1 //===- yaml2macho - Convert YAML to a Mach object file --------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 /// 9 /// \file 10 /// The Mach component of yaml2obj. 11 /// 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/BinaryFormat/MachO.h" 15 #include "llvm/ObjectYAML/DWARFEmitter.h" 16 #include "llvm/ObjectYAML/ObjectYAML.h" 17 #include "llvm/ObjectYAML/yaml2obj.h" 18 #include "llvm/Support/Errc.h" 19 #include "llvm/Support/Error.h" 20 #include "llvm/Support/LEB128.h" 21 #include "llvm/Support/YAMLTraits.h" 22 #include "llvm/Support/raw_ostream.h" 23 24 #include "llvm/Support/Format.h" 25 26 using namespace llvm; 27 28 namespace { 29 30 class MachOWriter { 31 public: 32 MachOWriter(MachOYAML::Object &Obj) : Obj(Obj), is64Bit(true), fileStart(0) { 33 is64Bit = Obj.Header.magic == MachO::MH_MAGIC_64 || 34 Obj.Header.magic == MachO::MH_CIGAM_64; 35 memset(reinterpret_cast<void *>(&Header), 0, sizeof(MachO::mach_header_64)); 36 } 37 38 Error writeMachO(raw_ostream &OS); 39 40 private: 41 void writeHeader(raw_ostream &OS); 42 void writeLoadCommands(raw_ostream &OS); 43 Error writeSectionData(raw_ostream &OS); 44 void writeRelocations(raw_ostream &OS); 45 void writeLinkEditData(raw_ostream &OS); 46 47 void writeBindOpcodes(raw_ostream &OS, 48 std::vector<MachOYAML::BindOpcode> &BindOpcodes); 49 // LinkEdit writers 50 void writeRebaseOpcodes(raw_ostream &OS); 51 void writeBasicBindOpcodes(raw_ostream &OS); 52 void writeWeakBindOpcodes(raw_ostream &OS); 53 void writeLazyBindOpcodes(raw_ostream &OS); 54 void writeNameList(raw_ostream &OS); 55 void writeStringTable(raw_ostream &OS); 56 void writeExportTrie(raw_ostream &OS); 57 58 void dumpExportEntry(raw_ostream &OS, MachOYAML::ExportEntry &Entry); 59 void ZeroToOffset(raw_ostream &OS, size_t offset); 60 61 MachOYAML::Object &Obj; 62 bool is64Bit; 63 uint64_t fileStart; 64 MachO::mach_header_64 Header; 65 66 // Old PPC Object Files didn't have __LINKEDIT segments, the data was just 67 // stuck at the end of the file. 68 bool FoundLinkEditSeg = false; 69 }; 70 71 Error MachOWriter::writeMachO(raw_ostream &OS) { 72 fileStart = OS.tell(); 73 writeHeader(OS); 74 writeLoadCommands(OS); 75 if (Error Err = writeSectionData(OS)) 76 return Err; 77 writeRelocations(OS); 78 if (!FoundLinkEditSeg) 79 writeLinkEditData(OS); 80 return Error::success(); 81 } 82 83 void MachOWriter::writeHeader(raw_ostream &OS) { 84 Header.magic = Obj.Header.magic; 85 Header.cputype = Obj.Header.cputype; 86 Header.cpusubtype = Obj.Header.cpusubtype; 87 Header.filetype = Obj.Header.filetype; 88 Header.ncmds = Obj.Header.ncmds; 89 Header.sizeofcmds = Obj.Header.sizeofcmds; 90 Header.flags = Obj.Header.flags; 91 Header.reserved = Obj.Header.reserved; 92 93 if (Obj.IsLittleEndian != sys::IsLittleEndianHost) 94 MachO::swapStruct(Header); 95 96 auto header_size = 97 is64Bit ? sizeof(MachO::mach_header_64) : sizeof(MachO::mach_header); 98 OS.write((const char *)&Header, header_size); 99 } 100 101 template <typename SectionType> 102 SectionType constructSection(MachOYAML::Section Sec) { 103 SectionType TempSec; 104 memcpy(reinterpret_cast<void *>(&TempSec.sectname[0]), &Sec.sectname[0], 16); 105 memcpy(reinterpret_cast<void *>(&TempSec.segname[0]), &Sec.segname[0], 16); 106 TempSec.addr = Sec.addr; 107 TempSec.size = Sec.size; 108 TempSec.offset = Sec.offset; 109 TempSec.align = Sec.align; 110 TempSec.reloff = Sec.reloff; 111 TempSec.nreloc = Sec.nreloc; 112 TempSec.flags = Sec.flags; 113 TempSec.reserved1 = Sec.reserved1; 114 TempSec.reserved2 = Sec.reserved2; 115 return TempSec; 116 } 117 118 template <typename StructType> 119 size_t writeLoadCommandData(MachOYAML::LoadCommand &LC, raw_ostream &OS, 120 bool IsLittleEndian) { 121 return 0; 122 } 123 124 template <> 125 size_t writeLoadCommandData<MachO::segment_command>(MachOYAML::LoadCommand &LC, 126 raw_ostream &OS, 127 bool IsLittleEndian) { 128 size_t BytesWritten = 0; 129 for (const auto &Sec : LC.Sections) { 130 auto TempSec = constructSection<MachO::section>(Sec); 131 if (IsLittleEndian != sys::IsLittleEndianHost) 132 MachO::swapStruct(TempSec); 133 OS.write(reinterpret_cast<const char *>(&(TempSec)), 134 sizeof(MachO::section)); 135 BytesWritten += sizeof(MachO::section); 136 } 137 return BytesWritten; 138 } 139 140 template <> 141 size_t writeLoadCommandData<MachO::segment_command_64>( 142 MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) { 143 size_t BytesWritten = 0; 144 for (const auto &Sec : LC.Sections) { 145 auto TempSec = constructSection<MachO::section_64>(Sec); 146 TempSec.reserved3 = Sec.reserved3; 147 if (IsLittleEndian != sys::IsLittleEndianHost) 148 MachO::swapStruct(TempSec); 149 OS.write(reinterpret_cast<const char *>(&(TempSec)), 150 sizeof(MachO::section_64)); 151 BytesWritten += sizeof(MachO::section_64); 152 } 153 return BytesWritten; 154 } 155 156 size_t writePayloadString(MachOYAML::LoadCommand &LC, raw_ostream &OS) { 157 size_t BytesWritten = 0; 158 if (!LC.PayloadString.empty()) { 159 OS.write(LC.PayloadString.c_str(), LC.PayloadString.length()); 160 BytesWritten = LC.PayloadString.length(); 161 } 162 return BytesWritten; 163 } 164 165 template <> 166 size_t writeLoadCommandData<MachO::dylib_command>(MachOYAML::LoadCommand &LC, 167 raw_ostream &OS, 168 bool IsLittleEndian) { 169 return writePayloadString(LC, OS); 170 } 171 172 template <> 173 size_t writeLoadCommandData<MachO::dylinker_command>(MachOYAML::LoadCommand &LC, 174 raw_ostream &OS, 175 bool IsLittleEndian) { 176 return writePayloadString(LC, OS); 177 } 178 179 template <> 180 size_t writeLoadCommandData<MachO::rpath_command>(MachOYAML::LoadCommand &LC, 181 raw_ostream &OS, 182 bool IsLittleEndian) { 183 return writePayloadString(LC, OS); 184 } 185 186 template <> 187 size_t writeLoadCommandData<MachO::build_version_command>( 188 MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) { 189 size_t BytesWritten = 0; 190 for (const auto &T : LC.Tools) { 191 struct MachO::build_tool_version tool = T; 192 if (IsLittleEndian != sys::IsLittleEndianHost) 193 MachO::swapStruct(tool); 194 OS.write(reinterpret_cast<const char *>(&tool), 195 sizeof(MachO::build_tool_version)); 196 BytesWritten += sizeof(MachO::build_tool_version); 197 } 198 return BytesWritten; 199 } 200 201 void