C++ MCStreamer::EmitIntValue方法代码示例

void BTFTypeFuncProto::emitType(MCStreamer &OS) {
  BTFTypeBase::emitType(OS);
  for (const auto &Param : Parameters) {
    OS.EmitIntValue(Param.NameOff, 4);
    OS.EmitIntValue(Param.Type, 4);
  }
}

/// emitModuleFlags - Emit the module flags that specify the garbage collection
/// information.
void TargetLoweringObjectFileMachO::
emitModuleFlags(MCStreamer &Streamer,
                ArrayRef<Module::ModuleFlagEntry> ModuleFlags,
                Mangler *Mang, const TargetMachine &TM) const {
  unsigned VersionVal = 0;
  unsigned ImageInfoFlags = 0;
  StringRef SectionVal;

  for (ArrayRef<Module::ModuleFlagEntry>::iterator
         i = ModuleFlags.begin(), e = ModuleFlags.end(); i != e; ++i) {
    const Module::ModuleFlagEntry &MFE = *i;

    // Ignore flags with 'Require' behavior.
    if (MFE.Behavior == Module::Require)
      continue;

    StringRef Key = MFE.Key->getString();
    Value *Val = MFE.Val;

    if (Key == "Objective-C Image Info Version")
      VersionVal = cast<ConstantInt>(Val)->getZExtValue();
    else if (Key == "Objective-C Garbage Collection" ||
             Key == "Objective-C GC Only" ||
             Key == "Objective-C Is Simulated")
      ImageInfoFlags |= cast<ConstantInt>(Val)->getZExtValue();
    else if (Key == "Objective-C Image Info Section")
      SectionVal = cast<MDString>(Val)->getString();
  }

  // The section is mandatory. If we don't have it, then we don't have GC info.
  if (SectionVal.empty()) return;

  StringRef Segment, Section;
  unsigned TAA = 0, StubSize = 0;
  bool TAAParsed;
  std::string ErrorCode =
    MCSectionMachO::ParseSectionSpecifier(SectionVal, Segment, Section,
                                          TAA, TAAParsed, StubSize);
  if (!ErrorCode.empty())
    // If invalid, report the error with report_fatal_error.
    report_fatal_error("Invalid section specifier '" + Section + "': " +
                       ErrorCode + ".");

  // Get the section.
  const MCSectionMachO *S =
    getContext().getMachOSection(Segment, Section, TAA, StubSize,
                                 SectionKind::getDataNoRel());
  Streamer.SwitchSection(S);
  Streamer.EmitLabel(getContext().
                     GetOrCreateSymbol(StringRef("L_OBJC_IMAGE_INFO")));
  Streamer.EmitIntValue(VersionVal, 4);
  Streamer.EmitIntValue(ImageInfoFlags, 4);
  Streamer.AddBlankLine();
}

static void
writeIndexTable(MCStreamer &Out, ArrayRef<unsigned> ContributionOffsets,
                const MapVector<uint64_t, UnitIndexEntry> &IndexEntries,
                uint32_t DWARFUnitIndex::Entry::SectionContribution::*Field) {
  for (const auto &E : IndexEntries)
    for (size_t i = 0; i != array_lengthof(E.second.Contributions); ++i)
      if (ContributionOffsets[i])
        Out.EmitIntValue(E.second.Contributions[i].*Field, 4);
}

void TargetLoweringObjectFileELF::emitModuleMetadata(
    MCStreamer &Streamer, Module &M, const TargetMachine &TM) const {
  unsigned Version = 0;
  unsigned Flags = 0;
  StringRef Section;

