diff options
Diffstat (limited to 'lld/lib/ReaderWriter/ELF/ExecutableWriter.h')
-rw-r--r-- | lld/lib/ReaderWriter/ELF/ExecutableWriter.h | 319 |
1 files changed, 24 insertions, 295 deletions
diff --git a/lld/lib/ReaderWriter/ELF/ExecutableWriter.h b/lld/lib/ReaderWriter/ELF/ExecutableWriter.h index 89e9ed4089a..eb3d16ad953 100644 --- a/lld/lib/ReaderWriter/ELF/ExecutableWriter.h +++ b/lld/lib/ReaderWriter/ELF/ExecutableWriter.h @@ -9,15 +9,7 @@ #ifndef LLD_READER_WRITER_ELF_EXECUTABLE_WRITER_H #define LLD_READER_WRITER_ELF_EXECUTABLE_WRITER_H -#include "lld/ReaderWriter/Writer.h" - -#include "DefaultLayout.h" -#include "TargetLayout.h" -#include "ExecutableAtoms.h" - -#include "lld/ReaderWriter/ELFTargetInfo.h" - -#include "llvm/ADT/StringSet.h" +#include "OutputELFWriter.h" namespace lld { namespace elf { @@ -31,148 +23,29 @@ class ExecutableWriter; // ExecutableWriter Class //===----------------------------------------------------------------------===// template<class ELFT> -class ExecutableWriter : public ELFWriter { +class ExecutableWriter : public OutputELFWriter<ELFT> { 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); + ExecutableWriter(const ELFTargetInfo &ti) + : OutputELFWriter<ELFT>(ti), _runtimeFile(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() {} + virtual void addDefaultAtoms(); + virtual void addFiles(InputFiles&); + virtual void finalizeDefaultAtomValues(); - 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; - /// @} 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.addUndefinedAtom(this->_targetInfo.getEntry()); _runtimeFile.addAbsoluteAtom("__bss_start"); _runtimeFile.addAbsoluteAtom("__bss_end"); _runtimeFile.addAbsoluteAtom("_end"); @@ -193,17 +66,17 @@ void ExecutableWriter<ELFT>::addFiles(InputFiles &inputFiles) { addDefaultAtoms(); inputFiles.prependFile(_runtimeFile); // Give a chance for the target to add atoms - _targetHandler.addFiles(inputFiles); + this->_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 bssStartAtomIter = this->_layout->findAbsoluteAtom("__bss_start"); + auto bssEndAtomIter = this->_layout->findAbsoluteAtom("__bss_end"); + auto underScoreEndAtomIter = this->_layout->findAbsoluteAtom("_end"); + auto endAtomIter = this->_layout->findAbsoluteAtom("end"); auto startEnd = [&](StringRef sym, StringRef sec) -> void { // TODO: This looks like a good place to use Twine... @@ -212,9 +85,9 @@ void ExecutableWriter<ELFT>::finalizeDefaultAtomValues() { start += "_start"; end += sym; end += "_end"; - auto s = _layout->findAbsoluteAtom(start); - auto e = _layout->findAbsoluteAtom(end); - auto section = _layout->findOutputSection(sec); + auto s = this->_layout->findAbsoluteAtom(start); + auto e = this->_layout->findAbsoluteAtom(end); + auto section = this->_layout->findOutputSection(sec); if (section) { (*s)->_virtualAddr = section->virtualAddr(); (*e)->_virtualAddr = section->virtualAddr() + section->memSize(); @@ -229,16 +102,16 @@ void ExecutableWriter<ELFT>::finalizeDefaultAtomValues() { 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()) && + assert(!(bssStartAtomIter == this->_layout->absoluteAtoms().end() || + bssEndAtomIter == this->_layout->absoluteAtoms().end() || + underScoreEndAtomIter == this->_layout->absoluteAtoms().end() || + endAtomIter == this->_layout->absoluteAtoms().end()) && "Unable to find the absolute atoms that have been added by lld"); - auto phe = _programHeader->findProgramHeader( + auto phe = this->_programHeader->findProgramHeader( llvm::ELF::PT_LOAD, llvm::ELF::PF_W, llvm::ELF::PF_X); - assert(!(phe == _programHeader->end()) && + assert(!(phe == this->_programHeader->end()) && "Can't find a data segment in the program header!"); (*bssStartAtomIter)->_virtualAddr = (*phe)->p_vaddr + (*phe)->p_filesz; @@ -247,153 +120,9 @@ void ExecutableWriter<ELFT>::finalizeDefaultAtomValues() { (*endAtomIter)->_virtualAddr = (*phe)->p_vaddr + (*phe)->p_memsz; // Give a chance for the target to finalize its atom values - _targetHandler.finalizeSymbolValues(); + this->_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()) { - _dynamicTable->createDefaultEntries(); - 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()) - _dynamicTable->updateDynamicTable(_hashTable.get(), - _dynamicSymbolTable.get()); - - 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 } // namespace lld |