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Diffstat (limited to 'gnu/llvm/tools/lld/ELF/OutputSections.cpp')
| -rw-r--r-- | gnu/llvm/tools/lld/ELF/OutputSections.cpp | 1965 |
1 files changed, 1965 insertions, 0 deletions
diff --git a/gnu/llvm/tools/lld/ELF/OutputSections.cpp b/gnu/llvm/tools/lld/ELF/OutputSections.cpp new file mode 100644 index 00000000000..50b94015f22 --- /dev/null +++ b/gnu/llvm/tools/lld/ELF/OutputSections.cpp @@ -0,0 +1,1965 @@ +//===- OutputSections.cpp -------------------------------------------------===// +// +// The LLVM Linker +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "OutputSections.h" +#include "Config.h" +#include "EhFrame.h" +#include "LinkerScript.h" +#include "Strings.h" +#include "SymbolTable.h" +#include "Target.h" +#include "lld/Core/Parallel.h" +#include "llvm/Support/Dwarf.h" +#include "llvm/Support/MD5.h" +#include "llvm/Support/MathExtras.h" +#include "llvm/Support/SHA1.h" +#include <map> + +using namespace llvm; +using namespace llvm::dwarf; +using namespace llvm::object; +using namespace llvm::support::endian; +using namespace llvm::ELF; + +using namespace lld; +using namespace lld::elf; + +template <class ELFT> +OutputSectionBase<ELFT>::OutputSectionBase(StringRef Name, uint32_t Type, + uintX_t Flags) + : Name(Name) { + memset(&Header, 0, sizeof(Elf_Shdr)); + Header.sh_type = Type; + Header.sh_flags = Flags; + Header.sh_addralign = 1; +} + +template <class ELFT> +void OutputSectionBase<ELFT>::writeHeaderTo(Elf_Shdr *Shdr) { + *Shdr = Header; +} + +template <class ELFT> +GotPltSection<ELFT>::GotPltSection() + : OutputSectionBase<ELFT>(".got.plt", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE) { + this->Header.sh_addralign = Target->GotPltEntrySize; +} + +template <class ELFT> void GotPltSection<ELFT>::addEntry(SymbolBody &Sym) { + Sym.GotPltIndex = Target->GotPltHeaderEntriesNum + Entries.size(); + Entries.push_back(&Sym); +} + +template <class ELFT> bool GotPltSection<ELFT>::empty() const { + return Entries.empty(); +} + +template <class ELFT> void GotPltSection<ELFT>::finalize() { + this->Header.sh_size = (Target->GotPltHeaderEntriesNum + Entries.size()) * + Target->GotPltEntrySize; +} + +template <class ELFT> void GotPltSection<ELFT>::writeTo(uint8_t *Buf) { + Target->writeGotPltHeader(Buf); + Buf += Target->GotPltHeaderEntriesNum * Target->GotPltEntrySize; + for (const SymbolBody *B : Entries) { + Target->writeGotPlt(Buf, *B); + Buf += sizeof(uintX_t); + } +} + +template <class ELFT> +GotSection<ELFT>::GotSection() + : OutputSectionBase<ELFT>(".got", SHT_PROGBITS, SHF_ALLOC | SHF_WRITE) { + if (Config->EMachine == EM_MIPS) + this->Header.sh_flags |= SHF_MIPS_GPREL; + this->Header.sh_addralign = Target->GotEntrySize; +} + +template <class ELFT> +void GotSection<ELFT>::addEntry(SymbolBody &Sym) { + Sym.GotIndex = Entries.size(); + Entries.push_back(&Sym); +} + +template <class ELFT> +void GotSection<ELFT>::addMipsEntry(SymbolBody &Sym, uintX_t Addend, + RelExpr Expr) { + // For "true" local symbols which can be referenced from the same module + // only compiler creates two instructions for address loading: + // + // lw $8, 0($gp) # R_MIPS_GOT16 + // addi $8, $8, 0 # R_MIPS_LO16 + // + // The first instruction loads high 16 bits of the symbol address while + // the second adds an offset. That allows to reduce number of required + // GOT entries because only one global offset table entry is necessary + // for every 64 KBytes of local