| //===- MipsLDBackend.cpp --------------------------------------------------===// |
| // |
| // The MCLinker Project |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| #include "Mips.h" |
| #include "MipsGNUInfo.h" |
| #include "MipsELFDynamic.h" |
| #include "MipsLDBackend.h" |
| #include "MipsRelocator.h" |
| |
| #include <llvm/ADT/Triple.h> |
| #include <llvm/Support/ELF.h> |
| |
| #include <mcld/Module.h> |
| #include <mcld/LinkerConfig.h> |
| #include <mcld/IRBuilder.h> |
| #include <mcld/MC/Attribute.h> |
| #include <mcld/Fragment/FillFragment.h> |
| #include <mcld/Fragment/FragmentLinker.h> |
| #include <mcld/Support/MemoryRegion.h> |
| #include <mcld/Support/MemoryArea.h> |
| #include <mcld/Support/MsgHandling.h> |
| #include <mcld/Support/TargetRegistry.h> |
| #include <mcld/Target/OutputRelocSection.h> |
| #include <mcld/Object/ObjectBuilder.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 |
| }; |
| |
| using namespace mcld; |
| |
| //===----------------------------------------------------------------------===// |
| // MipsGNULDBackend |
| //===----------------------------------------------------------------------===// |
| MipsGNULDBackend::MipsGNULDBackend(const LinkerConfig& pConfig, |
| MipsGNUInfo* pInfo) |
| : GNULDBackend(pConfig, pInfo), |
| m_pRelocator(NULL), |
| m_pGOT(NULL), |
| m_pRelDyn(NULL), |
| m_pDynamic(NULL), |
| m_pGOTSymbol(NULL), |
| m_pGpDispSymbol(NULL) |
| { |
| } |
| |
| MipsGNULDBackend::~MipsGNULDBackend() |
| { |
| delete m_pRelocator; |
| delete m_pGOT; |
| delete m_pRelDyn; |
| delete m_pDynamic; |
| } |
| |
| void MipsGNULDBackend::initTargetSections(Module& pModule, ObjectBuilder& pBuilder) |
| { |
| if (LinkerConfig::Object != config().codeGenType()) { |
| ELFFileFormat* file_format = getOutputFormat(); |
| |
| // initialize .got |
| LDSection& got = file_format->getGOT(); |
| m_pGOT = new MipsGOT(got); |
| |
| // initialize .rel.dyn |
| LDSection& reldyn = file_format->getRelDyn(); |
| m_pRelDyn = new OutputRelocSection(pModule, reldyn); |
| } |
| } |
| |
| void MipsGNULDBackend::initTargetSymbols(FragmentLinker& pLinker) |
| { |
| // Define the symbol _GLOBAL_OFFSET_TABLE_ if there is a symbol with the |
| // same name in input |
| m_pGOTSymbol = pLinker.defineSymbol<FragmentLinker::AsRefered, FragmentLinker::Resolve>( |
| "_GLOBAL_OFFSET_TABLE_", |
| false, |
| ResolveInfo::Object, |
| ResolveInfo::Define, |
| ResolveInfo::Local, |
| 0x0, // size |
| 0x0, // value |
| FragmentRef::Null(), // FragRef |
| ResolveInfo::Hidden); |
| |
| m_pGpDispSymbol = pLinker.defineSymbol<FragmentLinker::AsRefered, FragmentLinker::Resolve>( |
| "_gp_disp", |
| false, |
| ResolveInfo::Section, |
| ResolveInfo::Define, |
| ResolveInfo::Absolute, |
| 0x0, // size |
| 0x0, // value |
| FragmentRef::Null(), // FragRef |
| ResolveInfo::Default); |
| |
| if (NULL != m_pGpDispSymbol) { |
| m_pGpDispSymbol->resolveInfo()->setReserved(ReserveGpDisp); |
| } |
| } |
| |
| bool MipsGNULDBackend::initRelocator(const FragmentLinker& pLinker) |
| { |
| if (NULL == m_pRelocator) { |
| m_pRelocator = new MipsRelocator(*this); |
| m_pRelocator->setFragmentLinker(pLinker); |
| } |
| return true; |
| } |
| |
