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/MachOFormat.h"
  17 #include "llvm/Object/MachOObject.h"
  18 #include "llvm/Object/ObjectFile.h"
  19 #include "llvm/Support/MemoryBuffer.h"
  20 #include "llvm/Support/MachO.h"
  21
  22 #include <cctype>
  23 #include <cstring>
  24 #include <limits>
  25
  26 using namespace llvm;
  27 using namespace object;
  28
  29 namespace llvm {
  30
  31 typedef MachOObject::LoadCommandInfo LoadCommandInfo;
  32
  33 class MachOObjectFile : public ObjectFile {
  34 public:
  35   MachOObjectFile(MemoryBuffer *Object, MachOObject *MOO, error_code &ec)
  36     : ObjectFile(Binary::isMachO, Object, ec),
  37       MachOObj(MOO),
  38       RegisteredStringTable(std::numeric_limits<uint32_t>::max()) {}
  39
  40   virtual symbol_iterator begin_symbols() const;
  41   virtual symbol_iterator end_symbols() const;
  42   virtual section_iterator begin_sections() const;
  43   virtual section_iterator end_sections() const;
  44
  45   virtual uint8_t getBytesInAddress() const;
  46   virtual StringRef getFileFormatName() const;
  47   virtual unsigned getArch() const;
  48
  49 protected:
  50   virtual error_code getSymbolNext(DataRefImpl Symb, SymbolRef &Res) const;
  51   virtual error_code getSymbolName(DataRefImpl Symb, StringRef &Res) const;
  52   virtual error_code getSymbolAddress(DataRefImpl Symb, uint64_t &Res) const;
  53   virtual error_code getSymbolSize(DataRefImpl Symb, uint64_t &Res) const;
  54   virtual error_code getSymbolNMTypeChar(DataRefImpl Symb, char &Res) const;
  55   virtual error_code isSymbolInternal(DataRefImpl Symb, bool &Res) const;
  56
  57   virtual error_code getSectionNext(DataRefImpl Sec, SectionRef &Res) const;
  58   virtual error_code getSectionName(DataRefImpl Sec, StringRef &Res) const;
  59   virtual error_code getSectionAddress(DataRefImpl Sec, uint64_t &Res) const;
  60   virtual error_code getSectionSize(DataRefImpl Sec, uint64_t &Res) const;
  61   virtual error_code getSectionContents(DataRefImpl Sec, StringRef &Res) const;
  62   virtual error_code isSectionText(DataRefImpl Sec, bool &Res) const;
  63
  64 private:
  65   MachOObject *MachOObj;
  66   mutable uint32_t RegisteredStringTable;
  67
  68   void moveToNextSection(DataRefImpl &DRI) const;
  69   void getSymbolTableEntry(DataRefImpl DRI,
  70                            InMemoryStruct<macho::SymbolTableEntry> &Res) const;
  71   void getSymbol64TableEntry(DataRefImpl DRI,
  72                           InMemoryStruct<macho::Symbol64TableEntry> &Res) const;
  73   void moveToNextSymbol(DataRefImpl &DRI) const;
  74   void getSection(DataRefImpl DRI, InMemoryStruct<macho::Section> &Res) const;
  75   void getSection64(DataRefImpl DRI,
  76                     InMemoryStruct<macho::Section64> &Res) const;
  77 };
  78
  79 ObjectFile *ObjectFile::createMachOObjectFile(MemoryBuffer *Buffer) {
  80   error_code ec;
  81   std::string Err;
  82   MachOObject *MachOObj = MachOObject::LoadFromBuffer(Buffer, &Err);
  83   if (!MachOObj)
  84     return NULL;
  85   return new MachOObjectFile(Buffer, MachOObj, ec);
  86 }
  87
  88 /*===-- Symbols -----------------------------------------------------------===*/
  89
  90 void MachOObjectFile::moveToNextSymbol(DataRefImpl &DRI) const {
