1 //===-- MachODump.cpp - Object file dumping utility for llvm --------------===// 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 implements the MachO-specific dumper for llvm-objdump. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm-objdump.h" 15 #include "llvm/ADT/OwningPtr.h" 16 #include "llvm/ADT/STLExtras.h" 17 #include "llvm/ADT/StringExtras.h" 18 #include "llvm/ADT/Triple.h" 19 #include "llvm/DebugInfo/DIContext.h" 20 #include "llvm/MC/MCAsmInfo.h" 21 #include "llvm/MC/MCDisassembler.h" 22 #include "llvm/MC/MCInst.h" 23 #include "llvm/MC/MCInstPrinter.h" 24 #include "llvm/MC/MCInstrAnalysis.h" 25 #include "llvm/MC/MCInstrDesc.h" 26 #include "llvm/MC/MCInstrInfo.h" 27 #include "llvm/MC/MCRegisterInfo.h" 28 #include "llvm/MC/MCSubtargetInfo.h" 29 #include "llvm/Object/MachO.h" 30 #include "llvm/Support/Casting.h" 31 #include "llvm/Support/CommandLine.h" 32 #include "llvm/Support/Debug.h" 33 #include "llvm/Support/Format.h" 34 #include "llvm/Support/GraphWriter.h" 35 #include "llvm/Support/MachO.h" 36 #include "llvm/Support/MemoryBuffer.h" 37 #include "llvm/Support/TargetRegistry.h" 38 #include "llvm/Support/TargetSelect.h" 39 #include "llvm/Support/raw_ostream.h" 40 #include "llvm/Support/system_error.h" 41 #include <algorithm> 42 #include <cstring> 43 using namespace llvm; 44 using namespace object; 45 46 static cl::opt<bool> 47 UseDbg("g", cl::desc("Print line information from debug info if available")); 48 49 static cl::opt<std::string> 50 DSYMFile("dsym", cl::desc("Use .dSYM file for debug info")); 51 52 static const Target *GetTarget(const MachOObjectFile *MachOObj) { 53 // Figure out the target triple. 54 if (TripleName.empty()) { 55 llvm::Triple TT("unknown-unknown-unknown"); 56 TT.setArch(Triple::ArchType(MachOObj->getArch())); 57 TripleName = TT.str(); 58 } 59 60 // Get the target specific parser. 61 std::string Error; 62 const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error); 63 if (TheTarget) 64 return TheTarget; 65 66 errs() << "llvm-objdump: error: unable to get target for '" << TripleName 67 << "', see --version and --triple.\n"; 68 return 0; 69 } 70 71 struct SymbolSorter { 72 bool operator()(const SymbolRef &A, const SymbolRef &B) { 73 SymbolRef::Type AType, BType; 74 A.getType(AType); 75 B.getType(BType); 76 77 uint64_t AAddr, BAddr; 78 if (AType != SymbolRef::ST_Function) 79 AAddr = 0; 80 else 81 A.getAddress(AAddr); 82 if (BType != SymbolRef::ST_Function) 83 BAddr = 0; 84 else 85 B.getAddress(BAddr); 86 return AAddr < BAddr; 87 } 88 }; 89 90 // Types for the storted data in code table that is built before disassembly 91 // and the predicate function to sort them. 92 typedef std::pair<uint64_t, DiceRef> DiceTableEntry; 93 typedef std::vector<DiceTableEntry> DiceTable; 94 typedef DiceTable::iterator dice_table_iterator; 95 96 static bool 97 compareDiceTableEntries(const DiceTableEntry i, 98 const DiceTableEntry j) { 99 return i.first == j.first; 100 } 101 102 static void DumpDataInCode(const char *bytes, uint64_t Size, 103 unsigned short Kind) { 104 uint64_t Value; 105 106 switch (Kind) { 107 case macho::Data: 108 switch (Size) { 109 case 4: 110 Value = bytes[3] << 24 | 111 bytes[2] << 16 | 112 bytes[1] << 8 | 113 bytes[0]; 114 outs() << "\t.long " << Value; 115 break; 116 case 2: 117 Value = bytes[1] << 8 | 118 bytes[0]; 119 outs() << "\t.short " << Value; 120 break; 121 case 1: 122 Value = bytes[0]; 123 outs() << "\t.byte " << Value; 124 break; 125 } 126 outs() << "\t@ KIND_DATA\n"; 127 break; 128 case macho::JumpTable8: 129 Value = bytes[0]; 130 outs() << "\t.byte " << Value << "\t@ KIND_JUMP_TABLE8"; 131 break; 132 case macho::JumpTable16: 133 Value = bytes[1] << 8 | 134 bytes[0]; 135 outs() << "\t.short " << Value << "\t@ KIND_JUMP_TABLE16"; 136 break; 137 case macho::JumpTable32: 138 Value = bytes[3] << 24 | 139 bytes[2] << 16 | 140 bytes[1] << 8 | 141 bytes[0]; 142 outs() << "\t.long " << Value << "\t@ KIND_JUMP_TABLE32"; 143 break; 144 default: 145 outs() << "\t@ data in code kind = " << Kind << "\n"; 146 break; 147 } 148 } 149 150 static void 151 getSectionsAndSymbols(const macho::Header Header, 152 MachOObjectFile *MachOObj, 153 std::vector<SectionRef> &Sections, 154 std::vector<SymbolRef> &Symbols, 155 SmallVectorImpl<uint64_t> &FoundFns, 156 uint64_t &BaseSegmentAddress) { 157 error_code ec; 158 for (symbol_iterator SI = MachOObj->begin_symbols(), 159 SE = MachOObj->end_symbols(); SI != SE; SI.increment(ec)) 160 Symbols.push_back(*SI); 161 162 for (section_iterator SI = MachOObj->begin_sections(), 163 SE = MachOObj->end_sections(); SI != SE; SI.increment(ec)) { 164 SectionRef SR = *SI; 165 StringRef SectName; 166 SR.getName(SectName); 167 Sections.push_back(*SI); 168 } 169 170 MachOObjectFile::LoadCommandInfo Command = 171 MachOObj->getFirstLoadCommandInfo(); 172 bool BaseSegmentAddressSet = false; 173 for (unsigned i = 0; ; ++i) { 174 if (Command.C.Type == macho::LCT_FunctionStarts) { 175 // We found a function starts segment, parse the addresses for later 176 // consumption. 177 macho::LinkeditDataLoadCommand LLC = 178 MachOObj->getLinkeditDataLoadCommand(Command); 179 180 MachOObj->ReadULEB128s(LLC.DataOffset, FoundFns); 181 } 182 else if (Command.C.Type == macho::LCT_Segment) { 183 macho::SegmentLoadCommand SLC = 184 MachOObj->getSegmentLoadCommand(Command); 185 StringRef SegName = SLC.Name; 186 if(!BaseSegmentAddressSet && SegName != "__PAGEZERO") { 187 BaseSegmentAddressSet = true; 188 BaseSegmentAddress = SLC.VMAddress; 189 } 190 } 191 192 if (i == Header.NumLoadCommands - 1) 193 break; 194 else 195 Command = MachOObj->getNextLoadCommandInfo(Command); 196 } 197 } 198 199 static void DisassembleInputMachO2(StringRef Filename, 200 MachOObjectFile *MachOOF); 201 202 void llvm::DisassembleInputMachO(StringRef Filename) { 203 OwningPtr<MemoryBuffer> Buff; 204 205 if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename, Buff)) { 206 errs() << "llvm-objdump: " << Filename << ": " << ec.message() << "\n"; 207 return; 208 } 209 210 OwningPtr<MachOObjectFile> MachOOF(static_cast<MachOObjectFile*>( 211 ObjectFile::createMachOObjectFile(Buff.take()))); 212 213 DisassembleInputMachO2(Filename, MachOOF.get()); 214 } 215 216 static void DisassembleInputMachO2(StringRef Filename, 217 MachOObjectFile *MachOOF) { 218 const Target *TheTarget = GetTarget(MachOOF); 219 if (!TheTarget) { 220 // GetTarget prints out stuff. 221 return; 222 } 223 OwningPtr<const MCInstrInfo> InstrInfo(TheTarget->createMCInstrInfo()); 224 OwningPtr<MCInstrAnalysis> 225 InstrAnalysis(TheTarget->createMCInstrAnalysis(InstrInfo.get())); 226 227 // Set up disassembler. 228 OwningPtr<const MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName)); 229 OwningPtr<const MCAsmInfo> AsmInfo( 230 TheTarget->createMCAsmInfo(*MRI, TripleName)); 231 OwningPtr<const MCSubtargetInfo> 232 STI(TheTarget->createMCSubtargetInfo(TripleName, "", "")); 233 OwningPtr<const MCDisassembler> DisAsm(TheTarget->createMCDisassembler(*STI)); 234 int AsmPrinterVariant = AsmInfo->getAssemblerDialect(); 235 OwningPtr<MCInstPrinter> 236 IP(TheTarget->createMCInstPrinter(AsmPrinterVariant, *AsmInfo, *InstrInfo, 237 *MRI, *STI)); 238 239 if (!InstrAnalysis || !AsmInfo || !STI || !DisAsm || !IP) { 240 errs() << "error: couldn't initialize disassembler for target " 241 << TripleName << '\n'; 242 return; 243 } 244 245 outs() << '\n' << Filename << ":\n\n"; 246 247 macho::Header Header = MachOOF->getHeader(); 248 249 // FIXME: FoundFns isn't used anymore. Using symbols/LC_FUNCTION_STARTS to 250 // determine function locations will eventually go in MCObjectDisassembler. 