  GetObjCImageInfo(M, Version, Flags, Section);
  if (Section.empty())
    return;

  auto &C = getContext();
  auto *S = C.getELFSection(Section, ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
  Streamer.SwitchSection(S);
  Streamer.EmitLabel(C.getOrCreateSymbol(StringRef("OBJC_IMAGE_INFO")));
  Streamer.EmitIntValue(Version, 4);
  Streamer.EmitIntValue(Flags, 4);
  Streamer.AddBlankLine();
}

static void EmitUnwindCode(MCStreamer &streamer, MCSymbol *begin,
                           MCWin64EHInstruction &inst) {
  uint8_t b1, b2;
  uint16_t w;
  b2 = (inst.getOperation() & 0x0F);
  switch (inst.getOperation()) {
  case Win64EH::UOP_PushNonVol:
    EmitAbsDifference(streamer, inst.getLabel(), begin);
    b2 |= (inst.getRegister() & 0x0F) << 4;
    streamer.EmitIntValue(b2, 1);
    break;
  case Win64EH::UOP_AllocLarge:
    EmitAbsDifference(streamer, inst.getLabel(), begin);
    if (inst.getSize() > 512*1024-8) {
      b2 |= 0x10;
      streamer.EmitIntValue(b2, 1);
      w = inst.getSize() & 0xFFF8;
      streamer.EmitIntValue(w, 2);
      w = inst.getSize() >> 16;
    } else {

static void
writeIndex(MCStreamer &Out, MCSection *Section,
           ArrayRef<unsigned> ContributionOffsets,
           const MapVector<uint64_t, UnitIndexEntry> &IndexEntries) {
  if (IndexEntries.empty())
    return;

  unsigned Columns = 0;
  for (auto &C : ContributionOffsets)
    if (C)
      ++Columns;

  std::vector<unsigned> Buckets(NextPowerOf2(3 * IndexEntries.size() / 2));
  uint64_t Mask = Buckets.size() - 1;
  size_t i = 0;
  for (const auto &P : IndexEntries) {
    auto S = P.first;
    auto H = S & Mask;
    auto HP = ((S >> 32) & Mask) | 1;
    while (Buckets[H]) {
      assert(S != IndexEntries.begin()[Buckets[H] - 1].first &&
             "Duplicate unit");
      H = (H + HP) & Mask;
    }
    Buckets[H] = i + 1;
    ++i;
  }

  Out.SwitchSection(Section);
  Out.EmitIntValue(2, 4);                   // Version
  Out.EmitIntValue(Columns, 4);             // Columns
  Out.EmitIntValue(IndexEntries.size(), 4); // Num Units
  Out.EmitIntValue(Buckets.size(), 4);      // Num Buckets

  // Write the signatures.
  for (const auto &I : Buckets)
    Out.EmitIntValue(I ? IndexEntries.begin()[I - 1].first : 0, 8);

  // Write the indexes.
  for (const auto &I : Buckets)
    Out.EmitIntValue(I, 4);

  // Write the column headers (which sections will appear in the table)
  for (size_t i = 0; i != ContributionOffsets.size(); ++i)
    if (ContributionOffsets[i])
      Out.EmitIntValue(i + DW_SECT_INFO, 4);

  // Write the offsets.
  writeIndexTable(Out, ContributionOffsets, IndexEntries,
                  &DWARFUnitIndex::Entry::SectionContribution::Offset);

  // Write the lengths.
  writeIndexTable(Out, ContributionOffsets, IndexEntries,
                  &DWARFUnitIndex::Entry::SectionContribution::Length);
}

// Integrated assembler version
void
MipsReginfo::emitMipsReginfoSectionCG(MCStreamer &OS,
    const TargetLoweringObjectFile &TLOF,
    const MipsSubtarget &MST) const
{

  if (OS.hasRawTextSupport())
    return;

  const MipsTargetObjectFile &TLOFELF =
      static_cast<const MipsTargetObjectFile &>(TLOF);
  OS.SwitchSection(TLOFELF.getReginfoSection());

