| //===- MipsLDBackend.cpp --------------------------------------------------===// |
| // |
| // The MCLinker Project |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include <llvm/ADT/Triple.h> |
| #include <llvm/Support/ELF.h> |
| |
| #include <mcld/LD/SectionMap.h> |
| #include <mcld/MC/MCLDInfo.h> |
| #include <mcld/MC/MCLinker.h> |
| #include <mcld/Support/MemoryRegion.h> |
| #include <mcld/Support/TargetRegistry.h> |
| #include <mcld/Target/OutputRelocSection.h> |
| |
| #include "Mips.h" |
| #include "MipsELFDynamic.h" |
| #include "MipsLDBackend.h" |
| #include "MipsRelocationFactory.h" |
| |
| enum { |
| // The original o32 abi. |
| E_MIPS_ABI_O32 = 0x00001000, |
| // O32 extended to work on 64 bit architectures. |
| E_MIPS_ABI_O64 = 0x00002000, |
| // EABI in 32 bit mode. |
| E_MIPS_ABI_EABI32 = 0x00003000, |
| // EABI in 64 bit mode. |
| E_MIPS_ABI_EABI64 = 0x00004000 |
| }; |
| |
| namespace mcld { |
| |
| MipsGNULDBackend::MipsGNULDBackend() |
| : m_pRelocFactory(NULL), |
| m_pGOT(NULL), |
| m_pRelDyn(NULL), |
| m_pDynamic(NULL), |
| m_pGOTSymbol(NULL), |
| m_pGpDispSymbol(NULL) |
| { |
| } |
| |
| MipsGNULDBackend::~MipsGNULDBackend() |
| { |
| if (NULL != m_pRelocFactory) |
| delete m_pRelocFactory; |
| if (NULL != m_pGOT) |
| delete m_pGOT; |
| if (NULL != m_pRelDyn) |
| delete m_pRelDyn; |
| if (NULL != m_pDynamic) |
| delete m_pDynamic; |
| } |
| |
| bool MipsGNULDBackend::initTargetSectionMap(SectionMap& pSectionMap) |
| { |
| // Nothing to do because we do not support |
| // any MIPS specific sections now. |
| return true; |
| } |
| |
| void MipsGNULDBackend::initTargetSections(MCLinker& pLinker) |
| { |
| // Nothing to do because we do not support |
| // any MIPS specific sections now. |
| } |
| |
| void MipsGNULDBackend::initTargetSymbols(MCLinker& pLinker) |
| { |
| // Define the symbol _GLOBAL_OFFSET_TABLE_ if there is a symbol with the |
| // same name in input |
| m_pGOTSymbol = pLinker.defineSymbol<MCLinker::AsRefered, MCLinker::Resolve>( |
| "_GLOBAL_OFFSET_TABLE_", |
| false, |
| ResolveInfo::Object, |
| ResolveInfo::Define, |
| ResolveInfo::Local, |
| 0x0, // size |
| 0x0, // value |
| NULL, // FragRef |
| ResolveInfo::Hidden); |
| |
| m_pGpDispSymbol = pLinker.defineSymbol<MCLinker::AsRefered, MCLinker::Resolve>( |
| "_gp_disp", |
| false, |
| ResolveInfo::Section, |
| ResolveInfo::Define, |
| ResolveInfo::Absolute, |
| 0x0, // size |
| 0x0, // value |
| NULL, // FragRef |
| ResolveInfo::Default); |
| |
| if (NULL != m_pGpDispSymbol) { |
| m_pGpDispSymbol->resolveInfo()->setReserved(ReserveGpDisp); |
| } |
| } |
| |
| bool MipsGNULDBackend::initRelocFactory(const MCLinker& pLinker) |
| { |
| if (NULL == m_pRelocFactory) { |
| m_pRelocFactory = new MipsRelocationFactory(1024, *this); |
| m_pRelocFactory->setLayout(pLinker.getLayout()); |
| } |
| return true; |
| } |
| |
| RelocationFactory* MipsGNULDBackend::getRelocFactory() |
| { |
| assert(NULL != m_pRelocFactory); |
| return m_pRelocFactory; |
| } |
| |
| void MipsGNULDBackend::scanRelocation(Relocation& pReloc, |