| Relocator* MipsGNULDBackend::getRelocator() |
| { |
| assert(NULL != m_pRelocator); |
| return m_pRelocator; |
| } |
| |
| void MipsGNULDBackend::scanRelocation(Relocation& pReloc, |
| FragmentLinker& pLinker, |
| Module& pModule, |
| const LDSection& pSection) |
| { |
| // rsym - The relocation target symbol |
| ResolveInfo* rsym = pReloc.symInfo(); |
| assert(NULL != rsym && "ResolveInfo of relocation not set while scanRelocation"); |
| |
| // Skip relocation against _gp_disp |
| if (NULL != m_pGpDispSymbol) { |
| if (pReloc.symInfo() == m_pGpDispSymbol->resolveInfo()) |
| return; |
| } |
| |
| pReloc.updateAddend(); |
| |
| if (0 == (pSection.flag() & llvm::ELF::SHF_ALLOC)) |
| return; |
| |
| // We test isLocal or if pInputSym is not a dynamic symbol |
| // We assume -Bsymbolic to bind all symbols internaly via !rsym->isDyn() |
| // Don't put undef symbols into local entries. |
| if ((rsym->isLocal() || !isDynamicSymbol(*rsym) || |
| !rsym->isDyn()) && !rsym->isUndef()) |
| scanLocalReloc(pReloc, pLinker); |
| else |
| scanGlobalReloc(pReloc, pLinker); |
| |
| // check if we shoule issue undefined reference for the relocation target |
| // symbol |
| if (rsym->isUndef() && !rsym->isDyn() && !rsym->isWeak() && !rsym->isNull()) |
| fatal(diag::undefined_reference) << rsym->name(); |
| |
| if ((rsym->reserved() & ReserveRel) != 0x0) { |
| // set hasTextRelSection if needed |
| checkAndSetHasTextRel(pSection); |
| } |
| } |
| |
| 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; |
| } |
| |
| uint64_t MipsGNULDBackend::defaultTextSegmentAddr() const |
| { |
| return 0x80000; |
| } |
| |
| uint64_t MipsGNULDBackend::abiPageSize() const |
| { |
| if (config().options().maxPageSize() > 0) |
| return config().options().maxPageSize(); |
| else |
| return static_cast<uint64_t>(0x10000); |
| } |
| |
| void MipsGNULDBackend::doPreLayout(FragmentLinker& pLinker) |
| { |
| // set .got size |
| // when building shared object, the .got section is must. |
| if (LinkerConfig::Object != config().codeGenType()) { |
| if (LinkerConfig::DynObj == config().codeGenType() || |
| m_pGOT->hasGOT1() || |
| NULL != m_pGOTSymbol) { |
| m_pGOT->finalizeSectionSize(); |
| defineGOTSymbol(pLinker); |
| } |
| |
| ELFFileFormat* file_format = getOutputFormat(); |
| // set .rel.dyn size |
| if (!m_pRelDyn->empty()) |
| file_format->getRelDyn().setSize( |
| m_pRelDyn->numOfRelocs() * getRelEntrySize()); |
| } |
| } |
| void MipsGNULDBackend::doPostLayout(Module& pModule, |
| FragmentLinker& pLinker) |
| { |
| } |
| |
| /// 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, config()); |
| |
| 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 LDSection& pSection, |
| MemoryRegion& pRegion) const |
| { |
| assert(pRegion.size() && "Size of MemoryRegion is zero!"); |
| |
| const ELFFileFormat* file_format = getOutputFormat(); |
| |
| if (&pSection == &(file_format->getGOT())) { |
| assert(NULL != m_pGOT && "emitSectionData failed, m_pGOT is NULL!"); |
| uint64_t result = m_pGOT->emit(pRegion); |
| return result; |
| } |
| |
| fatal(diag::unrecognized_output_sectoin) |
| << pSection.name() |
| << "[email protected]"; |
| return 0; |
| } |
