C++ COFFSymbolRef类代码示例

Optional<coff_symbol16> Writer::createSymbol(Defined *Def) {
  // Relative symbols are unrepresentable in a COFF symbol table.
  if (isa<DefinedSynthetic>(Def))
    return None;

  if (auto *D = dyn_cast<DefinedRegular>(Def)) {
    // Don't write dead symbols or symbols in codeview sections to the symbol
    // table.
    if (!D->getChunk()->isLive() || D->getChunk()->isCodeView())
      return None;
  }

  if (auto *Sym = dyn_cast<DefinedImportData>(Def))
    if (!Sym->File->Live)
      return None;

  if (auto *Sym = dyn_cast<DefinedImportThunk>(Def))
    if (!Sym->WrappedSym->File->Live)
      return None;

  coff_symbol16 Sym;
  StringRef Name = Def->getName();
  if (Name.size() > COFF::NameSize) {
    Sym.Name.Offset.Zeroes = 0;
    Sym.Name.Offset.Offset = addEntryToStringTable(Name);
  } else {
    memset(Sym.Name.ShortName, 0, COFF::NameSize);
    memcpy(Sym.Name.ShortName, Name.data(), Name.size());
  }

  if (auto *D = dyn_cast<DefinedCOFF>(Def)) {
    COFFSymbolRef Ref = D->getCOFFSymbol();
    Sym.Type = Ref.getType();
    Sym.StorageClass = Ref.getStorageClass();
  } else {
    Sym.Type = IMAGE_SYM_TYPE_NULL;
    Sym.StorageClass = IMAGE_SYM_CLASS_EXTERNAL;
  }
  Sym.NumberOfAuxSymbols = 0;

  switch (Def->kind()) {
  case SymbolBody::DefinedAbsoluteKind:
    Sym.Value = Def->getRVA();
    Sym.SectionNumber = IMAGE_SYM_ABSOLUTE;
    break;
  default: {
    uint64_t RVA = Def->getRVA();
    OutputSection *Sec = nullptr;
    for (OutputSection *S : OutputSections) {
      if (S->getRVA() > RVA)
        break;
      Sec = S;
    }
    Sym.Value = RVA - Sec->getRVA();
    Sym.SectionNumber = Sec->SectionIndex;
    break;
  }
  }
  return Sym;
}

uint32_t COFFObjectFile::getSymbolFlags(DataRefImpl Ref) const {
  COFFSymbolRef Symb = getCOFFSymbol(Ref);
  uint32_t Result = SymbolRef::SF_None;

  if (Symb.isExternal() || Symb.isWeakExternal())
    Result |= SymbolRef::SF_Global;

  if (Symb.isWeakExternal())
    Result |= SymbolRef::SF_Weak;

  if (Symb.getSectionNumber() == COFF::IMAGE_SYM_ABSOLUTE)
    Result |= SymbolRef::SF_Absolute;

  if (Symb.isFileRecord())
    Result |= SymbolRef::SF_FormatSpecific;

  if (Symb.isSectionDefinition())
    Result |= SymbolRef::SF_FormatSpecific;

  if (Symb.isCommon())
    Result |= SymbolRef::SF_Common;

  if (Symb.isAnyUndefined())
    Result |= SymbolRef::SF_Undefined;

  return Result;
}

static char getSymbolNMTypeChar(COFFObjectFile &Obj, symbol_iterator I) {
  COFFSymbolRef Symb = Obj.getCOFFSymbol(*I);
  // OK, this is COFF.
  symbol_iterator SymI(I);

  StringRef Name;
  if (error(SymI->getName(Name)))
    return '?';

  char Ret = StringSwitch<char>(Name)
                 .StartsWith(".debug", 'N')
                 .StartsWith(".sxdata", 'N')
                 .Default('?');

  if (Ret != '?')
    return Ret;

  uint32_t Characteristics = 0;
  if (!COFF::isReservedSectionNumber(Symb.getSectionNumber())) {
    section_iterator SecI = Obj.section_end();
    if (error(SymI->getSection(SecI)))
      return '?';
    const coff_section *Section = Obj.getCOFFSection(*SecI);
    Characteristics = Section->Characteristics;
  }