data. So for local symbols we need to + // allocate number of GOT entries to hold all required "page" addresses. + // + // All global symbols (hidden and regular) considered by compiler uniformly. + // It always generates a single `lw` instruction and R_MIPS_GOT16 relocation + // to load address of the symbol. So for each such symbol we need to + // allocate dedicated GOT entry to store its address. + // + // If a symbol is preemptible we need help of dynamic linker to get its + // final address. The corresponding GOT entries are allocated in the + // "global" part of GOT. Entries for non preemptible global symbol allocated + // in the "local" part of GOT. + // + // See "Global Offset Table" in Chapter 5: + // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf + if (Expr == R_MIPS_GOT_LOCAL_PAGE) { + // At this point we do not know final symbol value so to reduce number + // of allocated GOT entries do the following trick. Save all output + // sections referenced by GOT relocations. Then later in the `finalize` + // method calculate number of "pages" required to cover all saved output + // section and allocate appropriate number of GOT entries. + auto *OutSec = cast<DefinedRegular<ELFT>>(&Sym)->Section->OutSec; + MipsOutSections.insert(OutSec); + return; + } + if (Sym.isTls()) { + // GOT entries created for MIPS TLS relocations behave like + // almost GOT entries from other ABIs. They go to the end + // of the global offset table. + Sym.GotIndex = Entries.size(); + Entries.push_back(&Sym); + return; + } + auto AddEntry = [&](SymbolBody &S, uintX_t A, MipsGotEntries &Items) { + if (S.isInGot() && !A) + return; + size_t NewIndex = Items.size(); + if (!MipsGotMap.insert({{&S, A}, NewIndex}).second) + return; + Items.emplace_back(&S, A); + if (!A) + S.GotIndex = NewIndex; + }; + if (Sym.isPreemptible()) { + // Ignore addends for preemptible symbols. They got single GOT entry anyway. + AddEntry(Sym, 0, MipsGlobal); + Sym.IsInGlobalMipsGot = true; + } else + AddEntry(Sym, Addend, MipsLocal); +} + +template <class ELFT> bool GotSection<ELFT>::addDynTlsEntry(SymbolBody &Sym) { + if (Sym.GlobalDynIndex != -1U) + return false; + Sym.GlobalDynIndex = Entries.size(); + // Global Dynamic TLS entries take two GOT slots. + Entries.push_back(nullptr); + Entries.push_back(&Sym); + return true; +} + +// Reserves TLS entries for a TLS module ID and a TLS block offset. +// In total it takes two GOT slots. +template <class ELFT> bool GotSection<ELFT>::addTlsIndex() { + if (TlsIndexOff != uint32_t(-1)) + return false; + TlsIndexOff = Entries.size() * sizeof(uintX_t); + Entries.push_back(nullptr); + Entries.push_back(nullptr); + return true; +} + +template <class ELFT> +typename GotSection<ELFT>::uintX_t +GotSection<ELFT>::getMipsLocalPageOffset(uintX_t EntryValue) { + // Initialize the entry by the %hi(EntryValue) expression + // but without right-shifting. + EntryValue = (EntryValue + 0x8000) & ~0xffff; + // Take into account MIPS GOT header. + // See comment in the GotSection::writeTo. + size_t NewIndex = MipsLocalGotPos.size() + 2; + auto P = MipsLocalGotPos.insert(std::make_pair(EntryValue, NewIndex)); + assert(!P.second || MipsLocalGotPos.size() <= MipsPageEntries); + return (uintX_t)P.first->second * sizeof(uintX_t) - MipsGPOffset; +} + +template <class ELFT> +typename GotSection<ELFT>::uintX_t +GotSection<ELFT>::getMipsGotOffset(const SymbolBody &B, uintX_t Addend) const { + uintX_t Off = MipsPageEntries; + if (B.isTls()) + Off += MipsLocal.size() + MipsGlobal.size() + B.GotIndex; + else if (B.IsInGlobalMipsGot) + Off += MipsLocal.size() + B.GotIndex; + else if (B.isInGot()) + Off += B.GotIndex; + else { + auto It = MipsGotMap.find({&B, Addend}); + assert(It != MipsGotMap.end()); + Off += It->second; + } + return Off * sizeof(uintX_t) - MipsGPOffset; +} + +template <class ELFT> +typename GotSection<ELFT>::uintX_t GotSection<ELFT>::getMipsTlsOffset() { + return (MipsPageEntries + MipsLocal.size() + MipsGlobal.size()) * + sizeof(uintX_t); +} + +template <class ELFT> +typename GotSection<ELFT>::uintX_t +GotSection<ELFT>::getGlobalDynAddr(const SymbolBody &B) const { + return this->getVA() + B.GlobalDynIndex * sizeof(uintX_t); +} + +template <class ELFT> +typename GotSection<ELFT>::uintX_t +GotSection<ELFT>::getGlobalDynOffset(const SymbolBody &B) const { + return B.GlobalDynIndex * sizeof(uintX_t); +} + +template <class ELFT> +const SymbolBody *GotSection<ELFT>::getMipsFirstGlobalEntry() const { + return MipsGlobal.empty() ? nullptr : MipsGlobal.front().first; +} + +template <class ELFT> +unsigned GotSection<ELFT>::getMipsLocalEntriesNum() const { + return MipsPageEntries + MipsLocal.size(); +} + +template <class ELFT> void GotSection<ELFT>::finalize() { + size_t EntriesNum = Entries.size(); + if (Config->EMachine == EM_MIPS) { + // Take into account MIPS GOT header. + // See comment in the GotSection::writeTo. + MipsPageEntries += 2; + for (const OutputSectionBase<ELFT> *OutSec : MipsOutSections) { + // Calculate an upper bound of MIPS GOT entries required to store page + // addresses of local symbols. We assume the worst case - each 64kb + // page of the output section has at least one GOT relocation against it. + // Add 0x8000 to the section's size because the page address stored + // in the GOT entry is calculated as (value + 0x8000) & ~0xffff. + MipsPageEntries += (OutSec->getSize() + 0x8000 + 0xfffe) / 0xffff; + } + EntriesNum += MipsPageEntries + MipsLocal.size() + MipsGlobal.size(); + } + this->Header.sh_size = EntriesNum * sizeof(uintX_t); +} + +template <class ELFT> void GotSection<ELFT>::writeMipsGot(uint8_t *&Buf) { + // Set the MSB of the second GOT slot. This is not required by any + // MIPS ABI documentation, though. + // + // There is a comment in glibc saying that "The MSB of got[1] of a + // gnu object is set to identify gnu objects," and in GNU gold it + // says "the second entry will be used by some runtime loaders". + // But how this field is being used is unclear. + // + // We are not really willing to mimic other linkers behaviors + // without understanding why they do that, but because all files + // generated by GNU tools have this special GOT value, and because + // we've been doing this for years, it is probably a safe bet to + // keep doing this for now. We really need to revisit this to see + // if we had to do this. + auto *P = reinterpret_cast<typename ELFT::Off *>(Buf); + P[1] = uintX_t(1) << (ELFT::Is64Bits ? 