C++ ErrorOr类代码示例

int main(int argc, char **argv) {
  sys::PrintStackTraceOnErrorSignal();
  PrettyStackTraceProgram X(argc, argv);
  cl::ParseCommandLineOptions(argc, argv);

  if (!ValidateCheckPrefixes()) {
    errs() << "Supplied check-prefix is invalid! Prefixes must be unique and "
              "start with a letter and contain only alphanumeric characters, "
              "hyphens and underscores\n";
    return 2;
  }

  AddCheckPrefixIfNeeded();

  SourceMgr SM;

  // Read the expected strings from the check file.
  std::vector<CheckString> CheckStrings;
  if (ReadCheckFile(SM, CheckStrings))
    return 2;

  // Open the file to check and add it to SourceMgr.
  ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
      MemoryBuffer::getFileOrSTDIN(InputFilename);
  if (std::error_code EC = FileOrErr.getError()) {
    errs() << "Could not open input file '" << InputFilename
           << "': " << EC.message() << '\n';
    return 2;
  }
  std::unique_ptr<MemoryBuffer> File = std::move(FileOrErr.get());

  if (File->getBufferSize() == 0) {
    errs() << "FileCheck error: '" << InputFilename << "' is empty.\n";
    return 2;
  }

  // Remove duplicate spaces in the input file if requested.
  // Remove DOS style line endings.
  MemoryBuffer *F =
    CanonicalizeInputFile(File.release(), NoCanonicalizeWhiteSpace);

  SM.AddNewSourceBuffer(F, SMLoc());

  /// VariableTable - This holds all the current filecheck variables.
  StringMap<StringRef> VariableTable;

  // Check that we have all of the expected strings, in order, in the input
  // file.
  StringRef Buffer = F->getBuffer();

  bool hasError = false;

  unsigned i = 0, j = 0, e = CheckStrings.size();

  while (true) {
    StringRef CheckRegion;
    if (j == e) {
      CheckRegion = Buffer;
    } else {
      const CheckString &CheckLabelStr = CheckStrings[j];
      if (CheckLabelStr.CheckTy != Check::CheckLabel) {
        ++j;
        continue;
      }

      // Scan to next CHECK-LABEL match, ignoring CHECK-NOT and CHECK-DAG
      size_t MatchLabelLen = 0;
      size_t MatchLabelPos = CheckLabelStr.Check(SM, Buffer, true,
                                                 MatchLabelLen, VariableTable);
      if (MatchLabelPos == StringRef::npos) {
        hasError = true;
        break;
      }

      CheckRegion = Buffer.substr(0, MatchLabelPos + MatchLabelLen);
      Buffer = Buffer.substr(MatchLabelPos + MatchLabelLen);
      ++j;
    }

    for ( ; i != j; ++i) {
      const CheckString &CheckStr = CheckStrings[i];

      // Check each string within the scanned region, including a second check
      // of any final CHECK-LABEL (to verify CHECK-NOT and CHECK-DAG)
      size_t MatchLen = 0;
      size_t MatchPos = CheckStr.Check(SM, CheckRegion, false, MatchLen,
                                       VariableTable);

      if (MatchPos == StringRef::npos) {
        hasError = true;
        i = j;
        break;
      }

      CheckRegion = CheckRegion.substr(MatchPos + MatchLen);
    }

    if (j == e)
      break;
  }
//.........这里部分代码省略.........

int main(int argc, char **argv) {
  // Print a stack trace if we signal out.
  sys::PrintStackTraceOnErrorSignal();
  PrettyStackTraceProgram X(argc, argv);
  llvm_shutdown_obj Y;  // Call llvm_shutdown() on exit.

  // Initialize targets and assembly printers/parsers.
  llvm::InitializeAllTargetInfos();
  llvm::InitializeAllTargetMCs();
  llvm::InitializeAllAsmParsers();
  llvm::InitializeAllDisassemblers();

  // Register the target printer for --version.
  cl::AddExtraVersionPrinter(TargetRegistry::printRegisteredTargetsForVersion);

  cl::ParseCommandLineOptions(argc, argv, "llvm machine code playground\n");
  MCTargetOptions MCOptions = InitMCTargetOptionsFromFlags();
  TripleName = Triple::normalize(TripleName);
  setDwarfDebugFlags(argc, argv);

  setDwarfDebugProducer();

  const char *ProgName = argv[0];
  const Target *TheTarget = GetTarget(ProgName);
  if (!TheTarget)
    return 1;
  // Now that GetTarget() has (potentially) replaced TripleName, it's safe to
  // construct the Triple object.
  Triple TheTriple(TripleName);

  ErrorOr<std::unique_ptr<MemoryBuffer>> BufferPtr =
      MemoryBuffer::getFileOrSTDIN(InputFilename);
  if (std::error_code EC = BufferPtr.getError()) {
    errs() << InputFilename << ": " << EC.message() << '\n';
    return 1;
  }
  MemoryBuffer *Buffer = BufferPtr->get();

  SourceMgr SrcMgr;

  // Tell SrcMgr about this buffer, which is what the parser will pick up.
  SrcMgr.AddNewSourceBuffer(std::move(*BufferPtr), SMLoc());

  // Record the location of the include directories so that the lexer can find
  // it later.
  SrcMgr.setIncludeDirs(IncludeDirs);

  std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
  assert(MRI && "Unable to create target register info!");

  std::unique_ptr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, TripleName));
  assert(MAI && "Unable to create target asm info!");

  MAI->setRelaxELFRelocations(RelaxELFRel);

  if (CompressDebugSections != DebugCompressionType::DCT_None) {
    if (!zlib::isAvailable()) {
      errs() << ProgName
             << ": build tools with zlib to enable -compress-debug-sections";
      return 1;
    }
    MAI->setCompressDebugSections(CompressDebugSections);
  }

  // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
  // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
  MCObjectFileInfo MOFI;
  MCContext Ctx(MAI.get(), MRI.get(), &MOFI, &SrcMgr);
  MOFI.InitMCObjectFileInfo(TheTriple, PIC, CMModel, Ctx);

  if (SaveTempLabels)
    Ctx.setAllowTemporaryLabels(false);

