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), 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 void writeDynamicSymbolTable(raw_ostream &OS); 58 59 void dumpExportEntry(raw_ostream &OS, MachOYAML::ExportEntry &Entry); 60 void ZeroToOffset(raw_ostream &OS, size_t offset); 61 62 MachOYAML::Object &Obj; 63 bool is64Bit; 64 uint64_t fileStart; 65 MachO::mach_header_64 Header; 66 67 // Old PPC Object Files didn't have __LINKEDIT segments, the data was just 68 // stuck at the end of the file. 69 bool FoundLinkEditSeg = false; 70 }; 71 72 Error MachOWriter::writeMachO(raw_ostream &OS) { 73 fileStart = OS.tell(); 74 writeHeader(OS); 75 writeLoadCommands(OS); 76 if (Error Err = writeSectionData(OS)) 77 return Err; 78 writeRelocations(OS); 79 if (!FoundLinkEditSeg) 80 writeLinkEditData(OS); 81 return Error::success(); 82 } 83 84 void MachOWriter::writeHeader(raw_ostream &OS) { 85 Header.magic = Obj.Header.magic; 86 Header.cputype = Obj.Header.cputype; 87 Header.cpusubtype = Obj.Header.cpusubtype; 88 Header.filetype = Obj.Header.filetype; 89 Header.ncmds = Obj.Header.ncmds; 90 Header.sizeofcmds = Obj.Header.sizeofcmds; 91 Header.flags = Obj.Header.flags; 92 Header.reserved = Obj.Header.reserved; 93 94 if (Obj.IsLittleEndian != sys::IsLittleEndianHost) 95 MachO::swapStruct(Header); 96 97 auto header_size = 98 is64Bit ? sizeof(MachO::mach_header_64) : sizeof(MachO::mach_header); 99 OS.write((const char *)&Header, header_size); 100 } 101 102 template <typename SectionType> 103 SectionType constructSection(MachOYAML::Section Sec) { 104 SectionType TempSec; 105 memcpy(reinterpret_cast<void *>(&TempSec.sectname[0]), &Sec.sectname[0], 16); 106 memcpy(reinterpret_cast<void *>(&TempSec.segname[0]), &Sec.segname[0], 16); 107 TempSec.addr = Sec.addr; 108 TempSec.size = Sec.size; 109 TempSec.offset = Sec.offset; 110 TempSec.align = Sec.align; 111 TempSec.reloff = Sec.reloff; 112 TempSec.nreloc = Sec.nreloc; 113 TempSec.flags = Sec.flags; 114 TempSec.reserved1 = Sec.reserved1; 115 TempSec.reserved2 = Sec.reserved2; 116 return TempSec; 117 } 118 119 template <typename StructType> 120 size_t writeLoadCommandData(MachOYAML::LoadCommand &LC, raw_ostream &OS, 121 bool IsLittleEndian) { 122 return 0; 123 } 124 125 template <> 126 size_t writeLoadCommandData<MachO::segment_command>(MachOYAML::LoadCommand &LC, 127 raw_ostream &OS, 128 bool IsLittleEndian) { 129 size_t BytesWritten = 0; 130 for (const auto &Sec : LC.Sections) { 131 auto TempSec = constructSection<MachO::section>(Sec); 132 if (IsLittleEndian != sys::IsLittleEndianHost) 133 MachO::swapStruct(TempSec); 134 OS.write(reinterpret_cast<const char *>(&(TempSec)), 135 sizeof(MachO::section)); 136 BytesWritten += sizeof(MachO::section); 137 } 138 return BytesWritten; 139 } 140 141 template <> 142 size_t writeLoadCommandData<MachO::segment_command_64>( 143 MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) { 144 size_t BytesWritten = 0; 145 for (const auto &Sec : LC.Sections) { 146 auto TempSec = constructSection<MachO::section_64>(Sec); 147 