251 // FIXME: Using the -cfg command line option, this code used to be able to 252 // annotate relocations with the referenced symbol's name, and if this was 253 // inside a __[cf]string section, the data it points to. This is now replaced 254 // by the upcoming MCSymbolizer, which needs the appropriate setup done above. 255 std::vector<SectionRef> Sections; 256 std::vector<SymbolRef> Symbols; 257 SmallVector<uint64_t, 8> FoundFns; 258 uint64_t BaseSegmentAddress; 259 260 getSectionsAndSymbols(Header, MachOOF, Sections, Symbols, FoundFns, 261 BaseSegmentAddress); 262 263 // Make a copy of the unsorted symbol list. FIXME: duplication 264 std::vector<SymbolRef> UnsortedSymbols(Symbols); 265 // Sort the symbols by address, just in case they didn't come in that way. 266 std::sort(Symbols.begin(), Symbols.end(), SymbolSorter()); 267 268 // Build a data in code table that is sorted on by the address of each entry. 269 uint64_t BaseAddress = 0; 270 if (Header.FileType == macho::HFT_Object) 271 Sections[0].getAddress(BaseAddress); 272 else 273 BaseAddress = BaseSegmentAddress; 274 DiceTable Dices; 275 error_code ec; 276 for (dice_iterator DI = MachOOF->begin_dices(), DE = MachOOF->end_dices(); 277 DI != DE; DI.increment(ec)){ 278 uint32_t Offset; 279 DI->getOffset(Offset); 280 Dices.push_back(std::make_pair(BaseAddress + Offset, *DI)); 281 } 282 array_pod_sort(Dices.begin(), Dices.end()); 283 284 #ifndef NDEBUG 285 raw_ostream &DebugOut = DebugFlag ? dbgs() : nulls(); 286 #else 287 raw_ostream &DebugOut = nulls(); 288 #endif 289 290 OwningPtr<DIContext> diContext; 291 ObjectFile *DbgObj = MachOOF; 292 // Try to find debug info and set up the DIContext for it. 293 if (UseDbg) { 294 // A separate DSym file path was specified, parse it as a macho file, 295 // get the sections and supply it to the section name parsing machinery. 296 if (!DSYMFile.empty()) { 297 OwningPtr<MemoryBuffer> Buf; 298 if (error_code ec = MemoryBuffer::getFileOrSTDIN(DSYMFile, Buf)) { 299 errs() << "llvm-objdump: " << Filename << ": " << ec.message() << '\n'; 300 return; 301 } 302 DbgObj = ObjectFile::createMachOObjectFile(Buf.take()); 303 } 304 305 // Setup the DIContext 306 diContext.reset(DIContext::getDWARFContext(DbgObj)); 307 } 308 309 for (unsigned SectIdx = 0; SectIdx != Sections.size(); SectIdx++) { 310 311 bool SectIsText = false; 312 Sections[SectIdx].isText(SectIsText); 313 if (SectIsText == false) 314 continue; 315 316 StringRef SectName; 317 if (Sections[SectIdx].getName(SectName) || 318 SectName != "__text") 319 continue; // Skip non-text sections 320 321 DataRefImpl DR = Sections[SectIdx].getRawDataRefImpl(); 322 323 StringRef SegmentName = MachOOF->getSectionFinalSegmentName(DR); 324 if (SegmentName != "__TEXT") 325 continue; 326 327 StringRef Bytes; 328 Sections[SectIdx].getContents(Bytes); 329 StringRefMemoryObject memoryObject(Bytes); 330 bool symbolTableWorked = false; 331 332 // Parse relocations. 333 std::vector<std::pair<uint64_t, SymbolRef> > Relocs; 334 error_code ec; 335 for (relocation_iterator RI = Sections[SectIdx].begin_relocations(), 336 RE = Sections[SectIdx].end_relocations(); RI != RE; RI.increment(ec)) { 337 uint64_t RelocOffset, SectionAddress; 338 RI->getOffset(RelocOffset); 339 Sections[SectIdx].getAddress(SectionAddress); 340 RelocOffset -= SectionAddress; 341 342 symbol_iterator RelocSym = RI->getSymbol(); 343 344 Relocs.push_back(std::make_pair(RelocOffset, *RelocSym)); 345 } 346 array_pod_sort(Relocs.begin(), Relocs.end()); 347 348 // Disassemble symbol by symbol. 