C++ SectionRef::getAddress方法代码示例

RelocationValueRef RuntimeDyldMachO::getRelocationValueRef(
    const ObjectFile &BaseTObj, const relocation_iterator &RI,
    const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID) {

  const MachOObjectFile &Obj =
      static_cast<const MachOObjectFile &>(BaseTObj);
  MachO::any_relocation_info RelInfo =
      Obj.getRelocation(RI->getRawDataRefImpl());
  RelocationValueRef Value;

  bool IsExternal = Obj.getPlainRelocationExternal(RelInfo);
  if (IsExternal) {
    symbol_iterator Symbol = RI->getSymbol();
    StringRef TargetName;
    Symbol->getName(TargetName);
    SymbolTableMap::const_iterator SI =
      GlobalSymbolTable.find(TargetName.data());
    if (SI != GlobalSymbolTable.end()) {
      Value.SectionID = SI->second.first;
      Value.Offset = SI->second.second + RE.Addend;
    } else {
      Value.SymbolName = TargetName.data();
      Value.Offset = RE.Addend;
    }
  } else {
    SectionRef Sec = Obj.getRelocationSection(RelInfo);
    bool IsCode = Sec.isText();
    Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
    uint64_t Addr = Sec.getAddress();
    Value.Offset = RE.Addend - Addr;
  }

  return Value;
}

MCMachObjectSymbolizer::MCMachObjectSymbolizer(
    MCContext &Ctx, std::unique_ptr<MCRelocationInfo> &RelInfo,
    const MachOObjectFile *MOOF)
    : MCObjectSymbolizer(Ctx, RelInfo, MOOF), MOOF(MOOF), StubsStart(0),
      StubsCount(0), StubSize(0), StubsIndSymIndex(0) {

  for (const SectionRef &Section : MOOF->sections()) {
    StringRef Name;
    Section.getName(Name);
    if (Name == "__stubs") {
      SectionRef StubsSec = Section;
      if (MOOF->is64Bit()) {
        MachO::section_64 S = MOOF->getSection64(StubsSec.getRawDataRefImpl());
        StubsIndSymIndex = S.reserved1;
        StubSize = S.reserved2;
      } else {
        MachO::section S = MOOF->getSection(StubsSec.getRawDataRefImpl());
        StubsIndSymIndex = S.reserved1;
        StubSize = S.reserved2;
      }
      assert(StubSize && "Mach-O stub entry size can't be zero!");
      StubsSec.getAddress(StubsStart);
      StubsSec.getSize(StubsCount);
      StubsCount /= StubSize;
    }
  }
}

 explicit section(const SectionRef& sec) {
     StringRef name;
     if(error_code err = sec.getName(name))
         llvm_binary_fail(err);
     this->name_ = name.str();
     if (error_code err = sec.getAddress(this->addr_))
         llvm_binary_fail(err);
     
     if (error_code err = sec.getSize(this->size_))
         llvm_binary_fail(err);
 }

/// Given a relocation from __compact_unwind, consisting of the RelocationRef
/// and data being relocated, determine the best base Name and Addend to use for
/// display purposes.
///
/// 1. An Extern relocation will directly reference a symbol (and the data is
///    then already an addend), so use that.
/// 2. Otherwise the data is an offset in the object file's layout; try to find
//     a symbol before it in the same section, and use the offset from there.
/// 3. Finally, if all that fails, fall back to an offset from the start of the
///    referenced section.
static void findUnwindRelocNameAddend(const MachOObjectFile *Obj,
                                      std::map<uint64_t, SymbolRef> &Symbols,
                                      const RelocationRef &Reloc,
                                      uint64_t Addr,
                                      StringRef &Name, uint64_t &Addend) {
  if (Reloc.getSymbol() != Obj->symbol_end()) {
    Reloc.getSymbol()->getName(Name);
    Addend = Addr;
    return;
  }

  auto RE = Obj->getRelocation(Reloc.getRawDataRefImpl());
  SectionRef RelocSection = Obj->getRelocationSection(RE);

  uint64_t SectionAddr;
  RelocSection.getAddress(SectionAddr);

  auto Sym = Symbols.upper_bound(Addr);
  if (Sym == Symbols.begin()) {
    // The first symbol in the object is after this reference, the best we can
    // do is section-relative notation.
    RelocSection.getName(Name);
    Addend = Addr - SectionAddr;
    return;
  }

  // Go back one so that SymbolAddress <= Addr.
  --Sym;

  section_iterator SymSection = Obj->section_end();
  Sym->second.getSection(SymSection);
  if (RelocSection == *SymSection) {
    // There's a valid symbol in the same section before this reference.
    Sym->second.getName(Name);
    Addend = Addr - Sym->first;
    return;
  }

