SymbolsEnd = Contents + DyldChainedFixups.datasize;
5195 
5196   if (ImportsEnd > Symbols)
5197     return malformedError("bad chained fixups: imports end " +
5198                           Twine(ImportsEndOffset) + " extends past end " +
5199                           Twine(DyldChainedFixups.datasize));
5200 
5201   if (ImportsEnd > Symbols)
5202     return malformedError("bad chained fixups: imports end " +
5203                           Twine(ImportsEndOffset) + " overlaps with symbols");
5204 
5205   // We use bit manipulation to extract data from the bitfields. This is correct
5206   // for both LE and BE hosts, but we assume that the object is little-endian.
5207   if (!isLittleEndian())
5208     return createError("parsing big-endian chained fixups is not implemented");
5209   for (const char *ImportPtr = Imports; ImportPtr < ImportsEnd;
5210        ImportPtr += ImportSize) {
5211     int LibOrdinal;
5212     bool WeakImport;
5213     uint32_t NameOffset;
5214     uint64_t Addend;
5215     if (Header.imports_format == MachO::DYLD_CHAINED_IMPORT) {
5216       static_assert(sizeof(uint32_t) == sizeof(MachO::dyld_chained_import));
5217       auto RawValue = getArray<uint32_t, 1>(*this, ImportPtr);
5218 
5219       LibOrdinal = getEncodedOrdinal<uint8_t>(RawValue[0] & 0xFF);
5220       WeakImport = (RawValue[0] >> 8) & 1;
5221       NameOffset = RawValue[0] >> 9;
5222       Addend = 0;
5223     } else if (Header.imports_format == MachO::DYLD_CHAINED_IMPORT_ADDEND) {
5224       static_assert(sizeof(uint64_t) ==
5225                     sizeof(MachO::dyld_chained_import_addend));
5226       auto RawValue = getArray<uint32_t, 2>(*this, ImportPtr);
5227 
5228       LibOrdinal = getEncodedOrdinal<uint8_t>(RawValue[0] & 0xFF);
5229       WeakImport = (RawValue[0] >> 8) & 1;
5230       NameOffset = RawValue[0] >> 9;
5231       Addend = bit_cast<int32_t>(RawValue[1]);
5232     } else if (Header.imports_format == MachO::DYLD_CHAINED_IMPORT_ADDEND64) {
5233       static_assert(2 * sizeof(uint64_t) ==
5234                     sizeof(MachO::dyld_chained_import_addend64));
5235       auto RawValue = getArray<uint64_t, 2>(*this, ImportPtr);
5236 
5237       LibOrdinal = getEncodedOrdinal<uint16_t>(RawValue[0] & 0xFFFF);
5238       NameOffset = (RawValue[0] >> 16) & 1;
5239       WeakImport = RawValue[0] >> 17;
5240       Addend = RawValue[1];
5241     } else {
5242       llvm_unreachable("Import format should have been checked");
5243     }
5244 
5245     const char *Str = Symbols + NameOffset;
5246     if (Str >= SymbolsEnd)
5247       return malformedError("bad chained fixups: symbol offset " +
5248                             Twine(NameOffset) + " extends past end " +
5249                             Twine(DyldChainedFixups.datasize));
5250     Targets.emplace_back(LibOrdinal, NameOffset, Str, Addend, WeakImport);
5251   }
5252 
5253   return std::move(Targets);
5254 }
5255 
getDyldExportsTrie() const5256 ArrayRef<uint8_t> MachOObjectFile::getDyldExportsTrie() const {
5257   if (!DyldExportsTrieLoadCmd)
5258     return std::nullopt;
5259 
5260   auto DyldExportsTrieOrError = getStructOrErr<MachO::linkedit_data_command>(
5261       *this, DyldExportsTrieLoadCmd);
5262   if (!DyldExportsTrieOrError)
5263     return std::nullopt;
5264   MachO::linkedit_data_command DyldExportsTrie = DyldExportsTrieOrError.get();
5265   const uint8_t *Ptr =
5266       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldExportsTrie.dataoff));
5267   return ArrayRef(Ptr, DyldExportsTrie.datasize);
5268 }
5269 
getFunctionStarts() const5270 SmallVector<uint64_t> MachOObjectFile::getFunctionStarts() const {
5271   if (!FuncStartsLoadCmd)
5272     return {};
5273 
5274   auto InfoOrErr =
5275       getStructOrErr<MachO::linkedit_data_command>(*this, FuncStartsLoadCmd);
5276   if (!InfoOrErr)
5277     return {};
5278 
5279   MachO::linkedit_data_command Info = InfoOrErr.get();
5280   SmallVector<uint64_t, 8> FunctionStarts;
5281   this->ReadULEB128s(Info.dataoff, FunctionStarts);
5282   return std::move(FunctionStarts);
5283 }
5284 
getUuid() const5285 ArrayRef<uint8_t> MachOObjectFile::getUuid() const {
5286   if (!UuidLoadCmd)
5287     return std::nullopt;
5288   // Returning a pointer is fine as uuid doesn't need endian swapping.
