MachODump.cpp revision 8819c84aed10777ba91d4e862229882b8da0b272
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> 43using namespace llvm; 44using namespace object; 45 46static cl::opt<bool> 47 UseDbg("g", cl::desc("Print line information from debug info if available")); 48 49static cl::opt<std::string> 50 DSYMFile("dsym", cl::desc("Use .dSYM file for debug info")); 51 52static 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 71struct 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. 92typedef std::pair<uint64_t, DiceRef> DiceTableEntry; 93typedef std::vector<DiceTableEntry> DiceTable; 94typedef DiceTable::iterator dice_table_iterator; 95 96static bool 97compareDiceTableEntries(const DiceTableEntry i, 98 const DiceTableEntry j) { 99 return i.first == j.first; 100} 101 102static void DumpDataInCode(const char *bytes, uint64_t Size, 103 unsigned short Kind) { 104 uint64_t Value; 105 106 switch (Kind) { 107 case MachO::DICE_KIND_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::DICE_KIND_JUMP_TABLE8: 129 Value = bytes[0]; 130 outs() << "\t.byte " << Value << "\t@ KIND_JUMP_TABLE8"; 131 break; 132 case MachO::DICE_KIND_JUMP_TABLE16: 133 Value = bytes[1] << 8 | 134 bytes[0]; 135 outs() << "\t.short " << Value << "\t@ KIND_JUMP_TABLE16"; 136 break; 137 case MachO::DICE_KIND_JUMP_TABLE32: 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 150static void 151getSectionsAndSymbols(const MachO::mach_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.cmd == MachO::LC_FUNCTION_STARTS) { 175 // We found a function starts segment, parse the addresses for later 176 // consumption. 177 MachO::linkedit_data_command LLC = 178 MachOObj->getLinkeditDataLoadCommand(Command); 179 180 MachOObj->ReadULEB128s(LLC.dataoff, FoundFns); 181 } 182 else if (Command.C.cmd == MachO::LC_SEGMENT) { 183 MachO::segment_command SLC = 184 MachOObj->getSegmentLoadCommand(Command); 185 StringRef SegName = SLC.segname; 186 if(!BaseSegmentAddressSet && SegName != "__PAGEZERO") { 187 BaseSegmentAddressSet = true; 188 BaseSegmentAddress = SLC.vmaddr; 189 } 190 } 191 192 if (i == Header.ncmds - 1) 193 break; 194 else 195 Command = MachOObj->getNextLoadCommandInfo(Command); 196 } 197} 198 199static void DisassembleInputMachO2(StringRef Filename, 200 MachOObjectFile *MachOOF); 201 202void 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 216static 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::mach_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 // Sort the symbols by address, just in case they didn't come in that way. 264 std::sort(Symbols.begin(), Symbols.end(), SymbolSorter()); 265 266 // Build a data in code table that is sorted on by the address of each entry. 267 uint64_t BaseAddress = 0; 268 if (Header.filetype == MachO::MH_OBJECT) 269 Sections[0].getAddress(BaseAddress); 270 else 271 BaseAddress = BaseSegmentAddress; 272 DiceTable Dices; 273 error_code ec; 274 for (dice_iterator DI = MachOOF->begin_dices(), DE = MachOOF->end_dices(); 275 DI != DE; DI.increment(ec)){ 276 uint32_t Offset; 277 DI->getOffset(Offset); 278 Dices.push_back(std::make_pair(BaseAddress + Offset, *DI)); 279 } 280 array_pod_sort(Dices.begin(), Dices.end()); 281 282#ifndef NDEBUG 283 raw_ostream &DebugOut = DebugFlag ? dbgs() : nulls(); 284#else 285 raw_ostream &DebugOut = nulls(); 286#endif 287 288 OwningPtr<DIContext> diContext; 289 ObjectFile *DbgObj = MachOOF; 290 // Try to find debug info and set up the DIContext for it. 291 if (UseDbg) { 292 // A separate DSym file path was specified, parse it as a macho file, 293 // get the sections and supply it to the section name parsing machinery. 294 if (!DSYMFile.empty()) { 295 OwningPtr<MemoryBuffer> Buf; 296 if (error_code ec = MemoryBuffer::getFileOrSTDIN(DSYMFile, Buf)) { 297 errs() << "llvm-objdump: " << Filename << ": " << ec.message() << '\n'; 298 return; 299 } 300 DbgObj = ObjectFile::createMachOObjectFile(Buf.take()); 301 } 302 303 // Setup the DIContext 304 diContext.reset(DIContext::getDWARFContext(DbgObj)); 305 } 306 307 for (unsigned SectIdx = 0; SectIdx != Sections.size(); SectIdx++) { 308 309 bool SectIsText = false; 310 Sections[SectIdx].isText(SectIsText); 311 if (SectIsText == false) 312 continue; 313 314 StringRef SectName; 315 if (Sections[SectIdx].getName(SectName) || 316 SectName != "__text") 317 continue; // Skip non-text sections 318 319 DataRefImpl DR = Sections[SectIdx].getRawDataRefImpl(); 320 321 StringRef SegmentName = MachOOF->getSectionFinalSegmentName(DR); 322 if (SegmentName != "__TEXT") 323 continue; 324 325 StringRef Bytes; 326 Sections[SectIdx].getContents(Bytes); 327 StringRefMemoryObject memoryObject(Bytes); 328 bool symbolTableWorked = false; 329 330 // Parse relocations. 