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1//===------ macho2yaml.cpp - obj2yaml conversion tool -----------*- C++ -*-===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "obj2yaml.h"10#include "llvm/DebugInfo/DWARF/DWARFContext.h"11#include "llvm/Object/MachOUniversal.h"12#include "llvm/ObjectYAML/DWARFYAML.h"13#include "llvm/ObjectYAML/ObjectYAML.h"14#include "llvm/Support/Errc.h"15#include "llvm/Support/Error.h"16#include "llvm/Support/ErrorHandling.h"17#include "llvm/Support/LEB128.h"18 19#include <string.h> // for memcpy20 21using namespace llvm;22 23class MachODumper {24 25  template <typename StructType>26  Expected<const char *> processLoadCommandData(27      MachOYAML::LoadCommand &LC,28      const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,29      MachOYAML::Object &Y);30 31  const object::MachOObjectFile &Obj;32  std::unique_ptr<DWARFContext> DWARFCtx;33  unsigned RawSegment;34  void dumpHeader(std::unique_ptr<MachOYAML::Object> &Y);35  Error dumpLoadCommands(std::unique_ptr<MachOYAML::Object> &Y);36  void dumpLinkEdit(std::unique_ptr<MachOYAML::Object> &Y);37  void dumpRebaseOpcodes(std::unique_ptr<MachOYAML::Object> &Y);38  void dumpFunctionStarts(std::unique_ptr<MachOYAML::Object> &Y);39  void dumpBindOpcodes(std::vector<MachOYAML::BindOpcode> &BindOpcodes,40                       ArrayRef<uint8_t> OpcodeBuffer, bool Lazy = false);41  void dumpExportTrie(std::unique_ptr<MachOYAML::Object> &Y);42  void dumpSymbols(std::unique_ptr<MachOYAML::Object> &Y);43  void dumpIndirectSymbols(std::unique_ptr<MachOYAML::Object> &Y);44  void dumpChainedFixups(std::unique_ptr<MachOYAML::Object> &Y);45  void dumpDataInCode(std::unique_ptr<MachOYAML::Object> &Y);46 47  template <typename SectionType>48  Expected<MachOYAML::Section> constructSectionCommon(SectionType Sec,49                                                      size_t SecIndex);50  template <typename SectionType>51  Expected<MachOYAML::Section> constructSection(SectionType Sec,52                                                size_t SecIndex);53  template <typename SectionType, typename SegmentType>54  Expected<const char *>55  extractSections(const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,56                  std::vector<MachOYAML::Section> &Sections,57                  MachOYAML::Object &Y);58 59public:60  MachODumper(const object::MachOObjectFile &O,61              std::unique_ptr<DWARFContext> DCtx, unsigned RawSegments)62      : Obj(O), DWARFCtx(std::move(DCtx)), RawSegment(RawSegments) {}63  Expected<std::unique_ptr<MachOYAML::Object>> dump();64};65 66#define HANDLE_LOAD_COMMAND(LCName, LCValue, LCStruct)                         \67  case MachO::LCName:                                                          \68    memcpy((void *)&(LC.Data.LCStruct##_data), LoadCmd.Ptr,                    \69           sizeof(MachO::LCStruct));                                           \70    if (Obj.isLittleEndian() != sys::IsLittleEndianHost)                       \71      MachO::swapStruct(LC.Data.LCStruct##_data);                              \72    if (Expected<const char *> ExpectedEndPtr =                                \73            processLoadCommandData<MachO::LCStruct>(LC, LoadCmd, *Y.get()))    \74      EndPtr = *ExpectedEndPtr;                                                \75    else                                                                       \76      return ExpectedEndPtr.takeError();                                       \77    break;78 79template <typename SectionType>80Expected<MachOYAML::Section>81MachODumper::constructSectionCommon(SectionType Sec, size_t SecIndex) {82  MachOYAML::Section TempSec;83  memcpy(reinterpret_cast<void *>(&TempSec.sectname[0]), &Sec.sectname[0], 16);84  memcpy(reinterpret_cast<void *>(&TempSec.segname[0]), &Sec.segname[0], 16);85  TempSec.addr = Sec.addr;86  TempSec.size = Sec.size;87  TempSec.offset = Sec.offset;88  TempSec.align = Sec.align;89  TempSec.reloff = Sec.reloff;90  TempSec.nreloc = Sec.nreloc;91  TempSec.flags = Sec.flags;92  TempSec.reserved1 = Sec.reserved1;93  TempSec.reserved2 = Sec.reserved2;94  TempSec.reserved3 = 0;95  if (!MachO::isVirtualSection(Sec.flags & MachO::SECTION_TYPE))96    TempSec.content =97        yaml::BinaryRef(Obj.getSectionContents(Sec.offset, Sec.size));98 99  if (Expected<object::SectionRef> SecRef = Obj.getSection(SecIndex)) {100    TempSec.relocations.reserve(TempSec.nreloc);101    for (const object::RelocationRef &Reloc : SecRef->relocations()) {102      const object::DataRefImpl Rel = Reloc.getRawDataRefImpl();103      const MachO::any_relocation_info RE = Obj.getRelocation(Rel);104      MachOYAML::Relocation R;105      R.address = Obj.getAnyRelocationAddress(RE);106      R.is_pcrel = Obj.getAnyRelocationPCRel(RE);107      R.length = Obj.getAnyRelocationLength(RE);108      R.type = Obj.getAnyRelocationType(RE);109      R.is_scattered = Obj.isRelocationScattered(RE);110      R.symbolnum = (R.is_scattered ? 0 : Obj.getPlainRelocationSymbolNum(RE));111      R.is_extern =112          (R.is_scattered ? false : Obj.getPlainRelocationExternal(RE));113      R.value = (R.is_scattered ? Obj.getScatteredRelocationValue(RE) : 0);114      TempSec.relocations.push_back(R);115    }116  } else {117    return SecRef.takeError();118  }119  return TempSec;120}121 122template <>123Expected<MachOYAML::Section> MachODumper::constructSection(MachO::section Sec,124                                                           size_t SecIndex) {125  Expected<MachOYAML::Section> TempSec = constructSectionCommon(Sec, SecIndex);126  if (TempSec)127    TempSec->reserved3 = 0;128  return TempSec;129}130 131template <>132Expected<MachOYAML::Section>133MachODumper::constructSection(MachO::section_64 Sec, size_t SecIndex) {134  Expected<MachOYAML::Section> TempSec = constructSectionCommon(Sec, SecIndex);135  if (TempSec)136    TempSec->reserved3 = Sec.reserved3;137  return TempSec;138}139 140static Error dumpDebugSection(StringRef SecName, DWARFContext &DCtx,141                              DWARFYAML::Data &DWARF) {142  if (SecName == "__debug_abbrev")143    return dumpDebugAbbrev(DCtx, DWARF);144  if (SecName == "__debug_aranges")145    return dumpDebugARanges(DCtx, DWARF);146  if (SecName == "__debug_info") {147    dumpDebugInfo(DCtx, DWARF);148    return Error::success();149  }150  if (SecName == "__debug_line") {151    dumpDebugLines(DCtx, DWARF);152    return Error::success();153  }154  if (SecName.starts_with("__debug_pub")) {155    // FIXME: We should extract pub-section dumpers from this function.156    dumpDebugPubSections(DCtx, DWARF);157    return Error::success();158  }159  if (SecName == "__debug_ranges")160    return dumpDebugRanges(DCtx, DWARF);161  if (SecName == "__debug_str")162    return dumpDebugStrings(DCtx, DWARF);163  return createStringError(errc::not_supported,164                           "dumping " + SecName + " section is not supported");165}166 167template <typename