  // .reginfo
  if (MST.isABI_O32()) {
    OS.EmitIntValue(0, 4); // ri_gprmask
    OS.EmitIntValue(0, 4); // ri_cpr[0]mask
    OS.EmitIntValue(0, 4); // ri_cpr[1]mask
    OS.EmitIntValue(0, 4); // ri_cpr[2]mask
    OS.EmitIntValue(0, 4); // ri_cpr[3]mask
    OS.EmitIntValue(0, 4); // ri_gp_value
  }
  // .MIPS.options
  else if (MST.isABI_N64()) {
    OS.EmitIntValue(1, 1); // kind
    OS.EmitIntValue(40, 1); // size
    OS.EmitIntValue(0, 2); // section
    OS.EmitIntValue(0, 4); // info
    OS.EmitIntValue(0, 4); // ri_gprmask
    OS.EmitIntValue(0, 4); // pad
    OS.EmitIntValue(0, 4); // ri_cpr[0]mask
    OS.EmitIntValue(0, 4); // ri_cpr[1]mask
    OS.EmitIntValue(0, 4); // ri_cpr[2]mask
    OS.EmitIntValue(0, 4); // ri_cpr[3]mask
    OS.EmitIntValue(0, 8); // ri_gp_value
  }
  else llvm_unreachable("Unsupported abi for reginfo");
}

static std::error_code
writeStringsAndOffsets(MCStreamer &Out, StringMap<uint32_t> &Strings,
                       uint32_t &StringOffset, MCSection *StrSection,
                       MCSection *StrOffsetSection, StringRef CurStrSection,
                       StringRef CurStrOffsetSection) {
  // Could possibly produce an error or warning if one of these was non-null but
  // the other was null.
  if (CurStrSection.empty() || CurStrOffsetSection.empty())
    return std::error_code();

  DenseMap<uint32_t, uint32_t> OffsetRemapping;

  DataExtractor Data(CurStrSection, true, 0);
  uint32_t LocalOffset = 0;
  uint32_t PrevOffset = 0;
  while (const char *s = Data.getCStr(&LocalOffset)) {
    StringRef Str(s, LocalOffset - PrevOffset - 1);
    auto Pair = Strings.insert(std::make_pair(Str, StringOffset));
    if (Pair.second) {
      Out.SwitchSection(StrSection);
      Out.EmitBytes(
          StringRef(Pair.first->getKeyData(), Pair.first->getKeyLength() + 1));
      StringOffset += Str.size() + 1;
    }
    OffsetRemapping[PrevOffset] = Pair.first->second;
    PrevOffset = LocalOffset;
  }

  Data = DataExtractor(CurStrOffsetSection, true, 0);

  Out.SwitchSection(StrOffsetSection);

  uint32_t Offset = 0;
  uint64_t Size = CurStrOffsetSection.size();
  while (Offset < Size) {
    auto OldOffset = Data.getU32(&Offset);
    auto NewOffset = OffsetRemapping[OldOffset];
    Out.EmitIntValue(NewOffset, 4);
  }

  return std::error_code();
}

static void
emitNonLazySymbolPointer(MCStreamer &OutStreamer, MCSymbol *StubLabel,
                         MachineModuleInfoImpl::StubValueTy &MCSym) {
  // L_foo$stub:
  OutStreamer.EmitLabel(StubLabel);
  //   .indirect_symbol _foo
  OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);

  if (MCSym.getInt())
    // External to current translation unit.
    OutStreamer.EmitIntValue(0, 4/*size*/);
  else
    // Internal to current translation unit.
    //
    // When we place the LSDA into the TEXT section, the type info
    // pointers need to be indirect and pc-rel. We accomplish this by
    // using NLPs; however, sometimes the types are local to the file.
    // We need to fill in the value for the NLP in those cases.
    OutStreamer.EmitValue(
        MCSymbolRefExpr::create(MCSym.getPointer(), OutStreamer.getContext()),
        4 /*size*/);
}