63 : 31); + // Write 'page address' entries to the local part of the GOT. + for (std::pair<uintX_t, size_t> &L : MipsLocalGotPos) { + uint8_t *Entry = Buf + L.second * sizeof(uintX_t); + write<uintX_t, ELFT::TargetEndianness, sizeof(uintX_t)>(Entry, L.first); + } + Buf += MipsPageEntries * sizeof(uintX_t); + auto AddEntry = [&](const MipsGotEntry &SA) { + uint8_t *Entry = Buf; + Buf += sizeof(uintX_t); + const SymbolBody* Body = SA.first; + uintX_t VA = Body->template getVA<ELFT>(SA.second); + write<uintX_t, ELFT::TargetEndianness, sizeof(uintX_t)>(Entry, VA); + }; + std::for_each(std::begin(MipsLocal), std::end(MipsLocal), AddEntry); + std::for_each(std::begin(MipsGlobal), std::end(MipsGlobal), AddEntry); +} + +template <class ELFT> void GotSection<ELFT>::writeTo(uint8_t *Buf) { + if (Config->EMachine == EM_MIPS) + writeMipsGot(Buf); + for (const SymbolBody *B : Entries) { + uint8_t *Entry = Buf; + Buf += sizeof(uintX_t); + if (!B) + continue; + if (B->isPreemptible()) + continue; // The dynamic linker will take care of it. + uintX_t VA = B->getVA<ELFT>(); + write<uintX_t, ELFT::TargetEndianness, sizeof(uintX_t)>(Entry, VA); + } +} + +template <class ELFT> +PltSection<ELFT>::PltSection() + : OutputSectionBase<ELFT>(".plt", SHT_PROGBITS, SHF_ALLOC | SHF_EXECINSTR) { + this->Header.sh_addralign = 16; +} + +template <class ELFT> void PltSection<ELFT>::writeTo(uint8_t *Buf) { + // At beginning of PLT, we have code to call the dynamic linker + // to resolve dynsyms at runtime. Write such code. + Target->writePltHeader(Buf); + size_t Off = Target->PltHeaderSize; + + for (auto &I : Entries) { + const SymbolBody *B = I.first; + unsigned RelOff = I.second; + uint64_t Got = B->getGotPltVA<ELFT>(); + uint64_t Plt = this->getVA() + Off; + Target->writePlt(Buf + Off, Got, Plt, B->PltIndex, RelOff); + Off += Target->PltEntrySize; + } +} + +template <class ELFT> void PltSection<ELFT>::addEntry(SymbolBody &Sym) { + Sym.PltIndex = Entries.size(); + unsigned RelOff = Out<ELFT>::RelaPlt->getRelocOffset(); + Entries.push_back(std::make_pair(&Sym, RelOff)); +} + +template <class ELFT> void PltSection<ELFT>::finalize() { + this->Header.sh_size = + Target->PltHeaderSize + Entries.size() * Target->PltEntrySize; +} + +template <class ELFT> +RelocationSection<ELFT>::RelocationSection(StringRef Name, bool Sort) + : OutputSectionBase<ELFT>(Name, Config->Rela ? SHT_RELA : SHT_REL, + SHF_ALLOC), + Sort(Sort) { + this->Header.sh_entsize = Config->Rela ? sizeof(Elf_Rela) : sizeof(Elf_Rel); + this->Header.sh_addralign = sizeof(uintX_t); +} + +template <class ELFT> +void RelocationSection<ELFT>::addReloc(const DynamicReloc<ELFT> &Reloc) { + Relocs.push_back(Reloc); +} + +template <class ELFT, class RelTy> +static bool compRelocations(const RelTy &A, const RelTy &B) { + return A.getSymbol(Config->Mips64EL) < B.getSymbol(Config->Mips64EL); +} + +template <class ELFT> void RelocationSection<ELFT>::writeTo(uint8_t *Buf) { + uint8_t *BufBegin = Buf; + for (const DynamicReloc<ELFT> &Rel : Relocs) { + auto *P = reinterpret_cast<Elf_Rela *>(Buf); + Buf += Config->Rela ? sizeof(Elf_Rela) : sizeof(Elf_Rel); + + if (Config->Rela) + P->r_addend = Rel.getAddend(); + P->r_offset = Rel.getOffset(); + if (Config->EMachine == EM_MIPS && Rel.getOutputSec() == Out<ELFT>::Got) + // Dynamic relocation against MIPS GOT section make deal TLS entries + // allocated in the end of the GOT. We need to adjust the offset to take + // in account 'local' and 'global' GOT entries. + P->r_offset += Out<ELFT>::Got->getMipsTlsOffset(); + P->setSymbolAndType(Rel.getSymIndex(), Rel.Type, Config->Mips64EL); + } + + if (Sort) { + if (Config->Rela) + std::stable_sort((Elf_Rela *)BufBegin, + (Elf_Rela *)BufBegin + Relocs.size(), + compRelocations<ELFT, Elf_Rela>); + else + std::stable_sort((Elf_Rel *)BufBegin, (Elf_Rel *)BufBegin + Relocs.size(), + compRelocations<ELFT, Elf_Rel>); + } +} + +template <class ELFT> unsigned