SectionType, typename SegmentType>168Expected<const char *> MachODumper::extractSections(169    const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,170    std::vector<MachOYAML::Section> &Sections, MachOYAML::Object &Y) {171  auto End = LoadCmd.Ptr + LoadCmd.C.cmdsize;172  const SectionType *Curr =173      reinterpret_cast<const SectionType *>(LoadCmd.Ptr + sizeof(SegmentType));174  for (; reinterpret_cast<const void *>(Curr) < End; Curr++) {175    SectionType Sec;176    memcpy((void *)&Sec, Curr, sizeof(SectionType));177    if (Obj.isLittleEndian() != sys::IsLittleEndianHost)178      MachO::swapStruct(Sec);179    // For MachO section indices start from 1.180    if (Expected<MachOYAML::Section> S =181            constructSection(Sec, Sections.size() + 1)) {182      StringRef SecName(S->sectname);183 184      // Copy data sections if requested.185      if ((RawSegment & ::RawSegments::data) &&186          StringRef(S->segname).starts_with("__DATA"))187        S->content =188            yaml::BinaryRef(Obj.getSectionContents(Sec.offset, Sec.size));189 190      if (SecName.starts_with("__debug_")) {191        // If the DWARF section cannot be successfully parsed, emit raw content192        // instead of an entry in the DWARF section of the YAML.193        if (Error Err = dumpDebugSection(SecName, *DWARFCtx, Y.DWARF))194          consumeError(std::move(Err));195        else196          S->content.reset();197      }198      Sections.push_back(std::move(*S));199    } else200      return S.takeError();201  }202  return reinterpret_cast<const char *>(Curr);203}204 205template <typename StructType>206Expected<const char *> MachODumper::processLoadCommandData(207    MachOYAML::LoadCommand &LC,208    const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,209    MachOYAML::Object &Y) {210  return LoadCmd.Ptr + sizeof(StructType);211}212 213template <>214Expected<const char *>215MachODumper::processLoadCommandData<MachO::segment_command>(216    MachOYAML::LoadCommand &LC,217    const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,218    MachOYAML::Object &Y) {219  return extractSections<MachO::section, MachO::segment_command>(220      LoadCmd, LC.Sections, Y);221}222 223template <>224Expected<const char *>225MachODumper::processLoadCommandData<MachO::segment_command_64>(226    MachOYAML::LoadCommand &LC,227    const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,228    MachOYAML::Object &Y) {229  return extractSections<MachO::section_64, MachO::segment_command_64>(230      LoadCmd, LC.Sections, Y);231}232 233template <typename StructType>234const char *235readString(MachOYAML::LoadCommand &LC,236           const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd) {237  auto Start = LoadCmd.Ptr + sizeof(StructType);238  auto MaxSize = LoadCmd.C.cmdsize - sizeof(StructType);239  auto Size = strnlen(Start, MaxSize);240  LC.Content = StringRef(Start, Size).str();241  return Start + Size;242}243 244template <>245Expected<const char *>246MachODumper::processLoadCommandData<MachO::dylib_command>(247    MachOYAML::LoadCommand &LC,248    const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,249    MachOYAML::Object &Y) {250  return readString<MachO::dylib_command>(LC, LoadCmd);251}252 253template <>254Expected<const char *>255MachODumper::processLoadCommandData<MachO::dylinker_command>(256    MachOYAML::LoadCommand &LC,257    const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,258    MachOYAML::Object &Y) {259  return