  switch (Symb.getSectionNumber()) {
  case COFF::IMAGE_SYM_DEBUG:
    return 'n';
  default:
    // Check section type.
    if (Characteristics & COFF::IMAGE_SCN_CNT_CODE)
      return 't';
    else if (Characteristics & COFF::IMAGE_SCN_MEM_READ &&
             ~Characteristics & COFF::IMAGE_SCN_MEM_WRITE) // Read only.
      return 'r';
    else if (Characteristics & COFF::IMAGE_SCN_CNT_INITIALIZED_DATA)
      return 'd';
    else if (Characteristics & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA)
      return 'b';
    else if (Characteristics & COFF::IMAGE_SCN_LNK_INFO)
      return 'i';

    // Check for section symbol.
    else if (Symb.isSectionDefinition())
      return 's';
  }

  return '?';
}

Optional<coff_symbol16> Writer::createSymbol(Defined *Def) {
  if (auto *D = dyn_cast<DefinedRegular>(Def))
    if (!D->getChunk()->isLive())
      return None;

  coff_symbol16 Sym;
  StringRef Name = Def->getName();
  if (Name.size() > COFF::NameSize) {
    Sym.Name.Offset.Zeroes = 0;
    Sym.Name.Offset.Offset = addEntryToStringTable(Name);
  } else {
    memset(Sym.Name.ShortName, 0, COFF::NameSize);
    memcpy(Sym.Name.ShortName, Name.data(), Name.size());
  }

  if (auto *D = dyn_cast<DefinedCOFF>(Def)) {
    COFFSymbolRef Ref = D->getCOFFSymbol();
    Sym.Type = Ref.getType();
    Sym.StorageClass = Ref.getStorageClass();
  } else {
    Sym.Type = IMAGE_SYM_TYPE_NULL;
    Sym.StorageClass = IMAGE_SYM_CLASS_EXTERNAL;
  }
  Sym.NumberOfAuxSymbols = 0;

  switch (Def->kind()) {
  case SymbolBody::DefinedAbsoluteKind:
  case SymbolBody::DefinedRelativeKind:
    Sym.Value = Def->getRVA();
    Sym.SectionNumber = IMAGE_SYM_ABSOLUTE;
    break;
  default: {
    uint64_t RVA = Def->getRVA();
    OutputSection *Sec = nullptr;
    for (OutputSection *S : OutputSections) {
      if (S->getRVA() > RVA)
        break;
      Sec = S;
    }
    Sym.Value = RVA - Sec->getRVA();
    Sym.SectionNumber = Sec->SectionIndex;
    break;
  }
  }
  return Sym;
}

ErrorOr<uint64_t> COFFObjectFile::getSymbolAddress(DataRefImpl Ref) const {
  uint64_t Result = getSymbolValue(Ref);
  COFFSymbolRef Symb = getCOFFSymbol(Ref);
  int32_t SectionNumber = Symb.getSectionNumber();

  if (Symb.isAnyUndefined() || Symb.isCommon() ||
      COFF::isReservedSectionNumber(SectionNumber))
    return Result;

  const coff_section *Section = nullptr;
  if (std::error_code EC = getSection(SectionNumber, Section))
    return EC;
  Result += Section->VirtualAddress;

  // The section VirtualAddress does not include ImageBase, and we want to
  // return virtual addresses.
  Result += getImageBase();

  return Result;
}

ArrayRef<uint8_t>
COFFObjectFile::getSymbolAuxData(COFFSymbolRef Symbol) const {
  const uint8_t *Aux = nullptr;

  size_t SymbolSize = getSymbolTableEntrySize();
  if (Symbol.getNumberOfAuxSymbols() > 0) {
    // AUX data comes immediately after the symbol in COFF
    Aux = reinterpret_cast<const uint8_t *>(Symbol.getRawPtr()) + SymbolSize;
# ifndef NDEBUG
    // Verify that the Aux symbol points to a valid entry in the symbol table.
    uintptr_t Offset = uintptr_t(Aux) - uintptr_t(base());
    if (Offset < getPointerToSymbolTable() ||
        Offset >=
            getPointerToSymbolTable() + (getNumberOfSymbols() * SymbolSize))
      report_fatal_error("Aux Symbol data was outside of symbol table.");

