lib/Object/MachOObjectFile.cpp

   1 //===- MachOObjectFile.cpp - Mach-O object file binding ---------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file defines the MachOObjectFile class, which binds the MachOObject
  11 // class to the generic ObjectFile wrapper.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/ADT/Triple.h"
  16 #include "llvm/Object/MachO.h"
  17 #include "llvm/Object/MachOFormat.h"
  18 #include "llvm/Support/Format.h"
  19 #include "llvm/Support/MemoryBuffer.h"
  20
  21 #include <cctype>
  22 #include <cstring>
  23 #include <limits>
  24
  25 using namespace llvm;
  26 using namespace object;
  27
  28 namespace llvm {
  29 namespace object {
  30
  31 MachOObjectFile::MachOObjectFile(MemoryBuffer *Object, MachOObject *MOO,
  32                                  error_code &ec)
  33     : ObjectFile(Binary::isMachO, Object, ec),
  34       MachOObj(MOO),
  35       RegisteredStringTable(std::numeric_limits<uint32_t>::max()) {
  36   DataRefImpl DRI;
  37   DRI.d.a = DRI.d.b = 0;
  38   moveToNextSection(DRI);
  39   uint32_t LoadCommandCount = MachOObj->getHeader().NumLoadCommands;
  40   while (DRI.d.a < LoadCommandCount) {
  41     Sections.push_back(DRI);
  42     DRI.d.b++;
  43     moveToNextSection(DRI);
  44   }
  45 }
  46
  47
  48 ObjectFile *ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer) {
  49   error_code ec;
  50   std::string Err;
  51   MachOObject *MachOObj = MachOObject::LoadFromBuffer(Buffer, &Err);
  52   if (!MachOObj)
  53     return NULL;
  54   return new MachOObjectFile(Buffer, MachOObj, ec);
  55 }
  56
  57 /*===-- Symbols -----------------------------------------------------------===*/
  58
  59 void MachOObjectFile::moveToNextSymbol(DataRefImpl &DRI) const {
  60   uint32_t LoadCommandCount = MachOObj->getHeader().NumLoadCommands;
  61   while (DRI.d.a < LoadCommandCount) {
  62     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
  63     if (LCI.Command.Type == macho::LCT_Symtab) {
  64       InMemoryStruct<macho::SymtabLoadCommand> SymtabLoadCmd;
  65       MachOObj->ReadSymtabLoadCommand(LCI, SymtabLoadCmd);
  66       if (DRI.d.b < SymtabLoadCmd->NumSymbolTableEntries)
  67         return;
  68     }
  69
  70     DRI.d.a++;
  71     DRI.d.b = 0;
  72   }
  73 }
  74
  75 void MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI,
  76     InMemoryStruct<macho::SymbolTableEntry> &Res) const {
  77   InMemoryStruct<macho::SymtabLoadCommand> SymtabLoadCmd;
  78   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
  79   MachOObj->ReadSymtabLoadCommand(LCI, SymtabLoadCmd);
  80
  81   if (RegisteredStringTable != DRI.d.a) {
  82     MachOObj->RegisterStringTable(*SymtabLoadCmd);
  83     RegisteredStringTable = DRI.d.a;
  84   }
  85
  86   MachOObj->ReadSymbolTableEntry(SymtabLoadCmd->SymbolTableOffset, DRI.d.b,
  87                                  Res);
  88 }
  89
  90 void MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI,
  91     InMemoryStruct<macho::Symbol64TableEntry> &Res) const {
  92   InMemoryStruct<macho::SymtabLoadCommand> SymtabLoadCmd;
  93   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
  94   MachOObj->ReadSymtabLoadCommand(LCI, SymtabLoadCmd);
  95
  96   if (RegisteredStringTable != DRI.d.a) {
  97     MachOObj->RegisterStringTable(*SymtabLoadCmd);
  98     RegisteredStringTable = DRI.d.a;
  99   }
 100
 101   MachOObj->ReadSymbol64TableEntry(SymtabLoadCmd->SymbolTableOffset, DRI.d.b,
 102                                    Res);
 103 }
 104
 105
 106 error_code MachOObjectFile::getSymbolNext(DataRefImpl DRI,
 107                                           SymbolRef &Result) const {
 108   DRI.d.b++;
 109   moveToNextSymbol(DRI);
 110   Result = SymbolRef(DRI, this);
 111   return object_error::success;
 112 }
 113
 114 error_code MachOObjectFile::getSymbolName(DataRefImpl DRI,
 115                                           StringRef &Result) const {
 116   if (MachOObj->is64Bit()) {
 117     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 118     getSymbol64TableEntry(DRI, Entry);
 119     Result = MachOObj->getStringAtIndex(Entry->StringIndex);
 120   } else {
 121     InMemoryStruct<macho::SymbolTableEntry> Entry;
 122     getSymbolTableEntry(DRI, Entry);
 123     Result = MachOObj->getStringAtIndex(Entry->StringIndex);
 124   }
 125   return object_error::success;
 126 }
 127
 128 error_code MachOObjectFile::getSymbolOffset(DataRefImpl DRI,
 129                                              uint64_t &Result) const {
 130   uint64_t SectionOffset;
 131   uint8_t SectionIndex;
 132   if (MachOObj->is64Bit()) {
 133     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 134     getSymbol64TableEntry(DRI, Entry);
 135     Result = Entry->Value;
 136     SectionIndex = Entry->SectionIndex;
 137   } else {
 138     InMemoryStruct<macho::SymbolTableEntry> Entry;
 139     getSymbolTableEntry(DRI, Entry);
 140     Result = Entry->Value;
 141     SectionIndex = Entry->SectionIndex;
 142   }
 143   getSectionAddress(Sections[SectionIndex-1], SectionOffset);
 144   Result -= SectionOffset;
 145
 146   return object_error::success;
 147 }
 148
 149 error_code MachOObjectFile::getSymbolAddress(DataRefImpl DRI,
