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