| /// isGlobalGOTSymbol - return true if the symbol is the global GOT entry. |
| bool MipsGNULDBackend::isGlobalGOTSymbol(const LDSymbol& pSymbol) const |
| { |
| return std::find(m_GlobalGOTSyms.begin(), |
| m_GlobalGOTSyms.end(), &pSymbol) != m_GlobalGOTSyms.end(); |
| } |
| |
| /// sizeNamePools - compute the size of regular name pools |
| /// In ELF executable files, regular name pools are .symtab, .strtab, |
| /// .dynsym, .dynstr, .hash and .shstrtab. |
| void |
| MipsGNULDBackend::sizeNamePools(const Module& pModule, bool pIsStaticLink) |
| { |
| // number of entries in symbol tables starts from 1 to hold the special entry |
| // at index 0 (STN_UNDEF). See ELF Spec Book I, p1-21. |
| size_t symtab = 1; |
| size_t dynsym = pIsStaticLink ? 0 : 1; |
| |
| // size of string tables starts from 1 to hold the null character in their |
| // first byte |
| size_t strtab = 1; |
| size_t dynstr = pIsStaticLink ? 0 : 1; |
| size_t shstrtab = 1; |
| size_t hash = 0; |
| |
| // number of local symbol in the .dynsym |
| size_t dynsym_local_cnt = 0; |
| |
| /// compute the size of .symtab, .dynsym and .strtab |
| /// @{ |
| Module::const_sym_iterator symbol; |
| const Module::SymbolTable& symbols = pModule.getSymbolTable(); |
| size_t str_size = 0; |
| // compute the size of symbols in Local and File category |
| Module::const_sym_iterator symEnd = symbols.localEnd(); |
| for (symbol = symbols.localBegin(); symbol != symEnd; ++symbol) { |
| str_size = (*symbol)->nameSize() + 1; |
| if (!pIsStaticLink && isDynamicSymbol(**symbol)) { |
| ++dynsym; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| dynstr += str_size; |
| } |
| ++symtab; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| strtab += str_size; |
| } |
| // compute the size of symbols in TLS category |
| symEnd = symbols.tlsEnd(); |
| for (symbol = symbols.tlsBegin(); symbol != symEnd; ++symbol) { |
| str_size = (*symbol)->nameSize() + 1; |
| if (!pIsStaticLink) { |
| ++dynsym; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| dynstr += str_size; |
| } |
| ++symtab; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| strtab += str_size; |
| } |
| dynsym_local_cnt = dynsym; |
| // compute the size of the reset of symbols |
| symEnd = pModule.sym_end(); |
| for (symbol = symbols.tlsEnd(); symbol != symEnd; ++symbol) { |
| str_size = (*symbol)->nameSize() + 1; |
| if (!pIsStaticLink && isDynamicSymbol(**symbol)) { |
| ++dynsym; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| dynstr += str_size; |
| } |
| ++symtab; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| strtab += str_size; |
| } |
| |
| ELFFileFormat* file_format = getOutputFormat(); |
| |
| switch(config().codeGenType()) { |
| // compute size of .dynstr and .hash |
| case LinkerConfig::DynObj: { |
| // soname |
| if (!pIsStaticLink) |
| dynstr += pModule.name().size() + 1; |
| } |
| /** fall through **/ |
| case LinkerConfig::Exec: { |
| // add DT_NEED strings into .dynstr and .dynamic |
| // Rules: |
| // 1. ignore --no-add-needed |
| // 2. force count in --no-as-needed |
| // 3. judge --as-needed |
| if (!pIsStaticLink) { |
| Module::const_lib_iterator lib, libEnd = pModule.lib_end(); |
