コード例 #1
0
bool ARMGNULDBackend::readSection(Input& pInput,
                                  MCLinker& pLinker,
                                  LDSection& pInputSectHdr)
{
  LDSection& out_sect = pLinker.getOrCreateOutputSectHdr(pInputSectHdr.name(),
                                                         pInputSectHdr.kind(),
                                                         pInputSectHdr.type(),
                                                         pInputSectHdr.flag());
  // FIXME: (Luba)
  // Handle ARM attributes in the right way.
  // In current milestone, MCLinker goes through the shortcut.
  // It reads input's ARM attributes and copies the first ARM attributes
  // into the output file. The correct way is merge these sections, not
  // just copy.
  if ((0 == out_sect.name().compare(".ARM.attributes")) &&
      (0 != out_sect.size()))
    return true;

  MemoryRegion* region = pInput.memArea()->request(pInputSectHdr.offset(),
                                                   pInputSectHdr.size());

  llvm::MCSectionData& sect_data = pLinker.getOrCreateSectData(pInputSectHdr);

  new MCRegionFragment(*region, &sect_data);

  out_sect.setSize(out_sect.size() + pInputSectHdr.size());
  return true;
}
コード例 #2
0
void ARMGNULDBackend::createARMGOT(MCLinker& pLinker, const Output& pOutput)
{
  // get .got LDSection and create MCSectionData
  ELFFileFormat* file_format = getOutputFormat(pOutput);

  LDSection& got = file_format->getGOT();
  m_pGOT = new ARMGOT(got, pLinker.getOrCreateSectData(got));

  // define symbol _GLOBAL_OFFSET_TABLE_ when .got create
  if( m_pGOTSymbol != NULL ) {
    pLinker.defineSymbol<MCLinker::Force, MCLinker::Unresolve>(
                     "_GLOBAL_OFFSET_TABLE_",
                     false,
                     ResolveInfo::Object,
                     ResolveInfo::Define,
                     ResolveInfo::Local,
                     0x0, // size
                     0x0, // value
                     pLinker.getLayout().getFragmentRef(*(m_pGOT->begin()), 0x0),
                     ResolveInfo::Hidden);
  }
  else {
    m_pGOTSymbol = pLinker.defineSymbol<MCLinker::Force, MCLinker::Resolve>(
                     "_GLOBAL_OFFSET_TABLE_",
                     false,
                     ResolveInfo::Object,
                     ResolveInfo::Define,
                     ResolveInfo::Local,
                     0x0, // size
                     0x0, // value
                     pLinker.getLayout().getFragmentRef(*(m_pGOT->begin()), 0x0),
                     ResolveInfo::Hidden);
  }

}
コード例 #3
0
void ARMGNULDBackend::createARMPLTandRelPLT(MCLinker& pLinker,
                                            const Output& pOutput)
{
  ELFFileFormat* file_format = getOutputFormat(pOutput);

  // get .plt and .rel.plt LDSection
  LDSection& plt = file_format->getPLT();
  LDSection& relplt = file_format->getRelPlt();
  // create MCSectionData and ARMPLT
  m_pPLT = new ARMPLT(plt, pLinker.getOrCreateSectData(plt), *m_pGOT);
  // set info of .rel.plt to .plt
  relplt.setLink(&plt);
  // create MCSectionData and ARMRelDynSection
  m_pRelPLT = new OutputRelocSection(relplt,
                                     pLinker.getOrCreateSectData(relplt),
                                     8);
}
コード例 #4
0
void ARMGNULDBackend::createARMRelDyn(MCLinker& pLinker,
                                      const Output& pOutput)
{
  ELFFileFormat* file_format = getOutputFormat(pOutput);

  // get .rel.dyn LDSection and create MCSectionData
  LDSection& reldyn = file_format->getRelDyn();
  // create MCSectionData and ARMRelDynSection
  m_pRelDyn = new OutputRelocSection(reldyn,
                                     pLinker.getOrCreateSectData(reldyn),
                                     8);
}
コード例 #5
0
/// allocateCommonSymbols - allocate common symbols in the corresponding
/// sections.
/// @refer Google gold linker: common.cc: 214
bool
ARMGNULDBackend::allocateCommonSymbols(const MCLDInfo& pInfo, MCLinker& pLinker) const
{
  SymbolCategory& symbol_list = pLinker.getOutputSymbols();

  if (symbol_list.emptyCommons() && symbol_list.emptyLocals())
    return true;