| const LDSymbol& pInputSym, |
| MCLinker& pLinker, |
| const MCLDInfo& pLDInfo, |
| const Output& pOutput) |
| { |
| // rsym - The relocation target symbol |
| ResolveInfo* rsym = pReloc.symInfo(); |
| assert(NULL != rsym && "ResolveInfo of relocation not set while scanRelocation"); |
| |
| // A refernece to symbol _GLOBAL_OFFSET_TABLE_ implies |
| // that a .got section is needed. |
| if (NULL == m_pGOT && NULL != m_pGOTSymbol) { |
| if (rsym == m_pGOTSymbol->resolveInfo()) { |
| createGOT(pLinker, pOutput); |
| } |
| } |
| |
| if (rsym->isLocal()) |
| scanLocalReloc(pReloc, pInputSym, pLinker, pLDInfo, pOutput); |
| else |
| scanGlobalReloc(pReloc, pInputSym, pLinker, pLDInfo, pOutput); |
| } |
| |
| uint32_t MipsGNULDBackend::machine() const |
| { |
| return llvm::ELF::EM_MIPS; |
| } |
| |
| uint8_t MipsGNULDBackend::OSABI() const |
| { |
| return llvm::ELF::ELFOSABI_NONE; |
| } |
| |
| uint8_t MipsGNULDBackend::ABIVersion() const |
| { |
| return 0; |
| } |
| |
| uint64_t MipsGNULDBackend::flags() const |
| { |
| // TODO: (simon) The correct flag's set depend on command line |
| // arguments and flags from input .o files. |
| return llvm::ELF::EF_MIPS_ARCH_32R2 | |
| llvm::ELF::EF_MIPS_NOREORDER | |
| llvm::ELF::EF_MIPS_PIC | |
| llvm::ELF::EF_MIPS_CPIC | |
| E_MIPS_ABI_O32; |
| } |
| |
| bool MipsGNULDBackend::isLittleEndian() const |
| { |
| // Now we support little endian (mipsel) target only. |
| return true; |
| } |
| |
| unsigned int MipsGNULDBackend::bitclass() const |
| { |
| return 32; |
| } |
| |
| void MipsGNULDBackend::doPreLayout(const Output& pOutput, |
| const MCLDInfo& pInfo, |
| MCLinker& pLinker) |
| { |
| // when building shared object, the .got section is must. |
| if (pOutput.type() == Output::DynObj && NULL == m_pGOT) { |
| createGOT(pLinker, pOutput); |
| } |
| } |
| |
| void MipsGNULDBackend::doPostLayout(const Output& pOutput, |
| const MCLDInfo& pInfo, |
| MCLinker& pLinker) |
| { |
| // emit program headers |
| if (pOutput.type() == Output::DynObj || pOutput.type() == Output::Exec) |
| emitProgramHdrs(pLinker.getLDInfo().output()); |
| } |
| |
| /// dynamic - the dynamic section of the target machine. |
| /// Use co-variant return type to return its own dynamic section. |
| MipsELFDynamic& MipsGNULDBackend::dynamic() |
| { |
| if (NULL == m_pDynamic) |
| m_pDynamic = new MipsELFDynamic(*this); |
| |
| return *m_pDynamic; |
| } |
| |
| /// dynamic - the dynamic section of the target machine. |
| /// Use co-variant return type to return its own dynamic section. |
| const MipsELFDynamic& MipsGNULDBackend::dynamic() const |
| { |
| assert( NULL != m_pDynamic); |
| return *m_pDynamic; |
| } |
| |
| uint64_t MipsGNULDBackend::emitSectionData(const Output& pOutput, |
| const LDSection& pSection, |
| const MCLDInfo& pInfo, |
| MemoryRegion& pRegion) const |
| { |
| assert(pRegion.size() && "Size of MemoryRegion is zero!"); |
| |
| ELFFileFormat* file_format = getOutputFormat(pOutput); |
| |
| if (&pSection == &(file_format->getGOT())) { |
