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