  91   uint32_t LoadCommandCount = MachOObj->getHeader().NumLoadCommands;
  92   while (DRI.d.a < LoadCommandCount) {
  93     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
  94     if (LCI.Command.Type == macho::LCT_Symtab) {
  95       InMemoryStruct<macho::SymtabLoadCommand> SymtabLoadCmd;
  96       MachOObj->ReadSymtabLoadCommand(LCI, SymtabLoadCmd);
  97       if (DRI.d.b < SymtabLoadCmd->NumSymbolTableEntries)
  98         return;
  99     }
 100
 101     DRI.d.a++;
 102     DRI.d.b = 0;
 103   }
 104 }
 105
 106 void MachOObjectFile::getSymbolTableEntry(DataRefImpl DRI,
 107     InMemoryStruct<macho::SymbolTableEntry> &Res) const {
 108   InMemoryStruct<macho::SymtabLoadCommand> SymtabLoadCmd;
 109   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 110   MachOObj->ReadSymtabLoadCommand(LCI, SymtabLoadCmd);
 111
 112   if (RegisteredStringTable != DRI.d.a) {
 113     MachOObj->RegisterStringTable(*SymtabLoadCmd);
 114     RegisteredStringTable = DRI.d.a;
 115   }
 116
 117   MachOObj->ReadSymbolTableEntry(SymtabLoadCmd->SymbolTableOffset, DRI.d.b,
 118                                  Res);
 119 }
 120
 121 void MachOObjectFile::getSymbol64TableEntry(DataRefImpl DRI,
 122     InMemoryStruct<macho::Symbol64TableEntry> &Res) const {
 123   InMemoryStruct<macho::SymtabLoadCommand> SymtabLoadCmd;
 124   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 125   MachOObj->ReadSymtabLoadCommand(LCI, SymtabLoadCmd);
 126
 127   if (RegisteredStringTable != DRI.d.a) {
 128     MachOObj->RegisterStringTable(*SymtabLoadCmd);
 129     RegisteredStringTable = DRI.d.a;
 130   }
 131
 132   MachOObj->ReadSymbol64TableEntry(SymtabLoadCmd->SymbolTableOffset, DRI.d.b,
 133                                    Res);
 134 }
 135
 136
 137 error_code MachOObjectFile::getSymbolNext(DataRefImpl DRI,
 138                                           SymbolRef &Result) const {
 139   DRI.d.b++;
 140   moveToNextSymbol(DRI);
 141   Result = SymbolRef(DRI, this);
 142   return object_error::success;
 143 }
 144
 145 error_code MachOObjectFile::getSymbolName(DataRefImpl DRI,
 146                                           StringRef &Result) const {
 147   if (MachOObj->is64Bit()) {
 148     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 149     getSymbol64TableEntry(DRI, Entry);
 150     Result = MachOObj->getStringAtIndex(Entry->StringIndex);
 151   } else {
 152     InMemoryStruct<macho::SymbolTableEntry> Entry;
 153     getSymbolTableEntry(DRI, Entry);
 154     Result = MachOObj->getStringAtIndex(Entry->StringIndex);
 155   }
 156   return object_error::success;
 157 }
 158
 159 error_code MachOObjectFile::getSymbolAddress(DataRefImpl DRI,
 160                                              uint64_t &Result) const {
 161   if (MachOObj->is64Bit()) {
 162     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 163     getSymbol64TableEntry(DRI, Entry);
 164     Result = Entry->Value;
 165   } else {
 166     InMemoryStruct<macho::SymbolTableEntry> Entry;
 167     getSymbolTableEntry(DRI, Entry);
 168     Result = Entry->Value;
 169   }
 170   return object_error::success;
 171 }
 172
 173 error_code MachOObjectFile::getSymbolSize(DataRefImpl DRI,
 174                                           uint64_t &Result) const {
 175   Result = UnknownAddressOrSize;
 176   return object_error::success;