readString<MachO::dylinker_command>(LC, LoadCmd);260}261 262template <>263Expected<const char *>264MachODumper::processLoadCommandData<MachO::rpath_command>(265    MachOYAML::LoadCommand &LC,266    const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,267    MachOYAML::Object &Y) {268  return readString<MachO::rpath_command>(LC, LoadCmd);269}270 271template <>272Expected<const char *>273MachODumper::processLoadCommandData<MachO::build_version_command>(274    MachOYAML::LoadCommand &LC,275    const llvm::object::MachOObjectFile::LoadCommandInfo &LoadCmd,276    MachOYAML::Object &Y) {277  auto Start = LoadCmd.Ptr + sizeof(MachO::build_version_command);278  auto NTools = LC.Data.build_version_command_data.ntools;279  for (unsigned i = 0; i < NTools; ++i) {280    auto Curr = Start + i * sizeof(MachO::build_tool_version);281    MachO::build_tool_version BV;282    memcpy((void *)&BV, Curr, sizeof(MachO::build_tool_version));283    if (Obj.isLittleEndian() != sys::IsLittleEndianHost)284      MachO::swapStruct(BV);285    LC.Tools.push_back(BV);286  }287  return Start + NTools * sizeof(MachO::build_tool_version);288}289 290Expected<std::unique_ptr<MachOYAML::Object>> MachODumper::dump() {291  auto Y = std::make_unique<MachOYAML::Object>();292  Y->IsLittleEndian = Obj.isLittleEndian();293  dumpHeader(Y);294  if (Error Err = dumpLoadCommands(Y))295    return std::move(Err);296  if (RawSegment & ::RawSegments::linkedit)297    Y->RawLinkEditSegment =298        yaml::BinaryRef(Obj.getSegmentContents("__LINKEDIT"));299  else300    dumpLinkEdit(Y);301 302  return std::move(Y);303}304 305void MachODumper::dumpHeader(std::unique_ptr<MachOYAML::Object> &Y) {306  Y->Header.magic = Obj.getHeader().magic;307  Y->Header.cputype = Obj.getHeader().cputype;308  Y->Header.cpusubtype = Obj.getHeader().cpusubtype;309  Y->Header.filetype = Obj.getHeader().filetype;310  Y->Header.ncmds = Obj.getHeader().ncmds;311  Y->Header.sizeofcmds = Obj.getHeader().sizeofcmds;312  Y->Header.flags = Obj.getHeader().flags;313  Y->Header.reserved = 0;314}315 316Error MachODumper::dumpLoadCommands(std::unique_ptr<MachOYAML::Object> &Y) {317  for (auto LoadCmd : Obj.load_commands()) {318    MachOYAML::LoadCommand LC;319    const char *EndPtr = LoadCmd.Ptr;320    switch (LoadCmd.C.cmd) {321    default:322      memcpy((void *)&(LC.Data.load_command_data), LoadCmd.Ptr,323             sizeof(MachO::load_command));324      if (Obj.isLittleEndian() != sys::IsLittleEndianHost)325        MachO::swapStruct(LC.Data.load_command_data);326      if (Expected<const char *> ExpectedEndPtr =327              processLoadCommandData<MachO::load_command>(LC, LoadCmd, *Y))328        EndPtr = *ExpectedEndPtr;329      else330        return ExpectedEndPtr.takeError();331      break;332#include "llvm/BinaryFormat/MachO.def"333    }334    auto RemainingBytes = LoadCmd.C.cmdsize - (EndPtr - LoadCmd.Ptr);335    if (!std::all_of(EndPtr, &EndPtr[RemainingBytes],336                     [](const char C) { return C == 0; })) {337      LC.PayloadBytes.insert(LC.PayloadBytes.end(), EndPtr,338                             &EndPtr[RemainingBytes]);339      RemainingBytes = 0;340    }341    LC.ZeroPadBytes = RemainingBytes;342    Y->LoadCommands.push_back(std::move(LC));343  }344  return Error::success();345}346 347void MachODumper::dumpLinkEdit(std::unique_ptr<MachOYAML::Object> &Y) {348  dumpRebaseOpcodes(Y);349  dumpBindOpcodes(Y->LinkEdit.BindOpcodes, Obj.getDyldInfoBindOpcodes());350  