  // addralign := max value of all common symbols
  uint64_t addralign = 0x0;

  // Due to the visibility, some common symbols may be forcefully local.
  SymbolCategory::iterator com_sym, com_end = symbol_list.localEnd();
  for (com_sym = symbol_list.localBegin(); com_sym != com_end; ++com_sym) {
    if (ResolveInfo::Common == (*com_sym)->desc()) {
      if ((*com_sym)->value() > addralign)
        addralign = (*com_sym)->value();
    }
  }

  // global common symbols.
  com_end = symbol_list.commonEnd();
  for (com_sym = symbol_list.commonBegin(); com_sym != com_end; ++com_sym) {
    if ((*com_sym)->value() > addralign)
      addralign = (*com_sym)->value();
  }

  // FIXME: If the order of common symbols is defined, then sort common symbols
  // com_sym = symbol_list.commonBegin();
  // std::sort(com_sym, com_end, some kind of order);

  // get or create corresponding BSS LDSection
  LDSection* bss_sect_hdr = NULL;
  if (ResolveInfo::ThreadLocal == (*com_sym)->type()) {
    bss_sect_hdr = &pLinker.getOrCreateOutputSectHdr(
                                   ".tbss",
                                   LDFileFormat::BSS,
                                   llvm::ELF::SHT_NOBITS,
                                   llvm::ELF::SHF_WRITE | llvm::ELF::SHF_ALLOC);
  }
  else {
    bss_sect_hdr = &pLinker.getOrCreateOutputSectHdr(".bss",
                                   LDFileFormat::BSS,
                                   llvm::ELF::SHT_NOBITS,
                                   llvm::ELF::SHF_WRITE | llvm::ELF::SHF_ALLOC);
  }

  // get or create corresponding BSS MCSectionData
  assert(NULL != bss_sect_hdr);
  llvm::MCSectionData& bss_section = pLinker.getOrCreateSectData(*bss_sect_hdr);

  // allocate all common symbols
  uint64_t offset = bss_sect_hdr->size();

  // allocate all local common symbols
  com_end = symbol_list.localEnd();
  for (com_sym = symbol_list.localBegin(); com_sym != com_end; ++com_sym) {
    if (ResolveInfo::Common == (*com_sym)->desc()) {
      // We have to reset the description of the symbol here. When doing
      // incremental linking, the output relocatable object may have common
      // symbols. Therefore, we can not treat common symbols as normal symbols
      // when emitting the regular name pools. We must change the symbols'
      // description here.
      (*com_sym)->resolveInfo()->setDesc(ResolveInfo::Define);
      llvm::MCFragment* frag = new llvm::MCFillFragment(0x0, 1, (*com_sym)->size());
      (*com_sym)->setFragmentRef(new MCFragmentRef(*frag, 0));
      uint64_t size = pLinker.getLayout().appendFragment(*frag,
                                                         bss_section,
                                                         (*com_sym)->value());
      offset += size;
    }
  }

  // allocate all global common symbols
  com_end = symbol_list.commonEnd();
  for (com_sym = symbol_list.commonBegin(); com_sym != com_end; ++com_sym) {
    // We have to reset the description of the symbol here. When doing
    // incremental linking, the output relocatable object may have common
    // symbols. Therefore, we can not treat common symbols as normal symbols
    // when emitting the regular name pools. We must change the symbols'
    // description here.
    (*com_sym)->resolveInfo()->setDesc(ResolveInfo::Define);
    llvm::MCFragment* frag = new llvm::MCFillFragment(0x0, 1, (*com_sym)->size());
    (*com_sym)->setFragmentRef(new MCFragmentRef(*frag, 0));
    uint64_t size = pLinker.getLayout().appendFragment(*frag,
                                                       bss_section,
                                                       (*com_sym)->value());
    offset += size;
  }

  bss_sect_hdr->setSize(offset);
  symbol_list.changeCommonsToGlobal();
  return true;
}