C++ SymbolBody::isUndefined方法代码示例

std::vector<SymbolBody *> SymbolTable<ELFT>::findAll(StringRef Pattern) {
  std::vector<SymbolBody *> Res;
  for (Symbol *Sym : SymVector) {
    SymbolBody *B = Sym->body();
    if (!B->isUndefined() && globMatch(Pattern, B->getName()))
      Res.push_back(B);
  }
  return Res;
}

// We have a new defined symbol with the specified binding. Return 1 if the new
// symbol should win, -1 if the new symbol should lose, or 0 if both symbols are
// strong defined symbols.
static int compareDefined(Symbol *S, bool WasInserted, uint8_t Binding) {
  if (WasInserted)
    return 1;
  SymbolBody *Body = S->body();
  if (Body->isLazy() || Body->isUndefined() || Body->isShared())
    return 1;
  if (Binding == STB_WEAK)
    return -1;
  if (S->isWeak())
    return 1;
  return 0;
}

// Print out a log message for --trace-symbol.
void elf::printTraceSymbol(Symbol *Sym) {
  SymbolBody *B = Sym->body();
  outs() << getFilename(B->File);

  if (B->isUndefined())
    outs() << ": reference to ";
  else if (B->isCommon())
    outs() << ": common definition of ";
  else
    outs() << ": definition of ";
  outs() << B->getName() << "\n";
}

template <class ELFT> void LinkerScript<ELFT>::addScriptedSymbols() {
  for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
    auto *Cmd = dyn_cast<SymbolAssignment>(Base.get());
    if (!Cmd || Cmd->Name == ".")
      continue;

    SymbolBody *B = Symtab<ELFT>::X->find(Cmd->Name);
    // The semantic of PROVIDE is that of introducing a symbol only if
    // it's not defined and there's at least a reference to it.
    if ((!B && !Cmd->Provide) || (B && B->isUndefined()))
      Symtab<ELFT>::X->addAbsolute(Cmd->Name,
                                   Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT);
    else
      // Symbol already exists in symbol table. If it is provided
      // then we can't override its value.
      Cmd->Ignore = Cmd->Provide;
  }
}

void Writer<ELFT>::scanRelocs(
    InputSectionBase<ELFT> &C,
    iterator_range<const Elf_Rel_Impl<ELFT, isRela> *> Rels) {
  typedef Elf_Rel_Impl<ELFT, isRela> RelType;
  const ObjectFile<ELFT> &File = *C.getFile();
  for (const RelType &RI : Rels) {
    uint32_t SymIndex = RI.getSymbol(Config->Mips64EL);
    SymbolBody *Body = File.getSymbolBody(SymIndex);
    uint32_t Type = RI.getType(Config->Mips64EL);

    if (Target->isTlsLocalDynamicReloc(Type)) {
      if (Target->isTlsOptimized(Type, nullptr))
        continue;
      if (Out<ELFT>::LocalModuleTlsIndexOffset == uint32_t(-1)) {
        Out<ELFT>::LocalModuleTlsIndexOffset =
            Out<ELFT>::Got->addLocalModuleTlsIndex();
        Out<ELFT>::RelaDyn->addReloc({&C, &RI});
      }
      continue;
    }

    // Set "used" bit for --as-needed.
    if (Body && Body->isUndefined() && !Body->isWeak())
      if (auto *S = dyn_cast<SharedSymbol<ELFT>>(Body->repl()))
        S->File->IsUsed = true;

    if (Body)
      Body = Body->repl();

    if (Body && Body->isTLS() && Target->isTlsGlobalDynamicReloc(Type)) {
      if (Target->isTlsOptimized(Type, Body))
        continue;
      if (Body->isInGot())
        continue;
      Out<ELFT>::Got->addDynTlsEntry(Body);
      Out<ELFT>::RelaDyn->addReloc({&C, &RI});
      Out<ELFT>::RelaDyn->addReloc({nullptr, nullptr});
      Body->setUsedInDynamicReloc();
      continue;
    }

    if (Body && Body->isTLS() && !Target->isTlsDynReloc(Type))
      continue;

    bool NeedsGot = false;
    bool NeedsPlt = false;
    if (Body) {
      if (auto *E = dyn_cast<SharedSymbol<ELFT>>(Body)) {
        if (E->needsCopy())
          continue;
        if (Target->relocNeedsCopy(Type, *Body))
          E->OffsetInBSS = 0;
      }
      NeedsPlt = Target->relocNeedsPlt(Type, *Body);
      if (NeedsPlt) {
        if (Body->isInPlt())
          continue;
        Out<ELFT>::Plt->addEntry(Body);
      }
      NeedsGot = Target->relocNeedsGot(Type, *Body);
      if (NeedsGot) {
        if (NeedsPlt && Target->supportsLazyRelocations()) {
          Out<ELFT>::GotPlt->addEntry(Body);
        } else {
          if (Body->isInGot())
            continue;
          Out<ELFT>::Got->addEntry(Body);
        }
      }
    }

    if (Config->EMachine == EM_MIPS && NeedsGot) {
      // MIPS ABI has special rules to process GOT entries
      // and doesn't require relocation entries for them.
      // See "Global Offset Table" in Chapter 5 in the following document
      // for detailed description:
      // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf
      Body->setUsedInDynamicReloc();
      continue;
    }
    bool CBP = canBePreempted(Body, NeedsGot);
    if (!CBP && (!Config->Shared || Target->isRelRelative(Type)))
      continue;
    if (CBP)
      Body->setUsedInDynamicReloc();
    if (NeedsPlt && Target->supportsLazyRelocations())
      Out<ELFT>::RelaPlt->addReloc({&C, &RI});
    else
      Out<ELFT>::RelaDyn->addReloc({&C, &RI});
  }
}