331 std::vector<std::pair<uint64_t, SymbolRef> > Relocs; 332 error_code ec; 333 for (relocation_iterator RI = Sections[SectIdx].begin_relocations(), 334 RE = Sections[SectIdx].end_relocations(); RI != RE; RI.increment(ec)) { 335 uint64_t RelocOffset, SectionAddress; 336 RI->getOffset(RelocOffset); 337 Sections[SectIdx].getAddress(SectionAddress); 338 RelocOffset -= SectionAddress; 339 340 symbol_iterator RelocSym = RI->getSymbol(); 341 342 Relocs.push_back(std::make_pair(RelocOffset, *RelocSym)); 343 } 344 array_pod_sort(Relocs.begin(), Relocs.end()); 345 346 // Disassemble symbol by symbol. 347 for (unsigned SymIdx = 0; SymIdx != Symbols.size(); SymIdx++) { 348 StringRef SymName; 349 Symbols[SymIdx].getName(SymName); 350 351 SymbolRef::Type ST; 352 Symbols[SymIdx].getType(ST); 353 if (ST != SymbolRef::ST_Function) 354 continue; 355 356 // Make sure the symbol is defined in this section. 357 bool containsSym = false; 358 Sections[SectIdx].containsSymbol(Symbols[SymIdx], containsSym); 359 if (!containsSym) 360 continue; 361 362 // Start at the address of the symbol relative to the section's address. 363 uint64_t SectionAddress = 0; 364 uint64_t Start = 0; 365 Sections[SectIdx].getAddress(SectionAddress); 366 Symbols[SymIdx].getAddress(Start); 367 Start -= SectionAddress; 368 369 // Stop disassembling either at the beginning of the next symbol or at 370 // the end of the section. 371 bool containsNextSym = false; 372 uint64_t NextSym = 0; 373 uint64_t NextSymIdx = SymIdx+1; 374 while (Symbols.size() > NextSymIdx) { 375 SymbolRef::Type NextSymType; 376 Symbols[NextSymIdx].getType(NextSymType); 377 if (NextSymType == SymbolRef::ST_Function) { 378 Sections[SectIdx].containsSymbol(Symbols[NextSymIdx], 379 containsNextSym); 380 Symbols[NextSymIdx].getAddress(NextSym); 381 NextSym -= SectionAddress; 382 break; 383 } 384 ++NextSymIdx; 385 } 386 387 uint64_t SectSize; 388 Sections[SectIdx].getSize(SectSize); 389 uint64_t End = containsNextSym ? NextSym : SectSize; 390 uint64_t Size; 391 392 symbolTableWorked = true; 393 394 outs() << SymName << ":\n"; 395 DILineInfo lastLine; 396 for (uint64_t Index = Start; Index < End; Index += Size) { 397 MCInst Inst; 398 399 uint64_t SectAddress = 0; 400 Sections[SectIdx].getAddress(SectAddress); 401 outs() << format("%8" PRIx64 ":\t", SectAddress + Index); 402 403 // Check the data in code table here to see if this is data not an 404 // instruction to be disassembled. 405 DiceTable Dice; 406 Dice.push_back(std::make_pair(SectAddress + Index, DiceRef())); 407 dice_table_iterator DTI = std::search(Dices.begin(), Dices.end(), 408 Dice.begin(), Dice.end(), 409 compareDiceTableEntries); 410 if (DTI != Dices.end()){ 411 uint16_t Length; 412 DTI->second.getLength(Length); 413 DumpBytes(StringRef(Bytes.data() + Index, Length)); 414 uint16_t Kind; 415 DTI->second.getKind(Kind); 416 DumpDataInCode(Bytes.data() + Index, Length, Kind); 417 continue; 418 } 419 420 if (DisAsm->getInstruction(Inst, Size, memoryObject, Index, 421 DebugOut, nulls())) { 422 DumpBytes(StringRef(Bytes.data() + Index, Size)); 423 IP->printInst(&Inst, outs(), ""); 424 425 // Print debug info. 426 if (diContext) { 427 DILineInfo dli = 428 diContext->getLineInfoForAddress(SectAddress + Index); 429 // Print valid line info if it changed. 430 if (dli != lastLine && dli.getLine() != 0) 431 outs() << "\t## " << dli.getFileName() << ':' 432 << dli.getLine() << ':' << dli.getColumn(); 433 lastLine = dli; 434 } 435 outs() << "\n"; 436 } else { 437 errs() << "llvm-objdump: warning: invalid instruction encoding\n"; 438 if (Size == 0) 439 Size = 1; // skip illegible bytes 440 } 441 } 442 } 443 if (!symbolTableWorked) { 444 // Reading the symbol table didn't work, disassemble the whole section. 445 uint64_t SectAddress; 446 Sections[SectIdx].getAddress(SectAddress); 447 uint64_t SectSize; 448 Sections[SectIdx].getSize(SectSize); 449 uint64_t InstSize; 450 for (uint64_t Index = 0; Index < SectSize; Index += InstSize) { 451 MCInst Inst; 452 453 if (DisAsm->getInstruction(Inst, InstSize, memoryObject, Index, 454 DebugOut, nulls())) { 455 outs() << format("%8" PRIx64 ":\t", SectAddress + Index); 456 DumpBytes(StringRef(Bytes.data() + Index, InstSize)); 457 IP->printInst(&Inst, outs(), ""); 458 outs() << "\n"; 459 } else { 460 errs() << "llvm-objdump: warning: invalid instruction encoding\n"; 461 if (InstSize == 0) 462 InstSize = 1; // skip illegible bytes 463 } 464 } 465 } 466 } 467} 468