/// emitModuleFlags - Perform code emission for module flags.
void TargetLoweringObjectFileMachO::
emitModuleFlags(MCStreamer &Streamer,
                ArrayRef<Module::ModuleFlagEntry> ModuleFlags,
                Mangler &Mang, const TargetMachine &TM) const {
  unsigned VersionVal = 0;
  unsigned ImageInfoFlags = 0;
  MDNode *LinkerOptions = nullptr;
  StringRef SectionVal;

  for (ArrayRef<Module::ModuleFlagEntry>::iterator
         i = ModuleFlags.begin(), e = ModuleFlags.end(); i != e; ++i) {
    const Module::ModuleFlagEntry &MFE = *i;

    // Ignore flags with 'Require' behavior.
    if (MFE.Behavior == Module::Require)
      continue;

    StringRef Key = MFE.Key->getString();
    Metadata *Val = MFE.Val;

    if (Key == "Objective-C Image Info Version") {
      VersionVal = mdconst::extract<ConstantInt>(Val)->getZExtValue();
    } else if (Key == "Objective-C Garbage Collection" ||
               Key == "Objective-C GC Only" ||
               Key == "Objective-C Is Simulated" ||
               Key == "Objective-C Image Swift Version") {
      ImageInfoFlags |= mdconst::extract<ConstantInt>(Val)->getZExtValue();
    } else if (Key == "Objective-C Image Info Section") {
      SectionVal = cast<MDString>(Val)->getString();
    } else if (Key == "Linker Options") {
      LinkerOptions = cast<MDNode>(Val);
    }
  }

  // Emit the linker options if present.
  if (LinkerOptions) {
    for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) {
      MDNode *MDOptions = cast<MDNode>(LinkerOptions->getOperand(i));
      SmallVector<std::string, 4> StrOptions;

      // Convert to strings.
      for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
        MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
        StrOptions.push_back(MDOption->getString());
      }

      Streamer.EmitLinkerOptions(StrOptions);
    }
  }

  // The section is mandatory. If we don't have it, then we don't have GC info.
  if (SectionVal.empty()) return;

  StringRef Segment, Section;
  unsigned TAA = 0, StubSize = 0;
  bool TAAParsed;
  std::string ErrorCode =
    MCSectionMachO::ParseSectionSpecifier(SectionVal, Segment, Section,
                                          TAA, TAAParsed, StubSize);
  if (!ErrorCode.empty())
    // If invalid, report the error with report_fatal_error.
    report_fatal_error("Invalid section specifier '" + Section + "': " +
                       ErrorCode + ".");

  // Get the section.
  const MCSectionMachO *S =
    getContext().getMachOSection(Segment, Section, TAA, StubSize,
                                 SectionKind::getDataNoRel());
  Streamer.SwitchSection(S);
  Streamer.EmitLabel(getContext().
                     GetOrCreateSymbol(StringRef("L_OBJC_IMAGE_INFO")));
  Streamer.EmitIntValue(VersionVal, 4);
  Streamer.EmitIntValue(ImageInfoFlags, 4);
  Streamer.AddBlankLine();
}

static std::error_code write(MCStreamer &Out, ArrayRef<std::string> Inputs) {
  const auto &MCOFI = *Out.getContext().getObjectFileInfo();
  MCSection *const StrSection = MCOFI.getDwarfStrDWOSection();
  MCSection *const StrOffsetSection = MCOFI.getDwarfStrOffDWOSection();
  const StringMap<std::pair<MCSection *, DWARFSectionKind>> KnownSections = {
      {"debug_info.dwo", {MCOFI.getDwarfInfoDWOSection(), DW_SECT_INFO}},
      {"debug_types.dwo", {MCOFI.getDwarfTypesDWOSection(), DW_SECT_TYPES}},
      {"debug_str_offsets.dwo", {StrOffsetSection, DW_SECT_STR_OFFSETS}},
      {"debug_str.dwo", {StrSection, static_cast<DWARFSectionKind>(0)}},
      {"debug_loc.dwo", {MCOFI.getDwarfLocDWOSection(), DW_SECT_LOC}},
      {"debug_abbrev.dwo", {MCOFI.getDwarfAbbrevDWOSection(), DW_SECT_ABBREV}}};

  struct UnitIndexEntry {
    uint64_t Signature;
    DWARFUnitIndex::Entry::SectionContribution Contributions[8];
  };

  std::vector<UnitIndexEntry> IndexEntries;