 177 }
 178
 179 error_code MachOObjectFile::getSymbolNMTypeChar(DataRefImpl DRI,
 180                                                 char &Result) const {
 181   uint8_t Type, Flags;
 182   if (MachOObj->is64Bit()) {
 183     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 184     getSymbol64TableEntry(DRI, Entry);
 185     Type = Entry->Type;
 186     Flags = Entry->Flags;
 187   } else {
 188     InMemoryStruct<macho::SymbolTableEntry> Entry;
 189     getSymbolTableEntry(DRI, Entry);
 190     Type = Entry->Type;
 191     Flags = Entry->Flags;
 192   }
 193
 194   char Char;
 195   switch (Type & macho::STF_TypeMask) {
 196     case macho::STT_Undefined:
 197       Char = 'u';
 198       break;
 199     case macho::STT_Absolute:
 200     case macho::STT_Section:
 201       Char = 's';
 202       break;
 203     default:
 204       Char = '?';
 205       break;
 206   }
 207
 208   if (Flags & (macho::STF_External | macho::STF_PrivateExtern))
 209     Char = toupper(Char);
 210   Result = Char;
 211   return object_error::success;
 212 }
 213
 214 error_code MachOObjectFile::isSymbolInternal(DataRefImpl DRI,
 215                                              bool &Result) const {
 216   if (MachOObj->is64Bit()) {
 217     InMemoryStruct<macho::Symbol64TableEntry> Entry;
 218     getSymbol64TableEntry(DRI, Entry);
 219     Result = Entry->Flags & macho::STF_StabsEntryMask;
 220   } else {
 221     InMemoryStruct<macho::SymbolTableEntry> Entry;
 222     getSymbolTableEntry(DRI, Entry);
 223     Result = Entry->Flags & macho::STF_StabsEntryMask;
 224   }
 225   return object_error::success;
 226 }
 227
 228 ObjectFile::symbol_iterator MachOObjectFile::begin_symbols() const {
 229   // DRI.d.a = segment number; DRI.d.b = symbol index.
 230   DataRefImpl DRI;
 231   DRI.d.a = DRI.d.b = 0;
 232   moveToNextSymbol(DRI);
 233   return symbol_iterator(SymbolRef(DRI, this));
 234 }
 235
 236 ObjectFile::symbol_iterator MachOObjectFile::end_symbols() const {
 237   DataRefImpl DRI;
 238   DRI.d.a = MachOObj->getHeader().NumLoadCommands;
 239   DRI.d.b = 0;
 240   return symbol_iterator(SymbolRef(DRI, this));
 241 }
 242
 243
 244 /*===-- Sections ----------------------------------------------------------===*/
 245
 246 void MachOObjectFile::moveToNextSection(DataRefImpl &DRI) const {
 247   uint32_t LoadCommandCount = MachOObj->getHeader().NumLoadCommands;
 248   while (DRI.d.a < LoadCommandCount) {
 249     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 250     if (LCI.Command.Type == macho::LCT_Segment) {
 251       InMemoryStruct<macho::SegmentLoadCommand> SegmentLoadCmd;
 252       MachOObj->ReadSegmentLoadCommand(LCI, SegmentLoadCmd);
 253       if (DRI.d.b < SegmentLoadCmd->NumSections)
 254         return;
 255     } else if (LCI.Command.Type == macho::LCT_Segment64) {
 256       InMemoryStruct<macho::Segment64LoadCommand> Segment64LoadCmd;
 257       MachOObj->ReadSegment64LoadCommand(LCI, Segment64LoadCmd);
 258       if (DRI.d.b < Segment64LoadCmd->NumSections)
 259         return;
 260     }
 261
 262     DRI.d.a++;
 263     DRI.d.b = 0;
 264   }
 265 }
 266
 267 error_code MachOObjectFile::getSectionNext(DataRefImpl DRI,
 268                                            SectionRef &Result) const {
 269   DRI.d.b++;
 270   moveToNextSection(DRI);