| for (lib = pModule.lib_begin(); lib != libEnd; ++lib) { |
| // --add-needed |
| if ((*lib)->attribute()->isAddNeeded()) { |
| // --no-as-needed |
| if (!(*lib)->attribute()->isAsNeeded()) { |
| dynstr += (*lib)->name().size() + 1; |
| dynamic().reserveNeedEntry(); |
| } |
| // --as-needed |
| else if ((*lib)->isNeeded()) { |
| dynstr += (*lib)->name().size() + 1; |
| dynamic().reserveNeedEntry(); |
| } |
| } |
| } |
| |
| // compute .hash |
| // Both Elf32_Word and Elf64_Word are 4 bytes |
| hash = (2 + getHashBucketCount(dynsym, false) + dynsym) * |
| sizeof(llvm::ELF::Elf32_Word); |
| } |
| |
| // set size |
| if (config().targets().is32Bits()) |
| file_format->getDynSymTab().setSize(dynsym*sizeof(llvm::ELF::Elf32_Sym)); |
| else |
| file_format->getDynSymTab().setSize(dynsym*sizeof(llvm::ELF::Elf64_Sym)); |
| file_format->getDynStrTab().setSize(dynstr); |
| file_format->getHashTab().setSize(hash); |
| |
| // set .dynsym sh_info to one greater than the symbol table |
| // index of the last local symbol |
| file_format->getDynSymTab().setInfo(dynsym_local_cnt); |
| } |
| /* fall through */ |
| case LinkerConfig::Object: { |
| if (config().targets().is32Bits()) |
| file_format->getSymTab().setSize(symtab*sizeof(llvm::ELF::Elf32_Sym)); |
| else |
| file_format->getSymTab().setSize(symtab*sizeof(llvm::ELF::Elf64_Sym)); |
| file_format->getStrTab().setSize(strtab); |
| |
| // set .symtab sh_info to one greater than the symbol table |
| // index of the last local symbol |
| file_format->getSymTab().setInfo(symbols.numOfLocals() + 1); |
| break; |
| } |
| default: { |
| fatal(diag::fatal_illegal_codegen_type) << pModule.name(); |
| break; |
| } |
| } // end of switch |
| /// @} |
| |
| /// reserve fixed entries in the .dynamic section. |
| /// @{ |
| if (LinkerConfig::DynObj == config().codeGenType() || |
| LinkerConfig::Exec == config().codeGenType()) { |
| // Because some entries in .dynamic section need information of .dynsym, |
| // .dynstr, .symtab, .strtab and .hash, we can not reserve non-DT_NEEDED |
| // entries until we get the size of the sections mentioned above |
| dynamic().reserveEntries(*file_format); |
| file_format->getDynamic().setSize(dynamic().numOfBytes()); |
| } |
| /// @} |
| |
| /// compute the size of .shstrtab section. |
| /// @{ |
| Module::const_iterator sect, sectEnd = pModule.end(); |
| for (sect = pModule.begin(); sect != sectEnd; ++sect) { |
| // StackNote sections will always be in output! |
| if (0 != (*sect)->size() || LDFileFormat::StackNote == (*sect)->kind()) { |
| shstrtab += ((*sect)->name().size() + 1); |
| } |
| } |
| shstrtab += (strlen(".shstrtab") + 1); |
| file_format->getShStrTab().setSize(shstrtab); |
| /// @} |
| } |
| |
| /// emitSymbol32 - emit an ELF32 symbol |
| void MipsGNULDBackend::emitSymbol32(llvm::ELF::Elf32_Sym& pSym, |
| LDSymbol& pSymbol, |
| char* pStrtab, |
| size_t pStrtabsize, |
| size_t pSymtabIdx) |
| { |
| // FIXME: check the endian between host and target |
| // write out symbol |
| if (ResolveInfo::Section != pSymbol.type() || |
| &pSymbol == m_pGpDispSymbol) { |
| pSym.st_name = pStrtabsize; |
| strcpy((pStrtab + pStrtabsize), pSymbol.name()); |
| } |
| else { |
| pSym.st_name = 0; |
| } |