 150                                              uint64_t &Result) const {
 151   if (MachOObj->is64Bit()) {
 152     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 153     getSymbol64TableEntry(DRI, Entry);
 154     Result = Entry->Value;
 155   } else {
 156     InMemoryStruct<macho::SymbolTableEntry> Entry;
 157     getSymbolTableEntry(DRI, Entry);
 158     Result = Entry->Value;
 159   }
 160   return object_error::success;
 161 }
 162
 163 error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
 164                                           uint64_t &Result) const {
 165   Result = UnknownAddressOrSize;
 166   return object_error::success;
 167 }
 168
 169 error_code MachOObjectFile::getSymbolNMTypeChar(DataRefImpl DRI,
 170                                                 char &Result) const {
 171   uint8_t Type, Flags;
 172   if (MachOObj->is64Bit()) {
 173     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 174     getSymbol64TableEntry(DRI, Entry);
 175     Type = Entry->Type;
 176     Flags = Entry->Flags;
 177   } else {
 178     InMemoryStruct<macho::SymbolTableEntry> Entry;
 179     getSymbolTableEntry(DRI, Entry);
 180     Type = Entry->Type;
 181     Flags = Entry->Flags;
 182   }
 183
 184   char Char;
 185   switch (Type & macho::STF_TypeMask) {
 186     case macho::STT_Undefined:
 187       Char = 'u';
 188       break;
 189     case macho::STT_Absolute:
 190     case macho::STT_Section:
 191       Char = 's';
 192       break;
 193     default:
 194       Char = '?';
 195       break;
 196   }
 197
 198   if (Flags & (macho::STF_External | macho::STF_PrivateExtern))
 199     Char = toupper(Char);
 200   Result = Char;
 201   return object_error::success;
 202 }
 203
 204 error_code MachOObjectFile::isSymbolInternal(DataRefImpl DRI,
 205                                              bool &Result) const {
 206   if (MachOObj->is64Bit()) {
 207     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 208     getSymbol64TableEntry(DRI, Entry);
 209     Result = Entry->Flags & macho::STF_StabsEntryMask;
 210   } else {
 211     InMemoryStruct<macho::SymbolTableEntry> Entry;
 212     getSymbolTableEntry(DRI, Entry);
 213     Result = Entry->Flags & macho::STF_StabsEntryMask;
 214   }
 215   return object_error::success;
 216 }
 217
 218 error_code MachOObjectFile::isSymbolGlobal(DataRefImpl Symb, bool &Res) const {
 219
 220   if (MachOObj->is64Bit()) {
 221     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 222     getSymbol64TableEntry(Symb, Entry);
 223     Res = Entry->Type & MachO::NlistMaskExternal;
 224   } else {
 225     InMemoryStruct<macho::SymbolTableEntry> Entry;
 226     getSymbolTableEntry(Symb, Entry);
 227     Res = Entry->Type & MachO::NlistMaskExternal;
 228   }
 229   return object_error::success;
 230 }
 231
 232 error_code MachOObjectFile::isSymbolWeak(DataRefImpl Symb, bool &Res) const {
 233
 234   if (MachOObj->is64Bit()) {
 235     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 236     getSymbol64TableEntry(Symb, Entry);
 237     Res = Entry->Flags & (MachO::NListDescWeakRef | MachO::NListDescWeakDef);
 238   } else {
 239     InMemoryStruct<macho::SymbolTableEntry> Entry;
 240     getSymbolTableEntry(Symb, Entry);
 241     Res = Entry->Flags & (MachO::NListDescWeakRef | MachO::NListDescWeakDef);
 242   }
 243   return object_error::success;
 244 }
 245
 246 error_code MachOObjectFile::isSymbolAbsolute(DataRefImpl Symb, bool &Res) const{
 247   uint8_t n_type;
 248   if (MachOObj->is64Bit()) {
 249     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 250     getSymbol64TableEntry(Symb, Entry);
 251     n_type = Entry->Type;
 252   } else {
 253     InMemoryStruct<macho::SymbolTableEntry> Entry;
 254     getSymbolTableEntry(Symb, Entry);
 255     n_type = Entry->Type;
 256   }
 257
 258   Res = (n_type & MachO::NlistMaskType) == MachO::NListTypeAbsolute;
 259   return object_error::success;
 260 }
 261
 262 error_code MachOObjectFile::getSymbolSection(DataRefImpl Symb,
 263                                              section_iterator &Res) const {
 264   uint8_t index;
 265   if (MachOObj->is64Bit()) {
 266     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 267     getSymbol64TableEntry(Symb, Entry);
 268     index = Entry->SectionIndex;
 269   } else {
 270     InMemoryStruct<macho::SymbolTableEntry> Entry;
 271     getSymbolTableEntry(Symb, Entry);
 272     index = Entry->SectionIndex;
 273   }
 274
 275   if (index == 0)
 276     Res = end_sections();
 277   else
 278     Res = section_iterator(SectionRef(Sections[index], this));
 279
 280   return object_error::success;
 281 }
 282
 283 error_code MachOObjectFile::getSymbolType(DataRefImpl Symb,
 284                                           SymbolRef::Type &Res) const {
 285   uint8_t n_type;
 286   if (MachOObj->is64Bit()) {
 287     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 288     getSymbol64TableEntry(Symb, Entry);
 289     n_type = Entry->Type;
 290   } else {
 291     InMemoryStruct<macho::SymbolTableEntry> Entry;
 292     getSymbolTableEntry(Symb, Entry);
 293     n_type = Entry->Type;
 294   }
 295   Res = SymbolRef::ST_Other;
 296
 297   // If this is a STAB debugging symbol, we can do nothing more.