  // There is a symbol before this reference, but it's in a different
  // section. Probably not helpful to mention it, so use the section name.
  RelocSection.getName(Name);
  Addend = Addr - SectionAddr;
}

RelocationValueRef RuntimeDyldMachO::getRelocationValueRef(
    const ObjectFile &BaseTObj, const relocation_iterator &RI,
    const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID) {

  const MachOObjectFile &Obj =
      static_cast<const MachOObjectFile &>(BaseTObj);
  MachO::any_relocation_info RelInfo =
      Obj.getRelocation(RI->getRawDataRefImpl());
  RelocationValueRef Value;

  bool IsExternal = Obj.getPlainRelocationExternal(RelInfo);
  if (IsExternal) {
    symbol_iterator Symbol = RI->getSymbol();
    ErrorOr<StringRef> TargetNameOrErr = Symbol->getName();
    if (std::error_code EC = TargetNameOrErr.getError())
      report_fatal_error(EC.message());
    StringRef TargetName = *TargetNameOrErr;
    RTDyldSymbolTable::const_iterator SI =
      GlobalSymbolTable.find(TargetName.data());
    if (SI != GlobalSymbolTable.end()) {
      const auto &SymInfo = SI->second;
      Value.SectionID = SymInfo.getSectionID();
      Value.Offset = SymInfo.getOffset() + RE.Addend;
    } else {
      Value.SymbolName = TargetName.data();
      Value.Offset = RE.Addend;
    }
  } else {
    SectionRef Sec = Obj.getAnyRelocationSection(RelInfo);
    bool IsCode = Sec.isText();
    Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
    uint64_t Addr = Sec.getAddress();
    Value.Offset = RE.Addend - Addr;
  }

  return Value;
}

void RuntimeDyldMachO::processRelocationRef(unsigned SectionID,
                                            RelocationRef RelI,
                                            ObjectImage &Obj,
                                            ObjSectionToIDMap &ObjSectionToID,
                                            const SymbolTableMap &Symbols,
                                            StubMap &Stubs) {
  const ObjectFile *OF = Obj.getObjectFile();
  const MachOObjectFile *MachO = static_cast<const MachOObjectFile*>(OF);
  MachO::any_relocation_info RE= MachO->getRelocation(RelI.getRawDataRefImpl());

  uint32_t RelType = MachO->getAnyRelocationType(RE);

  // FIXME: Properly handle scattered relocations.
  //        For now, optimistically skip these: they can often be ignored, as
  //        the static linker will already have applied the relocation, and it
  //        only needs to be reapplied if symbols move relative to one another.
  //        Note: This will fail horribly where the relocations *do* need to be
  //        applied, but that was already the case.
  if (MachO->isRelocationScattered(RE))
    return;

  RelocationValueRef Value;
  SectionEntry &Section = Sections[SectionID];

  bool isExtern = MachO->getPlainRelocationExternal(RE);
  bool IsPCRel = MachO->getAnyRelocationPCRel(RE);
  unsigned Size = MachO->getAnyRelocationLength(RE);
  uint64_t Offset;
  RelI.getOffset(Offset);
  uint8_t *LocalAddress = Section.Address + Offset;
  unsigned NumBytes = 1 << Size;
  uint64_t Addend = 0;
  memcpy(&Addend, LocalAddress, NumBytes);

  if (isExtern) {
    // Obtain the symbol name which is referenced in the relocation
    symbol_iterator Symbol = RelI.getSymbol();
    StringRef TargetName;
    Symbol->getName(TargetName);
    // First search for the symbol in the local symbol table
    SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data());
    if (lsi != Symbols.end()) {
      Value.SectionID = lsi->second.first;
      Value.Addend = lsi->second.second + Addend;
    } else {
      // Search for the symbol in the global symbol table
      SymbolTableMap::const_iterator gsi = GlobalSymbolTable.find(TargetName.data());
      if (gsi != GlobalSymbolTable.end()) {
        Value.SectionID = gsi->second.first;
        Value.Addend = gsi->second.second + Addend;
      } else {
        Value.SymbolName = TargetName.data();
        Value.Addend = Addend;
      }
    }
  } else {
    SectionRef Sec = MachO->getRelocationSection(RE);
    bool IsCode = false;
    Sec.isText(IsCode);
    Value.SectionID = findOrEmitSection(Obj, Sec, IsCode, ObjSectionToID);
    uint64_t Addr;
    Sec.getAddress(Addr);
    Value.Addend = Addend - Addr;
    if (IsPCRel)
      Value.Addend += Offset + NumBytes;
  }

