diff options
Diffstat (limited to 'lld/lib/ReaderWriter/ELF/Writer.cpp')
| -rw-r--r-- | lld/lib/ReaderWriter/ELF/Writer.cpp | 484 |
1 files changed, 0 insertions, 484 deletions
diff --git a/lld/lib/ReaderWriter/ELF/Writer.cpp b/lld/lib/ReaderWriter/ELF/Writer.cpp deleted file mode 100644 index a32aa61ee9c..00000000000 --- a/lld/lib/ReaderWriter/ELF/Writer.cpp +++ /dev/null @@ -1,484 +0,0 @@ -//===- lib/ReaderWriter/ELF/WriterELF.cpp ---------------------------------===// -// -// The LLVM Linker -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// - -#include "lld/ReaderWriter/Writer.h" - -#include "DefaultLayout.h" -#include "TargetLayout.h" -#include "ExecutableAtoms.h" - -#include "lld/ReaderWriter/ELFTargetInfo.h" - -#include "llvm/ADT/StringSet.h" - -using namespace llvm; -using namespace llvm::object; -namespace lld { -namespace elf { -template<class ELFT> -class ExecutableWriter; - -//===----------------------------------------------------------------------===// -// ExecutableWriter Class -//===----------------------------------------------------------------------===// -template<class ELFT> -class ExecutableWriter : public ELFWriter { -public: - typedef Elf_Shdr_Impl<ELFT> Elf_Shdr; - typedef Elf_Sym_Impl<ELFT> Elf_Sym; - typedef Elf_Dyn_Impl<ELFT> Elf_Dyn; - - ExecutableWriter(const ELFTargetInfo &ti); - -private: - // build the sections that need to be created - void buildChunks(const File &file); - virtual error_code writeFile(const File &File, StringRef path); - void buildAtomToAddressMap(); - void buildStaticSymbolTable(const File &file); - void buildDynamicSymbolTable(const File &file); - void buildSectionHeaderTable(); - void assignSectionsWithNoSegments(); - void addDefaultAtoms(); - void addFiles(InputFiles&); - void finalizeDefaultAtomValues(); - - uint64_t addressOfAtom(const Atom *atom) { - return _atomToAddressMap[atom]; - } - - void createDefaultSections(); - - void createDefaultDynamicEntries() { - Elf_Dyn dyn; - dyn.d_un.d_val = 0; - - dyn.d_tag = DT_HASH; - _dt_hash = _dynamicTable->addEntry(dyn); - dyn.d_tag = DT_STRTAB; - _dt_strtab = _dynamicTable->addEntry(dyn); - dyn.d_tag = DT_SYMTAB; - _dt_symtab = _dynamicTable->addEntry(dyn); - dyn.d_tag = DT_STRSZ; - _dt_strsz = _dynamicTable->addEntry(dyn); - dyn.d_tag = DT_SYMENT; - _dt_syment = _dynamicTable->addEntry(dyn); - if (_layout->hasDynamicRelocationTable()) { - dyn.d_tag = DT_RELA; - _dt_rela = _dynamicTable->addEntry(dyn); - dyn.d_tag = DT_RELASZ; - _dt_relasz = _dynamicTable->addEntry(dyn); - dyn.d_tag = DT_RELAENT; - _dt_relaent = _dynamicTable->addEntry(dyn); - } - if (_layout->hasPLTRelocationTable()) { - dyn.d_tag = DT_PLTRELSZ; - _dt_pltrelsz = _dynamicTable->addEntry(dyn); - dyn.d_tag = DT_PLTGOT; - _dt_pltgot = _dynamicTable->addEntry(dyn); - dyn.d_tag = DT_PLTREL; - dyn.d_un.d_val = DT_RELA; - _dt_pltrel = _dynamicTable->addEntry(dyn); - dyn.d_un.d_val = 0; - dyn.d_tag = DT_JMPREL; - _dt_jmprel = _dynamicTable->addEntry(dyn); - } - } - - void updateDynamicTable() { - auto tbl = _dynamicTable->entries(); - tbl[_dt_hash].d_un.d_val = _hashTable->virtualAddr(); - tbl[_dt_strtab].d_un.d_val = _dynamicStringTable->virtualAddr(); - tbl[_dt_symtab].d_un.d_val = _dynamicSymbolTable->virtualAddr(); - tbl[_dt_strsz].d_un.d_val = _dynamicStringTable->memSize(); - tbl[_dt_syment].d_un.d_val = _dynamicSymbolTable->getEntSize(); - if (_layout->hasDynamicRelocationTable()) { - auto relaTbl = _layout->getDynamicRelocationTable(); - tbl[_dt_rela].d_un.d_val = relaTbl->virtualAddr(); - tbl[_dt_relasz].d_un.d_val = relaTbl->memSize(); - tbl[_dt_relaent].d_un.d_val = relaTbl->getEntSize(); - } - if (_layout->hasPLTRelocationTable()) { - auto relaTbl = _layout->getPLTRelocationTable(); - tbl[_dt_jmprel].d_un.d_val = relaTbl->virtualAddr(); - tbl[_dt_pltrelsz].d_un.d_val = relaTbl->memSize(); - auto gotplt = _layout->findOutputSection(".got.plt"); - tbl[_dt_pltgot].d_un.d_val = gotplt->virtualAddr(); - } - } - - llvm::BumpPtrAllocator _alloc; - - const ELFTargetInfo &_targetInfo; - TargetHandler<ELFT> &_targetHandler; - - typedef llvm::DenseMap<const Atom *, uint64_t> AtomToAddress; - AtomToAddress _atomToAddressMap; - TargetLayout<ELFT> *_layout; - LLD_UNIQUE_BUMP_PTR(Header<ELFT>) _Header; - LLD_UNIQUE_BUMP_PTR(ProgramHeader<ELFT>) _programHeader; - LLD_UNIQUE_BUMP_PTR(SymbolTable<ELFT>) _symtab; - LLD_UNIQUE_BUMP_PTR(StringTable<ELFT>) _strtab; - LLD_UNIQUE_BUMP_PTR(StringTable<ELFT>) _shstrtab; - LLD_UNIQUE_BUMP_PTR(SectionHeader<ELFT>) _shdrtab; - /// \name Dynamic sections. - /// @{ - LLD_UNIQUE_BUMP_PTR(DynamicTable<ELFT>) _dynamicTable; - LLD_UNIQUE_BUMP_PTR(DynamicSymbolTable<ELFT>) _dynamicSymbolTable; - LLD_UNIQUE_BUMP_PTR(StringTable<ELFT>) _dynamicStringTable; - LLD_UNIQUE_BUMP_PTR(InterpSection<ELFT>) _interpSection; - LLD_UNIQUE_BUMP_PTR(HashSection<ELFT>) _hashTable; - llvm::StringSet<> _soNeeded; - std::size_t _dt_hash; - std::size_t _dt_strtab; - std::size_t _dt_symtab; - std::size_t _dt_rela; - std::size_t _dt_relasz; - std::size_t _dt_relaent; - std::size_t _dt_strsz; - std::size_t _dt_syment; - std::size_t _dt_pltrelsz; - std::size_t _dt_pltgot; - std::size_t _dt_pltrel; - std::size_t _dt_jmprel; - /// @} - CRuntimeFile<ELFT> _runtimeFile; -}; - -//===----------------------------------------------------------------------===// -// ExecutableWriter -//===----------------------------------------------------------------------===// -template <class ELFT> -ExecutableWriter<ELFT>::ExecutableWriter(const ELFTargetInfo &ti) - : _targetInfo(ti), _targetHandler(ti.getTargetHandler<ELFT>()), - _runtimeFile(ti) { - _layout = &_targetHandler.targetLayout(); -} - -template <class ELFT> -void ExecutableWriter<ELFT>::buildChunks(const File &file) { - for (const DefinedAtom *definedAtom : file.defined()) { - _layout->addAtom(definedAtom); - } - for (const AbsoluteAtom *absoluteAtom : file.absolute()) - _layout->addAtom(absoluteAtom); -} - -template <class ELFT> -void ExecutableWriter<ELFT>::buildStaticSymbolTable(const File &file) { - for (auto sec : _layout->sections()) - if (auto section = dyn_cast<AtomSection<ELFT>>(sec)) - for (const auto &atom : section->atoms()) - _symtab->addSymbol(atom->_atom, section->ordinal(), atom->_virtualAddr); - for (auto &atom : _layout->absoluteAtoms()) - _symtab->addSymbol(atom->_atom, ELF::SHN_ABS, atom->_virtualAddr); - for (const UndefinedAtom *a : file.undefined()) - _symtab->addSymbol(a, ELF::SHN_UNDEF); -} - -template <class ELFT> -void ExecutableWriter<ELFT>::buildDynamicSymbolTable(const File &file) { - for (const auto sla : file.sharedLibrary()) { - _dynamicSymbolTable->addSymbol(sla, ELF::SHN_UNDEF); - _soNeeded.insert(sla->loadName()); - } - for (const auto &loadName : _soNeeded) { - Elf_Dyn dyn; - dyn.d_tag = DT_NEEDED; - dyn.d_un.d_val = _dynamicStringTable->addString(loadName.getKey()); - _dynamicTable->addEntry(dyn); - } -} - -template <class ELFT> void ExecutableWriter<ELFT>::buildAtomToAddressMap() { - for (auto sec : _layout->sections()) - if (auto section = dyn_cast<AtomSection<ELFT>>(sec)) - for (const auto &atom : section->atoms()) - _atomToAddressMap[atom->_atom] = atom->_virtualAddr; - // build the atomToAddressMap that contains absolute symbols too - for (auto &atom : _layout->absoluteAtoms()) - _atomToAddressMap[atom->_atom] = atom->_virtualAddr; -} - -template<class ELFT> -void ExecutableWriter<ELFT>::buildSectionHeaderTable() { - for (auto mergedSec : _layout->mergedSections()) { - if (mergedSec->kind() != Chunk<ELFT>::K_ELFSection && - mergedSec->kind() != Chunk<ELFT>::K_AtomSection) - continue; - if (mergedSec->hasSegment()) - _shdrtab->appendSection(mergedSec); - } -} - -template<class ELFT> -void ExecutableWriter<ELFT>::assignSectionsWithNoSegments() { - for (auto mergedSec : _layout->mergedSections()) { - if (mergedSec->kind() != Chunk<ELFT>::K_ELFSection && - mergedSec->kind() != Chunk<ELFT>::K_AtomSection) - continue; - if (!mergedSec->hasSegment()) - _shdrtab->appendSection(mergedSec); - } - _layout->assignOffsetsForMiscSections(); - for (auto sec : _layout->sections()) - if (auto section = dyn_cast<Section<ELFT>>(sec)) - if (!DefaultLayout<ELFT>::hasOutputSegment(section)) - _shdrtab->updateSection(section); -} - -/// \brief Add absolute symbols by default. These are linker added -/// absolute symbols -template<class ELFT> -void ExecutableWriter<ELFT>::addDefaultAtoms() { - _runtimeFile.addUndefinedAtom(_targetInfo.getEntry()); - _runtimeFile.addAbsoluteAtom("__bss_start"); - _runtimeFile.addAbsoluteAtom("__bss_end"); - _runtimeFile.addAbsoluteAtom("_end"); - _runtimeFile.addAbsoluteAtom("end"); - _runtimeFile.addAbsoluteAtom("__preinit_array_start"); - _runtimeFile.addAbsoluteAtom("__preinit_array_end"); - _runtimeFile.addAbsoluteAtom("__init_array_start"); - _runtimeFile.addAbsoluteAtom("__init_array_end"); - _runtimeFile.addAbsoluteAtom("__rela_iplt_start"); - _runtimeFile.addAbsoluteAtom("__rela_iplt_end"); - _runtimeFile.addAbsoluteAtom("__fini_array_start"); - _runtimeFile.addAbsoluteAtom("__fini_array_end"); -} - -/// \brief Hook in lld to add CRuntime file -template <class ELFT> -void ExecutableWriter<ELFT>::addFiles(InputFiles &inputFiles) { - addDefaultAtoms(); - inputFiles.prependFile(_runtimeFile); - // Give a chance for the target to add atoms - _targetHandler.addFiles(inputFiles); -} - -/// Finalize the value of all the absolute symbols that we -/// created -template<class ELFT> -void ExecutableWriter<ELFT>::finalizeDefaultAtomValues() { - auto bssStartAtomIter = _layout->findAbsoluteAtom("__bss_start"); - auto bssEndAtomIter = _layout->findAbsoluteAtom("__bss_end"); - auto underScoreEndAtomIter = _layout->findAbsoluteAtom("_end"); - auto endAtomIter = _layout->findAbsoluteAtom("end"); - - auto startEnd = [&](StringRef sym, StringRef sec) -> void { - // TODO: This looks like a good place to use Twine... - std::string start("__"), end("__"); - start += sym; - start += "_start"; - end += sym; - end += "_end"; - auto s = _layout->findAbsoluteAtom(start); - auto e = _layout->findAbsoluteAtom(end); - auto section = _layout->findOutputSection(sec); - if (section) { - (*s)->_virtualAddr = section->virtualAddr(); - (*e)->_virtualAddr = section->virtualAddr() + section->memSize(); - } else { - (*s)->_virtualAddr = 0; - (*e)->_virtualAddr = 0; - } - }; - - startEnd("preinit_array", ".preinit_array"); - startEnd("init_array", ".init_array"); - startEnd("rela_iplt", ".rela.plt"); - startEnd("fini_array", ".fini_array"); - - assert(!