 298   if (n_type & MachO::NlistMaskStab) {
 299     Res = SymbolRef::ST_Debug;
 300     return object_error::success;
 301   }
 302
 303   switch (n_type & MachO::NlistMaskType) {
 304     case MachO::NListTypeUndefined :
 305       Res = SymbolRef::ST_External;
 306       break;
 307     case MachO::NListTypeSection :
 308       Res = SymbolRef::ST_Function;
 309       break;
 310   }
 311   return object_error::success;
 312 }
 313
 314
 315 symbol_iterator MachOObjectFile::begin_symbols() const {
 316   // DRI.d.a = segment number; DRI.d.b = symbol index.
 317   DataRefImpl DRI;
 318   DRI.d.a = DRI.d.b = 0;
 319   moveToNextSymbol(DRI);
 320   return symbol_iterator(SymbolRef(DRI, this));
 321 }
 322
 323 symbol_iterator MachOObjectFile::end_symbols() const {
 324   DataRefImpl DRI;
 325   DRI.d.a = MachOObj->getHeader().NumLoadCommands;
 326   DRI.d.b = 0;
 327   return symbol_iterator(SymbolRef(DRI, this));
 328 }
 329
 330
 331 /*===-- Sections ----------------------------------------------------------===*/
 332
 333 void MachOObjectFile::moveToNextSection(DataRefImpl &DRI) const {
 334   uint32_t LoadCommandCount = MachOObj->getHeader().NumLoadCommands;
 335   while (DRI.d.a < LoadCommandCount) {
 336     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 337     if (LCI.Command.Type == macho::LCT_Segment) {
 338       InMemoryStruct<macho::SegmentLoadCommand> SegmentLoadCmd;
 339       MachOObj->ReadSegmentLoadCommand(LCI, SegmentLoadCmd);
 340       if (DRI.d.b < SegmentLoadCmd->NumSections)
 341         return;
 342     } else if (LCI.Command.Type == macho::LCT_Segment64) {
 343       InMemoryStruct<macho::Segment64LoadCommand> Segment64LoadCmd;
 344       MachOObj->ReadSegment64LoadCommand(LCI, Segment64LoadCmd);
 345       if (DRI.d.b < Segment64LoadCmd->NumSections)
 346         return;
 347     }
 348
 349     DRI.d.a++;
 350     DRI.d.b = 0;
 351   }
 352 }
 353
 354 error_code MachOObjectFile::getSectionNext(DataRefImpl DRI,
 355                                            SectionRef &Result) const {
 356   DRI.d.b++;
 357   moveToNextSection(DRI);
 358   Result = SectionRef(DRI, this);
 359   return object_error::success;
 360 }
 361
 362 void
 363 MachOObjectFile::getSection(DataRefImpl DRI,
 364                             InMemoryStruct<macho::Section> &Res) const {
 365   InMemoryStruct<macho::SegmentLoadCommand> SLC;
 366   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 367   MachOObj->ReadSegmentLoadCommand(LCI, SLC);
 368   MachOObj->ReadSection(LCI, DRI.d.b, Res);
 369 }
 370
 371 std::size_t MachOObjectFile::getSectionIndex(DataRefImpl Sec) const {
 372   SectionList::const_iterator loc =
 373     std::find(Sections.begin(), Sections.end(), Sec);
 374   assert(loc != Sections.end() && "Sec is not a valid section!");
 375   return std::distance(Sections.begin(), loc);
 376 }
 377
 378 void
 379 MachOObjectFile::getSection64(DataRefImpl DRI,
 380                             InMemoryStruct<macho::Section64> &Res) const {
 381   InMemoryStruct<macho::Segment64LoadCommand> SLC;
 382   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 383   MachOObj->ReadSegment64LoadCommand(LCI, SLC);
 384   MachOObj->ReadSection64(LCI, DRI.d.b, Res);
 385 }
 386
 387 static bool is64BitLoadCommand(const MachOObject *MachOObj, DataRefImpl DRI) {
 388   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 389   if (LCI.Command.Type == macho::LCT_Segment64)
 390     return true;
 391   assert(LCI.Command.Type == macho::LCT_Segment && "Unexpected Type.");
 392   return false;
 393 }
 394
 395 error_code MachOObjectFile::getSectionName(DataRefImpl DRI,
 396                                            StringRef &Result) const {
 397   // FIXME: thread safety.