  if (Arch == Triple::x86_64 && (RelType == MachO::X86_64_RELOC_GOT ||
                                 RelType == MachO::X86_64_RELOC_GOT_LOAD)) {
    assert(IsPCRel);
    assert(Size == 2);
    StubMap::const_iterator i = Stubs.find(Value);
    uint8_t *Addr;
    if (i != Stubs.end()) {
      Addr = Section.Address + i->second;
    } else {
      Stubs[Value] = Section.StubOffset;
      uint8_t *GOTEntry = Section.Address + Section.StubOffset;
      RelocationEntry RE(SectionID, Section.StubOffset,
                         MachO::X86_64_RELOC_UNSIGNED, 0, false, 3);
      if (Value.SymbolName)
        addRelocationForSymbol(RE, Value.SymbolName);
      else
        addRelocationForSection(RE, Value.SectionID);
      Section.StubOffset += 8;
      Addr = GOTEntry;
    }
    resolveRelocation(Section, Offset, (uint64_t)Addr,
                      MachO::X86_64_RELOC_UNSIGNED, Value.Addend, true, 2);
  } else if (Arch == Triple::arm &&
             (RelType & 0xf) == MachO::ARM_RELOC_BR24) {
    // This is an ARM branch relocation, need to use a stub function.

    //  Look up for existing stub.
    StubMap::const_iterator i = Stubs.find(Value);
    if (i != Stubs.end())
      resolveRelocation(Section, Offset,
                        (uint64_t)Section.Address + i->second,
                        RelType, 0, IsPCRel, Size);
    else {
//.........这里部分代码省略.........

bool Decoder::dumpXDataRecord(const COFFObjectFile &COFF,
                              const SectionRef &Section,
                              uint64_t FunctionAddress, uint64_t VA) {
  ArrayRef<uint8_t> Contents;
  if (COFF.getSectionContents(COFF.getCOFFSection(Section), Contents))
    return false;

  uint64_t SectionVA = Section.getAddress();
  uint64_t Offset = VA - SectionVA;
  const ulittle32_t *Data =
    reinterpret_cast<const ulittle32_t *>(Contents.data() + Offset);
  const ExceptionDataRecord XData(Data);

  DictScope XRS(SW, "ExceptionData");
  SW.printNumber("FunctionLength", XData.FunctionLength() << 1);
  SW.printNumber("Version", XData.Vers());
  SW.printBoolean("ExceptionData", XData.X());
  SW.printBoolean("EpiloguePacked", XData.E());
  SW.printBoolean("Fragment", XData.F());
  SW.printNumber(XData.E() ? "EpilogueOffset" : "EpilogueScopes",
                 XData.EpilogueCount());
  SW.printNumber("ByteCodeLength",
                 static_cast<uint64_t>(XData.CodeWords() * sizeof(uint32_t)));

  if (XData.E()) {
    ArrayRef<uint8_t> UC = XData.UnwindByteCode();
    if (!XData.F()) {
      ListScope PS(SW, "Prologue");
      decodeOpcodes(UC, 0, /*Prologue=*/true);
    }
    if (XData.EpilogueCount()) {
      ListScope ES(SW, "Epilogue");
      decodeOpcodes(UC, XData.EpilogueCount(), /*Prologue=*/false);
    }
  } else {
    ArrayRef<ulittle32_t> EpilogueScopes = XData.EpilogueScopes();
    ListScope ESS(SW, "EpilogueScopes");
    for (const EpilogueScope ES : EpilogueScopes) {
      DictScope ESES(SW, "EpilogueScope");
      SW.printNumber("StartOffset", ES.EpilogueStartOffset());
      SW.printNumber("Condition", ES.Condition());
      SW.printNumber("EpilogueStartIndex", ES.EpilogueStartIndex());

      ListScope Opcodes(SW, "Opcodes");
      decodeOpcodes(XData.UnwindByteCode(), ES.EpilogueStartIndex(),
                    /*Prologue=*/false);
    }
  }

  if (XData.X()) {
    const uint32_t Address = XData.ExceptionHandlerRVA();
    const uint32_t Parameter = XData.ExceptionHandlerParameter();
    const size_t HandlerOffset = HeaderWords(XData)
                               + (XData.E() ? 0 : XData.EpilogueCount())
                               + XData.CodeWords();

    ErrorOr<SymbolRef> Symbol =
      getRelocatedSymbol(COFF, Section, HandlerOffset * sizeof(uint32_t));
    if (!Symbol)
      Symbol = getSymbol(COFF, Address, /*FunctionOnly=*/true);

    StringRef Name;
    if (Symbol)
      Symbol->getName(Name);

    ListScope EHS(SW, "ExceptionHandler");
    SW.printString("Routine", formatSymbol(Name, Address));
    SW.printHex("Parameter", Parameter);
  }

  return true;
}

uint64_t    getAddr(const SectionRef &sec) { return sec.getAddress(); }

static bool SectionStartsBefore(const SectionRef &S, uint64_t Addr) {
  uint64_t SAddr; S.getAddress(SAddr);
  return SAddr < Addr;
}