  Ctx.setGenDwarfForAssembly(GenDwarfForAssembly);
  // Default to 4 for dwarf version.
  unsigned DwarfVersion = MCOptions.DwarfVersion ? MCOptions.DwarfVersion : 4;
  if (DwarfVersion < 2 || DwarfVersion > 4) {
    errs() << ProgName << ": Dwarf version " << DwarfVersion
           << " is not supported." << '\n';
    return 1;
  }
  Ctx.setDwarfVersion(DwarfVersion);
  if (!DwarfDebugFlags.empty())
    Ctx.setDwarfDebugFlags(StringRef(DwarfDebugFlags));
  if (!DwarfDebugProducer.empty())
    Ctx.setDwarfDebugProducer(StringRef(DwarfDebugProducer));
  if (!DebugCompilationDir.empty())
    Ctx.setCompilationDir(DebugCompilationDir);
  else {
    // If no compilation dir is set, try to use the current directory.
    SmallString<128> CWD;
    if (!sys::fs::current_path(CWD))
      Ctx.setCompilationDir(CWD);
  }
  if (!MainFileName.empty())
    Ctx.setMainFileName(MainFileName);

  // Package up features to be passed to target/subtarget
  std::string FeaturesStr;
  if (MAttrs.size()) {
//.........这里部分代码省略.........

static void dumpSymbolNamesFromObject(SymbolicFile &Obj, bool printName,
                                      std::string ArchiveName = std::string(),
                                      std::string ArchitectureName =
                                        std::string()) {
  auto Symbols = Obj.symbols();
  if (DynamicSyms) {
    const auto *E = dyn_cast<ELFObjectFileBase>(&Obj);
    if (!E) {
      error("File format has no dynamic symbol table", Obj.getFileName());
      return;
    }
    auto DynSymbols = E->getDynamicSymbolIterators();
    Symbols =
        make_range<basic_symbol_iterator>(DynSymbols.begin(), DynSymbols.end());
  }
  std::string NameBuffer;
  raw_string_ostream OS(NameBuffer);
  // If a "-s segname sectname" option was specified and this is a Mach-O
  // file get the section number for that section in this object file.
  unsigned int Nsect = 0;
  MachOObjectFile *MachO = dyn_cast<MachOObjectFile>(&Obj);
  if (SegSect.size() != 0 && MachO) {
    Nsect = getNsectForSegSect(MachO);
    // If this section is not in the object file no symbols are printed.
    if (Nsect == 0)
      return;
  }
  for (BasicSymbolRef Sym : Symbols) {
    uint32_t SymFlags = Sym.getFlags();
    if (!DebugSyms && (SymFlags & SymbolRef::SF_FormatSpecific))
      continue;
    if (WithoutAliases) {
      if (IRObjectFile *IR = dyn_cast<IRObjectFile>(&Obj)) {
        const GlobalValue *GV = IR->getSymbolGV(Sym.getRawDataRefImpl());
        if (GV && isa<GlobalAlias>(GV))
          continue;
      }
    }
    // If a "-s segname sectname" option was specified and this is a Mach-O
    // file and this section appears in this file, Nsect will be non-zero then
    // see if this symbol is a symbol from that section and if not skip it.
    if (Nsect && Nsect != getNsectInMachO(*MachO, Sym))
      continue;
    NMSymbol S;
    S.Size = 0;
    S.Address = 0;
    if (PrintSize) {
      if (isa<ELFObjectFileBase>(&Obj))
        S.Size = ELFSymbolRef(Sym).getSize();
    }
    if (PrintAddress && isa<ObjectFile>(Obj)) {
      SymbolRef SymRef(Sym);
      ErrorOr<uint64_t> AddressOrErr = SymRef.getAddress();
      if (error(AddressOrErr.getError()))
        break;
      S.Address = *AddressOrErr;
    }
    S.TypeChar = getNMTypeChar(Obj, Sym);
    if (error(Sym.printName(OS)))
      break;
    OS << '\0';
    S.Sym = Sym;
    SymbolList.push_back(S);
  }

  OS.flush();
  const char *P = NameBuffer.c_str();
  for (unsigned I = 0; I < SymbolList.size(); ++I) {
    SymbolList[I].Name = P;
    P += strlen(P) + 1;
  }

  CurrentFilename = Obj.getFileName();
  sortAndPrintSymbolList(Obj, printName, ArchiveName, ArchitectureName);
}

// Load and link the objects specified on the command line, but do not execute
// anything. Instead, attach a RuntimeDyldChecker instance and call it to
// verify the correctness of the linked memory.
static int linkAndVerify() {

  // Check for missing triple.
  if (TripleName == "")
    ErrorAndExit("-triple required when running in -verify mode.");

  // Look up the target and build the disassembler.
  Triple TheTriple(Triple::normalize(TripleName));
  std::string ErrorStr;
  const Target *TheTarget =
    TargetRegistry::lookupTarget("", TheTriple, ErrorStr);
  if (!TheTarget)
    ErrorAndExit("Error accessing target '" + TripleName + "': " + ErrorStr);

  TripleName = TheTriple.getTriple();

  std::unique_ptr<MCSubtargetInfo> STI(
    TheTarget->createMCSubtargetInfo(TripleName, MCPU, ""));
  if (!STI)
    ErrorAndExit("Unable to create subtarget info!");

  std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TripleName));
  if (!MRI)
    ErrorAndExit("Unable to create target register info!");

  std::unique_ptr<MCAsmInfo> MAI(TheTarget->createMCAsmInfo(*MRI, TripleName));
  if (!MAI)
    ErrorAndExit("Unable to create target asm info!");

  MCContext Ctx(MAI.get(), MRI.get(), nullptr);

  std::unique_ptr<MCDisassembler> Disassembler(
    TheTarget->createMCDisassembler(*STI, Ctx));
  if (!Disassembler)
    ErrorAndExit("Unable to create disassembler!");

  std::unique_ptr<MCInstrInfo> MII(TheTarget->createMCInstrInfo());

  std::unique_ptr<MCInstPrinter> InstPrinter(
      TheTarget->createMCInstPrinter(Triple(TripleName), 0, *MAI, *MII, *MRI));

  // Load any dylibs requested on the command line.
  loadDylibs();

  // Instantiate a dynamic linker.
  TrivialMemoryManager MemMgr;
  doPreallocation(MemMgr);
  RuntimeDyld Dyld(MemMgr, MemMgr);
  Dyld.setProcessAllSections(true);
  RuntimeDyldChecker Checker(Dyld, Disassembler.get(), InstPrinter.get(),
                             llvm::dbgs());

  // If we don't have any input files, read from stdin.
  if (!InputFileList.size())
    InputFileList.push_back("-");
  for (auto &Filename : InputFileList) {
    // Load the input memory buffer.
    ErrorOr<std::unique_ptr<MemoryBuffer>> InputBuffer =
        MemoryBuffer::getFileOrSTDIN(Filename);

    if (std::error_code EC = InputBuffer.getError())
      ErrorAndExit("unable to read input: '" + EC.message() + "'");