| assert(NULL != m_pGOT && "emitSectionData failed, m_pGOT is NULL!"); |
| uint64_t result = m_pGOT->emit(pRegion); |
| return result; |
| } |
| |
| llvm::report_fatal_error(llvm::Twine("Unable to emit section `") + |
| pSection.name() + |
| llvm::Twine("'.\n")); |
| return 0; |
| } |
| /// isGOTSymbol - return true if the symbol is the GOT entry. |
| bool MipsGNULDBackend::isGOTSymbol(const LDSymbol& pSymbol) const |
| { |
| return std::find(m_LocalGOTSyms.begin(), |
| m_LocalGOTSyms.end(), &pSymbol) != m_LocalGOTSyms.end() || |
| std::find(m_GlobalGOTSyms.begin(), |
| m_GlobalGOTSyms.end(), &pSymbol) != m_GlobalGOTSyms.end(); |
| } |
| |
| /// emitDynamicSymbol - emit dynamic symbol. |
| void MipsGNULDBackend::emitDynamicSymbol(llvm::ELF::Elf32_Sym& sym32, |
| Output& pOutput, |
| LDSymbol& pSymbol, |
| const Layout& pLayout, |
| char* strtab, |
| size_t strtabsize, |
| size_t symtabIdx) |
| { |
| // maintain output's symbol and index map |
| bool sym_exist = false; |
| HashTableType::entry_type* entry = 0; |
| entry = m_pSymIndexMap->insert(&pSymbol, sym_exist); |
| entry->setValue(symtabIdx); |
| |
| // FIXME: check the endian between host and target |
| // write out symbol |
| sym32.st_name = strtabsize; |
| sym32.st_value = pSymbol.value(); |
| sym32.st_size = getSymbolSize(pSymbol); |
| sym32.st_info = getSymbolInfo(pSymbol); |
| sym32.st_other = pSymbol.visibility(); |
| sym32.st_shndx = getSymbolShndx(pSymbol, pLayout); |
| // write out string |
| strcpy((strtab + strtabsize), pSymbol.name()); |
| } |
| |
| /// emitNamePools - emit dynamic name pools - .dyntab, .dynstr, .hash |
| /// |
| /// the size of these tables should be computed before layout |
| /// layout should computes the start offset of these tables |
| void MipsGNULDBackend::emitDynNamePools(Output& pOutput, |
| SymbolCategory& pSymbols, |
| const Layout& pLayout, |
| const MCLDInfo& pLDInfo) |
| { |
| assert(pOutput.hasMemArea()); |
| ELFFileFormat* file_format = getOutputFormat(pOutput); |
| |
| LDSection& symtab_sect = file_format->getDynSymTab(); |
| LDSection& strtab_sect = file_format->getDynStrTab(); |
| LDSection& hash_sect = file_format->getHashTab(); |
| LDSection& dyn_sect = file_format->getDynamic(); |
| |
| MemoryRegion* symtab_region = pOutput.memArea()->request(symtab_sect.offset(), |
| symtab_sect.size()); |
| MemoryRegion* strtab_region = pOutput.memArea()->request(strtab_sect.offset(), |
| strtab_sect.size()); |
| MemoryRegion* hash_region = pOutput.memArea()->request(hash_sect.offset(), |
| hash_sect.size()); |
| MemoryRegion* dyn_region = pOutput.memArea()->request(dyn_sect.offset(), |
| dyn_sect.size()); |
| // set up symtab_region |
| llvm::ELF::Elf32_Sym* symtab32 = NULL; |
| symtab32 = (llvm::ELF::Elf32_Sym*)symtab_region->start(); |
| |
| symtab32[0].st_name = 0; |
| symtab32[0].st_value = 0; |
| symtab32[0].st_size = 0; |
| symtab32[0].st_info = 0; |
| symtab32[0].st_other = 0; |
| symtab32[0].st_shndx = 0; |
| |
| // set up strtab_region |
| char* strtab = (char*)strtab_region->start(); |
| strtab[0] = '\0'; |
| |