 398   static char result[34];
 399   if (is64BitLoadCommand(MachOObj, DRI)) {
 400     InMemoryStruct<macho::Segment64LoadCommand> SLC;
 401     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 402     MachOObj->ReadSegment64LoadCommand(LCI, SLC);
 403     InMemoryStruct<macho::Section64> Sect;
 404     MachOObj->ReadSection64(LCI, DRI.d.b, Sect);
 405
 406     strcpy(result, Sect->SegmentName);
 407     strcat(result, ",");
 408     strcat(result, Sect->Name);
 409   } else {
 410     InMemoryStruct<macho::SegmentLoadCommand> SLC;
 411     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 412     MachOObj->ReadSegmentLoadCommand(LCI, SLC);
 413     InMemoryStruct<macho::Section> Sect;
 414     MachOObj->ReadSection(LCI, DRI.d.b, Sect);
 415
 416     strcpy(result, Sect->SegmentName);
 417     strcat(result, ",");
 418     strcat(result, Sect->Name);
 419   }
 420   Result = StringRef(result);
 421   return object_error::success;
 422 }
 423
 424 error_code MachOObjectFile::getSectionAddress(DataRefImpl DRI,
 425                                               uint64_t &Result) const {
 426   if (is64BitLoadCommand(MachOObj, DRI)) {
 427     InMemoryStruct<macho::Section64> Sect;
 428     getSection64(DRI, Sect);
 429     Result = Sect->Address;
 430   } else {
 431     InMemoryStruct<macho::Section> Sect;
 432     getSection(DRI, Sect);
 433     Result = Sect->Address;
 434   }
 435   return object_error::success;
 436 }
 437
 438 error_code MachOObjectFile::getSectionSize(DataRefImpl DRI,
 439                                            uint64_t &Result) const {
 440   if (is64BitLoadCommand(MachOObj, DRI)) {
 441     InMemoryStruct<macho::Section64> Sect;
 442     getSection64(DRI, Sect);
 443     Result = Sect->Size;
 444   } else {
 445     InMemoryStruct<macho::Section> Sect;
 446     getSection(DRI, Sect);
 447     Result = Sect->Size;
 448   }
 449   return object_error::success;
 450 }
 451
 452 error_code MachOObjectFile::getSectionContents(DataRefImpl DRI,
 453                                                StringRef &Result) const {
 454   if (is64BitLoadCommand(MachOObj, DRI)) {
 455     InMemoryStruct<macho::Section64> Sect;
 456     getSection64(DRI, Sect);
 457     Result = MachOObj->getData(Sect->Offset, Sect->Size);
 458   } else {
 459     InMemoryStruct<macho::Section> Sect;
 460     getSection(DRI, Sect);
 461     Result = MachOObj->getData(Sect->Offset, Sect->Size);
 462   }
 463   return object_error::success;
 464 }
 465
 466 error_code MachOObjectFile::getSectionAlignment(DataRefImpl DRI,
 467                                                 uint64_t &Result) const {
 468   if (is64BitLoadCommand(MachOObj, DRI)) {
 469     InMemoryStruct<macho::Section64> Sect;
 470     getSection64(DRI, Sect);
 471     Result = uint64_t(1) << Sect->Align;
 472   } else {
 473     InMemoryStruct<macho::Section> Sect;
 474     getSection(DRI, Sect);
 475     Result = uint64_t(1) << Sect->Align;
 476   }
 477   return object_error::success;
 478 }
 479
 480 error_code MachOObjectFile::isSectionText(DataRefImpl DRI,
 481                                           bool &Result) const {
 482   if (is64BitLoadCommand(MachOObj, DRI)) {
 483     InMemoryStruct<macho::Section64> Sect;
 484     getSection64(DRI, Sect);
 485     Result = !strcmp(Sect->Name, "__text");
 486   } else {
 487     InMemoryStruct<macho::Section> Sect;
 488     getSection(DRI, Sect);
 489     Result = !strcmp(Sect->Name, "__text");
 490   }
 491   return object_error::success;
 492 }
 493
 494 error_code MachOObjectFile::isSectionData(DataRefImpl DRI,
 495                                           bool &Result) const {
 496   // FIXME: Unimplemented.
 497   Result = false;
 498   return object_error::success;
 499 }
 500
 501 error_code MachOObjectFile::isSectionBSS(DataRefImpl DRI,
 502                                          bool &Result) const {
 503   // FIXME: Unimplemented.
 504   Result = false;
 505   return object_error::success;
 506 }
 507
 508 error_code MachOObjectFile::sectionContainsSymbol(DataRefImpl Sec,
 509                                                   DataRefImpl Symb,
 510                                                   bool &Result) const {
 511   SymbolRef::Type ST;
 512   getSymbolType(Symb, ST);
 513   if (ST == SymbolRef::ST_External) {
 514     Result = false;
 515     return object_error::success;
 516   }
 517
 518   uint64_t SectBegin, SectEnd;
 519   getSectionAddress(Sec, SectBegin);
 520   getSectionSize(Sec, SectEnd);
 521   SectEnd += SectBegin;
 522
 523   if (MachOObj->is64Bit()) {
 524     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 525     getSymbol64TableEntry(Symb, Entry);
 526     uint64_t SymAddr= Entry->Value;
 527     Result = (SymAddr >= SectBegin) && (SymAddr < SectEnd);