    Expected<std::unique_ptr<ObjectFile>> MaybeObj(
      ObjectFile::createObjectFile((*InputBuffer)->getMemBufferRef()));

    if (!MaybeObj) {
      std::string Buf;
      raw_string_ostream OS(Buf);
      logAllUnhandledErrors(MaybeObj.takeError(), OS, "");
      OS.flush();
      ErrorAndExit("unable to create object file: '" + Buf + "'");
    }

    ObjectFile &Obj = **MaybeObj;

    // Load the object file
    Dyld.loadObject(Obj);
    if (Dyld.hasError()) {
      ErrorAndExit(Dyld.getErrorString());
    }
  }

  // Re-map the section addresses into the phony target address space and add
  // dummy symbols.
  remapSectionsAndSymbols(TheTriple, MemMgr, Checker);

  // Resolve all the relocations we can.
  Dyld.resolveRelocations();

  // Register EH frames.
  Dyld.registerEHFrames();

  int ErrorCode = checkAllExpressions(Checker);
  if (Dyld.hasError())
    ErrorAndExit("RTDyld reported an error applying relocations:\n  " +
                 Dyld.getErrorString());
//.........这里部分代码省略.........

static void runThinLTOBackend(ModuleSummaryIndex *CombinedIndex, Module *M,
                              std::unique_ptr<raw_pwrite_stream> OS,
                              std::string SampleProfile) {
  StringMap<std::map<GlobalValue::GUID, GlobalValueSummary *>>
      ModuleToDefinedGVSummaries;
  CombinedIndex->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);

  // We can simply import the values mentioned in the combined index, since
  // we should only invoke this using the individual indexes written out
  // via a WriteIndexesThinBackend.
  FunctionImporter::ImportMapTy ImportList;
  for (auto &GlobalList : *CombinedIndex) {
    auto GUID = GlobalList.first;
    assert(GlobalList.second.size() == 1 &&
           "Expected individual combined index to have one summary per GUID");
    auto &Summary = GlobalList.second[0];
    // Skip the summaries for the importing module. These are included to
    // e.g. record required linkage changes.
    if (Summary->modulePath() == M->getModuleIdentifier())
      continue;
    // Doesn't matter what value we plug in to the map, just needs an entry
    // to provoke importing by thinBackend.
    ImportList[Summary->modulePath()][GUID] = 1;
  }

  std::vector<std::unique_ptr<llvm::MemoryBuffer>> OwnedImports;
  MapVector<llvm::StringRef, llvm::BitcodeModule> ModuleMap;

  for (auto &I : ImportList) {
    ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr =
        llvm::MemoryBuffer::getFile(I.first());
    if (!MBOrErr) {
      errs() << "Error loading imported file '" << I.first()
             << "': " << MBOrErr.getError().message() << "\n";
      return;
    }

    Expected<std::vector<BitcodeModule>> BMsOrErr =
        getBitcodeModuleList(**MBOrErr);
    if (!BMsOrErr) {
      handleAllErrors(BMsOrErr.takeError(), [&](ErrorInfoBase &EIB) {
        errs() << "Error loading imported file '" << I.first()
               << "': " << EIB.message() << '\n';
      });
      return;
    }

    // The bitcode file may contain multiple modules, we want the one with a
    // summary.
    bool FoundModule = false;
    for (BitcodeModule &BM : *BMsOrErr) {
      Expected<bool> HasSummary = BM.hasSummary();
      if (HasSummary && *HasSummary) {
        ModuleMap.insert({I.first(), BM});
        FoundModule = true;
        break;
      }
    }
    if (!FoundModule) {
      errs() << "Error loading imported file '" << I.first()
             << "': Could not find module summary\n";
      return;
    }

    OwnedImports.push_back(std::move(*MBOrErr));
  }
  auto AddStream = [&](size_t Task) {
    return llvm::make_unique<lto::NativeObjectStream>(std::move(OS));
  };
  lto::Config Conf;
  Conf.SampleProfile = SampleProfile;
  if (Error E = thinBackend(
          Conf, 0, AddStream, *M, *CombinedIndex, ImportList,
          ModuleToDefinedGVSummaries[M->getModuleIdentifier()], ModuleMap)) {
    handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) {
      errs() << "Error running ThinLTO backend: " << EIB.message() << '\n';
    });
  }
}

static void runMRIScript() {
  enum class MRICommand { AddLib, AddMod, Create, Save, End, Invalid };

  ErrorOr<std::unique_ptr<MemoryBuffer>> Buf = MemoryBuffer::getSTDIN();
  failIfError(Buf.getError());
  const MemoryBuffer &Ref = *Buf.get();
  bool Saved = false;
  std::vector<NewArchiveMember> NewMembers;
  std::vector<std::unique_ptr<MemoryBuffer>> ArchiveBuffers;
  std::vector<std::unique_ptr<object::Archive>> Archives;

  for (line_iterator I(Ref, /*SkipBlanks*/ true, ';'), E; I != E; ++I) {
    StringRef Line = *I;
    StringRef CommandStr, Rest;
    std::tie(CommandStr, Rest) = Line.split(' ');
    Rest = Rest.trim();
    if (!Rest.empty() && Rest.front() == '"' && Rest.back() == '"')
      Rest = Rest.drop_front().drop_back();
    auto Command = StringSwitch<MRICommand>(CommandStr.lower())
                       .Case("addlib", MRICommand::AddLib)
                       .Case("addmod", MRICommand::AddMod)
                       .Case("create", MRICommand::Create)
                       .Case("save", MRICommand::Save)
                       .Case("end", MRICommand::End)
                       .Default(MRICommand::Invalid);

    switch (Command) {
    case MRICommand::AddLib: {
      auto BufOrErr = MemoryBuffer::getFile(Rest, -1, false);
      failIfError(BufOrErr.getError(), "Could not open library");
      ArchiveBuffers.push_back(std::move(*BufOrErr));
      auto LibOrErr =
          object::Archive::create(ArchiveBuffers.back()->getMemBufferRef());
      failIfError(errorToErrorCode(LibOrErr.takeError()),
                  "Could not parse library");
      Archives.push_back(std::move(*LibOrErr));
      object::Archive &Lib = *Archives.back();
      {
        Error Err;
        for (auto &Member : Lib.children(Err))
          addMember(NewMembers, Member);
        failIfError(std::move(Err));
      }
      break;
    }
    case MRICommand::AddMod:
      addMember(NewMembers, Rest);
      break;
    case MRICommand::Create:
      Create = true;
      if (!ArchiveName.empty())
        fail("Editing multiple archives not supported");
      if (Saved)
        fail("File already saved");
      ArchiveName = Rest;
      break;
    case MRICommand::Save:
      Saved = true;
      break;
    case MRICommand::End:
      break;
    case MRICommand::Invalid:
      fail("Unknown command: " + CommandStr);
    }
  }