| bool sym_exist = false; |
| HashTableType::entry_type* entry = 0; |
| |
| // add index 0 symbol into SymIndexMap |
| entry = m_pSymIndexMap->insert(NULL, sym_exist); |
| entry->setValue(0); |
| |
| size_t symtabIdx = 1; |
| size_t strtabsize = 1; |
| |
| // emit of .dynsym, and .dynstr except GOT entries |
| for (SymbolCategory::iterator symbol = pSymbols.begin(), |
| sym_end = pSymbols.end(); symbol != sym_end; ++symbol) { |
| if (!isDynamicSymbol(**symbol, pOutput)) |
| continue; |
| |
| if (isGOTSymbol(**symbol)) |
| continue; |
| |
| emitDynamicSymbol(symtab32[symtabIdx], pOutput, **symbol, pLayout, strtab, |
| strtabsize, symtabIdx); |
| |
| // sum up counters |
| ++symtabIdx; |
| strtabsize += (*symbol)->nameSize() + 1; |
| } |
| |
| // emit global GOT |
| for (std::vector<LDSymbol*>::const_iterator symbol = m_GlobalGOTSyms.begin(), |
| symbol_end = m_GlobalGOTSyms.end(); |
| symbol != symbol_end; ++symbol) { |
| |
| emitDynamicSymbol(symtab32[symtabIdx], pOutput, **symbol, pLayout, strtab, |
| strtabsize, symtabIdx); |
| |
| // sum up counters |
| ++symtabIdx; |
| strtabsize += (*symbol)->nameSize() + 1; |
| } |
| |
| // emit DT_NEED |
| // add DT_NEED strings into .dynstr |
| // Rules: |
| // 1. ignore --no-add-needed |
| // 2. force count in --no-as-needed |
| // 3. judge --as-needed |
| ELFDynamic::iterator dt_need = dynamic().needBegin(); |
| InputTree::const_bfs_iterator input, inputEnd = pLDInfo.inputs().bfs_end(); |
| for (input = pLDInfo.inputs().bfs_begin(); input != inputEnd; ++input) { |
| if (Input::DynObj == (*input)->type()) { |
| // --add-needed |
| if ((*input)->attribute()->isAddNeeded()) { |
| // --no-as-needed |
| if (!(*input)->attribute()->isAsNeeded()) { |
| strcpy((strtab + strtabsize), (*input)->name().c_str()); |
| (*dt_need)->setValue(llvm::ELF::DT_NEEDED, strtabsize); |
| strtabsize += (*input)->name().size() + 1; |
| ++dt_need; |
| } |
| // --as-needed |
| else if ((*input)->isNeeded()) { |
| strcpy((strtab + strtabsize), (*input)->name().c_str()); |
| (*dt_need)->setValue(llvm::ELF::DT_NEEDED, strtabsize); |
| strtabsize += (*input)->name().size() + 1; |
| ++dt_need; |
| } |
| } |
| } |
| } // for |
| |
| // emit soname |
| // initialize value of ELF .dynamic section |
| dynamic().applySoname(strtabsize); |
| dynamic().applyEntries(pLDInfo, *file_format); |
| dynamic().emit(dyn_sect, *dyn_region); |
| |
| strcpy((strtab + strtabsize), pOutput.name().c_str()); |
| strtabsize += pOutput.name().size() + 1; |
| |
| // emit hash table |
| // FIXME: this verion only emit SVR4 hash section. |
| // Please add GNU new hash section |
| |
| // both 32 and 64 bits hash table use 32-bit entry |
| // set up hash_region |
| uint32_t* word_array = (uint32_t*)hash_region->start(); |
| uint32_t& nbucket = word_array[0]; |
| uint32_t& nchain = word_array[1]; |
| |
| nbucket = getHashBucketCount(symtabIdx, false); |
| nchain = symtabIdx; |
| |
| uint32_t* bucket = (word_array + 2); |
| uint32_t* chain = (bucket + nbucket); |
| |
| // initialize bucket |
| bzero((void*)bucket, nbucket); |