  StringMap<uint32_t> Strings;
  uint32_t StringOffset = 0;

  uint64_t UnitIndex = 0;
  uint32_t ContributionOffsets[8] = {};

  for (const auto &Input : Inputs) {
    auto ErrOrObj = object::ObjectFile::createObjectFile(Input);
    if (!ErrOrObj)
      return ErrOrObj.getError();

    IndexEntries.emplace_back();
    UnitIndexEntry &CurEntry = IndexEntries.back();
    CurEntry.Signature = UnitIndex++;

    StringRef CurStrSection;
    StringRef CurStrOffsetSection;

    for (const auto &Section : ErrOrObj->getBinary()->sections()) {
      StringRef Name;
      if (std::error_code Err = Section.getName(Name))
        return Err;

      auto SectionPair =
          KnownSections.find(Name.substr(Name.find_first_not_of("._")));
      if (SectionPair == KnownSections.end())
        continue;

      StringRef Contents;
      if (auto Err = Section.getContents(Contents))
        return Err;

      if (DWARFSectionKind Kind = SectionPair->second.second) {
        auto Index = Kind - DW_SECT_INFO;
        CurEntry.Contributions[Index].Offset = ContributionOffsets[Index];
        ContributionOffsets[Index] +=
            (CurEntry.Contributions[Index].Length = Contents.size());
      }

      MCSection *OutSection = SectionPair->second.first;
      if (OutSection == StrOffsetSection)
        CurStrOffsetSection = Contents;
      else if (OutSection == StrSection)
        CurStrSection = Contents;
      else {
        Out.SwitchSection(OutSection);
        Out.EmitBytes(Contents);
      }
    }

    if (auto Err = writeStringsAndOffsets(Out, Strings, StringOffset,
                                          StrSection, StrOffsetSection,
                                          CurStrSection, CurStrOffsetSection))
      return Err;
  }

  Out.SwitchSection(MCOFI.getDwarfCUIndexSection());
  Out.EmitIntValue(2, 4);                   // Version
  Out.EmitIntValue(8, 4);                   // Columns
  Out.EmitIntValue(IndexEntries.size(), 4); // Num Units
  // FIXME: This is not the right number of buckets for a real hash.
  Out.EmitIntValue(IndexEntries.size(), 4); // Num Buckets

  // Write the signatures.
  for (const auto &E : IndexEntries)
    Out.EmitIntValue(E.Signature, 8);

  // Write the indexes.
  for (size_t i = 0; i != IndexEntries.size(); ++i)
    Out.EmitIntValue(i + 1, 4);

  // Write the column headers (which sections will appear in the table)
  for (size_t i = 1; i != 9; ++i)
    Out.EmitIntValue(i, 4);

  // Write the offsets.
  for (const auto &E : IndexEntries)
    for (const auto &C : E.Contributions)
      Out.EmitIntValue(C.Offset, 4);

  // Write the lengths.
//.........这里部分代码省略.........

void EmitCFIInstruction(MCStreamer &Streamer,
                        const MCCFIInstruction &Instr,
                        int &CFAOffset, int DataAlignmentFactor) {
  // Same as MCDwarf::EmitCFIInstruction ()
  // FIXME: Unify
  int dataAlignmentFactor = DataAlignmentFactor;
  bool VerboseAsm = Streamer.isVerboseAsm();