| pSym.st_value = pSymbol.value(); |
| pSym.st_size = getSymbolSize(pSymbol); |
| pSym.st_info = getSymbolInfo(pSymbol); |
| pSym.st_other = pSymbol.visibility(); |
| pSym.st_shndx = getSymbolShndx(pSymbol); |
| } |
| |
| /// 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(const Module& pModule, |
| MemoryArea& pOutput) |
| { |
| ELFFileFormat* file_format = getOutputFormat(); |
| if (!file_format->hasDynSymTab() || |
| !file_format->hasDynStrTab() || |
| !file_format->hasHashTab() || |
| !file_format->hasDynamic()) |
| return; |
| |
| 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.request(symtab_sect.offset(), |
| symtab_sect.size()); |
| MemoryRegion* strtab_region = pOutput.request(strtab_sect.offset(), |
| strtab_sect.size()); |
| MemoryRegion* hash_region = pOutput.request(hash_sect.offset(), |
| hash_sect.size()); |
| MemoryRegion* dyn_region = pOutput.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 |
| Module::const_sym_iterator symbol; |
| const Module::SymbolTable& symbols = pModule.getSymbolTable(); |
| // emit symbol in File and Local category if it's dynamic symbol |
| Module::const_sym_iterator symEnd = symbols.localEnd(); |
| for (symbol = symbols.localBegin(); symbol != symEnd; ++symbol) { |
| if (!isDynamicSymbol(**symbol)) |
| continue; |
| |
| if (isGlobalGOTSymbol(**symbol)) |
| continue; |
| |
| emitSymbol32(symtab32[symtabIdx], **symbol, strtab, strtabsize, |
| symtabIdx); |
| |
| // maintain output's symbol and index map |
| entry = m_pSymIndexMap->insert(*symbol, sym_exist); |
| entry->setValue(symtabIdx); |
| // sum up counters |
| ++symtabIdx; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| strtabsize += (*symbol)->nameSize() + 1; |
| } |
| |
| // emit symbols in TLS category, all symbols in TLS category shold be emitited |
| // directly, except GOT entries |
| symEnd = symbols.tlsEnd(); |
| for (symbol = symbols.tlsBegin(); symbol != symEnd; ++symbol) { |
| if (isGlobalGOTSymbol(**symbol)) |
| continue; |
| |
| emitSymbol32(symtab32[symtabIdx], **symbol, strtab, strtabsize, |
| symtabIdx); |
| |
| // maintain output's symbol and index map |
| entry = m_pSymIndexMap->insert(*symbol, sym_exist); |
| entry->setValue(symtabIdx); |
| // sum up counters |
| ++symtabIdx; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| strtabsize += (*symbol)->nameSize() + 1; |
| } |
| |
| // emit the reset of the symbols if the symbol is dynamic symbol |
| symEnd = pModule.sym_end(); |
| for (symbol = symbols.tlsEnd(); symbol != symEnd; ++symbol) { |
| if (!isDynamicSymbol(**symbol)) |
| continue; |
| |
| if (isGlobalGOTSymbol(**symbol)) |
| continue; |
| |
| emitSymbol32(symtab32[symtabIdx], **symbol, strtab, strtabsize, |
| symtabIdx); |
| |
| // maintain output's symbol and index map |
| entry = m_pSymIndexMap->insert(*symbol, sym_exist); |
| entry->setValue(symtabIdx); |
| // sum up counters |
| ++symtabIdx; |
| if (ResolveInfo::Section != (*symbol)->type() || *symbol == m_pGpDispSymbol) |
| 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) { |
| |
| // Make sure this golbal GOT entry is a dynamic symbol. |
| // If not, something is wrong earlier when putting this symbol into |
| // global GOT. |