 528   } else {
 529     InMemoryStruct<macho::SymbolTableEntry> Entry;
 530     getSymbolTableEntry(Symb, Entry);
 531     uint64_t SymAddr= Entry->Value;
 532     Result = (SymAddr >= SectBegin) && (SymAddr < SectEnd);
 533   }
 534
 535   return object_error::success;
 536 }
 537
 538 relocation_iterator MachOObjectFile::getSectionRelBegin(DataRefImpl Sec) const {
 539   DataRefImpl ret;
 540   ret.d.a = 0;
 541   ret.d.b = getSectionIndex(Sec);
 542   return relocation_iterator(RelocationRef(ret, this));
 543 }
 544 relocation_iterator MachOObjectFile::getSectionRelEnd(DataRefImpl Sec) const {
 545   uint32_t last_reloc;
 546   if (is64BitLoadCommand(MachOObj, Sec)) {
 547     InMemoryStruct<macho::Section64> Sect;
 548     getSection64(Sec, Sect);
 549     last_reloc = Sect->NumRelocationTableEntries;
 550   } else {
 551     InMemoryStruct<macho::Section> Sect;
 552     getSection(Sec, Sect);
 553     last_reloc = Sect->NumRelocationTableEntries;
 554   }
 555   DataRefImpl ret;
 556   ret.d.a = last_reloc;
 557   ret.d.b = getSectionIndex(Sec);
 558   return relocation_iterator(RelocationRef(ret, this));
 559 }
 560
 561 section_iterator MachOObjectFile::begin_sections() const {
 562   DataRefImpl DRI;
 563   DRI.d.a = DRI.d.b = 0;
 564   moveToNextSection(DRI);
 565   return section_iterator(SectionRef(DRI, this));
 566 }
 567
 568 section_iterator MachOObjectFile::end_sections() const {
 569   DataRefImpl DRI;
 570   DRI.d.a = MachOObj->getHeader().NumLoadCommands;
 571   DRI.d.b = 0;
 572   return section_iterator(SectionRef(DRI, this));
 573 }
 574
 575 /*===-- Relocations -------------------------------------------------------===*/
 576
 577 void MachOObjectFile::
 578 getRelocation(DataRefImpl Rel,
 579               InMemoryStruct<macho::RelocationEntry> &Res) const {
 580   uint32_t relOffset;
 581   if (MachOObj->is64Bit()) {
 582     InMemoryStruct<macho::Section64> Sect;
 583     getSection64(Sections[Rel.d.b], Sect);
 584     relOffset = Sect->RelocationTableOffset;
 585   } else {
 586     InMemoryStruct<macho::Section> Sect;
 587     getSection(Sections[Rel.d.b], Sect);
 588     relOffset = Sect->RelocationTableOffset;
 589   }
 590   MachOObj->ReadRelocationEntry(relOffset, Rel.d.a, Res);
 591 }
 592 error_code MachOObjectFile::getRelocationNext(DataRefImpl Rel,
 593                                               RelocationRef &Res) const {
 594   ++Rel.d.a;
 595   Res = RelocationRef(Rel, this);
 596   return object_error::success;
 597 }
 598 error_code MachOObjectFile::getRelocationAddress(DataRefImpl Rel,
 599                                                  uint64_t &Res) const {
 600   const uint8_t* sectAddress = 0;
 601   if (MachOObj->is64Bit()) {
 602     InMemoryStruct<macho::Section64> Sect;
 603     getSection64(Sections[Rel.d.b], Sect);
 604     sectAddress += Sect->Address;
 605   } else {
 606     InMemoryStruct<macho::Section> Sect;
 607     getSection(Sections[Rel.d.b], Sect);
 608     sectAddress += Sect->Address;
 609   }
 610   InMemoryStruct<macho::RelocationEntry> RE;
 611   getRelocation(Rel, RE);
 612
 613   unsigned Arch = getArch();
 614   bool isScattered = (Arch != Triple::x86_64) &&
 615                      (RE->Word0 & macho::RF_Scattered);
 616   uint64_t RelAddr = 0;
 617   if (isScattered)
 618     RelAddr = RE->Word0 & 0xFFFFFF;
 619   else
 620     RelAddr = RE->Word0;
 621
 622   Res = reinterpret_cast<uintptr_t>(sectAddress + RelAddr);
 623   return object_error::success;
 624 }
 625 error_code MachOObjectFile::getRelocationSymbol(DataRefImpl Rel,
 626                                                 SymbolRef &Res) const {
 627   InMemoryStruct<macho::RelocationEntry> RE;
 628   getRelocation(Rel, RE);
 629   uint32_t SymbolIdx = RE->Word1 & 0xffffff;
 630   bool isExtern = (RE->Word1 >> 27) & 1;
 631
 632   DataRefImpl Sym;
 633   Sym.d.a = Sym.d.b = 0;
 634   moveToNextSymbol(Sym);
 635   if (isExtern) {
 636     for (unsigned i = 0; i < SymbolIdx; i++) {
 637       Sym.d.b++;
 638       moveToNextSymbol(Sym);
 639       assert(Sym.d.a < MachOObj->getHeader().NumLoadCommands &&
 640              "Relocation symbol index out of range!");
 641     }
 642   }
 643   Res = SymbolRef(Sym, this);
 644   return object_error::success;
 645 }
 646 error_code MachOObjectFile::getRelocationType(DataRefImpl Rel,
 647                                               uint64_t &Res) const {
 648   InMemoryStruct<macho::RelocationEntry> RE;
 649   getRelocation(Rel, RE);
 650   Res = RE->Word0;
 651   Res <<= 32;
 652   Res |= RE->Word1;
 653   return object_error::success;
 654 }
 655 error_code MachOObjectFile::getRelocationTypeName(DataRefImpl Rel,
 656                                           SmallVectorImpl<char> &Result) const {
 657   // TODO: Support scattered relocations.