  // Nothing to do if not saved.
  if (Saved)
    performOperation(ReplaceOrInsert, &NewMembers);
  exit(0);
}

static int printLineInfoForInput(bool LoadObjects, bool UseDebugObj) {
  assert(LoadObjects || !UseDebugObj);

  // Load any dylibs requested on the command line.
  loadDylibs();

  // If we don't have any input files, read from stdin.
  if (!InputFileList.size())
    InputFileList.push_back("-");
  for (auto &File : InputFileList) {
    // Instantiate a dynamic linker.
    TrivialMemoryManager MemMgr;
    RuntimeDyld Dyld(MemMgr, MemMgr);

    // Load the input memory buffer.

    ErrorOr<std::unique_ptr<MemoryBuffer>> InputBuffer =
        MemoryBuffer::getFileOrSTDIN(File);
    if (std::error_code EC = InputBuffer.getError())
      ErrorAndExit("unable to read input: '" + EC.message() + "'");

    Expected<std::unique_ptr<ObjectFile>> MaybeObj(
      ObjectFile::createObjectFile((*InputBuffer)->getMemBufferRef()));

    if (!MaybeObj) {
      std::string Buf;
      raw_string_ostream OS(Buf);
      logAllUnhandledErrors(MaybeObj.takeError(), OS, "");
      OS.flush();
      ErrorAndExit("unable to create object file: '" + Buf + "'");
    }

    ObjectFile &Obj = **MaybeObj;

    OwningBinary<ObjectFile> DebugObj;
    std::unique_ptr<RuntimeDyld::LoadedObjectInfo> LoadedObjInfo = nullptr;
    ObjectFile *SymbolObj = &Obj;
    if (LoadObjects) {
      // Load the object file
      LoadedObjInfo =
        Dyld.loadObject(Obj);

      if (Dyld.hasError())
        ErrorAndExit(Dyld.getErrorString());

      // Resolve all the relocations we can.
      Dyld.resolveRelocations();

      if (UseDebugObj) {
        DebugObj = LoadedObjInfo->getObjectForDebug(Obj);
        SymbolObj = DebugObj.getBinary();
        LoadedObjInfo.reset();
      }
    }

    std::unique_ptr<DIContext> Context(
      new DWARFContextInMemory(*SymbolObj,LoadedObjInfo.get()));

    std::vector<std::pair<SymbolRef, uint64_t>> SymAddr =
        object::computeSymbolSizes(*SymbolObj);

    // Use symbol info to iterate functions in the object.
    for (const auto &P : SymAddr) {
      object::SymbolRef Sym = P.first;
      Expected<SymbolRef::Type> TypeOrErr = Sym.getType();
      if (!TypeOrErr) {
        // TODO: Actually report errors helpfully.
        consumeError(TypeOrErr.takeError());
        continue;
      }
      SymbolRef::Type Type = *TypeOrErr;
      if (Type == object::SymbolRef::ST_Function) {
        Expected<StringRef> Name = Sym.getName();
        if (!Name) {
          // TODO: Actually report errors helpfully.
          consumeError(Name.takeError());
          continue;
        }
        Expected<uint64_t> AddrOrErr = Sym.getAddress();
        if (!AddrOrErr) {
          // TODO: Actually report errors helpfully.
          consumeError(AddrOrErr.takeError());
          continue;
        }
        uint64_t Addr = *AddrOrErr;

        uint64_t Size = P.second;
        // If we're not using the debug object, compute the address of the
        // symbol in memory (rather than that in the unrelocated object file)
        // and use that to query the DWARFContext.
        if (!UseDebugObj && LoadObjects) {
          auto SecOrErr = Sym.getSection();
          if (!SecOrErr) {
            // TODO: Actually report errors helpfully.
            consumeError(SecOrErr.takeError());
            continue;
          }
          object::section_iterator Sec = *SecOrErr;
          StringRef SecName;
          Sec->getName(SecName);
//.........这里部分代码省略.........

//.........这里部分代码省略.........
        .Case("debug_loc", &LocSection.Relocs)
        .Case("debug_info.dwo", &InfoDWOSection.Relocs)
        .Case("debug_line", &LineSection.Relocs)
        .Case("apple_names", &AppleNamesSection.Relocs)
        .Case("apple_types", &AppleTypesSection.Relocs)
        .Case("apple_namespaces", &AppleNamespacesSection.Relocs)
        .Case("apple_namespac", &AppleNamespacesSection.Relocs)
        .Case("apple_objc", &AppleObjCSection.Relocs)
        .Default(nullptr);
    if (!Map) {
      // Find debug_types relocs by section rather than name as there are
      // multiple, comdat grouped, debug_types sections.
      if (RelSecName == "debug_types")
        Map = &TypesSections[*RelocatedSection].Relocs;
      else if (RelSecName == "debug_types.dwo")
        Map = &TypesDWOSections[*RelocatedSection].Relocs;
      else
        continue;
    }

    if (Section.relocation_begin() != Section.relocation_end()) {
      uint64_t SectionSize = RelocatedSection->getSize();
      for (const RelocationRef &Reloc : Section.relocations()) {
        uint64_t Address = Reloc.getOffset();
        uint64_t Type = Reloc.getType();
        uint64_t SymAddr = 0;
        uint64_t SectionLoadAddress = 0;
        object::symbol_iterator Sym = Reloc.getSymbol();
        object::section_iterator RSec = Obj.section_end();

        // First calculate the address of the symbol or section as it appears
        // in the objct file
        if (Sym != Obj.symbol_end()) {
          ErrorOr<uint64_t> SymAddrOrErr = Sym->getAddress();
          if (std::error_code EC = SymAddrOrErr.getError()) {
            errs() << "error: failed to compute symbol address: "
                   << EC.message() << '\n';
            continue;
          }
          SymAddr = *SymAddrOrErr;
          // Also remember what section this symbol is in for later
          Sym->getSection(RSec);
        } else if (auto *MObj = dyn_cast<MachOObjectFile>(&Obj)) {
          // MachO also has relocations that point to sections and
          // scattered relocations.
          auto RelocInfo = MObj->getRelocation(Reloc.getRawDataRefImpl());
          if (MObj->isRelocationScattered(RelocInfo)) {
            // FIXME: it's not clear how to correctly handle scattered
            // relocations.
            continue;
          } else {
            RSec = MObj->getRelocationSection(Reloc.getRawDataRefImpl());
            SymAddr = RSec->getAddress();
          }
        }