TempSec.reserved3 = Sec.reserved3; 148 if (IsLittleEndian != sys::IsLittleEndianHost) 149 MachO::swapStruct(TempSec); 150 OS.write(reinterpret_cast<const char *>(&(TempSec)), 151 sizeof(MachO::section_64)); 152 BytesWritten += sizeof(MachO::section_64); 153 } 154 return BytesWritten; 155 } 156 157 size_t writePayloadString(MachOYAML::LoadCommand &LC, raw_ostream &OS) { 158 size_t BytesWritten = 0; 159 if (!LC.Content.empty()) { 160 OS.write(LC.Content.c_str(), LC.Content.length()); 161 BytesWritten = LC.Content.length(); 162 } 163 return BytesWritten; 164 } 165 166 template <> 167 size_t writeLoadCommandData<MachO::dylib_command>(MachOYAML::LoadCommand &LC, 168 raw_ostream &OS, 169 bool IsLittleEndian) { 170 return writePayloadString(LC, OS); 171 } 172 173 template <> 174 size_t writeLoadCommandData<MachO::dylinker_command>(MachOYAML::LoadCommand &LC, 175 raw_ostream &OS, 176 bool IsLittleEndian) { 177 return writePayloadString(LC, OS); 178 } 179 180 template <> 181 size_t writeLoadCommandData<MachO::rpath_command>(MachOYAML::LoadCommand &LC, 182 raw_ostream &OS, 183 bool IsLittleEndian) { 184 return writePayloadString(LC, OS); 185 } 186 187 template <> 188 size_t writeLoadCommandData<MachO::sub_framework_command>( 189 MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) { 190 return writePayloadString(LC, OS); 191 } 192 193 template <> 194 size_t writeLoadCommandData<MachO::sub_umbrella_command>( 195 MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) { 196 return writePayloadString(LC, OS); 197 } 198 199 template <> 200 size_t writeLoadCommandData<MachO::sub_client_command>( 201 MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) { 202 return writePayloadString(LC, OS); 203 } 204 205 template <> 206 size_t writeLoadCommandData<MachO::sub_library_command>( 207 MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) { 208 return writePayloadString(LC, OS); 209 } 210 211 template <> 212 size_t writeLoadCommandData<MachO::build_version_command>( 213 MachOYAML::LoadCommand &LC, raw_ostream &OS, bool IsLittleEndian) { 214 size_t BytesWritten = 0; 215 for (const auto &T : LC.Tools) { 216 struct MachO::build_tool_version tool = T; 217 if (IsLittleEndian != sys::IsLittleEndianHost) 218 MachO::swapStruct(tool); 219 OS.write(reinterpret_cast<const char *>(&tool), 220 sizeof(MachO::build_tool_version)); 221 BytesWritten += sizeof(MachO::build_tool_version); 222 } 223 return BytesWritten; 224 } 225 226 void ZeroFillBytes(raw_ostream &OS, size_t Size) { 227 std::vector<uint8_t> FillData(Size, 0); 228 OS.write(reinterpret_cast<char *>(FillData.data()), Size); 229 } 230 231 void Fill(raw_ostream &OS, size_t Size, uint32_t Data) { 232 std::vector<uint32_t> FillData((Size / 4) + 1, Data); 233 OS.write(reinterpret_cast<char *>(FillData.data()), Size); 234 } 235 236 void MachOWriter::ZeroToOffset(raw_ostream &OS, size_t Offset) { 237 auto currOffset = OS.tell() - fileStart; 238 if (currOffset < Offset) 239 ZeroFillBytes(OS, Offset - currOffset); 240 } 241 242 void MachOWriter::writeLoadCommands(raw_ostream &OS) { 243 for (auto &LC : Obj.LoadCommands) { 244 size_t BytesWritten = 0; 245 llvm::MachO::macho_load_command Data = LC.Data; 246 247 #define HANDLE_LOAD_COMMAND(LCName, LCValue, LCStruct) \ 248 case MachO::LCName: \ 249 if (Obj.IsLittleEndian != sys::IsLittleEndianHost) \ 250 MachO::swapStruct(Data.LCStruct##_data); \ 251 OS.write(reinterpret_cast<const char *>(&(Data.LCStruct##_data)), \ 252 sizeof(MachO::LCStruct)); \ 253 BytesWritten = sizeof(MachO::LCStruct); \ 254 BytesWritten += \ 255 writeLoadCommandData<MachO::LCStruct>(LC, OS, Obj.IsLittleEndian); \ 256 break; 257 258 switch (LC.Data.load_command_data.cmd) { 259 default: 260 if (Obj.IsLittleEndian != sys::IsLittleEndianHost) 261 MachO::swapStruct(Data.load_command_data); 262 OS.write(reinterpret_cast<const char *>(&(Data.load_command_data)), 263 sizeof(MachO::load_command)); 264 BytesWritten = sizeof(MachO::load_command); 265 BytesWritten += 266 writeLoadCommandData<MachO::load_command>(LC, OS, Obj.IsLittleEndian); 267 break; 268 #include "llvm/BinaryFormat/MachO.def" 269 } 270 271 if (LC.PayloadBytes.size() > 0) { 272 OS.write(reinterpret_cast<const char *>(LC.PayloadBytes.data()), 273 LC.PayloadBytes.size()); 274 BytesWritten += LC.PayloadBytes.size(); 275 } 276 277 if (LC.ZeroPadBytes > 0) { 278 ZeroFillBytes(OS, LC.ZeroPadBytes); 279 BytesWritten += LC.ZeroPadBytes; 280 } 281 282 // Fill remaining bytes with 0. This will only get hit in partially 283 // specified test cases. 284 auto BytesRemaining = LC.Data.load_command_data.cmdsize - BytesWritten; 285 if (BytesRemaining > 0) { 286 ZeroFillBytes(OS, BytesRemaining); 287 } 288 } 289 } 290 291 Error MachOWriter::writeSectionData(raw_ostream &OS) { 292 uint64_t LinkEditOff = 0; 293 for (auto &LC : Obj.LoadCommands) { 294 switch (LC.Data.load_command_data.cmd) { 295 case MachO::LC_SEGMENT: 296 case MachO::LC_SEGMENT_64: 297 uint64_t segOff = is64Bit ? LC.Data.segment_command_64_data.fileoff 298 : LC.Data.segment_command_data.fileoff; 299 if (0 == 300 strncmp(&LC.Data.segment_command_data.segname[0], "__LINKEDIT", 16)) { 301 FoundLinkEditSeg = true; 302 LinkEditOff = segOff; 303 if (Obj.RawLinkEditSegment) 304 continue; 305 writeLinkEditData(OS); 306 } 307 for (auto &Sec : LC.Sections) { 308 ZeroToOffset(OS, Sec.offset); 309 // Zero Fill any data between the end of the last thing we wrote and the 310 // start of this section. 311 if (OS.tell() - fileStart > Sec.offset && Sec.offset != (uint32_t)0) 312 return createStringError( 313 errc::invalid_argument, 314 "wrote too much data somewhere, section offsets don't line up"); 315 316 StringRef SectName(Sec.sectname, 317 strnlen(Sec.sectname, sizeof(Sec.sectname))); 318 // If the section's content is specified in the 'DWARF' entry, we will 319 // emit it regardless of the section's segname. 