| if (!isDynamicSymbol(**symbol)) |
| fatal(diag::mips_got_symbol) << (*symbol)->name(); |
| |
| emitSymbol32(symtab32[symtabIdx], **symbol, strtab, strtabsize, |
| symtabIdx); |
| // maintain output's symbol and index map |
| entry = m_pSymIndexMap->insert(*symbol, sym_exist); |
| entry->setValue(symtabIdx); |
| |
| // sum up counters |
| ++symtabIdx; |
| if (ResolveInfo::Section != (*symbol)->type()) |
| 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(); |
| Module::const_lib_iterator lib, libEnd = pModule.lib_end(); |
| for (lib = pModule.lib_begin(); lib != libEnd; ++lib) { |
| // --add-needed |
| if ((*lib)->attribute()->isAddNeeded()) { |
| // --no-as-needed |
| if (!(*lib)->attribute()->isAsNeeded()) { |
| strcpy((strtab + strtabsize), (*lib)->name().c_str()); |
| (*dt_need)->setValue(llvm::ELF::DT_NEEDED, strtabsize); |
| strtabsize += (*lib)->name().size() + 1; |
| ++dt_need; |
| } |
| // --as-needed |
| else if ((*lib)->isNeeded()) { |
| strcpy((strtab + strtabsize), (*lib)->name().c_str()); |
| (*dt_need)->setValue(llvm::ELF::DT_NEEDED, strtabsize); |
| strtabsize += (*lib)->name().size() + 1; |
| ++dt_need; |
| } |
| } |
| } // for |
| |
| // emit soname |
| // initialize value of ELF .dynamic section |
| if (LinkerConfig::DynObj == config().codeGenType()) |
| dynamic().applySoname(strtabsize); |
| dynamic().applyEntries(*file_format); |
| dynamic().emit(dyn_sect, *dyn_region); |
| |
| strcpy((strtab + strtabsize), pModule.name().c_str()); |
| strtabsize += pModule.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 LDSection& pSectHdr) const |
| { |
| const ELFFileFormat* file_format = getOutputFormat(); |
| |
| if (&pSectHdr == &file_format->getGOT()) |
| return SHO_DATA; |
| |
| return SHO_UNDEFINED; |
| } |
| |
| /// finalizeSymbol - finalize the symbol value |
| bool MipsGNULDBackend::finalizeTargetSymbols(FragmentLinker& pLinker) |
| { |
| if (NULL != m_pGpDispSymbol) |
| m_pGpDispSymbol->setValue(m_pGOT->addr() + 0x7FF0); |
| return true; |
| } |
| |
| /// allocateCommonSymbols - allocate common symbols in the corresponding |
| /// sections. This is called at pre-layout stage. |
| /// @refer Google gold linker: common.cc: 214 |
| /// FIXME: Mips needs to allocate small common symbol |
| bool MipsGNULDBackend::allocateCommonSymbols(Module& pModule) |
| { |
| SymbolCategory& symbol_list = pModule.getSymbolTable(); |
| |
| if (symbol_list.emptyCommons() && symbol_list.emptyLocals()) |
| return true; |
| |
| SymbolCategory::iterator com_sym, com_end; |
| |
| // FIXME: If the order of common symbols is defined, then sort common symbols |
| // std::sort(com_sym, com_end, some kind of order); |
| |
| // get corresponding BSS LDSection |
| ELFFileFormat* file_format = getOutputFormat(); |
| LDSection& bss_sect = file_format->getBSS(); |
| LDSection& tbss_sect = file_format->getTBSS(); |
| |
| // get or create corresponding BSS SectionData |
| SectionData* bss_sect_data = NULL; |
| if (bss_sect.hasSectionData()) |
| bss_sect_data = bss_sect.getSectionData(); |
| else |
| bss_sect_data = IRBuilder::CreateSectionData(bss_sect); |
| |
| SectionData* tbss_sect_data = NULL; |
| if (tbss_sect.hasSectionData()) |