        // If we are given load addresses for the sections, we need to adjust:
        // SymAddr = (Address of Symbol Or Section in File) -
        //           (Address of Section in File) +
        //           (Load Address of Section)
        if (L != nullptr && RSec != Obj.section_end()) {
          // RSec is now either the section being targetted or the section
          // containing the symbol being targetted. In either case,
          // we need to perform the same computation.
          StringRef SecName;
          RSec->getName(SecName);

// Returns true on error.
static bool format(StringRef FileName) {
  ErrorOr<std::unique_ptr<MemoryBuffer>> CodeOrErr =
      MemoryBuffer::getFileOrSTDIN(FileName);
  if (std::error_code EC = CodeOrErr.getError()) {
    errs() << EC.message() << "\n";
    return true;
  }
  std::unique_ptr<llvm::MemoryBuffer> Code = std::move(CodeOrErr.get());
  if (Code->getBufferSize() == 0)
    return false; // Empty files are formatted correctly.
  std::vector<tooling::Range> Ranges;
  if (fillRanges(Code.get(), Ranges))
    return true;
  StringRef AssumedFileName = (FileName == "-") ? AssumeFileName : FileName;
  FormatStyle FormatStyle =
      getStyle(Style, AssumedFileName, FallbackStyle, Code->getBuffer());
  if (SortIncludes.getNumOccurrences() != 0)
    FormatStyle.SortIncludes = SortIncludes;
  unsigned CursorPosition = Cursor;
  Replacements Replaces = sortIncludes(FormatStyle, Code->getBuffer(), Ranges,
                                       AssumedFileName, &CursorPosition);
  auto ChangedCode = tooling::applyAllReplacements(Code->getBuffer(), Replaces);
  if (!ChangedCode) {
    llvm::errs() << llvm::toString(ChangedCode.takeError()) << "\n";
    return true;
  }
  // Get new affected ranges after sorting `#includes`.
  Ranges = tooling::calculateRangesAfterReplacements(Replaces, Ranges);
  bool IncompleteFormat = false;
  Replacements FormatChanges = reformat(FormatStyle, *ChangedCode, Ranges,
                                        AssumedFileName, &IncompleteFormat);
  Replaces = Replaces.merge(FormatChanges);
  if (OutputXML) {
    outs() << "<?xml version='1.0'?>\n<replacements "
              "xml:space='preserve' incomplete_format='"
           << (IncompleteFormat ? "true" : "false") << "'>\n";
    if (Cursor.getNumOccurrences() != 0)
      outs() << "<cursor>"
             << FormatChanges.getShiftedCodePosition(CursorPosition)
             << "</cursor>\n";

    outputReplacementsXML(Replaces);
    outs() << "</replacements>\n";
  } else {
    IntrusiveRefCntPtr<vfs::InMemoryFileSystem> InMemoryFileSystem(
        new vfs::InMemoryFileSystem);
    FileManager Files(FileSystemOptions(), InMemoryFileSystem);
    DiagnosticsEngine Diagnostics(
        IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
        new DiagnosticOptions);
    SourceManager Sources(Diagnostics, Files);
    FileID ID = createInMemoryFile(AssumedFileName, Code.get(), Sources, Files,
                                   InMemoryFileSystem.get());
    Rewriter Rewrite(Sources, LangOptions());
    tooling::applyAllReplacements(Replaces, Rewrite);
    if (Inplace) {
      if (FileName == "-")
        errs() << "error: cannot use -i when reading from stdin.\n";
      else if (Rewrite.overwriteChangedFiles())
        return true;
    } else {
      if (Cursor.getNumOccurrences() != 0)
        outs() << "{ \"Cursor\": "
               << FormatChanges.getShiftedCodePosition(CursorPosition)
               << ", \"IncompleteFormat\": "
               << (IncompleteFormat ? "true" : "false") << " }\n";
      Rewrite.getEditBuffer(ID).write(outs());
    }
  }
  return false;
}

static std::unique_ptr<Module>
getModuleForFile(LLVMContext &Context, claimed_file &F, raw_fd_ostream *ApiFile,
                 StringSet<> &Internalize, StringSet<> &Maybe) {
  ld_plugin_input_file File;
  if (get_input_file(F.handle, &File) != LDPS_OK)
    message(LDPL_FATAL, "Failed to get file information");

  if (get_symbols(F.handle, F.syms.size(), &F.syms[0]) != LDPS_OK)
    message(LDPL_FATAL, "Failed to get symbol information");

  const void *View;
  if (get_view(F.handle, &View) != LDPS_OK)
    message(LDPL_FATAL, "Failed to get a view of file");

  llvm::ErrorOr<MemoryBufferRef> MBOrErr =
      object::IRObjectFile::findBitcodeInMemBuffer(
          MemoryBufferRef(StringRef((const char *)View, File.filesize), ""));
  if (std::error_code EC = MBOrErr.getError())
    message(LDPL_FATAL, "Could not read bitcode from file : %s",
            EC.message().c_str());

  std::unique_ptr<MemoryBuffer> Buffer =
      MemoryBuffer::getMemBuffer(MBOrErr->getBuffer(), "", false);

  if (release_input_file(F.handle) != LDPS_OK)
    message(LDPL_FATAL, "Failed to release file information");

  ErrorOr<Module *> MOrErr = getLazyBitcodeModule(std::move(Buffer), Context);

  if (std::error_code EC = MOrErr.getError())
    message(LDPL_FATAL, "Could not read bitcode from file : %s",
            EC.message().c_str());

  std::unique_ptr<Module> M(MOrErr.get());

  SmallPtrSet<GlobalValue *, 8> Used;
  collectUsedGlobalVariables(*M, Used, /*CompilerUsed*/ false);

  DenseSet<GlobalValue *> Drop;
  std::vector<GlobalAlias *> KeptAliases;
  for (ld_plugin_symbol &Sym : F.syms) {
    ld_plugin_symbol_resolution Resolution =
        (ld_plugin_symbol_resolution)Sym.resolution;

    if (options::generate_api_file)
      *ApiFile << Sym.name << ' ' << getResolutionName(Resolution) << '\n';