 658   StringRef res;
 659   InMemoryStruct<macho::RelocationEntry> RE;
 660   getRelocation(Rel, RE);
 661
 662   unsigned Arch = getArch();
 663   bool isScattered = (Arch != Triple::x86_64) &&
 664                      (RE->Word0 & macho::RF_Scattered);
 665
 666   unsigned r_type;
 667   if (isScattered)
 668     r_type = (RE->Word0 >> 24) & 0xF;
 669   else
 670     r_type = (RE->Word1 >> 28) & 0xF;
 671
 672   switch (Arch) {
 673     case Triple::x86: {
 674       const char* Table[] =  {
 675         "GENERIC_RELOC_VANILLA",
 676         "GENERIC_RELOC_PAIR",
 677         "GENERIC_RELOC_SECTDIFF",
 678         "GENERIC_RELOC_LOCAL_SECTDIFF",
 679         "GENERIC_RELOC_PB_LA_PTR" };
 680
 681       if (r_type > 4)
 682         res = "Unknown";
 683       else
 684         res = Table[r_type];
 685       break;
 686     }
 687     case Triple::x86_64: {
 688       const char* Table[] =  {
 689         "X86_64_RELOC_UNSIGNED",
 690         "X86_64_RELOC_SIGNED",
 691         "X86_64_RELOC_BRANCH",
 692         "X86_64_RELOC_GOT_LOAD",
 693         "X86_64_RELOC_GOT",
 694         "X86_64_RELOC_SUBTRACTOR",
 695         "X86_64_RELOC_SIGNED_1",
 696         "X86_64_RELOC_SIGNED_2",
 697         "X86_64_RELOC_SIGNED_4",
 698         "X86_64_RELOC_TLV" };
 699
 700       if (r_type > 9)
 701         res = "Unknown";
 702       else
 703         res = Table[r_type];
 704       break;
 705     }
 706     case Triple::arm: {
 707       const char* Table[] =  {
 708         "ARM_RELOC_VANILLA",
 709         "ARM_RELOC_PAIR",
 710         "ARM_RELOC_SECTDIFF",
 711         "ARM_RELOC_LOCAL_SECTDIFF",
 712         "ARM_RELOC_PB_LA_PTR",
 713         "ARM_RELOC_BR24",
 714         "ARM_THUMB_RELOC_BR22",
 715         "ARM_THUMB_32BIT_BRANCH",
 716         "ARM_RELOC_HALF",
 717         "ARM_RELOC_HALF_SECTDIFF" };
 718
 719       if (r_type > 9)
 720         res = "Unknown";
 721       else
 722         res = Table[r_type];
 723       break;
 724     }
 725     case Triple::ppc: {
 726       const char* Table[] =  {
 727         "PPC_RELOC_VANILLA",
 728         "PPC_RELOC_PAIR",
 729         "PPC_RELOC_BR14",
 730         "PPC_RELOC_BR24",
 731         "PPC_RELOC_HI16",
 732         "PPC_RELOC_LO16",
 733         "PPC_RELOC_HA16",
 734         "PPC_RELOC_LO14",
 735         "PPC_RELOC_SECTDIFF",
 736         "PPC_RELOC_PB_LA_PTR",
 737         "PPC_RELOC_HI16_SECTDIFF",
 738         "PPC_RELOC_LO16_SECTDIFF",
 739         "PPC_RELOC_HA16_SECTDIFF",
 740         "PPC_RELOC_JBSR",
 741         "PPC_RELOC_LO14_SECTDIFF",
 742         "PPC_RELOC_LOCAL_SECTDIFF" };
 743
 744       res = Table[r_type];
 745       break;
 746     }
 747     case Triple::UnknownArch:
 748       res = "Unknown";
 749       break;
 750   }
 751   Result.append(res.begin(), res.end());
 752   return object_error::success;
 753 }
 754 error_code MachOObjectFile::getRelocationAdditionalInfo(DataRefImpl Rel,
 755                                                         int64_t &Res) const {
 756   InMemoryStruct<macho::RelocationEntry> RE;
 757   getRelocation(Rel, RE);
 758   bool isExtern = (RE->Word1 >> 27) & 1;
 759   Res = 0;
 760   if (!isExtern) {
 761     const uint8_t* sectAddress = base();
 762     if (MachOObj->is64Bit()) {
 763       InMemoryStruct<macho::Section64> Sect;
 764       getSection64(Sections[Rel.d.b], Sect);
 765       sectAddress += Sect->Offset;
 766     } else {
 767       InMemoryStruct<macho::Section> Sect;
 768       getSection(Sections[Rel.d.b], Sect);
 769       sectAddress += Sect->Offset;
 770     }
 771     Res = reinterpret_cast<uintptr_t>(sectAddress);
 772   }
 773   return object_error::success;
 774 }
 775
 776 // Helper to advance a section or symbol iterator multiple increments at a time.
 777 template<class T>
 778 error_code advance(T &it, size_t Val) {
 779   error_code ec;
 780   while (Val--) {
 781     it.increment(ec);
 782   }
 783   return ec;
 784 }
 785
 786 template<class T>
 787 void advanceTo(T &it, size_t Val) {
 788   if (error_code ec = advance(it, Val))
 789     report_fatal_error(ec.message());
 790 }
 791
 792 void MachOObjectFile::printRelocationTargetName(
 793                                      InMemoryStruct<macho::RelocationEntry>& RE,
 794                                      raw_string_ostream &fmt) const {
 795   unsigned Arch = getArch();
 796   bool isScattered = (Arch != Triple::x86_64) &&
 797                      (RE->Word0 & macho::RF_Scattered);
 798
 799   // Target of a scattered relocation is an address.  In the interest of
 800   // generating pretty output, scan through the symbol table looking for a
 801   // symbol that aligns with that address.  If we find one, print it.
 802   // Otherwise, we just print the hex address of the target.
 803   if (isScattered) {
 804     uint32_t Val = RE->Word1;
 805
 806     error_code ec;
 807     for (symbol_iterator SI = begin_symbols(), SE = end_symbols(); SI != SE;
 808         SI.increment(ec)) {
 809       if (ec) report_fatal_error(ec.message());
 810
 811       uint64_t Addr;
 812       StringRef Name;
 813
 814       if ((ec = SI->getAddress(Addr)))
 815         report_fatal_error(ec.message());
 816       if (Addr != Val) continue;
 817       if ((ec = SI->getName(Name)))
 818         report_fatal_error(ec.message());
 819       fmt << Name;
 820       return;
 821     }
 822
 823     fmt << format("0x%x", Val);
 824     return;
 825   }
 826
 827   StringRef S;
 828   bool isExtern = (RE->Word1 >> 27) & 1;
 829   uint32_t Val = RE->Word1 & 0xFFFFFF;
 830
 831   if (isExtern) {
 832     symbol_iterator SI = begin_symbols();
 833     advanceTo(SI, Val);
 834     SI->getName(S);
 835   } else {
 836     section_iterator SI = begin_sections();
 837     advanceTo(SI, Val);
 838     SI->getName(S);
 839   }
 840
 841   fmt << S;
 842 }
 843
 844 error_code MachOObjectFile::getRelocationValueString(DataRefImpl Rel,
 845                                           SmallVectorImpl<char> &Result) const {
 846   InMemoryStruct<macho::RelocationEntry> RE;
 847   getRelocation(Rel, RE);
 848
 849   unsigned Arch = getArch();
 850   bool isScattered = (Arch != Triple::x86_64) &&
 851                      (RE->Word0 & macho::RF_Scattered);
 852
 853   std::string fmtbuf;
 854   raw_string_ostream fmt(fmtbuf);
 855
 856   unsigned Type;
 857   if (isScattered)
 858     Type = (RE->Word0 >> 24) & 0xF;
 859   else
 860     Type = (RE->Word1 >> 28) & 0xF;
 861
 862   // Determine any addends that should be displayed with the relocation.