ZeroFillBytes(raw_ostream &OS, size_t Size) { 202 std::vector<uint8_t> FillData; 203 FillData.insert(FillData.begin(), Size, 0); 204 OS.write(reinterpret_cast<char *>(FillData.data()), Size); 205 } 206 207 void Fill(raw_ostream &OS, size_t Size, uint32_t Data) { 208 std::vector<uint32_t> FillData; 209 FillData.insert(FillData.begin(), (Size / 4) + 1, Data); 210 OS.write(reinterpret_cast<char *>(FillData.data()), Size); 211 } 212 213 void MachOWriter::ZeroToOffset(raw_ostream &OS, size_t Offset) { 214 auto currOffset = OS.tell() - fileStart; 215 if (currOffset < Offset) 216 ZeroFillBytes(OS, Offset - currOffset); 217 } 218 219 void MachOWriter::writeLoadCommands(raw_ostream &OS) { 220 for (auto &LC : Obj.LoadCommands) { 221 size_t BytesWritten = 0; 222 llvm::MachO::macho_load_command Data = LC.Data; 223 224 #define HANDLE_LOAD_COMMAND(LCName, LCValue, LCStruct) \ 225 case MachO::LCName: \ 226 if (Obj.IsLittleEndian != sys::IsLittleEndianHost) \ 227 MachO::swapStruct(Data.LCStruct##_data); \ 228 OS.write(reinterpret_cast<const char *>(&(Data.LCStruct##_data)), \ 229 sizeof(MachO::LCStruct)); \ 230 BytesWritten = sizeof(MachO::LCStruct); \ 231 BytesWritten += \ 232 writeLoadCommandData<MachO::LCStruct>(LC, OS, Obj.IsLittleEndian); \ 233 break; 234 235 switch (LC.Data.load_command_data.cmd) { 236 default: 237 if (Obj.IsLittleEndian != sys::IsLittleEndianHost) 238 MachO::swapStruct(Data.load_command_data); 239 OS.write(reinterpret_cast<const char *>(&(Data.load_command_data)), 240 sizeof(MachO::load_command)); 241 BytesWritten = sizeof(MachO::load_command); 242 BytesWritten += 243 writeLoadCommandData<MachO::load_command>(LC, OS, Obj.IsLittleEndian); 244 break; 245 #include "llvm/BinaryFormat/MachO.def" 246 } 247 248 if (LC.PayloadBytes.size() > 0) { 249 OS.write(reinterpret_cast<const char *>(LC.PayloadBytes.data()), 250 LC.PayloadBytes.size()); 251 BytesWritten += LC.PayloadBytes.size(); 252 } 253 254 if (LC.ZeroPadBytes > 0) { 255 ZeroFillBytes(OS, LC.ZeroPadBytes); 256 BytesWritten += LC.ZeroPadBytes; 257 } 258 259 // Fill remaining bytes with 0. This will only get hit in partially 260 // specified test cases. 261 auto BytesRemaining = LC.Data.load_command_data.cmdsize - BytesWritten; 262 if (BytesRemaining > 0) { 263 ZeroFillBytes(OS, BytesRemaining); 264 } 265 } 266 } 267 268 Error MachOWriter::writeSectionData(raw_ostream &OS) { 269 for (auto &LC : Obj.LoadCommands) { 270 switch (LC.Data.load_command_data.cmd) { 271 case MachO::LC_SEGMENT: 272 case MachO::LC_SEGMENT_64: 273 uint64_t segOff = is64Bit ? LC.Data.segment_command_64_data.fileoff 274 : LC.Data.segment_command_data.fileoff; 275 if (0 == 276 strncmp(&LC.Data.segment_command_data.segname[0], "__LINKEDIT", 16)) { 277 FoundLinkEditSeg = true; 278 writeLinkEditData(OS); 279 } 280 for (auto &Sec : LC.Sections) { 281 ZeroToOffset(OS, Sec.offset); 282 // Zero Fill any data between the end of the last thing we wrote and the 283 // start of this section. 