349 for (unsigned SymIdx = 0; SymIdx != Symbols.size(); SymIdx++) { 350 StringRef SymName; 351 Symbols[SymIdx].getName(SymName); 352 353 SymbolRef::Type ST; 354 Symbols[SymIdx].getType(ST); 355 if (ST != SymbolRef::ST_Function) 356 continue; 357 358 // Make sure the symbol is defined in this section. 359 bool containsSym = false; 360 Sections[SectIdx].containsSymbol(Symbols[SymIdx], containsSym); 361 if (!containsSym) 362 continue; 363 364 // Start at the address of the symbol relative to the section's address. 365 uint64_t SectionAddress = 0; 366 uint64_t Start = 0; 367 Sections[SectIdx].getAddress(SectionAddress); 368 Symbols[SymIdx].getAddress(Start); 369 Start -= SectionAddress; 370 371 // Stop disassembling either at the beginning of the next symbol or at 372 // the end of the section. 373 bool containsNextSym = false; 374 uint64_t NextSym = 0; 375 uint64_t NextSymIdx = SymIdx+1; 376 while (Symbols.size() > NextSymIdx) { 377 SymbolRef::Type NextSymType; 378 Symbols[NextSymIdx].getType(NextSymType); 379 if (NextSymType == SymbolRef::ST_Function) { 380 Sections[SectIdx].containsSymbol(Symbols[NextSymIdx], 381 containsNextSym); 382 Symbols[NextSymIdx].getAddress(NextSym); 383 NextSym -= SectionAddress; 384 break; 385 } 386 ++NextSymIdx; 387 } 388 389 uint64_t SectSize; 390 Sections[SectIdx].getSize(SectSize); 391 uint64_t End = containsNextSym ? NextSym : SectSize; 392 uint64_t Size; 393 394 symbolTableWorked = true; 395 396 outs() << SymName << ":\n"; 397 DILineInfo lastLine; 398 for (uint64_t Index = Start; Index < End; Index += Size) { 399 MCInst Inst; 400 401 uint64_t SectAddress = 0; 402 Sections[SectIdx].getAddress(SectAddress); 403 outs() << format("%8" PRIx64 ":\t", SectAddress + Index); 404 405 // Check the data in code table here to see if this is data not an 406 // instruction to be disassembled. 407 DiceTable Dice; 408 Dice.push_back(std::make_pair(SectAddress + Index, DiceRef())); 409 dice_table_iterator DTI = std::search(Dices.begin(), Dices.end(), 410 Dice.begin(), Dice.end(), 411 compareDiceTableEntries); 412 if (DTI != Dices.end()){ 413 uint16_t Length; 414 DTI->second.getLength(Length); 415 DumpBytes(StringRef(Bytes.data() + Index, Length)); 416 uint16_t Kind; 417 DTI->second.getKind(Kind); 418 DumpDataInCode(Bytes.data() + Index, Length, Kind); 419 continue; 420 } 421 422 if (DisAsm->getInstruction(Inst, Size, memoryObject, Index, 423 DebugOut, nulls())) { 424 DumpBytes(StringRef(Bytes.data() + Index, Size)); 425 IP->printInst(&Inst, outs(), ""); 426 427 // Print debug info. 428 if (diContext) { 429 DILineInfo dli = 430 diContext->getLineInfoForAddress(SectAddress + Index); 431 // Print valid line info if it changed. 432 if (dli != lastLine && dli.getLine() != 0) 433 outs() << "\t## " << dli.getFileName() << ':' 434 << dli.getLine() << ':' << dli.getColumn(); 435 lastLine = dli; 436 } 437 outs() << "\n"; 438 } else { 439 errs() << "llvm-objdump: warning: invalid instruction encoding\n"; 440 if (Size == 0) 441 Size = 1; // skip illegible bytes 442 } 443 } 444 } 445 if (!symbolTableWorked) { 446 // Reading the symbol table didn't work, disassemble the whole section. 447 uint64_t SectAddress; 448 Sections[SectIdx].getAddress(SectAddress); 449 uint64_t SectSize; 450 Sections[SectIdx].getSize(SectSize); 451 uint64_t InstSize; 452 for (uint64_t Index = 0; Index < SectSize; Index += InstSize) { 453 MCInst Inst; 454 455 if (DisAsm->getInstruction(Inst, InstSize, memoryObject, Index, 456 DebugOut, nulls())) { 457 outs() << format("%8" PRIx64 ":\t", SectAddress + Index); 458 DumpBytes(StringRef(Bytes.data() + Index, InstSize)); 459 IP->printInst(&Inst, outs(), ""); 460 outs() << "\n"; 461 } else { 462 errs() << "llvm-objdump: warning: invalid instruction encoding\n"; 463 if (InstSize == 0) 464 InstSize = 1; // skip illegible bytes 465 } 466 } 467 } 468 } 469 } 470