    assert((Offset - getPointerToSymbolTable()) % SymbolSize == 0 &&
           "Aux Symbol data did not point to the beginning of a symbol");
# endif
  }
  return makeArrayRef(Aux, Symbol.getNumberOfAuxSymbols() * SymbolSize);
}

void ObjectFile::initializeSymbols() {
  uint32_t NumSymbols = COFFObj->getNumberOfSymbols();
  SymbolBodies.reserve(NumSymbols);
  SparseSymbolBodies.resize(NumSymbols);
  llvm::SmallVector<std::pair<Undefined *, uint32_t>, 8> WeakAliases;
  int32_t LastSectionNumber = 0;
  for (uint32_t I = 0; I < NumSymbols; ++I) {
    // Get a COFFSymbolRef object.
    auto SymOrErr = COFFObj->getSymbol(I);
    error(SymOrErr, Twine("broken object file: ") + getName());

    COFFSymbolRef Sym = *SymOrErr;

    const void *AuxP = nullptr;
    if (Sym.getNumberOfAuxSymbols())
      AuxP = COFFObj->getSymbol(I + 1)->getRawPtr();
    bool IsFirst = (LastSectionNumber != Sym.getSectionNumber());

    SymbolBody *Body = nullptr;
    if (Sym.isUndefined()) {
      Body = createUndefined(Sym);
    } else if (Sym.isWeakExternal()) {
      Body = createUndefined(Sym);
      uint32_t TagIndex =
          static_cast<const coff_aux_weak_external *>(AuxP)->TagIndex;
      WeakAliases.emplace_back((Undefined *)Body, TagIndex);
    } else {
      Body = createDefined(Sym, AuxP, IsFirst);
    }
    if (Body) {
      SymbolBodies.push_back(Body);
      SparseSymbolBodies[I] = Body;
    }
    I += Sym.getNumberOfAuxSymbols();
    LastSectionNumber = Sym.getSectionNumber();
  }
  for (auto WeakAlias : WeakAliases)
    WeakAlias.first->WeakAlias = SparseSymbolBodies[WeakAlias.second];
}

void ObjectFile::initializeSymbols() {
  uint32_t NumSymbols = COFFObj->getNumberOfSymbols();
  SymbolBodies.reserve(NumSymbols);
  SparseSymbolBodies.resize(NumSymbols);
  llvm::SmallVector<Undefined *, 8> WeakAliases;
  int32_t LastSectionNumber = 0;
  for (uint32_t I = 0; I < NumSymbols; ++I) {
    // Get a COFFSymbolRef object.
    auto SymOrErr = COFFObj->getSymbol(I);
    error(SymOrErr, Twine("broken object file: ") + getName());

    COFFSymbolRef Sym = *SymOrErr;

    const void *AuxP = nullptr;
    if (Sym.getNumberOfAuxSymbols())
      AuxP = COFFObj->getSymbol(I + 1)->getRawPtr();
    bool IsFirst = (LastSectionNumber != Sym.getSectionNumber());

    SymbolBody *Body = nullptr;
    if (Sym.isUndefined()) {
      Body = createUndefined(Sym);
    } else if (Sym.isWeakExternal()) {
      Body = createWeakExternal(Sym, AuxP);
      WeakAliases.push_back((Undefined *)Body);
    } else {
      Body = createDefined(Sym, AuxP, IsFirst);
    }
    if (Body) {
      SymbolBodies.push_back(Body);
      SparseSymbolBodies[I] = Body;
    }
    I += Sym.getNumberOfAuxSymbols();
    LastSectionNumber = Sym.getSectionNumber();
  }
  for (Undefined *U : WeakAliases)
    U->WeakAlias = SparseSymbolBodies[(uintptr_t)U->WeakAlias];
}

void COFFDumper::printSymbol(const SymbolRef &Sym) {
  DictScope D(W, "Symbol");

  COFFSymbolRef Symbol = Obj->getCOFFSymbol(Sym);
  const coff_section *Section;
  if (std::error_code EC = Obj->getSection(Symbol.getSectionNumber(), Section)) {
    W.startLine() << "Invalid section number: " << EC.message() << "\n";
    W.flush();
    return;
  }