  switch (Instr.getOperation()) {
  case MCCFIInstruction::OpWindowSave: {
    Streamer.EmitIntValue(dwarf::DW_CFA_GNU_window_save, 1);
    return;
  }
  case MCCFIInstruction::OpUndefined: {
    unsigned Reg = Instr.getRegister();
    if (VerboseAsm) {
      Streamer.AddComment("DW_CFA_undefined");
      Streamer.AddComment(Twine("Reg ") + Twine(Reg));
    }
    Streamer.EmitIntValue(dwarf::DW_CFA_undefined, 1);
    Streamer.EmitULEB128IntValue(Reg);
    return;
  }
  case MCCFIInstruction::OpAdjustCfaOffset:
  case MCCFIInstruction::OpDefCfaOffset: {
    const bool IsRelative =
      Instr.getOperation() == MCCFIInstruction::OpAdjustCfaOffset;

    if (VerboseAsm)
      Streamer.AddComment("DW_CFA_def_cfa_offset");
    Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_offset, 1);

    if (IsRelative)
      CFAOffset += Instr.getOffset();
    else
      // The backends pass in a negative value,
      // then createDefCfaOffset () negates it
      CFAOffset = Instr.getOffset();

    if (VerboseAsm)
      Streamer.AddComment(Twine("Offset " + Twine(CFAOffset)));
    Streamer.EmitULEB128IntValue(CFAOffset);

    return;
  }
  case MCCFIInstruction::OpDefCfa: {
    if (VerboseAsm)
      Streamer.AddComment("DW_CFA_def_cfa");
    Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa, 1);

    if (VerboseAsm)
      Streamer.AddComment(Twine("Reg ") + Twine(Instr.getRegister()));
    Streamer.EmitULEB128IntValue(Instr.getRegister());

    // Backends pass a negative value to createDefCfa () which
	// negates it back
    CFAOffset = Instr.getOffset();

    if (VerboseAsm)
      Streamer.AddComment(Twine("Offset " + Twine(CFAOffset)));
    Streamer.EmitULEB128IntValue(CFAOffset);

    return;
  }

  case MCCFIInstruction::OpDefCfaRegister: {
    if (VerboseAsm)
      Streamer.AddComment("DW_CFA_def_cfa_register");
    Streamer.EmitIntValue(dwarf::DW_CFA_def_cfa_register, 1);

    if (VerboseAsm)
      Streamer.AddComment(Twine("Reg ") + Twine(Instr.getRegister()));
    Streamer.EmitULEB128IntValue(Instr.getRegister());

    return;
  }

  case MCCFIInstruction::OpOffset:
  case MCCFIInstruction::OpRelOffset: {
    const bool IsRelative =
      Instr.getOperation() == MCCFIInstruction::OpRelOffset;

    unsigned Reg = Instr.getRegister();
    int Offset = Instr.getOffset();
    if (IsRelative)
      Offset -= CFAOffset;
    Offset = Offset / dataAlignmentFactor;

    if (Offset < 0) {
      if (VerboseAsm) Streamer.AddComment("DW_CFA_offset_extended_sf");
      Streamer.EmitIntValue(dwarf::DW_CFA_offset_extended_sf, 1);
      if (VerboseAsm) Streamer.AddComment(Twine("Reg ") + Twine(Reg));
      Streamer.EmitULEB128IntValue(Reg);
      if (VerboseAsm) Streamer.AddComment(Twine("Offset ") + Twine(Offset));
      Streamer.EmitSLEB128IntValue(Offset);
    } else if (Reg < 64) {
      if (VerboseAsm) Streamer.AddComment(Twine("DW_CFA_offset + Reg(") +
                                          Twine(Reg) + ")");
      Streamer.EmitIntValue(dwarf::DW_CFA_offset + Reg, 1);
      if (VerboseAsm) Streamer.AddComment(Twine("Offset ") + Twine(Offset));
//.........这里部分代码省略.........

static void EncodeTypes(MCStreamer &Streamer, ArrayRef<MVT> Types) {
  Streamer.EmitIntValue(Types.size(), sizeof(uint64_t));
  for (MVT Type : Types)
    Streamer.EmitIntValue(Type.SimpleTy, sizeof(uint64_t));
}