    GlobalValue *GV = M->getNamedValue(Sym.name);
    if (!GV)
      continue; // Asm symbol.

    if (Resolution != LDPR_PREVAILING_DEF_IRONLY && GV->hasCommonLinkage()) {
      // Common linkage is special. There is no single symbol that wins the
      // resolution. Instead we have to collect the maximum alignment and size.
      // The IR linker does that for us if we just pass it every common GV.
      // We still have to keep track of LDPR_PREVAILING_DEF_IRONLY so we
      // internalize once the IR linker has done its job.
      continue;
    }

    switch (Resolution) {
    case LDPR_UNKNOWN:
      llvm_unreachable("Unexpected resolution");

    case LDPR_RESOLVED_IR:
    case LDPR_RESOLVED_EXEC:
    case LDPR_RESOLVED_DYN:
    case LDPR_UNDEF:
      assert(GV->isDeclarationForLinker());
      break;

    case LDPR_PREVAILING_DEF_IRONLY: {
      keepGlobalValue(*GV, KeptAliases);
      if (!Used.count(GV)) {
        // Since we use the regular lib/Linker, we cannot just internalize GV
        // now or it will not be copied to the merged module. Instead we force
        // it to be copied and then internalize it.
        Internalize.insert(Sym.name);
      }
      break;
    }

    case LDPR_PREVAILING_DEF:
      keepGlobalValue(*GV, KeptAliases);
      break;

    case LDPR_PREEMPTED_IR:
      // Gold might have selected a linkonce_odr and preempted a weak_odr.
      // In that case we have to make sure we don't end up internalizing it.
      if (!GV->isDiscardableIfUnused())
        Maybe.erase(Sym.name);

      // fall-through
    case LDPR_PREEMPTED_REG:
      Drop.insert(GV);
      break;

    case LDPR_PREVAILING_DEF_IRONLY_EXP: {
      // We can only check for address uses after we merge the modules. The
      // reason is that this GV might have a copy in another module
//.........这里部分代码省略.........

/// Import any functions requested via the -import option.
static bool importFunctions(const char *argv0, LLVMContext &Context,
                            Linker &L) {
  if (SummaryIndex.empty())
    return true;
  ErrorOr<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
      llvm::getModuleSummaryIndexForFile(SummaryIndex, diagnosticHandler);
  std::error_code EC = IndexOrErr.getError();
  if (EC) {
    errs() << EC.message() << '\n';
    return false;
  }
  auto Index = std::move(IndexOrErr.get());

  // Map of Module -> List of globals to import from the Module
  std::map<StringRef, DenseSet<const GlobalValue *>> ModuleToGlobalsToImportMap;
  auto ModuleLoader = [&Context](const char *argv0,
                                 const std::string &Identifier) {
    return loadFile(argv0, Identifier, Context, false);
  };
  ModuleLazyLoaderCache ModuleLoaderCache(ModuleLoader);
  for (const auto &Import : Imports) {
    // Identify the requested function and its bitcode source file.
    size_t Idx = Import.find(':');
    if (Idx == std::string::npos) {
      errs() << "Import parameter bad format: " << Import << "\n";
      return false;
    }
    std::string FunctionName = Import.substr(0, Idx);
    std::string FileName = Import.substr(Idx + 1, std::string::npos);

    // Load the specified source module.
    auto &SrcModule = ModuleLoaderCache(argv0, FileName);

    if (verifyModule(SrcModule, &errs())) {
      errs() << argv0 << ": " << FileName
             << ": error: input module is broken!\n";
      return false;
    }

    Function *F = SrcModule.getFunction(FunctionName);
    if (!F) {
      errs() << "Ignoring import request for non-existent function "
             << FunctionName << " from " << FileName << "\n";
      continue;
    }
    // We cannot import weak_any functions without possibly affecting the
    // order they are seen and selected by the linker, changing program
    // semantics.
    if (F->hasWeakAnyLinkage()) {
      errs() << "Ignoring import request for weak-any function " << FunctionName
             << " from " << FileName << "\n";
      continue;
    }

    if (Verbose)
      errs() << "Importing " << FunctionName << " from " << FileName << "\n";

    auto &Entry = ModuleToGlobalsToImportMap[SrcModule.getModuleIdentifier()];
    Entry.insert(F);

    F->materialize();
  }

  // Do the actual import of globals now, one Module at a time
  for (auto &GlobalsToImportPerModule : ModuleToGlobalsToImportMap) {
    // Get the module for the import
    auto &GlobalsToImport = GlobalsToImportPerModule.second;
    std::unique_ptr<Module> SrcModule =
        ModuleLoaderCache.takeModule(GlobalsToImportPerModule.first);
    assert(&Context == &SrcModule->getContext() && "Context mismatch");

    // If modules were created with lazy metadata loading, materialize it
    // now, before linking it (otherwise this will be a noop).
    SrcModule->materializeMetadata();
    UpgradeDebugInfo(*SrcModule);

    // Linkage Promotion and renaming
    if (renameModuleForThinLTO(*SrcModule, *Index, &GlobalsToImport))
      return true;

    // Instruct the linker to not automatically import linkonce defintion.
    unsigned Flags = Linker::Flags::DontForceLinkLinkonceODR;

    if (L.linkInModule(std::move(SrcModule), Flags, &GlobalsToImport))
      return false;
  }

  return true;
}

/// Called by gold to see whether this file is one that our plugin can handle.
/// We'll try to open it and register all the symbols with add_symbol if
/// possible.
static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
                                        int *claimed) {
  LLVMContext Context;
  MemoryBufferRef BufferRef;
  std::unique_ptr<MemoryBuffer> Buffer;
  if (get_view) {
    const void *view;
    if (get_view(file->handle, &view) != LDPS_OK) {
      message(LDPL_ERROR, "Failed to get a view of %s", file->name);
      return LDPS_ERR;
    }
    BufferRef = MemoryBufferRef(StringRef((const char *)view, file->filesize), "");
  } else {
    int64_t offset = 0;
    // Gold has found what might be IR part-way inside of a file, such as
    // an .a archive.
    if (file->offset) {
      offset = file->offset;
    }
    ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
        MemoryBuffer::getOpenFileSlice(file->fd, file->name, file->filesize,
                                       offset);
    if (std::error_code EC = BufferOrErr.getError()) {
      message(LDPL_ERROR, EC.message().c_str());
      return LDPS_ERR;
    }
    Buffer = std::move(BufferOrErr.get());
    BufferRef = Buffer->getMemBufferRef();
  }