5289   const char *Ptr = UuidLoadCmd + offsetof(MachO::uuid_command, uuid);
5290   return ArrayRef(reinterpret_cast<const uint8_t *>(Ptr), 16);
5291 }
5292 
getStringTableData() const5293 StringRef MachOObjectFile::getStringTableData() const {
5294   MachO::symtab_command S = getSymtabLoadCommand();
5295   return getData().substr(S.stroff, S.strsize);
5296 }
5297 
is64Bit() const5298 bool MachOObjectFile::is64Bit() const {
5299   return getType() == getMachOType(false, true) ||
5300     getType() == getMachOType(true, true);
5301 }
5302 
ReadULEB128s(uint64_t Index,SmallVectorImpl<uint64_t> & Out) const5303 void MachOObjectFile::ReadULEB128s(uint64_t Index,
5304                                    SmallVectorImpl<uint64_t> &Out) const {
5305   DataExtractor extractor(ObjectFile::getData(), true, 0);
5306 
5307   uint64_t offset = Index;
5308   uint64_t data = 0;
5309   while (uint64_t delta = extractor.getULEB128(&offset)) {
5310     data += delta;
5311     Out.push_back(data);
5312   }
5313 }
5314 
isRelocatableObject() const5315 bool MachOObjectFile::isRelocatableObject() const {
5316   return getHeader().filetype == MachO::MH_OBJECT;
5317 }
5318 
5319 /// Create a MachOObjectFile instance from a given buffer.
5320 ///
5321 /// \param Buffer Memory buffer containing the MachO binary data.
5322 /// \param UniversalCputype CPU type when the MachO part of a universal binary.
5323 /// \param UniversalIndex Index of the MachO within a universal binary.
5324 /// \param MachOFilesetEntryOffset Offset of the MachO entry in a fileset MachO.
5325 /// \returns A std::unique_ptr to a MachOObjectFile instance on success.
createMachOObjectFile(MemoryBufferRef Buffer,uint32_t UniversalCputype,uint32_t UniversalIndex,size_t MachOFilesetEntryOffset)5326 Expected<std::unique_ptr<MachOObjectFile>> ObjectFile::createMachOObjectFile(
5327     MemoryBufferRef Buffer, uint32_t UniversalCputype, uint32_t UniversalIndex,
5328     size_t MachOFilesetEntryOffset) {
5329   StringRef Magic = Buffer.getBuffer().slice(0, 4);
5330   if (Magic == "\xFE\xED\xFA\xCE")
5331     return MachOObjectFile::create(Buffer, false, false, UniversalCputype,
5332                                    UniversalIndex, MachOFilesetEntryOffset);
5333   if (Magic == "\xCE\xFA\xED\xFE")
5334     return MachOObjectFile::create(Buffer, true, false, UniversalCputype,
5335                                    UniversalIndex, MachOFilesetEntryOffset);
5336   if (Magic == "\xFE\xED\xFA\xCF")
5337     return MachOObjectFile::create(Buffer, false, true, UniversalCputype,
5338                                    UniversalIndex, MachOFilesetEntryOffset);
5339   if (Magic == "\xCF\xFA\xED\xFE")
5340     return MachOObjectFile::create(Buffer, true, true, UniversalCputype,
5341                                    UniversalIndex, MachOFilesetEntryOffset);
5342   return make_error<GenericBinaryError>("Unrecognized MachO magic number",
5343                                         object_error::invalid_file_type);
5344 }
5345 
mapDebugSectionName(StringRef Name) const5346 StringRef MachOObjectFile::mapDebugSectionName(StringRef Name) const {
5347   return StringSwitch<StringRef>(Name)
5348       .Case("debug_str_offs", "debug_str_offsets")
5349       .Default(Name);
5350 }
5351 
5352 Expected<std::vector<std::string>>
findDsymObjectMembers(StringRef Path)5353 MachOObjectFile::findDsymObjectMembers(StringRef Path) {
5354   SmallString<256> BundlePath(Path);
5355   // Normalize input path. This is necessary to accept `bundle.dSYM/`.