 863   // These require decoding the relocation type, which is triple-specific.
 864
 865   // X86_64 has entirely custom relocation types.
 866   if (Arch == Triple::x86_64) {
 867     bool isPCRel = ((RE->Word1 >> 24) & 1);
 868
 869     switch (Type) {
 870       case macho::RIT_X86_64_GOTLoad:   // X86_64_RELOC_GOT_LOAD
 871       case macho::RIT_X86_64_GOT: {     // X86_64_RELOC_GOT
 872         printRelocationTargetName(RE, fmt);
 873         fmt << "@GOT";
 874         if (isPCRel) fmt << "PCREL";
 875         break;
 876       }
 877       case macho::RIT_X86_64_Subtractor: { // X86_64_RELOC_SUBTRACTOR
 878         InMemoryStruct<macho::RelocationEntry> RENext;
 879         DataRefImpl RelNext = Rel;
 880         RelNext.d.a++;
 881         getRelocation(RelNext, RENext);
 882
 883         // X86_64_SUBTRACTOR must be followed by a relocation of type
 884         // X86_64_RELOC_UNSIGNED.
 885         // NOTE: Scattered relocations don't exist on x86_64.
 886         unsigned RType = (RENext->Word1 >> 28) & 0xF;
 887         if (RType != 0)
 888           report_fatal_error("Expected X86_64_RELOC_UNSIGNED after "
 889                              "X86_64_RELOC_SUBTRACTOR.");
 890
 891         // The X86_64_RELOC_UNSIGNED contains the minuend symbol,
 892         // X86_64_SUBTRACTOR contains to the subtrahend.
 893         printRelocationTargetName(RENext, fmt);
 894         fmt << "-";
 895         printRelocationTargetName(RE, fmt);
 896       }
 897       case macho::RIT_X86_64_Signed1: // X86_64_RELOC_SIGNED1
 898         printRelocationTargetName(RE, fmt);
 899         fmt << "-1";
 900         break;
 901       case macho::RIT_X86_64_Signed2: // X86_64_RELOC_SIGNED2
 902         printRelocationTargetName(RE, fmt);
 903         fmt << "-2";
 904         break;
 905       case macho::RIT_X86_64_Signed4: // X86_64_RELOC_SIGNED4
 906         printRelocationTargetName(RE, fmt);
 907         fmt << "-4";
 908         break;
 909       default:
 910         printRelocationTargetName(RE, fmt);
 911         break;
 912     }
 913   // X86 and ARM share some relocation types in common.
 914   } else if (Arch == Triple::x86 || Arch == Triple::arm) {
 915     // Generic relocation types...
 916     switch (Type) {
 917       case macho::RIT_Pair: // GENERIC_RELOC_PAIR - prints no info
 918         return object_error::success;
 919       case macho::RIT_Difference:                // GENERIC_RELOC_SECTDIFF
 920       case macho::RIT_Generic_LocalDifference: { // GENERIC_RELOC_LOCAL_SECTDIFF
 921         InMemoryStruct<macho::RelocationEntry> RENext;
 922         DataRefImpl RelNext = Rel;
 923         RelNext.d.a++;
 924         getRelocation(RelNext, RENext);
 925
 926         // X86 sect diff's must be followed by a relocation of type
 927         // GENERIC_RELOC_PAIR.
 928         bool isNextScattered = (Arch != Triple::x86_64) &&
 929                                (RENext->Word0 & macho::RF_Scattered);
 930         unsigned RType;
 931         if (isNextScattered)
 932           RType = (RENext->Word0 >> 24) & 0xF;
 933         else
 934           RType = (RENext->Word1 >> 28) & 0xF;
 935         if (RType != 1)
 936           report_fatal_error("Expected GENERIC_RELOC_PAIR after "
 937                              "GENERIC_RELOC_SECTDIFF or "
 938                              "GENERIC_RELOC_LOCAL_SECTDIFF.");
 939
 940         printRelocationTargetName(RE, fmt);
 941         fmt << "-";
 942         printRelocationTargetName(RENext, fmt);
 943         break;
 944       }
 945     }
 946
 947     if (Arch == Triple::x86) {
 948       // All X86 relocations that need special printing were already
 949       // handled in the generic code.
 950       printRelocationTargetName(RE, fmt);
 951     } else { // ARM-specific relocations
 952       switch (Type) {
 953         case macho::RIT_ARM_Half:             // ARM_RELOC_HALF
 954         case macho::RIT_ARM_HalfDifference: { // ARM_RELOC_HALF_SECTDIFF
 955           // Half relocations steal a bit from the length field to encode
 956           // whether this is an upper16 or a lower16 relocation.
 957           bool isUpper;
 958           if (isScattered)
 959             isUpper = (RE->Word0 >> 28) & 1;
 960           else
 961             isUpper = (RE->Word1 >> 25) & 1;
 962
 963           if (isUpper)
 964             fmt << ":upper16:(";
 965           else
 966             fmt << ":lower16:(";
 967           printRelocationTargetName(RE, fmt);
 968
 969           InMemoryStruct<macho::RelocationEntry> RENext;
 970           DataRefImpl RelNext = Rel;
 971           RelNext.d.a++;
 972           getRelocation(RelNext, RENext);
 973
 974           // ARM half relocs must be followed by a relocation of type
 975           // ARM_RELOC_PAIR.