(bssStartAtomIter == _layout->absoluteAtoms().end() || - bssEndAtomIter == _layout->absoluteAtoms().end() || - underScoreEndAtomIter == _layout->absoluteAtoms().end() || - endAtomIter == _layout->absoluteAtoms().end()) && - "Unable to find the absolute atoms that have been added by lld"); - - auto phe = _programHeader->findProgramHeader( - llvm::ELF::PT_LOAD, llvm::ELF::PF_W, llvm::ELF::PF_X); - - assert(!(phe == _programHeader->end()) && - "Can't find a data segment in the program header!"); - - (*bssStartAtomIter)->_virtualAddr = (*phe)->p_vaddr + (*phe)->p_filesz; - (*bssEndAtomIter)->_virtualAddr = (*phe)->p_vaddr + (*phe)->p_memsz; - (*underScoreEndAtomIter)->_virtualAddr = (*phe)->p_vaddr + (*phe)->p_memsz; - (*endAtomIter)->_virtualAddr = (*phe)->p_vaddr + (*phe)->p_memsz; - - // Give a chance for the target to finalize its atom values - _targetHandler.finalizeSymbolValues(); -} - -template <class ELFT> -error_code ExecutableWriter<ELFT>::writeFile(const File &file, StringRef path) { - buildChunks(file); - - // Call the preFlight callbacks to modify the sections and the atoms - // contained in them, in anyway the targets may want - _layout->doPreFlight(); - - // Create the default sections like the symbol table, string table, and the - // section string table - createDefaultSections(); - - if (_targetInfo.isDynamic()) { - createDefaultDynamicEntries(); - buildDynamicSymbolTable(file); - } - - // Set the Layout - _layout->assignSectionsToSegments(); - _layout->assignFileOffsets(); - _layout->assignVirtualAddress(); - - // Finalize the default value of symbols that the linker adds - finalizeDefaultAtomValues(); - - // Build the Atom To Address map for applying relocations - buildAtomToAddressMap(); - - // Create symbol table and section string table - buildStaticSymbolTable(file); - - // Finalize the layout by calling the finalize() functions - _layout->finalize(); - - // build Section Header table - buildSectionHeaderTable(); - - // assign Offsets and virtual addresses - // for sections with no segments - assignSectionsWithNoSegments(); - - if (_targetInfo.isDynamic()) - updateDynamicTable(); - - uint64_t totalSize = _shdrtab->fileOffset() + _shdrtab->fileSize(); - - OwningPtr<FileOutputBuffer> buffer; - error_code ec = FileOutputBuffer::create(path, - totalSize, buffer, - FileOutputBuffer::F_executable); - if (ec) - return ec; - - _Header->e_ident(ELF::EI_CLASS, _targetInfo.is64Bits() ? ELF::ELFCLASS64 : - ELF::ELFCLASS32); - _Header->e_ident(ELF::EI_DATA, _targetInfo.isLittleEndian() ? - ELF::ELFDATA2LSB : ELF::ELFDATA2MSB); - _Header->e_type(_targetInfo.getOutputType()); - _Header->e_machine(_targetInfo.getOutputMachine()); - - if (!_targetHandler.doesOverrideHeader()) { - _Header->e_ident(ELF::EI_VERSION, 1); - _Header->e_ident(ELF::EI_OSABI, 0); - _Header->e_version(1); - } else { - // override the contents of the ELF Header - _targetHandler.setHeaderInfo(_Header.get()); - } - _Header->e_phoff(_programHeader->fileOffset()); - _Header->e_shoff(_shdrtab->fileOffset()); - _Header->e_phentsize(_programHeader->entsize()); - _Header->e_phnum(_programHeader->numHeaders()); - _Header->e_shentsize(_shdrtab->entsize()); - _Header->e_shnum(_shdrtab->numHeaders()); - _Header->e_shstrndx(_shstrtab->ordinal()); - uint64_t virtualAddr = 0; - _layout->findAtomAddrByName(_targetInfo.getEntry(), virtualAddr); - _Header->e_entry(virtualAddr); - - // HACK: We have to write out the header and program header here even though - // they are a member of a segment because only sections are written in the - // following