284 if (OS.tell() - fileStart > Sec.offset && Sec.offset != (uint32_t)0) 285 return createStringError( 286 errc::invalid_argument, 287 "wrote too much data somewhere, section offsets don't line up"); 288 if (0 == strncmp(&Sec.segname[0], "__DWARF", 16)) { 289 Error Err = Error::success(); 290 cantFail(std::move(Err)); 291 292 if (0 == strncmp(&Sec.sectname[0], "__debug_str", 16)) 293 Err = DWARFYAML::emitDebugStr(OS, Obj.DWARF); 294 else if (0 == strncmp(&Sec.sectname[0], "__debug_abbrev", 16)) 295 Err = DWARFYAML::emitDebugAbbrev(OS, Obj.DWARF); 296 else if (0 == strncmp(&Sec.sectname[0], "__debug_aranges", 16)) 297 Err = DWARFYAML::emitDebugAranges(OS, Obj.DWARF); 298 else if (0 == strncmp(&Sec.sectname[0], "__debug_ranges", 16)) 299 Err = DWARFYAML::emitDebugRanges(OS, Obj.DWARF); 300 else if (0 == strncmp(&Sec.sectname[0], "__debug_pubnames", 16)) { 301 if (Obj.DWARF.PubNames) 302 Err = DWARFYAML::emitPubSection(OS, *Obj.DWARF.PubNames, 303 Obj.IsLittleEndian); 304 } else if (0 == strncmp(&Sec.sectname[0], "__debug_pubtypes", 16)) { 305 if (Obj.DWARF.PubTypes) 306 Err = DWARFYAML::emitPubSection(OS, *Obj.DWARF.PubTypes, 307 Obj.IsLittleEndian); 308 } else if (0 == strncmp(&Sec.sectname[0], "__debug_info", 16)) 309 Err = DWARFYAML::emitDebugInfo(OS, Obj.DWARF); 310 else if (0 == strncmp(&Sec.sectname[0], "__debug_line", 16)) 311 Err = DWARFYAML::emitDebugLine(OS, Obj.DWARF); 312 313 if (Err) 314 return Err; 315 316 continue; 317 } 318 319 // Skip if it's a virtual section. 320 if (MachO::isVirtualSection(Sec.flags & MachO::SECTION_TYPE)) 321 continue; 322 323 if (Sec.content) { 324 yaml::BinaryRef Content = *Sec.content; 325 Content.writeAsBinary(OS); 326 ZeroFillBytes(OS, Sec.size - Content.binary_size()); 327 } else { 328 // Fill section data with 0xDEADBEEF. 329 Fill(OS, Sec.size, 0xDEADBEEFu); 330 } 331 } 332 uint64_t segSize = is64Bit ? LC.Data.segment_command_64_data.filesize 333 : LC.Data.segment_command_data.filesize; 334 ZeroToOffset(OS, segOff + segSize); 335 break; 336 } 337 } 338 339 return Error::success(); 340 } 341 342 // The implementation of makeRelocationInfo and makeScatteredRelocationInfo is 343 // consistent with how libObject parses MachO binary files. For the reference 344 // see getStruct, getRelocation, getPlainRelocationPCRel, 345 // getPlainRelocationLength and related methods in MachOObjectFile.cpp 346 static MachO::any_relocation_info 347 makeRelocationInfo(const MachOYAML::Relocation &R, bool IsLE) { 348 assert(!R.is_scattered && "non-scattered relocation expected"); 349 MachO::any_relocation_info MRE; 350 MRE.r_word0 = R.address; 351 if (IsLE) 352 MRE.r_word1 = ((unsigned)R.symbolnum << 0) | ((unsigned)R.is_pcrel << 24) | 353 ((unsigned)R.length << 25) | ((unsigned)R.is_extern << 27) | 354 ((unsigned)R.type << 28); 355 else 356 MRE.r_word1 = ((unsigned)R.symbolnum << 8) | ((unsigned)R.is_pcrel << 7) | 357 ((unsigned)R.length << 5) | ((unsigned)R.is_extern << 4) | 358 ((unsigned)R.type << 0); 359 return MRE; 360 } 361 362 static MachO::any_relocation_info 363 makeScatteredRelocationInfo(const MachOYAML::Relocation &R) { 364 assert(R.is_scattered && "scattered relocation expected"); 365 MachO::any_relocation_info MRE; 366 MRE.r_word0 = (((unsigned)R.address << 0) | ((unsigned)R.type << 24) | 367 ((unsigned)R.length << 28) | ((unsigned)R.is_pcrel << 30) | 368 MachO::R_SCATTERED); 369 MRE.r_word1 = R.value; 370 return MRE; 371 } 372 373 void MachOWriter::writeRelocations(raw_ostream &OS) { 374 for (const MachOYAML::LoadCommand &LC : Obj.LoadCommands) { 375 switch (LC.Data.load_command_data.cmd) { 376 case MachO::LC_SEGMENT: 377 case MachO::LC_SEGMENT_64: 378 for (const MachOYAML::Section &Sec : LC.Sections) { 379 if (Sec.relocations.empty()) 380 continue; 381 ZeroToOffset(OS, Sec.reloff); 382 for (const MachOYAML::Relocation &R : Sec.relocations) { 383 MachO::any_relocation_info MRE = 384 R.is_scattered ? makeScatteredRelocationInfo(R) 385 : makeRelocationInfo(R, Obj.IsLittleEndian); 386 if (Obj.IsLittleEndian != sys::IsLittleEndianHost) 387 MachO::swapStruct(MRE); 388 OS.write(reinterpret_cast<const char *>(&MRE), 389 sizeof(MachO::any_relocation_info)); 390 } 391 } 392 } 393 } 394 } 395 396 void MachOWriter::writeBindOpcodes( 397 raw_ostream &OS, std::vector<MachOYAML::BindOpcode> &BindOpcodes) { 398 399 for (auto Opcode : BindOpcodes) { 400 uint8_t OpByte = Opcode.Opcode | Opcode.Imm; 401 OS.write(reinterpret_cast<char *>(&OpByte), 1); 402 for (auto Data : Opcode.ULEBExtraData) { 403 encodeULEB128(Data, OS); 404 } 405 for (auto Data : Opcode.SLEBExtraData) { 406 encodeSLEB128(Data, OS); 407 } 408 if (!Opcode.Symbol.empty()) { 409 OS.write(Opcode.Symbol.data(), Opcode.Symbol.size()); 410 OS.write('\0'); 411 } 412 } 413 } 414 415 void MachOWriter::dumpExportEntry(raw_ostream &OS, 416 MachOYAML::ExportEntry &Entry) { 417 encodeSLEB128(Entry.TerminalSize, OS); 418 if (Entry.TerminalSize > 0) { 419 encodeSLEB128(Entry.Flags, OS); 420 if (Entry.Flags & MachO::EXPORT_SYMBOL_FLAGS_REEXPORT) { 421 encodeSLEB128(Entry.Other, OS); 422 OS << Entry.ImportName; 423 OS.write('\0'); 424 } else { 425 encodeSLEB128(Entry.Address, OS); 426 if (Entry.Flags & MachO::EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER) 427 encodeSLEB128(Entry.Other, OS); 428 } 429 } 430 OS.write(static_cast<uint8_t>(Entry.Children.size())); 431 for (auto EE : Entry.Children) { 432 OS << EE.Name; 433 OS.write('\0'); 434 encodeSLEB128(EE.NodeOffset, OS); 435 } 436 for (auto EE : Entry.Children) 437 dumpExportEntry(OS, EE); 438 } 439 440 void MachOWriter::writeExportTrie(raw_ostream &OS) { 441 dumpExportEntry(OS, Obj.LinkEdit.ExportTrie); 442 } 443 444 template <typename NListType> 445 void writeNListEntry(MachOYAML::NListEntry &NLE, raw_ostream &OS, 446 bool IsLittleEndian) { 447 NListType ListEntry; 448 ListEntry.n_strx = NLE.n_strx; 449 ListEntry.n_type = NLE.n_type; 450 ListEntry.n_sect = NLE.n_sect; 451 ListEntry.n_desc = NLE.n_desc; 452 ListEntry.n_value = NLE.n_value; 453 454 if (IsLittleEndian != sys::IsLittleEndianHost) 455 MachO::swapStruct(ListEntry); 456 OS.write(reinterpret_cast<const char *>(&ListEntry), sizeof(NListType)); 457 } 458 459 void MachOWriter::writeLinkEditData(raw_ostream &OS) { 460 typedef void (MachOWriter::*writeHandler)(raw_ostream &); 461 typedef std::pair<uint64_t, writeHandler> writeOperation; 462 std::vector<writeOperation> WriteQueue; 463 464 MachO::dyld_info_command *DyldInfoOnlyCmd = 0; 465 MachO::symtab_command *SymtabCmd = 0; 466 for (auto &LC : Obj.LoadCommands) { 467 switch (LC.Data.load_command_data.cmd) { 468 case MachO::LC_SYMTAB: 469 SymtabCmd = &LC.Data.symtab_command_data; 470 WriteQueue.push_back( 471 std::make_pair(SymtabCmd->symoff, &MachOWriter::writeNameList)); 472 WriteQueue.push_back( 473 std::make_pair(SymtabCmd->stroff, &MachOWriter::writeStringTable)); 474 break; 475 case MachO::LC_DYLD_INFO_ONLY: 476 DyldInfoOnlyCmd = &LC.Data.dyld_info_command_data; 477 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->rebase_off, 478 &MachOWriter::writeRebaseOpcodes)); 479 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->bind_off, 480 &MachOWriter::writeBasicBindOpcodes)); 481 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->weak_bind_off, 482 &MachOWriter::writeWeakBindOpcodes)); 483 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->lazy_bind_off, 484 &MachOWriter::writeLazyBindOpcodes)); 485 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->export_off, 486 &MachOWriter::writeExportTrie)); 487 break; 488 } 489 } 490 491 llvm::sort(WriteQueue, [](const writeOperation &a, const writeOperation &b) { 492 return a.first < b.first; 493 }); 494 495 for (auto writeOp : WriteQueue) { 496 ZeroToOffset(OS, writeOp.first); 497 (this->*writeOp.second)(OS); 498 } 499 } 500 501 void MachOWriter::writeRebaseOpcodes(raw_ostream &OS) { 502 MachOYAML::LinkEditData &LinkEdit = Obj.LinkEdit; 503 504 for (auto Opcode : LinkEdit.RebaseOpcodes) { 505 uint8_t OpByte = Opcode.Opcode | Opcode.Imm; 506 OS.write(reinterpret_cast<char *>(&OpByte), 1); 507 for (auto Data : Opcode.ExtraData) 508 encodeULEB128(Data, OS); 509 } 510 } 511 512 void MachOWriter::writeBasicBindOpcodes(raw_ostream &OS) { 513 writeBindOpcodes(OS, Obj.LinkEdit.BindOpcodes); 514 } 515 516 void MachOWriter::writeWeakBindOpcodes(raw_ostream &OS) { 517 writeBindOpcodes(OS, Obj.LinkEdit.WeakBindOpcodes); 518 } 519 520 void MachOWriter::writeLazyBindOpcodes(raw_ostream &OS) { 521 writeBindOpcodes(OS, Obj.LinkEdit.LazyBindOpcodes); 522 } 523 524 void MachOWriter::writeNameList(raw_ostream &OS) { 525 for (auto NLE : Obj.LinkEdit.NameList) { 526 if (is64Bit) 527 writeNListEntry<MachO::nlist_64>(NLE, OS, Obj.IsLittleEndian); 528 else 529 writeNListEntry<MachO::nlist>(NLE, OS, Obj.IsLittleEndian); 530 } 531 } 532 533 void MachOWriter::writeStringTable(raw_ostream &OS) { 534 for (auto Str : Obj.LinkEdit.StringTable) { 535 OS.write(Str.data(), Str.size()); 536 OS.write('\0'); 537 } 538 } 539 540 class UniversalWriter { 541 public: 542 UniversalWriter(yaml::YamlObjectFile &ObjectFile) 543 : ObjectFile(ObjectFile), fileStart(0) {} 544 545 Error writeMachO(raw_ostream &OS); 546 547 private: 548 void writeFatHeader(raw_ostream &OS); 549 void writeFatArchs(raw_ostream &OS); 550 551 void ZeroToOffset(raw_ostream &OS, size_t offset); 552 553 yaml::YamlObjectFile &ObjectFile; 554 uint64_t fileStart; 555 }; 556 557 Error UniversalWriter::writeMachO(raw_ostream &OS) { 558 fileStart = OS.tell(); 559 if (ObjectFile.MachO) { 560 MachOWriter Writer(*ObjectFile.MachO); 561 return