RelocationSection<ELFT>::getRelocOffset() { + return this->Header.sh_entsize * Relocs.size(); +} + +template <class ELFT> void RelocationSection<ELFT>::finalize() { + this->Header.sh_link = Static ? Out<ELFT>::SymTab->SectionIndex + : Out<ELFT>::DynSymTab->SectionIndex; + this->Header.sh_size = Relocs.size() * this->Header.sh_entsize; +} + +template <class ELFT> +InterpSection<ELFT>::InterpSection() + : OutputSectionBase<ELFT>(".interp", SHT_PROGBITS, SHF_ALLOC) { + this->Header.sh_size = Config->DynamicLinker.size() + 1; +} + +template <class ELFT> void InterpSection<ELFT>::writeTo(uint8_t *Buf) { + StringRef S = Config->DynamicLinker; + memcpy(Buf, S.data(), S.size()); +} + +template <class ELFT> +HashTableSection<ELFT>::HashTableSection() + : OutputSectionBase<ELFT>(".hash", SHT_HASH, SHF_ALLOC) { + this->Header.sh_entsize = sizeof(Elf_Word); + this->Header.sh_addralign = sizeof(Elf_Word); +} + +static uint32_t hashSysv(StringRef Name) { + uint32_t H = 0; + for (char C : Name) { + H = (H << 4) + C; + uint32_t G = H & 0xf0000000; + if (G) + H ^= G >> 24; + H &= ~G; + } + return H; +} + +template <class ELFT> void HashTableSection<ELFT>::finalize() { + this->Header.sh_link = Out<ELFT>::DynSymTab->SectionIndex; + + unsigned NumEntries = 2; // nbucket and nchain. + NumEntries += Out<ELFT>::DynSymTab->getNumSymbols(); // The chain entries. + + // Create as many buckets as there are symbols. + // FIXME: This is simplistic. We can try to optimize it, but implementing + // support for SHT_GNU_HASH is probably even more profitable. + NumEntries += Out<ELFT>::DynSymTab->getNumSymbols(); + this->Header.sh_size = NumEntries * sizeof(Elf_Word); +} + +template <class ELFT> void HashTableSection<ELFT>::writeTo(uint8_t *Buf) { + unsigned NumSymbols = Out<ELFT>::DynSymTab->getNumSymbols(); + auto *P = reinterpret_cast<Elf_Word *>(Buf); + *P++ = NumSymbols; // nbucket + *P++ = NumSymbols; // nchain + + Elf_Word *Buckets = P; + Elf_Word *Chains = P + NumSymbols; + + for (const std::pair<SymbolBody *, unsigned> &P : + Out<ELFT>::DynSymTab->getSymbols()) { + SymbolBody *Body = P.first; + StringRef Name = Body->getName(); + unsigned I = Body->DynsymIndex; + uint32_t Hash = hashSysv(Name) % NumSymbols; + Chains[I] = Buckets[Hash]; + Buckets[Hash] = I; + } +} + +static uint32_t hashGnu(StringRef Name) { + uint32_t H = 5381; + for (uint8_t C : Name) + H = (H << 5) + H + C; + return H; +} + +template <class ELFT> +GnuHashTableSection<ELFT>::GnuHashTableSection() + : OutputSectionBase<ELFT>(".gnu.hash", SHT_GNU_HASH, SHF_ALLOC) { + this->Header.sh_entsize = ELFT::Is64Bits ? 0 : 4; + this->Header.sh_addralign = sizeof(uintX_t); +} + +template <class ELFT> +unsigned GnuHashTableSection<ELFT>::calcNBuckets(unsigned NumHashed) { + if (!NumHashed) + return 0; + + // These values are prime numbers which are not greater than 2^(N-1) + 1. + // In result, for any particular NumHashed we return a prime number + // which is not greater than NumHashed. + static const unsigned Primes[] = { + 1, 1, 3, 3, 7, 13, 31, 61, 127, 251, + 509, 1021, 2039, 4093, 8191, 16381, 32749, 65521, 131071}; + + return Primes[std::min<unsigned>(Log2_32_Ceil(NumHashed), + array_lengthof(Primes) - 1)]; +} + +// Bloom filter estimation: at least 8 bits for each hashed symbol. +// GNU Hash table requirement: it should be a power of 2, +// the minimum value is 1, even for an empty table. +// Expected results for a 32-bit target: +// calcMaskWords(0..4) = 1 +// calcMaskWords(5..8) = 2 +// calcMaskWords(9..16) = 4 +// For a 64-bit target: +// calcMaskWords(0..8) = 1 +// calcMaskWords(9..16) = 2 +// calcMaskWords(17..32) = 4 +template <class ELFT> +unsigned GnuHashTableSection<ELFT>::calcMaskWords(unsigned NumHashed) { + if (!NumHashed) + return 1; + return NextPowerOf2((NumHashed - 1) / sizeof(Elf_Off)); +} + +template <class ELFT> void GnuHashTableSection<ELFT>::finalize() { + unsigned NumHashed = Symbols.size(); + NBuckets = calcNBuckets(NumHashed); + MaskWords = calcMaskWords(NumHashed); + // Second hash shift estimation: just predefined values. + Shift2 = ELFT::Is64Bits ? 6 : 5; + + this->Header.sh_link = Out<ELFT>::DynSymTab->SectionIndex; + this->Header.sh_size = sizeof(Elf_Word) * 4 // Header + + sizeof(Elf_Off) * MaskWords // Bloom Filter + + sizeof(Elf_Word) * NBuckets // Hash Buckets + + sizeof(Elf_Word) * NumHashed; // Hash Values +} + +template <class ELFT> void GnuHashTableSection<ELFT>::writeTo(uint8_t *Buf) { + writeHeader(Buf); + if (Symbols.empty()) + return; + writeBloomFilter(Buf); + writeHashTable(Buf); +} + +template <class ELFT> +void GnuHashTableSection<ELFT>::writeHeader(uint8_t *&Buf) { + auto *P = reinterpret_cast<Elf_Word *>(Buf); + *P++ = NBuckets; + *P++ = Out<ELFT>::DynSymTab->getNumSymbols() - Symbols.size(); + *P++ = MaskWords; + *P++ = Shift2; + Buf = reinterpret_cast<uint8_t *>(P); +} + +template <class ELFT> +void GnuHashTableSection<ELFT>::writeBloomFilter(uint8_t *&Buf) { + unsigned C = sizeof(Elf_Off) * 8; + + auto *Masks = reinterpret_cast<Elf_Off *>(Buf); + for (const SymbolData &Sym : Symbols) { + size_t Pos = (Sym.Hash / C) & (MaskWords - 1); + uintX_t V = (uintX_t(1) << (Sym.Hash % C)) | + (uintX_t(1) << ((Sym.Hash >> Shift2) % C)); + Masks[Pos] |= V; + } + Buf += sizeof(Elf_Off) * MaskWords; +} + +template <class ELFT> +void GnuHashTableSection<ELFT>::writeHashTable(uint8_t *Buf) { + Elf_Word *Buckets = reinterpret_cast<Elf_Word *>(Buf); + Elf_Word *Values = Buckets + NBuckets; + + int PrevBucket = -1; + int I = 0; + for (const SymbolData &Sym : Symbols) { + int Bucket = Sym.Hash % NBuckets; + assert(PrevBucket <= Bucket); + if (Bucket != PrevBucket) { + Buckets[Bucket] = Sym.Body->DynsymIndex; + PrevBucket = Bucket; + if (I > 0) + Values[I - 1] |= 1; + } + Values[I] = Sym.Hash & ~1; + ++I; + } + if (I > 0) + Values[I - 1] |= 1; +} + +// Add symbols to this symbol hash table. Note that this function +// destructively sort a given vector -- which is needed because +// GNU-style hash table places some sorting requirements. +template <class ELFT> +void GnuHashTableSection<ELFT>::addSymbols( + std::vector<std::pair<SymbolBody *, size_t>> &V) { + // Ideally this will just be 'auto' but GCC 6.1 is not able + // to deduce it correctly. + std::vector<std::pair<SymbolBody *, size_t>>::iterator Mid = + std::stable_partition(V.begin(), V.end(), + [](std::pair<SymbolBody *, size_t> &P) { + return P.first->isUndefined(); + }); + if (Mid == V.end()) + return; + for (auto I = Mid, E = V.end(); I != E; ++I) { + SymbolBody *B = I->first; + size_t StrOff = I->second; + Symbols.push_back({B, StrOff, hashGnu(B->getName())}); + } + + unsigned NBuckets = calcNBuckets(Symbols.size()); + std::stable_sort(Symbols.begin(), Symbols.end(), + [&](const SymbolData &L, const SymbolData &R) { + return L.Hash % NBuckets < R.Hash % NBuckets; + }); + + V.erase(Mid, V.end()); + for (const SymbolData &Sym : Symbols) + V.push_back({Sym.Body, Sym.STName}); +} + +// Returns the