lld/lib/ReaderWriter/ELF/Hexagon/HexagonSectionChunks.h

//===- lib/ReaderWriter/ELF/Hexagon/HexagonSectionChunks.h-----------------===//
//
//                             The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "HexagonTargetHandler.h"

namespace lld {
namespace elf {
typedef llvm::object::ELFType<llvm::support::little, 4, false> HexagonELFType;
template <typename ELFT> class HexagonTargetLayout;
class HexagonTargetInfo;

/// \brief Handle Hexagon SData section
template <class HexagonELFType>
class SDataSection : public AtomSection<HexagonELFType> {
public:
  SDataSection(const HexagonTargetInfo &hti)
      : AtomSection<HexagonELFType>(
            hti, ".sdata", DefinedAtom::typeDataFast, 0,
            HexagonTargetLayout<HexagonELFType>::ORDER_SDATA) {
    this->_type = SHT_PROGBITS;
    this->_flags = SHF_ALLOC | SHF_WRITE;
  }

  /// \brief Finalize the section contents before writing
  virtual void doPreFlight();

  /// \brief Does this section have an output segment.
  virtual bool hasOutputSegment() { return true; }

  const AtomLayout &appendAtom(const Atom *atom) {
    const DefinedAtom *definedAtom = cast<DefinedAtom>(atom);
    DefinedAtom::Alignment atomAlign = definedAtom->alignment();
    uint64_t align2 = 1u << atomAlign.powerOf2;
    this->_atoms.push_back(new (this->_alloc) AtomLayout(atom, 0, 0));
    // Set the section alignment to the largest alignment
    // std::max doesnot support uint64_t
    if (this->_align2 < align2)
      this->_align2 = align2;
    return *(this->_atoms.back());
  }

}; // SDataSection

template <class HexagonELFType>
void SDataSection<HexagonELFType>::doPreFlight() {
  // sort the atoms on the alignments they have been set
  std::stable_sort(this->_atoms.begin(), this->_atoms.end(),
                   [](const AtomLayout * A, const AtomLayout * B) {
    const DefinedAtom *definedAtomA = cast<DefinedAtom>(A->_atom);
    const DefinedAtom *definedAtomB = cast<DefinedAtom>(B->_atom);
    int64_t align2A = 1 << definedAtomA->alignment().powerOf2;
    int64_t align2B = 1 << definedAtomB->alignment().powerOf2;
    return align2A < align2B;
  });

  // Set the fileOffset, and the appropriate size of the section
  for (auto &ai : this->_atoms) {
    const DefinedAtom *definedAtom = cast<DefinedAtom>(ai->_atom);
    DefinedAtom::Alignment atomAlign = definedAtom->alignment();
    uint64_t fOffset = this->alignOffset(this->fileSize(), atomAlign);
    uint64_t mOffset = this->alignOffset(this->memSize(), atomAlign);
    ai->_fileOffset = fOffset;
    this->_fsize = fOffset + definedAtom->size();
    this->_msize = mOffset + definedAtom->size();
  }
} // finalize

} // elf
} // lld