  StringRef SymbolName;
  if (Obj->getSymbolName(Symbol, SymbolName))
    SymbolName = "";

  StringRef SectionName = "";
  ErrorOr<StringRef> Res =
      getSectionName(Obj, Symbol.getSectionNumber(), Section);
  if (Res)
    SectionName = *Res;

  W.printString("Name", SymbolName);
  W.printNumber("Value", Symbol.getValue());
  W.printNumber("Section", SectionName, Symbol.getSectionNumber());
  W.printEnum  ("BaseType", Symbol.getBaseType(), makeArrayRef(ImageSymType));
  W.printEnum  ("ComplexType", Symbol.getComplexType(),
                                                   makeArrayRef(ImageSymDType));
  W.printEnum  ("StorageClass", Symbol.getStorageClass(),
                                                   makeArrayRef(ImageSymClass));
  W.printNumber("AuxSymbolCount", Symbol.getNumberOfAuxSymbols());

  for (uint8_t I = 0; I < Symbol.getNumberOfAuxSymbols(); ++I) {
    if (Symbol.isFunctionDefinition()) {
      const coff_aux_function_definition *Aux;
      error(getSymbolAuxData(Obj, Symbol, I, Aux));

      DictScope AS(W, "AuxFunctionDef");
      W.printNumber("TagIndex", Aux->TagIndex);
      W.printNumber("TotalSize", Aux->TotalSize);
      W.printHex("PointerToLineNumber", Aux->PointerToLinenumber);
      W.printHex("PointerToNextFunction", Aux->PointerToNextFunction);

    } else if (Symbol.isAnyUndefined()) {
      const coff_aux_weak_external *Aux;
      error(getSymbolAuxData(Obj, Symbol, I, Aux));

      ErrorOr<COFFSymbolRef> Linked = Obj->getSymbol(Aux->TagIndex);
      StringRef LinkedName;
      std::error_code EC = Linked.getError();
      if (EC || (EC = Obj->getSymbolName(*Linked, LinkedName))) {
        LinkedName = "";
        error(EC);
      }

      DictScope AS(W, "AuxWeakExternal");
      W.printNumber("Linked", LinkedName, Aux->TagIndex);
      W.printEnum  ("Search", Aux->Characteristics,
                    makeArrayRef(WeakExternalCharacteristics));

    } else if (Symbol.isFileRecord()) {
      const char *FileName;
      error(getSymbolAuxData(Obj, Symbol, I, FileName));

      DictScope AS(W, "AuxFileRecord");

      StringRef Name(FileName, Symbol.getNumberOfAuxSymbols() *
                                   Obj->getSymbolTableEntrySize());
      W.printString("FileName", Name.rtrim(StringRef("\0", 1)));
      break;
    } else if (Symbol.isSectionDefinition()) {
      const coff_aux_section_definition *Aux;
      error(getSymbolAuxData(Obj, Symbol, I, Aux));

      int32_t AuxNumber = Aux->getNumber(Symbol.isBigObj());

      DictScope AS(W, "AuxSectionDef");
      W.printNumber("Length", Aux->Length);
      W.printNumber("RelocationCount", Aux->NumberOfRelocations);
      W.printNumber("LineNumberCount", Aux->NumberOfLinenumbers);
      W.printHex("Checksum", Aux->CheckSum);
      W.printNumber("Number", AuxNumber);
      W.printEnum("Selection", Aux->Selection, makeArrayRef(ImageCOMDATSelect));

      if (Section && Section->Characteristics & COFF::IMAGE_SCN_LNK_COMDAT
          && Aux->Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) {
        const coff_section *Assoc;
        StringRef AssocName = "";
        std::error_code EC = Obj->getSection(AuxNumber, Assoc);
        ErrorOr<StringRef> Res = getSectionName(Obj, AuxNumber, Assoc);
        if (Res)
          AssocName = *Res;
        if (!EC)
          EC = Res.getError();
        if (EC) {
          AssocName = "";
          error(EC);
        }

        W.printNumber("AssocSection", AssocName, AuxNumber);
      }
//.........这里部分代码省略.........

std::error_code COFFObjectFile::getSymbolName(COFFSymbolRef Symbol,
                                              StringRef &Res) const {
  return getSymbolName(Symbol.getGeneric(), Res);
}