| |
| StringHash<ELF> hash_func; |
| |
| for (size_t sym_idx=0; sym_idx < symtabIdx; ++sym_idx) { |
| llvm::StringRef name(strtab + symtab32[sym_idx].st_name); |
| size_t bucket_pos = hash_func(name) % nbucket; |
| chain[sym_idx] = bucket[bucket_pos]; |
| bucket[bucket_pos] = sym_idx; |
| } |
| |
| } |
| |
| MipsGOT& MipsGNULDBackend::getGOT() |
| { |
| assert(NULL != m_pGOT); |
| return *m_pGOT; |
| } |
| |
| const MipsGOT& MipsGNULDBackend::getGOT() const |
| { |
| assert(NULL != m_pGOT); |
| return *m_pGOT; |
| } |
| |
| OutputRelocSection& MipsGNULDBackend::getRelDyn() |
| { |
| assert(NULL != m_pRelDyn); |
| return *m_pRelDyn; |
| } |
| |
| const OutputRelocSection& MipsGNULDBackend::getRelDyn() const |
| { |
| assert(NULL != m_pRelDyn); |
| return *m_pRelDyn; |
| } |
| |
| unsigned int |
| MipsGNULDBackend::getTargetSectionOrder(const Output& pOutput, |
| const LDSection& pSectHdr) const |
| { |
| ELFFileFormat* file_format = getOutputFormat(pOutput); |
| |
| if (&pSectHdr == &file_format->getGOT()) |
| return SHO_DATA; |
| |
| return SHO_UNDEFINED; |
| } |
| |
| /// finalizeSymbol - finalize the symbol value |
| /// If the symbol's reserved field is not zero, MCLinker will call back this |
| /// function to ask the final value of the symbol |
| bool MipsGNULDBackend::finalizeSymbol(LDSymbol& pSymbol) const |
| { |
| if (&pSymbol == m_pGpDispSymbol) { |
| m_pGpDispSymbol->setValue(m_pGOT->getSection().addr() + 0x7FF0); |
| return true; |
| } |
| return false; |
| } |
| |
| /// allocateCommonSymbols - allocate common symbols in the corresponding |
| /// sections. |
| /// @refer Google gold linker: common.cc: 214 |
| /// FIXME: Mips needs to allocate small common symbol |
| bool |
| MipsGNULDBackend::allocateCommonSymbols(const MCLDInfo& pInfo, MCLinker& pLinker) const |
| { |
| // SymbolCategory contains all symbols that must emit to the output files. |
| // We are not like Google gold linker, we don't remember symbols before symbol |
| // resolution. All symbols in SymbolCategory are already resolved. Therefore, we |
| // don't need to care about some symbols may be changed its category due to symbol |
| // resolution. |
| 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()) { |
| alignAddress(offset, (*com_sym)->value()); |
| // 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(), &bss_section); |
| (*com_sym)->setFragmentRef(new MCFragmentRef(*frag, 0)); |
| offset += (*com_sym)->size(); |
| } |
| } |
| |
| // allocate all global common symbols |
| com_end = symbol_list.commonEnd(); |
| for (com_sym = symbol_list.commonBegin(); com_sym != com_end; ++com_sym) { |
| alignAddress(offset, (*com_sym)->value()); |
| |
| // 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(), &bss_section); |
| (*com_sym)->setFragmentRef(new MCFragmentRef(*frag, 0)); |
| offset += (*com_sym)->size(); |
| } |
| |
| bss_sect_hdr->setSize(offset); |
| symbol_list.changeCommonsToGlobal(); |
| return true; |
| } |
| |
| void MipsGNULDBackend::updateAddend(Relocation& pReloc, |
