8de2b8fb81
1. Re-implement PLT entries and dynamic relocations emitting to keep PLT and relocations table in a consistent state. 2. Initialize st_value and st_other fields for dynamic symbols table entry if this entry corresponds to an external function which address is taken in a non-PIC executable. In that case the st_value field holds an address of the function's PLT entry. Also set STO_MIPS_PLT bit in the st_other field. llvm-svn: 207494
122 lines
3.6 KiB
C++
122 lines
3.6 KiB
C++
//===- lib/ReaderWriter/ELF/Mips/MipsSectionChunks.h ----------------------===//
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//
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// The LLVM Linker
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLD_READER_WRITER_ELF_MIPS_MIPS_SECTION_CHUNKS_H
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#define LLD_READER_WRITER_ELF_MIPS_MIPS_SECTION_CHUNKS_H
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namespace lld {
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namespace elf {
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template <typename ELFT> class MipsTargetLayout;
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class MipsLinkingContext;
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/// \brief Handle Mips GOT section
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template <class ELFType> class MipsGOTSection : public AtomSection<ELFType> {
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public:
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MipsGOTSection(const MipsLinkingContext &context)
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: AtomSection<ELFType>(context, ".got", DefinedAtom::typeGOT,
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DefinedAtom::permRW_,
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MipsTargetLayout<ELFType>::ORDER_GOT),
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_globalCount(0) {
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this->_flags |= SHF_MIPS_GPREL;
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this->_align2 = 4;
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}
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/// \brief Number of local GOT entries.
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std::size_t getLocalCount() const {
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return this->_atoms.size() - _globalCount;
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}
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/// \brief Number of global GOT entries.
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std::size_t getGlobalCount() const { return _globalCount; }
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/// \brief Does the atom have a global GOT entry?
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bool hasGlobalGOTEntry(const Atom *a) const { return _posMap.count(a); }
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/// \brief Compare two atoms accordingly theirs positions in the GOT.
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bool compare(const Atom *a, const Atom *b) const {
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auto ia = _posMap.find(a);
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auto ib = _posMap.find(b);
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if (ia != _posMap.end() && ib != _posMap.end())
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return ia->second < ib->second;
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return ia == _posMap.end() && ib != _posMap.end();
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}
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const lld::AtomLayout &appendAtom(const Atom *atom) override {
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const DefinedAtom *da = dyn_cast<DefinedAtom>(atom);
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const Atom *ta = nullptr;
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for (const auto &r : *da) {
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if (r->kindNamespace() != lld::Reference::KindNamespace::ELF)
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continue;
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assert(r->kindArch() == Reference::KindArch::Mips);
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if (r->kindValue() == LLD_R_MIPS_GLOBAL_GOT) {
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ta = r->target();
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break;
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}
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}
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if (ta) {
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_posMap[ta] = _posMap.size();
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++_globalCount;
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}
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return AtomSection<ELFType>::appendAtom(atom);
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}
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private:
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/// \brief Number of global GOT entries.
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std::size_t _globalCount;
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/// \brief Map Atoms to their GOT entry index.
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llvm::DenseMap<const Atom *, std::size_t> _posMap;
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};
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/// \brief Handle Mips PLT section
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template <class ELFType> class MipsPLTSection : public AtomSection<ELFType> {
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public:
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MipsPLTSection(const MipsLinkingContext &context)
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: AtomSection<ELFType>(context, ".plt", DefinedAtom::typeGOT,
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DefinedAtom::permR_X,
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MipsTargetLayout<ELFType>::ORDER_PLT) {}
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const AtomLayout *findPLTLayout(const Atom *plt) const {
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auto it = _pltLayoutMap.find(plt);
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return it != _pltLayoutMap.end() ? it->second : nullptr;
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}
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const lld::AtomLayout &appendAtom(const Atom *atom) override {
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const auto &layout = AtomSection<ELFType>::appendAtom(atom);
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const DefinedAtom *da = cast<DefinedAtom>(atom);
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for (const auto &r : *da) {
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if (r->kindNamespace() != lld::Reference::KindNamespace::ELF)
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continue;
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assert(r->kindArch() == Reference::KindArch::Mips);
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if (r->kindValue() == LLD_R_MIPS_STO_PLT) {
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_pltLayoutMap[r->target()] = &layout;
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break;
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}
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}
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return layout;
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}
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private:
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/// \brief Map PLT Atoms to their layouts.
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std::unordered_map<const Atom *, const AtomLayout *> _pltLayoutMap;
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};
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} // elf
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} // lld
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#endif
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