 271   Result = SectionRef(DRI, this);
 272   return object_error::success;
 273 }
 274
 275 void
 276 MachOObjectFile::getSection(DataRefImpl DRI,
 277                             InMemoryStruct<macho::Section> &Res) const {
 278   InMemoryStruct<macho::SegmentLoadCommand> SLC;
 279   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 280   MachOObj->ReadSegmentLoadCommand(LCI, SLC);
 281   MachOObj->ReadSection(LCI, DRI.d.b, Res);
 282 }
 283
 284 void
 285 MachOObjectFile::getSection64(DataRefImpl DRI,
 286                             InMemoryStruct<macho::Section64> &Res) const {
 287   InMemoryStruct<macho::Segment64LoadCommand> SLC;
 288   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 289   MachOObj->ReadSegment64LoadCommand(LCI, SLC);
 290   MachOObj->ReadSection64(LCI, DRI.d.b, Res);
 291 }
 292
 293 static bool is64BitLoadCommand(const MachOObject *MachOObj, DataRefImpl DRI) {
 294   LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 295   if (LCI.Command.Type == macho::LCT_Segment64)
 296     return true;
 297   assert(LCI.Command.Type == macho::LCT_Segment && "Unexpected Type.");
 298   return false;
 299 }
 300
 301 error_code MachOObjectFile::getSectionName(DataRefImpl DRI,
 302                                            StringRef &Result) const {
 303   // FIXME: thread safety.
 304   static char result[34];
 305   if (is64BitLoadCommand(MachOObj, DRI)) {
 306     InMemoryStruct<macho::Segment64LoadCommand> SLC;
 307     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 308     MachOObj->ReadSegment64LoadCommand(LCI, SLC);
 309     InMemoryStruct<macho::Section64> Sect;
 310     MachOObj->ReadSection64(LCI, DRI.d.b, Sect);
 311
 312     strcpy(result, Sect->SegmentName);
 313     strcat(result, ",");
 314     strcat(result, Sect->Name);
 315   } else {
 316     InMemoryStruct<macho::SegmentLoadCommand> SLC;
 317     LoadCommandInfo LCI = MachOObj->getLoadCommandInfo(DRI.d.a);
 318     MachOObj->ReadSegmentLoadCommand(LCI, SLC);
 319     InMemoryStruct<macho::Section> Sect;
 320     MachOObj->ReadSection(LCI, DRI.d.b, Sect);
 321
 322     strcpy(result, Sect->SegmentName);
 323     strcat(result, ",");
 324     strcat(result, Sect->Name);
 325   }
 326   Result = StringRef(result);
 327   return object_error::success;
 328 }
 329
 330 error_code MachOObjectFile::getSectionAddress(DataRefImpl DRI,
 331                                               uint64_t &Result) const {
 332   if (is64BitLoadCommand(MachOObj, DRI)) {
 333     InMemoryStruct<macho::Section64> Sect;
 334     getSection64(DRI, Sect);
 335     Result = Sect->Address;
 336   } else {
 337     InMemoryStruct<macho::Section> Sect;
 338     getSection(DRI, Sect);
 339     Result = Sect->Address;
 340   }
 341   return object_error::success;
 342 }
 343
 344 error_code MachOObjectFile::getSectionSize(DataRefImpl DRI,
 345                                            uint64_t &Result) const {
 346   if (is64BitLoadCommand(MachOObj, DRI)) {
 347     InMemoryStruct<macho::Section64> Sect;
 348     getSection64(DRI, Sect);
 349     Result = Sect->Size;
 350   } else {
 351     InMemoryStruct<macho::Section> Sect;
 352     getSection(DRI, Sect);
 353     Result = Sect->Size;
 354   }
 355   return object_error::success;
 356 }
 357