  ErrorOr<std::unique_ptr<object::IRObjectFile>> ObjOrErr =
      object::IRObjectFile::createIRObjectFile(BufferRef, Context);
  std::error_code EC = ObjOrErr.getError();
  if (EC == BitcodeError::InvalidBitcodeSignature ||
      EC == object::object_error::invalid_file_type ||
      EC == object::object_error::bitcode_section_not_found)
    return LDPS_OK;

  *claimed = 1;

  if (EC) {
    message(LDPL_ERROR, "LLVM gold plugin has failed to create LTO module: %s",
            EC.message().c_str());
    return LDPS_ERR;
  }
  std::unique_ptr<object::IRObjectFile> Obj = std::move(*ObjOrErr);

  Modules.resize(Modules.size() + 1);
  claimed_file &cf = Modules.back();

  cf.handle = file->handle;

  for (auto &Sym : Obj->symbols()) {
    uint32_t Symflags = Sym.getFlags();
    if (!(Symflags & object::BasicSymbolRef::SF_Global))
      continue;

    if (Symflags & object::BasicSymbolRef::SF_FormatSpecific)
      continue;

    cf.syms.push_back(ld_plugin_symbol());
    ld_plugin_symbol &sym = cf.syms.back();
    sym.version = nullptr;

    SmallString<64> Name;
    {
      raw_svector_ostream OS(Name);
      Sym.printName(OS);
    }
    sym.name = strdup(Name.c_str());

    const GlobalValue *GV = Obj->getSymbolGV(Sym.getRawDataRefImpl());

    sym.visibility = LDPV_DEFAULT;
    if (GV) {
      switch (GV->getVisibility()) {
      case GlobalValue::DefaultVisibility:
        sym.visibility = LDPV_DEFAULT;
        break;
      case GlobalValue::HiddenVisibility:
        sym.visibility = LDPV_HIDDEN;
        break;
      case GlobalValue::ProtectedVisibility:
        sym.visibility = LDPV_PROTECTED;
        break;
      }
    }

    if (Symflags & object::BasicSymbolRef::SF_Undefined) {
      sym.def = LDPK_UNDEF;
      if (GV && GV->hasExternalWeakLinkage())
        sym.def = LDPK_WEAKUNDEF;
    } else {
      sym.def = LDPK_DEF;
      if (GV) {
        assert(!GV->hasExternalWeakLinkage() &&
               !GV->hasAvailableExternallyLinkage() && "Not a declaration!");
//.........这里部分代码省略.........

LTOModule *LTOModule::makeLTOModule(MemoryBufferRef Buffer,
                                    TargetOptions options, std::string &errMsg,
                                    LLVMContext *Context) {
  std::unique_ptr<LLVMContext> OwnedContext;
  if (!Context) {
    OwnedContext = llvm::make_unique<LLVMContext>();
    Context = OwnedContext.get();
  }

  ErrorOr<MemoryBufferRef> MBOrErr =
      IRObjectFile::findBitcodeInMemBuffer(Buffer);
  if (std::error_code EC = MBOrErr.getError()) {
    errMsg = EC.message();
    return nullptr;
  }
  ErrorOr<Module *> MOrErr = parseBitcodeFile(*MBOrErr, *Context);
  if (std::error_code EC = MOrErr.getError()) {
    errMsg = EC.message();
    return nullptr;
  }
  std::unique_ptr<Module> M(MOrErr.get());

  std::string TripleStr = M->getTargetTriple();
  if (TripleStr.empty())
    TripleStr = sys::getDefaultTargetTriple();
  llvm::Triple Triple(TripleStr);

  // find machine architecture for this module
  const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
  if (!march)
    return nullptr;

  // construct LTOModule, hand over ownership of module and target
  SubtargetFeatures Features;
  Features.getDefaultSubtargetFeatures(Triple);
  std::string FeatureStr = Features.getString();
  // Set a default CPU for Darwin triples.
  std::string CPU;
  if (Triple.isOSDarwin()) {
    if (Triple.getArch() == llvm::Triple::x86_64)
      CPU = "core2";
    else if (Triple.getArch() == llvm::Triple::x86)
      CPU = "yonah";
    else if (Triple.getArch() == llvm::Triple::aarch64)
      CPU = "cyclone";
  }

  TargetMachine *target = march->createTargetMachine(TripleStr, CPU, FeatureStr,
                                                     options);
  M->setDataLayout(target->getSubtargetImpl()->getDataLayout());

  std::unique_ptr<object::IRObjectFile> IRObj(
      new object::IRObjectFile(Buffer, std::move(M)));

  LTOModule *Ret;
  if (OwnedContext)
    Ret = new LTOModule(std::move(IRObj), target, std::move(OwnedContext));
  else
    Ret = new LTOModule(std::move(IRObj), target);

  if (Ret->parseSymbols(errMsg)) {
    delete Ret;
    return nullptr;
  }

  Ret->parseMetadata();

  return Ret;
}

/// ReadCheckFile - Read the check file, which specifies the sequence of
/// expected strings.  The strings are added to the CheckStrings vector.
/// Returns true in case of an error, false otherwise.
static bool ReadCheckFile(SourceMgr &SM,
                          std::vector<CheckString> &CheckStrings) {
  ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
      MemoryBuffer::getFileOrSTDIN(CheckFilename);
  if (std::error_code EC = FileOrErr.getError()) {
    errs() << "Could not open check file '" << CheckFilename
           << "': " << EC.message() << '\n';
    return true;
  }

  // If we want to canonicalize whitespace, strip excess whitespace from the
  // buffer containing the CHECK lines. Remove DOS style line endings.
  MemoryBuffer *F = CanonicalizeInputFile(FileOrErr.get().release(),
                                          NoCanonicalizeWhiteSpace);

  SM.AddNewSourceBuffer(F, SMLoc());

  // Find all instances of CheckPrefix followed by : in the file.
  StringRef Buffer = F->getBuffer();
  std::vector<Pattern> DagNotMatches;

  // LineNumber keeps track of the line on which CheckPrefix instances are
  // found.
  unsigned LineNumber = 1;

  while (1) {
    Check::CheckType CheckTy;
    size_t PrefixLoc;

    // See if a prefix occurs in the memory buffer.
    StringRef UsedPrefix = FindFirstMatchingPrefix(Buffer,
                                                   LineNumber,
                                                   CheckTy,
                                                   PrefixLoc);
    if (UsedPrefix.empty())
      break;