| const LDSymbol& pInputSym, |
| const Layout& pLayout) const |
| { |
| // Update value keep in addend if we meet a section symbol |
| if(pReloc.symInfo()->type() == ResolveInfo::Section) { |
| pReloc.setAddend(pLayout.getOutputOffset( |
| *pInputSym.fragRef()) + pReloc.addend()); |
| } |
| } |
| |
| void MipsGNULDBackend::scanLocalReloc(Relocation& pReloc, |
| const LDSymbol& pInputSym, |
| MCLinker& pLinker, |
| const MCLDInfo& pLDInfo, |
| const Output& pOutput) |
| { |
| ResolveInfo* rsym = pReloc.symInfo(); |
| |
| updateAddend(pReloc, pInputSym, pLinker.getLayout()); |
| |
| switch (pReloc.type()){ |
| case llvm::ELF::R_MIPS_NONE: |
| case llvm::ELF::R_MIPS_16: |
| break; |
| case llvm::ELF::R_MIPS_32: |
| if (Output::DynObj == pOutput.type()) { |
| // TODO: (simon) The gold linker does not create an entry in .rel.dyn |
| // section if the symbol section flags contains SHF_EXECINSTR. |
| // 1. Find the reason of this condition. |
| // 2. Check this condition here. |
| if (NULL == m_pRelDyn) |
| createRelDyn(pLinker, pOutput); |
| |
| m_pRelDyn->reserveEntry(*m_pRelocFactory); |
| rsym->setReserved(rsym->reserved() | ReserveRel); |
| } |
| break; |
| case llvm::ELF::R_MIPS_REL32: |
| case llvm::ELF::R_MIPS_26: |
| case llvm::ELF::R_MIPS_HI16: |
| case llvm::ELF::R_MIPS_LO16: |
| case llvm::ELF::R_MIPS_PC16: |
| case llvm::ELF::R_MIPS_SHIFT5: |
| case llvm::ELF::R_MIPS_SHIFT6: |
| case llvm::ELF::R_MIPS_64: |
| case llvm::ELF::R_MIPS_GOT_PAGE: |
| case llvm::ELF::R_MIPS_GOT_OFST: |
| case llvm::ELF::R_MIPS_SUB: |
| case llvm::ELF::R_MIPS_INSERT_A: |
| case llvm::ELF::R_MIPS_INSERT_B: |
| case llvm::ELF::R_MIPS_DELETE: |
| case llvm::ELF::R_MIPS_HIGHER: |
| case llvm::ELF::R_MIPS_HIGHEST: |
| case llvm::ELF::R_MIPS_SCN_DISP: |
| case llvm::ELF::R_MIPS_REL16: |
| case llvm::ELF::R_MIPS_ADD_IMMEDIATE: |
| case llvm::ELF::R_MIPS_PJUMP: |
| case llvm::ELF::R_MIPS_RELGOT: |
| case llvm::ELF::R_MIPS_JALR: |
| case llvm::ELF::R_MIPS_GLOB_DAT: |
| case llvm::ELF::R_MIPS_COPY: |
| case llvm::ELF::R_MIPS_JUMP_SLOT: |
| break; |
| case llvm::ELF::R_MIPS_GOT16: |
| case llvm::ELF::R_MIPS_CALL16: |
| if (NULL == m_pGOT) |
| createGOT(pLinker, pOutput); |
| |
| if (!(rsym->reserved() & MipsGNULDBackend::ReserveGot)) { |
| m_pGOT->reserveLocalEntry(); |
| rsym->setReserved(rsym->reserved() | ReserveGot); |
| m_LocalGOTSyms.push_back(rsym->outSymbol()); |
| } |
| break; |
| case llvm::ELF::R_MIPS_GPREL32: |
| case llvm::ELF::R_MIPS_GPREL16: |
| case llvm::ELF::R_MIPS_LITERAL: |
| break; |
| case llvm::ELF::R_MIPS_GOT_DISP: |
| case llvm::ELF::R_MIPS_GOT_HI16: |
| case llvm::ELF::R_MIPS_CALL_HI16: |
| case llvm::ELF::R_MIPS_GOT_LO16: |
| case llvm::ELF::R_MIPS_CALL_LO16: |
| break; |
| case llvm::ELF::R_MIPS_TLS_DTPMOD32: |
| case llvm::ELF::R_MIPS_TLS_DTPREL32: |
| case llvm::ELF::R_MIPS_TLS_DTPMOD64: |
| case llvm::ELF::R_MIPS_TLS_DTPREL64: |
| case llvm::ELF::R_MIPS_TLS_GD: |
| case llvm::ELF::R_MIPS_TLS_LDM: |
| case llvm::ELF::R_MIPS_TLS_DTPREL_HI16: |
| case llvm::ELF::R_MIPS_TLS_DTPREL_LO16: |