| tbss_sect_data = tbss_sect.getSectionData(); |
| else |
| tbss_sect_data = IRBuilder::CreateSectionData(tbss_sect); |
| |
| // remember original BSS size |
| uint64_t bss_offset = bss_sect.size(); |
| uint64_t tbss_offset = tbss_sect.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()) { |
| // 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); |
| Fragment* frag = new FillFragment(0x0, 1, (*com_sym)->size()); |
| (*com_sym)->setFragmentRef(FragmentRef::Create(*frag, 0)); |
| |
| if (ResolveInfo::ThreadLocal == (*com_sym)->type()) { |
| // allocate TLS common symbol in tbss section |
| tbss_offset += ObjectBuilder::AppendFragment(*frag, |
| *tbss_sect_data, |
| (*com_sym)->value()); |
| } |
| // FIXME: how to identify small and large common symbols? |
| else { |
| bss_offset += ObjectBuilder::AppendFragment(*frag, |
| *bss_sect_data, |
| (*com_sym)->value()); |
| } |
| } |
| } |
| |
| // allocate all global common symbols |
| com_end = symbol_list.commonEnd(); |
| for (com_sym = symbol_list.commonBegin(); com_sym != com_end; ++com_sym) { |
| // 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); |
| Fragment* frag = new FillFragment(0x0, 1, (*com_sym)->size()); |
| (*com_sym)->setFragmentRef(FragmentRef::Create(*frag, 0)); |
| |
| if (ResolveInfo::ThreadLocal == (*com_sym)->type()) { |
| // allocate TLS common symbol in tbss section |
| tbss_offset += ObjectBuilder::AppendFragment(*frag, |
| *tbss_sect_data, |
| (*com_sym)->value()); |
| } |
| // FIXME: how to identify small and large common symbols? |
| else { |
| bss_offset += ObjectBuilder::AppendFragment(*frag, |
| *bss_sect_data, |
| (*com_sym)->value()); |
| } |
| } |
| |
| bss_sect.setSize(bss_offset); |
| tbss_sect.setSize(tbss_offset); |
| symbol_list.changeCommonsToGlobal(); |
| return true; |
| } |
| |
| void MipsGNULDBackend::scanLocalReloc(Relocation& pReloc, |
| FragmentLinker& pLinker) |
| { |
| ResolveInfo* rsym = pReloc.symInfo(); |
| |
| switch (pReloc.type()){ |
| case llvm::ELF::R_MIPS_NONE: |
| case llvm::ELF::R_MIPS_16: |
| break; |
| case llvm::ELF::R_MIPS_32: |
| if (LinkerConfig::DynObj == config().codeGenType()) { |
| // 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. |
| m_pRelDyn->reserveEntry(); |
| rsym->setReserved(rsym->reserved() | ReserveRel); |
| |
| // Remeber this rsym is a local GOT entry (as if it needs an entry). |
| // Actually we don't allocate an GOT entry. |
| m_pGOT->setLocal(rsym); |
| } |
| 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: |
| // For got16 section based relocations, we need to reserve got entries. |
| if (rsym->type() == ResolveInfo::Section) { |
| m_pGOT->reserveLocalEntry(); |
| // Remeber this rsym is a local GOT entry |
| m_pGOT->setLocal(rsym); |
| return; |
| } |
| |
| if (!(rsym->reserved() & MipsGNULDBackend::ReserveGot)) { |
| m_pGOT->reserveLocalEntry(); |
| rsym->setReserved(rsym->reserved() | ReserveGot); |
| // Remeber this rsym is a local GOT entry |
| m_pGOT->setLocal(rsym); |
| } |
| 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: |
| fatal(diag::unknown_relocation) << (int)pReloc.type() |
| << pReloc.symInfo()->name(); |
| } |
| } |
| |
| void MipsGNULDBackend::scanGlobalReloc(Relocation& pReloc, |