 358 error_code MachOObjectFile::getSectionContents(DataRefImpl DRI,
 359                                                StringRef &Result) const {
 360   if (is64BitLoadCommand(MachOObj, DRI)) {
 361     InMemoryStruct<macho::Section64> Sect;
 362     getSection64(DRI, Sect);
 363     Result = MachOObj->getData(Sect->Offset, Sect->Size);
 364   } else {
 365     InMemoryStruct<macho::Section> Sect;
 366     getSection(DRI, Sect);
 367     Result = MachOObj->getData(Sect->Offset, Sect->Size);
 368   }
 369   return object_error::success;
 370 }
 371
 372 error_code MachOObjectFile::isSectionText(DataRefImpl DRI,
 373                                           bool &Result) const {
 374   if (is64BitLoadCommand(MachOObj, DRI)) {
 375     InMemoryStruct<macho::Section64> Sect;
 376     getSection64(DRI, Sect);
 377     Result = !strcmp(Sect->Name, "__text");
 378   } else {
 379     InMemoryStruct<macho::Section> Sect;
 380     getSection(DRI, Sect);
 381     Result = !strcmp(Sect->Name, "__text");
 382   }
 383   return object_error::success;
 384 }
 385
 386 ObjectFile::section_iterator MachOObjectFile::begin_sections() const {
 387   DataRefImpl DRI;
 388   DRI.d.a = DRI.d.b = 0;
 389   moveToNextSection(DRI);
 390   return section_iterator(SectionRef(DRI, this));
 391 }
 392
 393 ObjectFile::section_iterator MachOObjectFile::end_sections() const {
 394   DataRefImpl DRI;
 395   DRI.d.a = MachOObj->getHeader().NumLoadCommands;
 396   DRI.d.b = 0;
 397   return section_iterator(SectionRef(DRI, this));
 398 }
 399
 400 /*===-- Miscellaneous -----------------------------------------------------===*/
 401
 402 uint8_t MachOObjectFile::getBytesInAddress() const {
 403   return MachOObj->is64Bit() ? 8 : 4;
 404 }
 405
 406 StringRef MachOObjectFile::getFileFormatName() const {
 407   if (!MachOObj->is64Bit()) {
 408     switch (MachOObj->getHeader().CPUType) {
 409     case llvm::MachO::CPUTypeI386:
 410       return "Mach-O 32-bit i386";
 411     case llvm::MachO::CPUTypeARM:
 412       return "Mach-O arm";
 413     case llvm::MachO::CPUTypePowerPC:
 414       return "Mach-O 32-bit ppc";
 415     default:
 416       assert((MachOObj->getHeader().CPUType & llvm::MachO::CPUArchABI64) == 0 &&
 417              "64-bit object file when we're not 64-bit?");
 418       return "Mach-O 32-bit unknown";
 419     }
 420   }
 421
 422   switch (MachOObj->getHeader().CPUType) {
 423   case llvm::MachO::CPUTypeX86_64:
 424     return "Mach-O 64-bit x86-64";
 425   case llvm::MachO::CPUTypePowerPC64:
 426     return "Mach-O 64-bit ppc64";
 427   default:
 428     assert((MachOObj->getHeader().CPUType & llvm::MachO::CPUArchABI64) == 1 &&
 429            "32-bit object file when we're 64-bit?");
 430     return "Mach-O 64-bit unknown";
 431   }
 432 }
 433
 434 unsigned MachOObjectFile::getArch() const {
 435   switch (MachOObj->getHeader().CPUType) {
 436   case llvm::MachO::CPUTypeI386:
 437     return Triple::x86;
 438   case llvm::MachO::CPUTypeX86_64:
 439     return Triple::x86_64;
 440   case llvm::MachO::CPUTypeARM:
 441     return Triple::arm;
 442   case llvm::MachO::CPUTypePowerPC:
 443     return Triple::ppc;
 444   case llvm::MachO::CPUTypePowerPC64:
 445     return Triple::ppc64;
 446   default:
 447     return Triple::UnknownArch;
 448   }
 449 }
 450
 451 } // end namespace llvm
 452