dumpBindOpcodes(Y->LinkEdit.WeakBindOpcodes,351                  Obj.getDyldInfoWeakBindOpcodes());352  dumpBindOpcodes(Y->LinkEdit.LazyBindOpcodes, Obj.getDyldInfoLazyBindOpcodes(),353                  true);354  dumpExportTrie(Y);355  dumpSymbols(Y);356  dumpIndirectSymbols(Y);357  dumpFunctionStarts(Y);358  dumpChainedFixups(Y);359  dumpDataInCode(Y);360}361 362void MachODumper::dumpFunctionStarts(std::unique_ptr<MachOYAML::Object> &Y) {363  MachOYAML::LinkEditData &LEData = Y->LinkEdit;364 365  auto FunctionStarts = Obj.getFunctionStarts();366  llvm::append_range(LEData.FunctionStarts, FunctionStarts);367}368 369void MachODumper::dumpRebaseOpcodes(std::unique_ptr<MachOYAML::Object> &Y) {370  MachOYAML::LinkEditData &LEData = Y->LinkEdit;371 372  auto RebaseOpcodes = Obj.getDyldInfoRebaseOpcodes();373  for (auto OpCode = RebaseOpcodes.begin(); OpCode != RebaseOpcodes.end();374       ++OpCode) {375    MachOYAML::RebaseOpcode RebaseOp;376    RebaseOp.Opcode =377        static_cast<MachO::RebaseOpcode>(*OpCode & MachO::REBASE_OPCODE_MASK);378    RebaseOp.Imm = *OpCode & MachO::REBASE_IMMEDIATE_MASK;379 380    unsigned Count;381    uint64_t ULEB = 0;382 383    switch (RebaseOp.Opcode) {384    case MachO::REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB:385 386      ULEB = decodeULEB128(OpCode + 1, &Count);387      RebaseOp.ExtraData.push_back(ULEB);388      OpCode += Count;389      [[fallthrough]];390    // Intentionally no break here -- This opcode has two ULEB values391    case MachO::REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:392    case MachO::REBASE_OPCODE_ADD_ADDR_ULEB:393    case MachO::REBASE_OPCODE_DO_REBASE_ULEB_TIMES:394    case MachO::REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB:395 396      ULEB = decodeULEB128(OpCode + 1, &Count);397      RebaseOp.ExtraData.push_back(ULEB);398      OpCode += Count;399      break;400    default:401      break;402    }403 404    LEData.RebaseOpcodes.push_back(RebaseOp);405 406    if (RebaseOp.Opcode == MachO::REBASE_OPCODE_DONE)407      break;408  }409}410 411StringRef ReadStringRef(const uint8_t *Start) {412  const uint8_t *Itr = Start;413  for (; *Itr; ++Itr)414    ;415  return StringRef(reinterpret_cast<const char *>(Start), Itr - Start);416}417 418void MachODumper::dumpBindOpcodes(419    std::vector<MachOYAML::BindOpcode> &BindOpcodes,420    ArrayRef<uint8_t> OpcodeBuffer, bool Lazy) {421  for (auto OpCode = OpcodeBuffer.begin(); OpCode != OpcodeBuffer.end();422       ++OpCode) {423    MachOYAML::BindOpcode BindOp;424    BindOp.Opcode =425        static_cast<MachO::BindOpcode>(*OpCode & MachO::BIND_OPCODE_MASK);426    BindOp.Imm = *OpCode & MachO::BIND_IMMEDIATE_MASK;427 428    unsigned Count;429    uint64_t ULEB = 0;430    int64_t SLEB = 0;431 432    switch (BindOp.Opcode) {433    case MachO::BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:434      ULEB = decodeULEB128(OpCode + 1, &Count);435      BindOp.ULEBExtraData.push_back(ULEB);436      OpCode += Count;437      [[fallthrough]];438    // Intentionally no break here -- this opcode has two ULEB values439 440    case MachO::BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:441    case MachO::BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:442    case MachO::BIND_OPCODE_ADD_ADDR_ULEB:443    case MachO::BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:444      ULEB = decodeULEB128(OpCode + 1, &Count);445      BindOp.ULEBExtraData.push_back(ULEB);446      OpCode += Count;447      break;448 