| FragmentLinker& pLinker) |
| { |
| 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 (symbolNeedsDynRel(pLinker, *rsym, false, true)) { |
| m_pRelDyn->reserveEntry(); |
| rsym->setReserved(rsym->reserved() | ReserveRel); |
| |
| // Remeber this rsym is a global GOT entry (as if it needs an entry). |
| // Actually we don't allocate an GOT entry. |
| m_pGOT->setGlobal(rsym); |
| } |
| 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 (!(rsym->reserved() & MipsGNULDBackend::ReserveGot)) { |
| m_pGOT->reserveGlobalEntry(); |
| rsym->setReserved(rsym->reserved() | ReserveGot); |
| m_GlobalGOTSyms.push_back(rsym->outSymbol()); |
| // Remeber this rsym is a global GOT entry |
| m_pGOT->setGlobal(rsym); |
| } |
| break; |
| case llvm::ELF::R_MIPS_LITERAL: |
| case llvm::ELF::R_MIPS_GPREL32: |
| fatal(diag::invalid_global_relocation) << (int)pReloc.type() |
| << pReloc.symInfo()->name(); |
| 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: |
| fatal(diag::dynamic_relocation) << (int)pReloc.type(); |
| break; |
| default: |
| fatal(diag::unknown_relocation) << (int)pReloc.type() |
| << pReloc.symInfo()->name(); |
| } |
| } |
| |
| void MipsGNULDBackend::defineGOTSymbol(FragmentLinker& pLinker) |
| { |
| // define symbol _GLOBAL_OFFSET_TABLE_ |
| if ( m_pGOTSymbol != NULL ) { |
| pLinker.defineSymbol<FragmentLinker::Force, FragmentLinker::Unresolve>( |
| "_GLOBAL_OFFSET_TABLE_", |
| false, |
| ResolveInfo::Object, |
| ResolveInfo::Define, |
| ResolveInfo::Local, |
| 0x0, // size |
| 0x0, // value |
| FragmentRef::Create(*(m_pGOT->begin()), 0x0), |
| ResolveInfo::Hidden); |
| } |
| else { |
| m_pGOTSymbol = pLinker.defineSymbol<FragmentLinker::Force, FragmentLinker::Resolve>( |
| "_GLOBAL_OFFSET_TABLE_", |
| false, |
| ResolveInfo::Object, |
| ResolveInfo::Define, |
| ResolveInfo::Local, |
| 0x0, // size |
| 0x0, // value |
| FragmentRef::Create(*(m_pGOT->begin()), 0x0), |
| ResolveInfo::Hidden); |
| } |
| } |
| |
| /// doCreateProgramHdrs - backend can implement this function to create the |
| /// target-dependent segments |
| void MipsGNULDBackend::doCreateProgramHdrs(Module& pModule, |
| const FragmentLinker& pLinker) |
| { |
| // TODO |
| } |
| |
| //===----------------------------------------------------------------------===// |
| /// createMipsLDBackend - the help funtion to create corresponding MipsLDBackend |
| /// |
| static TargetLDBackend* createMipsLDBackend(const llvm::Target& pTarget, |
| const LinkerConfig& pConfig) |
| { |
| if (pConfig.targets().triple().isOSDarwin()) { |
| assert(0 && "MachO linker is not supported yet"); |
| } |
| if (pConfig.targets().triple().isOSWindows()) { |
| assert(0 && "COFF linker is not supported yet"); |
| } |
| return new MipsGNULDBackend(pConfig, new MipsGNUInfo(pConfig.targets().triple())); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Force static initialization. |
| //===----------------------------------------------------------------------===// |
| extern "C" void MCLDInitializeMipsLDBackend() { |
| // Register the linker backend |
| mcld::TargetRegistry::RegisterTargetLDBackend(mcld::TheMipselTarget, |
| createMipsLDBackend); |
| } |
| |