 976           bool isNextScattered = (Arch != Triple::x86_64) &&
 977                                  (RENext->Word0 & macho::RF_Scattered);
 978           unsigned RType;
 979           if (isNextScattered)
 980             RType = (RENext->Word0 >> 24) & 0xF;
 981           else
 982             RType = (RENext->Word1 >> 28) & 0xF;
 983
 984           if (RType != 1)
 985             report_fatal_error("Expected ARM_RELOC_PAIR after "
 986                                "GENERIC_RELOC_HALF");
 987
 988           // NOTE: The half of the target virtual address is stashed in the
 989           // address field of the secondary relocation, but we can't reverse
 990           // engineer the constant offset from it without decoding the movw/movt
 991           // instruction to find the other half in its immediate field.
 992
 993           // ARM_RELOC_HALF_SECTDIFF encodes the second section in the
 994           // symbol/section pointer of the follow-on relocation.
 995           if (Type == macho::RIT_ARM_HalfDifference) {
 996             fmt << "-";
 997             printRelocationTargetName(RENext, fmt);
 998           }
 999
1000           fmt << ")";
1001           break;
1002         }
1003         default: {
1004           printRelocationTargetName(RE, fmt);
1005         }
1006       }
1007     }
1008   } else
1009     printRelocationTargetName(RE, fmt);
1010
1011   fmt.flush();
1012   Result.append(fmtbuf.begin(), fmtbuf.end());
1013   return object_error::success;
1014 }
1015
1016 error_code MachOObjectFile::getRelocationHidden(DataRefImpl Rel,
1017                                                 bool &Result) const {
1018   InMemoryStruct<macho::RelocationEntry> RE;
1019   getRelocation(Rel, RE);
1020
1021   unsigned Arch = getArch();
1022   bool isScattered = (Arch != Triple::x86_64) &&
1023                      (RE->Word0 & macho::RF_Scattered);
1024   unsigned Type;
1025   if (isScattered)
1026     Type = (RE->Word0 >> 24) & 0xF;
1027   else
1028     Type = (RE->Word1 >> 28) & 0xF;
1029
1030   Result = false;
1031
1032   // On arches that use the generic relocations, GENERIC_RELOC_PAIR
1033   // is always hidden.
1034   if (Arch == Triple::x86 || Arch == Triple::arm) {
1035     if (Type == macho::RIT_Pair) Result = true;
1036   } else if (Arch == Triple::x86_64) {
1037     // On x86_64, X86_64_RELOC_UNSIGNED is hidden only when it follows
1038     // an X864_64_RELOC_SUBTRACTOR.
1039     if (Type == macho::RIT_X86_64_Unsigned && Rel.d.a > 0) {
1040       DataRefImpl RelPrev = Rel;
1041       RelPrev.d.a--;
1042       InMemoryStruct<macho::RelocationEntry> REPrev;
1043       getRelocation(RelPrev, REPrev);
1044
1045       unsigned PrevType = (REPrev->Word1 >> 28) & 0xF;
1046
1047       if (PrevType == macho::RIT_X86_64_Subtractor) Result = true;
1048     }
1049   }
1050
1051   return object_error::success;
1052 }
1053
1054 /*===-- Miscellaneous -----------------------------------------------------===*/
1055
1056 uint8_t MachOObjectFile::getBytesInAddress() const {
1057   return MachOObj->is64Bit() ? 8 : 4;
1058 }
1059
1060 StringRef MachOObjectFile::getFileFormatName() const {
1061   if (!MachOObj->is64Bit()) {
1062     switch (MachOObj->getHeader().CPUType) {
1063     case llvm::MachO::CPUTypeI386:
1064       return "Mach-O 32-bit i386";
1065     case llvm::MachO::CPUTypeARM:
1066       return "Mach-O arm";
1067     case llvm::MachO::CPUTypePowerPC:
1068       return "Mach-O 32-bit ppc";
1069     default:
1070       assert((MachOObj->getHeader().CPUType & llvm::MachO::CPUArchABI64) == 0 &&
1071              "64-bit object file when we're not 64-bit?");
1072       return "Mach-O 32-bit unknown";
1073     }
1074   }
1075
1076   switch (MachOObj->getHeader().CPUType) {
1077   case llvm::MachO::CPUTypeX86_64:
1078     return "Mach-O 64-bit x86-64";
1079   case llvm::MachO::CPUTypePowerPC64:
1080     return "Mach-O 64-bit ppc64";
1081   default:
1082     assert((MachOObj->getHeader().CPUType & llvm::MachO::CPUArchABI64) == 1 &&
1083            "32-bit object file when we're 64-bit?");
1084     return "Mach-O 64-bit unknown";
1085   }
1086 }
1087
1088 unsigned MachOObjectFile::getArch() const {
1089   switch (MachOObj->getHeader().CPUType) {
1090   case llvm::MachO::CPUTypeI386:
1091     return Triple::x86;
1092   case llvm::MachO::CPUTypeX86_64:
1093     return Triple::x86_64;
1094   case llvm::MachO::CPUTypeARM:
1095     return Triple::arm;
1096   case llvm::MachO::CPUTypePowerPC:
1097     return Triple::ppc;
1098   case llvm::MachO::CPUTypePowerPC64:
1099     return Triple::ppc64;
1100   default:
1101     return Triple::UnknownArch;
1102   }
1103 }
1104
1105 } // end namespace object
1106 } // end namespace llvm