Writer.writeMachO(OS); 562 } 563 564 writeFatHeader(OS); 565 writeFatArchs(OS); 566 567 auto &FatFile = *ObjectFile.FatMachO; 568 if (FatFile.FatArchs.size() < FatFile.Slices.size()) 569 return createStringError( 570 errc::invalid_argument, 571 "cannot write 'Slices' if not described in 'FatArches'"); 572 573 for (size_t i = 0; i < FatFile.Slices.size(); i++) { 574 ZeroToOffset(OS, FatFile.FatArchs[i].offset); 575 MachOWriter Writer(FatFile.Slices[i]); 576 if (Error Err = Writer.writeMachO(OS)) 577 return Err; 578 579 auto SliceEnd = FatFile.FatArchs[i].offset + FatFile.FatArchs[i].size; 580 ZeroToOffset(OS, SliceEnd); 581 } 582 583 return Error::success(); 584 } 585 586 void UniversalWriter::writeFatHeader(raw_ostream &OS) { 587 auto &FatFile = *ObjectFile.FatMachO; 588 MachO::fat_header header; 589 header.magic = FatFile.Header.magic; 590 header.nfat_arch = FatFile.Header.nfat_arch; 591 if (sys::IsLittleEndianHost) 592 swapStruct(header); 593 OS.write(reinterpret_cast<const char *>(&header), sizeof(MachO::fat_header)); 594 } 595 596 template <typename FatArchType> 597 FatArchType constructFatArch(MachOYAML::FatArch &Arch) { 598 FatArchType FatArch; 599 FatArch.cputype = Arch.cputype; 600 FatArch.cpusubtype = Arch.cpusubtype; 601 FatArch.offset = Arch.offset; 602 FatArch.size = Arch.size; 603 FatArch.align = Arch.align; 604 return FatArch; 605 } 606 607 template <typename StructType> 608 void writeFatArch(MachOYAML::FatArch &LC, raw_ostream &OS) {} 609 610 template <> 611 void writeFatArch<MachO::fat_arch>(MachOYAML::FatArch &Arch, raw_ostream &OS) { 612 auto FatArch = constructFatArch<MachO::fat_arch>(Arch); 613 if (sys::IsLittleEndianHost) 614 swapStruct(FatArch); 615 OS.write(reinterpret_cast<const char *>(&FatArch), sizeof(MachO::fat_arch)); 616 } 617 618 template <> 619 void writeFatArch<MachO::fat_arch_64>(MachOYAML::FatArch &Arch, 620 raw_ostream &OS) { 621 auto FatArch = constructFatArch<MachO::fat_arch_64>(Arch); 622 FatArch.reserved = Arch.reserved; 623 if (sys::IsLittleEndianHost) 624 swapStruct(FatArch); 625 OS.write(reinterpret_cast<const char *>(&FatArch), 626 sizeof(MachO::fat_arch_64)); 627 } 628 629 void UniversalWriter::writeFatArchs(raw_ostream &OS) { 630 auto &FatFile = *ObjectFile.FatMachO; 631 bool is64Bit = FatFile.Header.magic == MachO::FAT_MAGIC_64; 632 for (auto Arch : FatFile.FatArchs) { 633 if (is64Bit) 634 writeFatArch<MachO::fat_arch_64>(Arch, OS); 635 else 636 writeFatArch<MachO::fat_arch>(Arch, OS); 637 } 638 } 639 640 void UniversalWriter::ZeroToOffset(raw_ostream &OS, size_t Offset) { 641 auto currOffset = OS.tell() - fileStart; 642 if (currOffset < Offset) 643 ZeroFillBytes(OS, Offset - currOffset); 644 } 645 646 } // end anonymous namespace 647 648 namespace llvm { 649 namespace yaml { 650 651 bool yaml2macho(YamlObjectFile &Doc, raw_ostream &Out, ErrorHandler EH) { 652 UniversalWriter Writer(Doc); 653 if (Error Err = Writer.writeMachO(Out)) { 654 handleAllErrors(std::move(Err), 655 [&](const ErrorInfoBase &Err) { EH(Err.message()); }); 656 return false; 657 } 658 return true; 659 } 660 661 } // namespace yaml 662 } // namespace llvm 663