loop. - _Header->write(this, *buffer); - _programHeader->write(this, *buffer); - - for (auto section : _layout->sections()) - section->write(this, *buffer); - - return buffer->commit(); -} - -template<class ELFT> -void ExecutableWriter<ELFT>::createDefaultSections() { - _Header.reset(new (_alloc) Header<ELFT>(_targetInfo)); - _programHeader.reset(new (_alloc) ProgramHeader<ELFT>(_targetInfo)); - _layout->setHeader(_Header.get()); - _layout->setProgramHeader(_programHeader.get()); - - _symtab.reset(new (_alloc) SymbolTable<ELFT>( - _targetInfo, ".symtab", DefaultLayout<ELFT>::ORDER_SYMBOL_TABLE)); - _strtab.reset(new (_alloc) StringTable<ELFT>( - _targetInfo, ".strtab", DefaultLayout<ELFT>::ORDER_STRING_TABLE)); - _shstrtab.reset(new (_alloc) StringTable<ELFT>( - _targetInfo, ".shstrtab", DefaultLayout<ELFT>::ORDER_SECTION_STRINGS)); - _shdrtab.reset(new (_alloc) SectionHeader<ELFT>( - _targetInfo, DefaultLayout<ELFT>::ORDER_SECTION_HEADERS)); - _layout->addSection(_symtab.get()); - _layout->addSection(_strtab.get()); - _layout->addSection(_shstrtab.get()); - _shdrtab->setStringSection(_shstrtab.get()); - _symtab->setStringSection(_strtab.get()); - _layout->addSection(_shdrtab.get()); - - if (_targetInfo.isDynamic()) { - _dynamicTable.reset(new (_alloc) DynamicTable<ELFT>( - _targetInfo, ".dynamic", DefaultLayout<ELFT>::ORDER_DYNAMIC)); - _dynamicStringTable.reset(new (_alloc) StringTable<ELFT>( - _targetInfo, ".dynstr", DefaultLayout<ELFT>::ORDER_DYNAMIC_STRINGS, - true)); - _dynamicSymbolTable.reset(new (_alloc) DynamicSymbolTable<ELFT>( - _targetInfo, ".dynsym", DefaultLayout<ELFT>::ORDER_DYNAMIC_SYMBOLS)); - _interpSection.reset(new (_alloc) InterpSection<ELFT>( - _targetInfo, ".interp", DefaultLayout<ELFT>::ORDER_INTERP, - _targetInfo.getInterpreter())); - _hashTable.reset(new (_alloc) HashSection<ELFT>( - _targetInfo, ".hash", DefaultLayout<ELFT>::ORDER_HASH)); - _layout->addSection(_dynamicTable.get()); - _layout->addSection(_dynamicStringTable.get()); - _layout->addSection(_dynamicSymbolTable.get()); - _layout->addSection(_interpSection.get()); - _layout->addSection(_hashTable.get()); - _dynamicSymbolTable->setStringSection(_dynamicStringTable.get()); - if (_layout->hasDynamicRelocationTable()) - _layout->getDynamicRelocationTable()->setSymbolTable( - _dynamicSymbolTable.get()); - if (_layout->hasPLTRelocationTable()) - _layout->getPLTRelocationTable()->setSymbolTable( - _dynamicSymbolTable.get()); - } - - // give a chance for the target to add sections - _targetHandler.createDefaultSections(); -} -} // namespace elf - -std::unique_ptr<Writer> createWriterELF(const ELFTargetInfo &TI) { - using llvm::object::ELFType; - // Set the default layout to be the static executable layout - // We would set the layout to a dynamic executable layout - // if we came across any shared libraries in the process - - if (!TI.is64Bits() && TI.isLittleEndian()) - return std::unique_ptr<Writer>(new - elf::ExecutableWriter<ELFType<support::little, 4, false>>(TI)); - else if (TI.is64Bits() && TI.isLittleEndian()) - return std::unique_ptr<Writer>(new - elf::ExecutableWriter<ELFType<support::little, 8, true>>(TI)); - else if (!TI.is64Bits() && !TI.isLittleEndian()) - return std::unique_ptr<Writer>(new - elf::ExecutableWriter<ELFType<support::big, 4, false>>(TI)); - else if (TI.is64Bits() && !TI.isLittleEndian()) - return std::unique_ptr<Writer>(new - elf::ExecutableWriter<ELFType<support::big, 8, true>>(TI)); - - llvm_unreachable("Invalid Options!"); -} -} // namespace lld |