449    case MachO::BIND_OPCODE_SET_ADDEND_SLEB:450      SLEB = decodeSLEB128(OpCode + 1, &Count);451      BindOp.SLEBExtraData.push_back(SLEB);452      OpCode += Count;453      break;454 455    case MachO::BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:456      BindOp.Symbol = ReadStringRef(OpCode + 1);457      OpCode += BindOp.Symbol.size() + 1;458      break;459    default:460      break;461    }462 463    BindOpcodes.push_back(BindOp);464 465    // Lazy bindings have DONE opcodes between operations, so we need to keep466    // processing after a DONE.467    if (!Lazy && BindOp.Opcode == MachO::BIND_OPCODE_DONE)468      break;469  }470}471 472/*!473 * /brief processes a node from the export trie, and its children.474 *475 * To my knowledge there is no documentation of the encoded format of this data476 * other than in the heads of the Apple linker engineers. To that end hopefully477 * this comment and the implementation below can serve to light the way for478 * anyone crazy enough to come down this path in the future.479 *480 * This function reads and preserves the trie structure of the export trie. To481 * my knowledge there is no code anywhere else that reads the data and preserves482 * the Trie. LD64 (sources available at opensource.apple.com) has a similar483 * implementation that parses the export trie into a vector. That code as well484 * as LLVM's libObject MachO implementation were the basis for this.485 *486 * The export trie is an encoded trie. The node serialization is a bit awkward.487 * The below pseudo-code is the best description I've come up with for it.488 *489 * struct SerializedNode {490 *   ULEB128 TerminalSize;491 *   struct TerminalData { <-- This is only present if TerminalSize > 0492 *     ULEB128 Flags;493 *     ULEB128 Address; <-- Present if (! Flags & REEXPORT )494 *     ULEB128 Other; <-- Present if ( Flags & REEXPORT ||495 *                                     Flags & STUB_AND_RESOLVER )496 *     char[] ImportName; <-- Present if ( Flags & REEXPORT )497 *   }498 *   uint8_t ChildrenCount;499 *   Pair<char[], ULEB128> ChildNameOffsetPair[ChildrenCount];500 *   SerializedNode Children[ChildrenCount]501 * }502 *503 * Terminal nodes are nodes that represent actual exports. They can appear504 * anywhere in the tree other than at the root; they do not need to be leaf505 * nodes. When reading the data out of the trie this routine reads it in-order,506 * but it puts the child names and offsets directly into the child nodes. This507 * results in looping over the children twice during serialization and508 * de-serialization, but it makes the YAML representation more human readable.509 *510 * Below is an example of the graph from a "Hello World" executable:511 *512 * -------513 * | ''  |514 * -------515 *    |516 * -------517 * | '_' |518 * -------519 *    |520 *    |----------------------------------------|521 *    |                                        |522 *  ------------------------      ---------------------523 *  | '_mh_execute_header' |      | 'main'            |524 *  | Flags: 0x00000000    |      | Flags: 0x00000000 |525 *  | Addr:  0x00000000    |      | Addr:  0x00001160 |526 *  ------------------------      ---------------------527 *528 * This graph represents the trie for the exports "__mh_execute_header" and529 * "_main". In the graph only the "_main" and "__mh_execute_header" nodes are530 * terminal.531*/532 533const uint8_t *processExportNode(const uint8_t *Start, const uint8_t *CurrPtr,534                                 const uint8_t *const End,535                                 MachOYAML::ExportEntry &Entry) {536  if (CurrPtr >= End)537    return CurrPtr;538  unsigned Count = 0;539  Entry.TerminalSize = decodeULEB128(CurrPtr, &Count);540  CurrPtr += Count;541  if (Entry.TerminalSize != 0) {542    Entry.Flags = decodeULEB128(CurrPtr, &Count);543    CurrPtr += Count;544    if (Entry.Flags & MachO::EXPORT_SYMBOL_FLAGS_REEXPORT) {545      Entry.Address = 0;546      Entry.Other = decodeULEB128(CurrPtr, &Count);547      CurrPtr += Count;548      Entry.ImportName = std::string(reinterpret_cast<const char *>(CurrPtr));549    } else {550      Entry.Address = decodeULEB128(CurrPtr, &Count);551      CurrPtr += Count;552      if (Entry.Flags & MachO::EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER) {553        Entry.Other = decodeULEB128(CurrPtr, &Count);554        CurrPtr += Count;555      } else556        Entry.Other = 0;557    }558  }559  uint8_t childrenCount = *CurrPtr++;560  if (childrenCount == 0)561    return CurrPtr;562 563  Entry.Children.insert(Entry.Children.begin(), (size_t)childrenCount,564                        MachOYAML::ExportEntry());565  for (auto &Child : Entry.Children) {566    Child.Name = std::string(reinterpret_cast<const char *>(CurrPtr));567    CurrPtr += Child.Name.length() + 1;568    Child.NodeOffset = decodeULEB128(CurrPtr, &Count);569    CurrPtr += Count;570  }571  for (auto &Child : Entry.Children) {572    CurrPtr = processExportNode(Start, Start + Child.NodeOffset, End, Child);573  }574  return CurrPtr;575}576 577void MachODumper::dumpExportTrie(std::unique_ptr<MachOYAML::Object> &Y) {578  MachOYAML::LinkEditData &LEData = Y->LinkEdit;579  // The exports trie can be in LC_DYLD_INFO or LC_DYLD_EXPORTS_TRIE580  auto ExportsTrie = Obj.getDyldInfoExportsTrie();581  if (ExportsTrie.empty())582    ExportsTrie = Obj.getDyldExportsTrie();583  processExportNode(ExportsTrie.begin(), ExportsTrie.begin(), ExportsTrie.end(),584                    LEData.ExportTrie);585}586 587template <typename nlist_t>588MachOYAML::NListEntry constructNameList(const nlist_t &nlist) {589  MachOYAML::NListEntry NL;590  NL.n_strx = nlist.n_strx;591  NL.n_type = nlist.n_type;592  NL.n_sect = nlist.n_sect;593  NL.n_desc = nlist.n_desc;594  NL.n_value = nlist.n_value;595  return NL;596}597 598void MachODumper::dumpSymbols(std::unique_ptr<MachOYAML::Object> &Y) {599  MachOYAML::LinkEditData &LEData = Y->LinkEdit;600 601  for (auto Symbol : Obj.symbols()) {602    MachOYAML::NListEntry NLE =603        Obj.is64Bit()604            ? constructNameList<MachO::nlist_64>(605                  Obj.getSymbol64TableEntry(Symbol.getRawDataRefImpl()))606            : constructNameList<MachO::nlist>(607                  Obj.getSymbolTableEntry(Symbol.getRawDataRefImpl()));608    LEData.NameList.push_back(NLE);609  }610 611  StringRef RemainingTable = Obj.getStringTableData();612  while (RemainingTable.size() > 0) {613    auto SymbolPair = RemainingTable.split('\0');614    RemainingTable = SymbolPair.second;615    LEData.StringTable.push_back(SymbolPair.first);616  }617}618 619void MachODumper::dumpIndirectSymbols(std::unique_ptr<MachOYAML::Object> &Y) {620  MachOYAML::LinkEditData &LEData = Y->LinkEdit;621 622  MachO::dysymtab_command DLC = Obj.getDysymtabLoadCommand();623  for (unsigned i = 0; i < DLC.nindirectsyms; ++i)624    LEData.IndirectSymbols.push_back(Obj.getIndirectSymbolTableEntry(DLC, i));625}626 627void