| case llvm::ELF::R_MIPS_TLS_GOTTPREL: |
| case llvm::ELF::R_MIPS_TLS_TPREL32: |
| case llvm::ELF::R_MIPS_TLS_TPREL64: |
| case llvm::ELF::R_MIPS_TLS_TPREL_HI16: |
| case llvm::ELF::R_MIPS_TLS_TPREL_LO16: |
| break; |
| default: |
| llvm::report_fatal_error(llvm::Twine("Unknown relocation ") + |
| llvm::Twine(pReloc.type()) + |
| llvm::Twine("for the local symbol `") + |
| pReloc.symInfo()->name() + |
| llvm::Twine("'.")); |
| } |
| } |
| |
| void MipsGNULDBackend::scanGlobalReloc(Relocation& pReloc, |
| const LDSymbol& pInputSym, |
| MCLinker& pLinker, |
| const MCLDInfo& pLDInfo, |
| const Output& pOutput) |
| { |
| ResolveInfo* rsym = pReloc.symInfo(); |
| |
| switch (pReloc.type()){ |
| case llvm::ELF::R_MIPS_NONE: |
| case llvm::ELF::R_MIPS_INSERT_A: |
| case llvm::ELF::R_MIPS_INSERT_B: |
| case llvm::ELF::R_MIPS_DELETE: |
| case llvm::ELF::R_MIPS_TLS_DTPMOD64: |
| case llvm::ELF::R_MIPS_TLS_DTPREL64: |
| case llvm::ELF::R_MIPS_REL16: |
| case llvm::ELF::R_MIPS_ADD_IMMEDIATE: |
| case llvm::ELF::R_MIPS_PJUMP: |
| case llvm::ELF::R_MIPS_RELGOT: |
| case llvm::ELF::R_MIPS_TLS_TPREL64: |
| break; |
| case llvm::ELF::R_MIPS_32: |
| case llvm::ELF::R_MIPS_64: |
| case llvm::ELF::R_MIPS_HI16: |
| case llvm::ELF::R_MIPS_LO16: |
| if (isSymbolNeedsDynRel(*rsym, pOutput)) { |
| if (NULL == m_pRelDyn) |
| createRelDyn(pLinker, pOutput); |
| |
| m_pRelDyn->reserveEntry(*m_pRelocFactory); |
| rsym->setReserved(rsym->reserved() | ReserveRel); |
| } |
| break; |
| case llvm::ELF::R_MIPS_GOT16: |
| case llvm::ELF::R_MIPS_CALL16: |
| case llvm::ELF::R_MIPS_GOT_DISP: |
| case llvm::ELF::R_MIPS_GOT_HI16: |
| case llvm::ELF::R_MIPS_CALL_HI16: |
| case llvm::ELF::R_MIPS_GOT_LO16: |
| case llvm::ELF::R_MIPS_CALL_LO16: |
| case llvm::ELF::R_MIPS_GOT_PAGE: |
| case llvm::ELF::R_MIPS_GOT_OFST: |
| if (NULL == m_pGOT) |
| createGOT(pLinker, pOutput); |
| |
| if (!(rsym->reserved() & MipsGNULDBackend::ReserveGot)) { |
| m_pGOT->reserveGlobalEntry(); |
| rsym->setReserved(rsym->reserved() | ReserveGot); |
| m_GlobalGOTSyms.push_back(rsym->outSymbol()); |
| } |
| break; |
| case llvm::ELF::R_MIPS_LITERAL: |
| case llvm::ELF::R_MIPS_GPREL32: |
| llvm::report_fatal_error(llvm::Twine("Relocation ") + |
| llvm::Twine(pReloc.type()) + |
| llvm::Twine(" is not defined for the " |
| "global symbol `") + |
| pReloc.symInfo()->name() + |
| llvm::Twine("'.")); |
| break; |
| case llvm::ELF::R_MIPS_GPREL16: |
| break; |
| case llvm::ELF::R_MIPS_26: |
| case llvm::ELF::R_MIPS_PC16: |
| break; |
| case llvm::ELF::R_MIPS_16: |
| case llvm::ELF::R_MIPS_SHIFT5: |
| case llvm::ELF::R_MIPS_SHIFT6: |
| case llvm::ELF::R_MIPS_SUB: |
| case llvm::ELF::R_MIPS_HIGHER: |
| case llvm::ELF::R_MIPS_HIGHEST: |
| case llvm::ELF::R_MIPS_SCN_DISP: |
| break; |
| case llvm::ELF::R_MIPS_TLS_DTPREL32: |
| case llvm::ELF::R_MIPS_TLS_GD: |
| case llvm::ELF::R_MIPS_TLS_LDM: |
| case llvm::ELF::R_MIPS_TLS_DTPREL_HI16: |
| case llvm::ELF::R_MIPS_TLS_DTPREL_LO16: |
| case llvm::ELF::R_MIPS_TLS_GOTTPREL: |
| case llvm::ELF::R_MIPS_TLS_TPREL32: |
| case llvm::ELF::R_MIPS_TLS_TPREL_HI16: |