    Buffer = Buffer.drop_front(PrefixLoc);

    // Location to use for error messages.
    const char *UsedPrefixStart = Buffer.data() + (PrefixLoc == 0 ? 0 : 1);

    // PrefixLoc is to the start of the prefix. Skip to the end.
    Buffer = Buffer.drop_front(UsedPrefix.size() + CheckTypeSize(CheckTy));

    // Okay, we found the prefix, yay. Remember the rest of the line, but ignore
    // leading and trailing whitespace.
    Buffer = Buffer.substr(Buffer.find_first_not_of(" \t"));

    // Scan ahead to the end of line.
    size_t EOL = Buffer.find_first_of("\n\r");

    // Remember the location of the start of the pattern, for diagnostics.
    SMLoc PatternLoc = SMLoc::getFromPointer(Buffer.data());

    // Parse the pattern.
    Pattern P(CheckTy);
    if (P.ParsePattern(Buffer.substr(0, EOL), UsedPrefix, SM, LineNumber))
      return true;

    // Verify that CHECK-LABEL lines do not define or use variables
    if ((CheckTy == Check::CheckLabel) && P.hasVariable()) {
      SM.PrintMessage(SMLoc::getFromPointer(UsedPrefixStart),
                      SourceMgr::DK_Error,
                      "found '" + UsedPrefix + "-LABEL:'"
                      " with variable definition or use");
      return true;
    }

    Buffer = Buffer.substr(EOL);

    // Verify that CHECK-NEXT lines have at least one CHECK line before them.
    if ((CheckTy == Check::CheckNext) && CheckStrings.empty()) {
      SM.PrintMessage(SMLoc::getFromPointer(UsedPrefixStart),
                      SourceMgr::DK_Error,
                      "found '" + UsedPrefix + "-NEXT:' without previous '"
                      + UsedPrefix + ": line");
      return true;
    }

    // Handle CHECK-DAG/-NOT.
    if (CheckTy == Check::CheckDAG || CheckTy == Check::CheckNot) {
      DagNotMatches.push_back(P);
      continue;
    }

    // Okay, add the string we captured to the output vector and move on.
    CheckStrings.push_back(CheckString(P,
                                       UsedPrefix,
                                       PatternLoc,
                                       CheckTy));
    std::swap(DagNotMatches, CheckStrings.back().DagNotStrings);
  }

  // Add an EOF pattern for any trailing CHECK-DAG/-NOTs, and use the first
  // prefix as a filler for the error message.
  if (!DagNotMatches.empty()) {
//.........这里部分代码省略.........

void ObjectLoadListener::getDebugInfoForObject(
    const ObjectFile &Obj, const RuntimeDyld::LoadedObjectInfo &L) {
  OwningBinary<ObjectFile> DebugObjOwner = L.getObjectForDebug(Obj);
  const ObjectFile &DebugObj = *DebugObjOwner.getBinary();

  // TODO: This extracts DWARF information from the object file, but we will
  // want to also be able to eventually extract WinCodeView information as well
  DWARFContextInMemory DwarfContext(DebugObj);

  // Use symbol info to find the function size.
  // If there are funclets, they will each have separate symbols, so we need
  // to sum the sizes, since the EE wants a single report for the entire
  // function+funclets.

  uint64_t Addr = UINT64_MAX;
  uint64_t Size = 0;

  std::vector<std::pair<SymbolRef, uint64_t>> SymbolSizes =
      object::computeSymbolSizes(DebugObj);

  for (const auto &Pair : SymbolSizes) {
    object::SymbolRef Symbol = Pair.first;
    SymbolRef::Type SymType = Symbol.getType();
    if (SymType != SymbolRef::ST_Function)
      continue;

    // Function info
    ErrorOr<uint64_t> AddrOrError = Symbol.getAddress();
    if (!AddrOrError) {
      continue; // Error.
    }
    uint64_t SingleAddr = AddrOrError.get();
    uint64_t SingleSize = Pair.second;
    if (SingleAddr < Addr) {
      // The main function is always laid out first
      Addr = SingleAddr;
    }
    Size += SingleSize;
  }

  uint32_t LastDebugOffset = (uint32_t)-1;
  uint32_t NumDebugRanges = 0;
  ICorDebugInfo::OffsetMapping *OM;

  DILineInfoTable Lines = DwarfContext.getLineInfoForAddressRange(Addr, Size);

  DILineInfoTable::iterator Begin = Lines.begin();
  DILineInfoTable::iterator End = Lines.end();

  // Count offset entries. Will skip an entry if the current IL offset
  // matches the previous offset.
  for (DILineInfoTable::iterator It = Begin; It != End; ++It) {
    uint32_t LineNumber = (It->second).Line;

    if (LineNumber != LastDebugOffset) {
      NumDebugRanges++;
      LastDebugOffset = LineNumber;
    }
  }

  // Reset offset
  LastDebugOffset = (uint32_t)-1;

  if (NumDebugRanges > 0) {
    // Allocate OffsetMapping array
    unsigned SizeOfArray =
        (NumDebugRanges) * sizeof(ICorDebugInfo::OffsetMapping);
    OM = (ICorDebugInfo::OffsetMapping *)Context->JitInfo->allocateArray(
        SizeOfArray);

    unsigned CurrentDebugEntry = 0;

    // Iterate through the debug entries and save IL offset, native
    // offset, and source reason
    for (DILineInfoTable::iterator It = Begin; It != End; ++It) {
      int Offset = It->first;
      uint32_t LineNumber = (It->second).Line;

      // We store info about if the instruction is being recorded because
      // it is a call in the column field
      bool IsCall = (It->second).Column == 1;

      if (LineNumber != LastDebugOffset) {
        LastDebugOffset = LineNumber;
        OM[CurrentDebugEntry].nativeOffset = Offset;
        OM[CurrentDebugEntry].ilOffset = LineNumber;
        OM[CurrentDebugEntry].source = IsCall ? ICorDebugInfo::CALL_INSTRUCTION
                                              : ICorDebugInfo::STACK_EMPTY;
        CurrentDebugEntry++;
      }
    }

    // Send array of OffsetMappings to CLR EE
    CORINFO_METHOD_INFO *MethodInfo = Context->MethodInfo;
    CORINFO_METHOD_HANDLE MethodHandle = MethodInfo->ftn;

    Context->JitInfo->setBoundaries(MethodHandle, NumDebugRanges, OM);

    getDebugInfoForLocals(DwarfContext, Addr, Size);
  }
//.........这里部分代码省略.........