5356   sys::path::remove_dots(BundlePath);
5357   if (!sys::fs::is_directory(BundlePath) ||
5358       sys::path::extension(BundlePath) != ".dSYM")
5359     return std::vector<std::string>();
5360   sys::path::append(BundlePath, "Contents", "Resources", "DWARF");
5361   bool IsDir;
5362   auto EC = sys::fs::is_directory(BundlePath, IsDir);
5363   if (EC == errc::no_such_file_or_directory || (!EC && !IsDir))
5364     return createStringError(
5365         EC, "%s: expected directory 'Contents/Resources/DWARF' in dSYM bundle",
5366         Path.str().c_str());
5367   if (EC)
5368     return createFileError(BundlePath, errorCodeToError(EC));
5369 
5370   std::vector<std::string> ObjectPaths;
5371   for (sys::fs::directory_iterator Dir(BundlePath, EC), DirEnd;
5372        Dir != DirEnd && !EC; Dir.increment(EC)) {
5373     StringRef ObjectPath = Dir->path();
5374     sys::fs::file_status Status;
5375     if (auto EC = sys::fs::status(ObjectPath, Status))
5376       return createFileError(ObjectPath, errorCodeToError(EC));
5377     switch (Status.type()) {
5378     case sys::fs::file_type::regular_file:
5379     case sys::fs::file_type::symlink_file:
5380     case sys::fs::file_type::type_unknown:
5381       ObjectPaths.push_back(ObjectPath.str());
5382       break;
5383     default: /*ignore*/;
5384     }
5385   }
5386   if (EC)
5387     return createFileError(BundlePath, errorCodeToError(EC));
5388   if (ObjectPaths.empty())
5389     return createStringError(std::error_code(),
5390                              "%s: no objects found in dSYM bundle",
5391                              Path.str().c_str());
5392   return ObjectPaths;
5393 }
5394 
5395 llvm::binaryformat::Swift5ReflectionSectionKind
mapReflectionSectionNameToEnumValue(StringRef SectionName) const5396 MachOObjectFile::mapReflectionSectionNameToEnumValue(
5397     StringRef SectionName) const {
5398 #define HANDLE_SWIFT_SECTION(KIND, MACHO, ELF, COFF)                           \
5399   .Case(MACHO, llvm::binaryformat::Swift5ReflectionSectionKind::KIND)
5400   return StringSwitch<llvm::binaryformat::Swift5ReflectionSectionKind>(
5401              SectionName)
5402 #include "llvm/BinaryFormat/Swift.def"
5403       .Default(llvm::binaryformat::Swift5ReflectionSectionKind::unknown);
5404 #undef HANDLE_SWIFT_SECTION
5405 }
5406 
isMachOPairedReloc(uint64_t RelocType,uint64_t Arch)5407 bool MachOObjectFile::isMachOPairedReloc(uint64_t RelocType, uint64_t Arch) {
5408   switch (Arch) {
5409   case Triple::x86:
5410     return RelocType == MachO::GENERIC_RELOC_SECTDIFF ||
5411            RelocType == MachO::GENERIC_RELOC_LOCAL_SECTDIFF;
5412   case Triple::x86_64:
5413     return RelocType == MachO::X86_64_RELOC_SUBTRACTOR;
5414   case Triple::arm:
5415   case Triple::thumb:
5416     return RelocType == MachO::ARM_RELOC_SECTDIFF ||
5417            RelocType == MachO::ARM_RELOC_LOCAL_SECTDIFF ||
5418            RelocType == MachO::ARM_RELOC_HALF ||
5419            RelocType == MachO::ARM_RELOC_HALF_SECTDIFF;
5420   case Triple::aarch64:
5421     return RelocType == MachO::ARM64_RELOC_SUBTRACTOR;
5422   default:
5423     return false;
5424   }
5425 }
5426