MachODumper::dumpChainedFixups(std::unique_ptr<MachOYAML::Object> &Y) {628  MachOYAML::LinkEditData &LEData = Y->LinkEdit;629 630  for (const auto &LC : Y->LoadCommands) {631    if (LC.Data.load_command_data.cmd == llvm::MachO::LC_DYLD_CHAINED_FIXUPS) {632      const MachO::linkedit_data_command &DC =633          LC.Data.linkedit_data_command_data;634      if (DC.dataoff) {635        assert(DC.dataoff < Obj.getData().size());636        assert(DC.dataoff + DC.datasize <= Obj.getData().size());637        const char *Bytes = Obj.getData().data() + DC.dataoff;638        llvm::append_range(LEData.ChainedFixups, ArrayRef(Bytes, DC.datasize));639      }640      break;641    }642  }643}644 645void MachODumper::dumpDataInCode(std::unique_ptr<MachOYAML::Object> &Y) {646  MachOYAML::LinkEditData &LEData = Y->LinkEdit;647 648  MachO::linkedit_data_command DIC = Obj.getDataInCodeLoadCommand();649  uint32_t NumEntries = DIC.datasize / sizeof(MachO::data_in_code_entry);650  for (uint32_t Idx = 0; Idx < NumEntries; ++Idx) {651    MachO::data_in_code_entry DICE =652        Obj.getDataInCodeTableEntry(DIC.dataoff, Idx);653    MachOYAML::DataInCodeEntry Entry{DICE.offset, DICE.length, DICE.kind};654    LEData.DataInCode.emplace_back(Entry);655  }656}657 658Error macho2yaml(raw_ostream &Out, const object::MachOObjectFile &Obj,659                 unsigned RawSegments) {660  std::unique_ptr<DWARFContext> DCtx = DWARFContext::create(Obj);661  MachODumper Dumper(Obj, std::move(DCtx), RawSegments);662  Expected<std::unique_ptr<MachOYAML::Object>> YAML = Dumper.dump();663  if (!YAML)664    return YAML.takeError();665 666  yaml::YamlObjectFile YAMLFile;667  YAMLFile.MachO = std::move(YAML.get());668 669  yaml::Output Yout(Out);670  Yout << YAMLFile;671  return Error::success();672}673 674Error macho2yaml(raw_ostream &Out, const object::MachOUniversalBinary &Obj,675                 unsigned RawSegments) {676  yaml::YamlObjectFile YAMLFile;677  YAMLFile.FatMachO.reset(new MachOYAML::UniversalBinary());678  MachOYAML::UniversalBinary &YAML = *YAMLFile.FatMachO;679  YAML.Header.magic = Obj.getMagic();680  YAML.Header.nfat_arch = Obj.getNumberOfObjects();681 682  for (auto Slice : Obj.objects()) {683    MachOYAML::FatArch arch;684    arch.cputype = Slice.getCPUType();685    arch.cpusubtype = Slice.getCPUSubType();686    arch.offset = Slice.getOffset();687    arch.size = Slice.getSize();688    arch.align = Slice.getAlign();689    arch.reserved = Slice.getReserved();690    YAML.FatArchs.push_back(arch);691 692    auto SliceObj = Slice.getAsObjectFile();693    if (!SliceObj)694      return SliceObj.takeError();695 696    std::unique_ptr<DWARFContext> DCtx = DWARFContext::create(*SliceObj.get());697    MachODumper Dumper(*SliceObj.get(), std::move(DCtx), RawSegments);698    Expected<std::unique_ptr<MachOYAML::Object>> YAMLObj = Dumper.dump();699    if (!YAMLObj)700      return YAMLObj.takeError();701    YAML.Slices.push_back(*YAMLObj.get());702  }703 704  yaml::Output Yout(Out);705  Yout << YAML;706  return Error::success();707}708 709Error macho2yaml(raw_ostream &Out, const object::Binary &Binary,710                 unsigned RawSegments) {711  if (const auto *MachOObj = dyn_cast<object::MachOUniversalBinary>(&Binary))712    return macho2yaml(Out, *MachOObj, RawSegments);713 714  if (const auto *MachOObj = dyn_cast<object::MachOObjectFile>(&Binary))715    return macho2yaml(Out, *MachOObj, RawSegments);716 717  llvm_unreachable("unexpected Mach-O file format");718}719