| case llvm::ELF::R_MIPS_TLS_TPREL_LO16: |
| break; |
| case llvm::ELF::R_MIPS_REL32: |
| break; |
| case llvm::ELF::R_MIPS_JALR: |
| break; |
| case llvm::ELF::R_MIPS_COPY: |
| case llvm::ELF::R_MIPS_GLOB_DAT: |
| case llvm::ELF::R_MIPS_JUMP_SLOT: |
| llvm::report_fatal_error(llvm::Twine("Relocation ") + |
| llvm::Twine(pReloc.type()) + |
| llvm::Twine("for the global symbol `") + |
| pReloc.symInfo()->name() + |
| llvm::Twine("' should only be seen " |
| "by the dynamic linker")); |
| break; |
| default: |
| llvm::report_fatal_error(llvm::Twine("Unknown relocation ") + |
| llvm::Twine(pReloc.type()) + |
| llvm::Twine("for the global symbol `") + |
| pReloc.symInfo()->name() + |
| llvm::Twine("'.")); |
| } |
| } |
| |
| bool MipsGNULDBackend::isSymbolNeedsPLT(ResolveInfo& pSym, |
| const Output& pOutput) const |
| { |
| return (Output::DynObj == pOutput.type() && |
| ResolveInfo::Function == pSym.type() && |
| (pSym.isDyn() || pSym.isUndef())); |
| } |
| |
| bool MipsGNULDBackend::isSymbolNeedsDynRel(ResolveInfo& pSym, |
| const Output& pOutput) const |
| { |
| if(pSym.isUndef() && Output::Exec == pOutput.type()) |
| return false; |
| if(pSym.isAbsolute()) |
| return false; |
| if(Output::DynObj == pOutput.type()) |
| return true; |
| if(pSym.isDyn() || pSym.isUndef()) |
| return true; |
| |
| return false; |
| } |
| |
| void MipsGNULDBackend::createGOT(MCLinker& pLinker, const Output& pOutput) |
| { |
| ELFFileFormat* file_format = getOutputFormat(pOutput); |
| |
| LDSection& got = file_format->getGOT(); |
| m_pGOT = new MipsGOT(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); |
| } |
| } |
| |
| void MipsGNULDBackend::createRelDyn(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); |
| } |
| |
| ELFFileFormat* MipsGNULDBackend::getOutputFormat(const Output& pOutput) const |
| { |
| switch (pOutput.type()) { |
| case Output::DynObj: |
| return getDynObjFileFormat(); |
| case Output::Exec: |
| return getExecFileFormat(); |
| case Output::Object: |
| return NULL; |
| default: |
| llvm::report_fatal_error(llvm::Twine("Unsupported output file format: ") + |
| llvm::Twine(pOutput.type())); |
| return NULL; |
| } |
| } |
| |
| //===----------------------------------------------------------------------===// |
| /// createMipsLDBackend - the help funtion to create corresponding MipsLDBackend |
| /// |
| static TargetLDBackend* createMipsLDBackend(const llvm::Target& pTarget, |
| const std::string& pTriple) |
| { |
| llvm::Triple theTriple(pTriple); |
| if (theTriple.isOSDarwin()) { |
| assert(0 && "MachO linker is not supported yet"); |
| } |
| if (theTriple.isOSWindows()) { |
| assert(0 && "COFF linker is not supported yet"); |
| } |
| return new MipsGNULDBackend(); |
| } |
| |
| } // namespace of mcld |
| |
| //============================= |
| // Force static initialization. |
| extern "C" void LLVMInitializeMipsLDBackend() { |
| // Register the linker backend |
| mcld::TargetRegistry::RegisterTargetLDBackend(mcld::TheMipselTarget, |
| mcld::createMipsLDBackend); |
| } |