320 if (Obj.DWARF.getNonEmptySectionNames().count(SectName.substr(2))) { 321 if (Sec.content) 322 return createStringError(errc::invalid_argument, 323 "cannot specify section '" + SectName + 324 "' contents in the 'DWARF' entry and " 325 "the 'content' at the same time"); 326 auto EmitFunc = DWARFYAML::getDWARFEmitterByName(SectName.substr(2)); 327 if (Error Err = EmitFunc(OS, Obj.DWARF)) 328 return Err; 329 continue; 330 } 331 332 // Skip if it's a virtual section. 333 if (MachO::isVirtualSection(Sec.flags & MachO::SECTION_TYPE)) 334 continue; 335 336 if (Sec.content) { 337 yaml::BinaryRef Content = *Sec.content; 338 Content.writeAsBinary(OS); 339 ZeroFillBytes(OS, Sec.size - Content.binary_size()); 340 } else { 341 // Fill section data with 0xDEADBEEF. 342 Fill(OS, Sec.size, 0xDEADBEEFu); 343 } 344 } 345 uint64_t segSize = is64Bit ? LC.Data.segment_command_64_data.filesize 346 : LC.Data.segment_command_data.filesize; 347 ZeroToOffset(OS, segOff + segSize); 348 break; 349 } 350 } 351 352 if (Obj.RawLinkEditSegment) { 353 ZeroToOffset(OS, LinkEditOff); 354 if (OS.tell() - fileStart > LinkEditOff || !LinkEditOff) 355 return createStringError(errc::invalid_argument, 356 "section offsets don't line up"); 357 Obj.RawLinkEditSegment->writeAsBinary(OS); 358 } 359 return Error::success(); 360 } 361 362 // The implementation of makeRelocationInfo and makeScatteredRelocationInfo is 363 // consistent with how libObject parses MachO binary files. For the reference 364 // see getStruct, getRelocation, getPlainRelocationPCRel, 365 // getPlainRelocationLength and related methods in MachOObjectFile.cpp 366 static MachO::any_relocation_info 367 makeRelocationInfo(const MachOYAML::Relocation &R, bool IsLE) { 368 assert(!R.is_scattered && "non-scattered relocation expected"); 369 MachO::any_relocation_info MRE; 370 MRE.r_word0 = R.address; 371 if (IsLE) 372 MRE.r_word1 = ((unsigned)R.symbolnum << 0) | ((unsigned)R.is_pcrel << 24) | 373 ((unsigned)R.length << 25) | ((unsigned)R.is_extern << 27) | 374 ((unsigned)R.type << 28); 375 else 376 MRE.r_word1 = ((unsigned)R.symbolnum << 8) | ((unsigned)R.is_pcrel << 7) | 377 ((unsigned)R.length << 5) | ((unsigned)R.is_extern << 4) | 378 ((unsigned)R.type << 0); 379 return MRE; 380 } 381 382 static MachO::any_relocation_info 383 makeScatteredRelocationInfo(const MachOYAML::Relocation &R) { 384 assert(R.is_scattered && "scattered relocation expected"); 385 MachO::any_relocation_info MRE; 386 MRE.r_word0 = (((unsigned)R.address << 0) | ((unsigned)R.type << 24) | 387 ((unsigned)R.length << 28) | ((unsigned)R.is_pcrel << 30) | 388 MachO::R_SCATTERED); 389 MRE.r_word1 = R.value; 390 return MRE; 391 } 392 393 void MachOWriter::writeRelocations(raw_ostream &OS) { 394 for (const MachOYAML::LoadCommand &LC : Obj.LoadCommands) { 395 switch (LC.Data.load_command_data.cmd) { 396 case MachO::LC_SEGMENT: 397 case MachO::LC_SEGMENT_64: 398 for (const MachOYAML::Section &Sec : LC.Sections) { 399 if (Sec.relocations.empty()) 400 continue; 401 ZeroToOffset(OS, Sec.reloff); 402 for (const MachOYAML::Relocation &R : Sec.relocations) { 403 MachO::any_relocation_info MRE = 404 R.is_scattered ? makeScatteredRelocationInfo(R) 405 : makeRelocationInfo(R, Obj.IsLittleEndian); 406 if (Obj.IsLittleEndian != sys::IsLittleEndianHost) 407 MachO::swapStruct(MRE); 408 OS.write(reinterpret_cast<const char *>(&MRE), 409 sizeof(MachO::any_relocation_info)); 410 } 411 } 412 } 413 } 414 } 415 416 void MachOWriter::writeBindOpcodes( 417 raw_ostream &OS, std::vector<MachOYAML::BindOpcode> &BindOpcodes) { 418 419 for (auto Opcode : BindOpcodes) { 420 uint8_t OpByte = Opcode.Opcode | Opcode.Imm; 421 OS.write(reinterpret_cast<char *>(&OpByte), 1); 422 for (auto Data : Opcode.ULEBExtraData) { 423 encodeULEB128(Data, OS); 424 } 425 for (auto Data : Opcode.SLEBExtraData) { 426 encodeSLEB128(Data, OS); 427 } 428 if (!Opcode.Symbol.empty()) { 429 OS.write(Opcode.Symbol.data(), Opcode.Symbol.size()); 430 OS.write('\0'); 431 } 432 } 433 } 434 435 void MachOWriter::dumpExportEntry(raw_ostream &OS, 436 MachOYAML::ExportEntry &Entry) { 437 encodeSLEB128(Entry.TerminalSize, OS); 438 if (Entry.TerminalSize > 0) { 439 encodeSLEB128(Entry.Flags, OS); 440 if (Entry.Flags & MachO::EXPORT_SYMBOL_FLAGS_REEXPORT) { 441 encodeSLEB128(Entry.Other, OS); 442 OS << Entry.ImportName; 443 OS.write('\0'); 444 } else { 445 encodeSLEB128(Entry.Address, OS); 446 if (Entry.Flags & MachO::EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER) 447 encodeSLEB128(Entry.Other, OS); 448 } 449 } 450 OS.write(static_cast<uint8_t>(Entry.Children.size())); 451 for (auto EE : Entry.Children) { 452 OS << EE.Name; 453 OS.write('\0'); 454 encodeSLEB128(EE.NodeOffset, OS); 455 } 456 for (auto EE : Entry.Children) 457 dumpExportEntry(OS, EE); 458 } 459 460 void MachOWriter::writeExportTrie(raw_ostream &OS) { 461 dumpExportEntry(OS, Obj.LinkEdit.ExportTrie); 462 } 463 464 template <typename NListType> 465 void writeNListEntry(MachOYAML::NListEntry &NLE, raw_ostream &OS, 466 bool IsLittleEndian) { 467 NListType ListEntry; 468 ListEntry.n_strx = NLE.n_strx; 469 ListEntry.n_type = NLE.n_type; 470 ListEntry.n_sect = NLE.n_sect; 471 ListEntry.n_desc = NLE.n_desc; 472 ListEntry.n_value = NLE.n_value; 473 474 if (IsLittleEndian != sys::IsLittleEndianHost) 475 MachO::swapStruct(ListEntry); 476 OS.write(reinterpret_cast<const char *>(&ListEntry), sizeof(NListType)); 477 } 478 479 void MachOWriter::writeLinkEditData(raw_ostream &OS) { 480 typedef void (MachOWriter::*writeHandler)(raw_ostream &); 481 typedef std::pair<uint64_t, writeHandler> writeOperation; 482 std::vector<writeOperation> WriteQueue; 483 484 MachO::dyld_info_command *DyldInfoOnlyCmd = 0; 485 MachO::symtab_command *SymtabCmd = 0; 486 MachO::dysymtab_command *DSymtabCmd = 0; 487 for (auto &LC : Obj.LoadCommands) { 488 switch (LC.Data.load_command_data.cmd) { 489 case MachO::LC_SYMTAB: 490 SymtabCmd = &LC.Data.symtab_command_data; 491 WriteQueue.push_back( 492 std::make_pair(SymtabCmd->symoff, &MachOWriter::writeNameList)); 493 WriteQueue.push_back( 494 std::make_pair(SymtabCmd->stroff, &MachOWriter::writeStringTable)); 495 break; 496 case MachO::LC_DYLD_INFO_ONLY: 497 DyldInfoOnlyCmd = &LC.Data.dyld_info_command_data; 498 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->rebase_off, 499 &MachOWriter::writeRebaseOpcodes)); 500 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->bind_off, 501 &MachOWriter::writeBasicBindOpcodes)); 502 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->weak_bind_off, 503 &MachOWriter::writeWeakBindOpcodes)); 504 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->lazy_bind_off, 505 &MachOWriter::writeLazyBindOpcodes)); 506 WriteQueue.push_back(std::make_pair(DyldInfoOnlyCmd->export_off, 507 &MachOWriter::writeExportTrie)); 508 break; 509 case MachO::LC_DYSYMTAB: 510 DSymtabCmd = &LC.Data.dysymtab_command_data; 511 WriteQueue.push_back(std::make_pair( 512 DSymtabCmd->indirectsymoff, &MachOWriter::writeDynamicSymbolTable)); 513 break; 514 } 515 } 516 517 llvm::sort(WriteQueue, [](const writeOperation &a, const writeOperation &b) { 518 return a.first < b.first; 519 }); 520 521 for (auto writeOp : WriteQueue) { 522 ZeroToOffset(OS, writeOp.first); 523 (this->*writeOp.second)(OS); 524 } 525 } 526 527 void MachOWriter::writeRebaseOpcodes(raw_ostream &OS) { 528 MachOYAML::LinkEditData &LinkEdit = Obj.LinkEdit; 529 530 for (auto Opcode : LinkEdit.RebaseOpcodes) { 531 uint8_t OpByte = Opcode.Opcode | Opcode.Imm; 532 OS.write(reinterpret_cast<char *>(&OpByte), 1); 533 for (auto Data : Opcode.ExtraData) 534 encodeULEB128(Data, OS); 535 } 536 } 537 538 void MachOWriter::writeBasicBindOpcodes(raw_ostream &OS) { 539 writeBindOpcodes(OS, Obj.LinkEdit.BindOpcodes); 540 } 541 542 void MachOWriter::writeWeakBindOpcodes(raw_ostream &OS) { 543 writeBindOpcodes(OS, Obj.LinkEdit.WeakBindOpcodes); 544 } 545 546 void MachOWriter::writeLazyBindOpcodes(raw_ostream &OS) { 547 writeBindOpcodes(OS, Obj.LinkEdit.LazyBindOpcodes); 548 } 549 550 void MachOWriter::writeNameList(raw_ostream &OS) { 551 for (auto NLE : Obj.LinkEdit.NameList) { 552 if (is64Bit) 553 writeNListEntry<MachO::nlist_64>(NLE, OS, Obj.IsLittleEndian); 554 else 555 writeNListEntry<MachO::nlist>(NLE, OS, Obj.IsLittleEndian); 556 } 557 } 558 559 void MachOWriter::writeStringTable(raw_ostream &OS) { 560 for (auto Str : Obj.LinkEdit.StringTable) { 561 OS.write(Str.data(), Str.size()); 562 OS.write('\0'); 563 } 564 } 565 566 void MachOWriter::writeDynamicSymbolTable(raw_ostream &OS) { 567 for (auto Data : Obj.LinkEdit.IndirectSymbols) 568 OS.write(reinterpret_cast<const char *>(&Data), 569 sizeof(yaml::Hex32::BaseType)); 570 } 571 572 class UniversalWriter { 573 public: 574 UniversalWriter(yaml::YamlObjectFile &ObjectFile) 575 : ObjectFile(ObjectFile), fileStart(0) {} 576 577 Error writeMachO(raw_ostream &OS); 578 579 private: 580 void writeFatHeader(raw_ostream &OS); 581 void writeFatArchs(raw_ostream &OS); 582 583 void ZeroToOffset(raw_ostream &OS, size_t offset); 584 585 yaml::YamlObjectFile &ObjectFile; 586 uint64_t fileStart; 587 }; 588 589 Error UniversalWriter::writeMachO(raw_ostream &OS) { 590 fileStart = OS.tell(); 591 if (ObjectFile.MachO) { 592 MachOWriter Writer(*ObjectFile.MachO); 593 return Writer.writeMachO(OS); 594 } 595 596 writeFatHeader(OS); 597 writeFatArchs(OS); 598 599 auto &FatFile = *ObjectFile.FatMachO; 600 if (FatFile.FatArchs.size() < FatFile.Slices.size()) 601 return createStringError( 602 errc::invalid_argument, 603 "cannot write 'Slices' if not described in 'FatArches'"); 604 605 for (size_t i = 0; i < FatFile.Slices.size(); i++) { 606 ZeroToOffset(OS, FatFile.FatArchs[i].offset); 607 MachOWriter Writer(FatFile.Slices[i]); 608 if (Error Err = Writer.writeMachO(OS)) 609 return Err; 610 611 auto SliceEnd = FatFile.FatArchs[i].offset + FatFile.FatArchs[i].size; 612 ZeroToOffset(OS, SliceEnd); 613 } 614 615 return Error::success(); 616 } 617 618 void UniversalWriter::writeFatHeader(raw_ostream &OS) { 619 auto &FatFile = *ObjectFile.FatMachO; 620 MachO::fat_header header; 621 header.magic = FatFile.Header.magic; 622 header.nfat_arch = FatFile.Header.nfat_arch; 623 if (sys::IsLittleEndianHost) 624 swapStruct(header); 625 OS.write(reinterpret_cast<const char *>(&header), sizeof(MachO::fat_header)); 626 } 627 628 template <typename FatArchType> 629 FatArchType constructFatArch(MachOYAML::FatArch &Arch) { 630 FatArchType FatArch; 631 FatArch.cputype = Arch.cputype; 632 FatArch.cpusubtype = Arch.cpusubtype; 633 FatArch.offset = Arch.offset; 634 FatArch.size = Arch.size; 635 FatArch.align = Arch.align; 636 return FatArch; 637 } 638 639 template <typename StructType> 640 void writeFatArch(MachOYAML::FatArch &LC, raw_ostream &OS) {} 641 642 template <> 643 void writeFatArch<MachO::fat_arch>(MachOYAML::FatArch &Arch, raw_ostream &OS) { 644 auto FatArch = constructFatArch<MachO::fat_arch>(Arch); 645 if (sys::IsLittleEndianHost) 646 swapStruct(FatArch); 647 OS.write(reinterpret_cast<const char *>(&FatArch), sizeof(MachO::fat_arch)); 648 } 649 650 template <> 651 void writeFatArch<MachO::fat_arch_64>(MachOYAML::FatArch &Arch, 652 raw_ostream &OS) { 653 auto FatArch = constructFatArch<MachO::fat_arch_64>(Arch); 654 FatArch.reserved = Arch.reserved; 655 if (sys::IsLittleEndianHost) 656 swapStruct(FatArch); 657 OS.write(reinterpret_cast<const char *>(&FatArch), 658 sizeof(MachO::fat_arch_64)); 659 } 660 661 void UniversalWriter::writeFatArchs(raw_ostream &OS) { 662 auto &FatFile = *ObjectFile.FatMachO; 663 bool is64Bit = FatFile.Header.magic == MachO::FAT_MAGIC_64; 664 for (auto Arch : FatFile.FatArchs) { 665 if (is64Bit) 666 writeFatArch<MachO::fat_arch_64>(Arch, OS); 667 else 668 writeFatArch<MachO::fat_arch>(Arch, OS); 669 } 670 } 671 672 void UniversalWriter::ZeroToOffset(raw_ostream &OS, size_t Offset) { 673 auto currOffset = OS.tell() - fileStart; 674 if (currOffset < Offset) 675 ZeroFillBytes(OS, Offset - currOffset); 676 } 677 678 } // end anonymous namespace 679 680 namespace llvm { 681 namespace yaml { 682 683 bool yaml2macho(YamlObjectFile &Doc, raw_ostream &Out, ErrorHandler EH) { 684 UniversalWriter Writer(Doc); 685 if (Error Err = Writer.writeMachO(Out)) { 686 handleAllErrors(std::move(Err), 687 [&](const ErrorInfoBase &Err) { EH(Err.message()); }); 688 return false; 689 } 690 return true; 691 } 692 693 } // namespace yaml 694 } // namespace llvm 695