number of version definition entries. Because the first entry +// is for the version definition itself, it is the number of versioned symbols +// plus one. Note that we don't support multiple versions yet. +static unsigned getVerDefNum() { return Config->VersionDefinitions.size() + 1; } + +template <class ELFT> +DynamicSection<ELFT>::DynamicSection() + : OutputSectionBase<ELFT>(".dynamic", SHT_DYNAMIC, SHF_ALLOC | SHF_WRITE) { + Elf_Shdr &Header = this->Header; + Header.sh_addralign = sizeof(uintX_t); + Header.sh_entsize = ELFT::Is64Bits ? 16 : 8; + + // .dynamic section is not writable on MIPS. + // See "Special Section" in Chapter 4 in the following document: + // ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf + if (Config->EMachine == EM_MIPS) + Header.sh_flags = SHF_ALLOC; +} + +template <class ELFT> void DynamicSection<ELFT>::finalize() { + if (this->Header.sh_size) + return; // Already finalized. + + Elf_Shdr &Header = this->Header; + Header.sh_link = Out<ELFT>::DynStrTab->SectionIndex; + + auto Add = [=](Entry E) { Entries.push_back(E); }; + + // Add strings. We know that these are the last strings to be added to + // DynStrTab and doing this here allows this function to set DT_STRSZ. + if (!Config->RPath.empty()) + Add({Config->EnableNewDtags ? DT_RUNPATH : DT_RPATH, + Out<ELFT>::DynStrTab->addString(Config->RPath)}); + for (const std::unique_ptr<SharedFile<ELFT>> &F : + Symtab<ELFT>::X->getSharedFiles()) + if (F->isNeeded()) + Add({DT_NEEDED, Out<ELFT>::DynStrTab->addString(F->getSoName())}); + if (!Config->SoName.empty()) + Add({DT_SONAME, Out<ELFT>::DynStrTab->addString(Config->SoName)}); + + Out<ELFT>::DynStrTab->finalize(); + + if (Out<ELFT>::RelaDyn->hasRelocs()) { + bool IsRela = Config->Rela; + Add({IsRela ? DT_RELA : DT_REL, Out<ELFT>::RelaDyn}); + Add({IsRela ? DT_RELASZ : DT_RELSZ, Out<ELFT>::RelaDyn->getSize()}); + Add({IsRela ? DT_RELAENT : DT_RELENT, + uintX_t(IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel))}); + } + if (Out<ELFT>::RelaPlt && Out<ELFT>::RelaPlt->hasRelocs()) { + Add({DT_JMPREL, Out<ELFT>::RelaPlt}); + Add({DT_PLTRELSZ, Out<ELFT>::RelaPlt->getSize()}); + Add({Config->EMachine == EM_MIPS ? DT_MIPS_PLTGOT : DT_PLTGOT, + Out<ELFT>::GotPlt}); + Add({DT_PLTREL, uint64_t(Config->Rela ? DT_RELA : DT_REL)}); + } + + Add({DT_SYMTAB, Out<ELFT>::DynSymTab}); + Add({DT_SYMENT, sizeof(Elf_Sym)}); + Add({DT_STRTAB, Out<ELFT>::DynStrTab}); + Add({DT_STRSZ, Out<ELFT>::DynStrTab->getSize()}); + if (Out<ELFT>::GnuHashTab) + Add({DT_GNU_HASH, Out<ELFT>::GnuHashTab}); + if (Out<ELFT>::HashTab) + Add({DT_HASH, Out<ELFT>::HashTab}); + + if (PreInitArraySec) { + Add({DT_PREINIT_ARRAY, PreInitArraySec}); + Add({DT_PREINIT_ARRAYSZ, PreInitArraySec->getSize()}); + } + if (InitArraySec) { + Add({DT_INIT_ARRAY, InitArraySec}); + Add({DT_INIT_ARRAYSZ, (uintX_t)InitArraySec->getSize()}); + } + if (FiniArraySec) { + Add({DT_FINI_ARRAY, FiniArraySec}); + Add({DT_FINI_ARRAYSZ, (uintX_t)FiniArraySec->getSize()}); + } + + if (SymbolBody *B = Symtab<ELFT>::X->find(Config->Init)) + Add({DT_INIT, B}); + if (SymbolBody *B = Symtab<ELFT>::X->find(Config->Fini)) + Add({DT_FINI, B}); + + uint32_t DtFlags = 0; + uint32_t DtFlags1 = 0; + if (Config->Bsymbolic) + DtFlags |= DF_SYMBOLIC; + if (Config->ZNodelete) + DtFlags1 |= DF_1_NODELETE; + if (Config->ZNow) { + DtFlags |= DF_BIND_NOW; + DtFlags1 |= DF_1_NOW; + } + if (Config->ZOrigin) { + DtFlags |= DF_ORIGIN; + DtFlags1 |= DF_1_ORIGIN; + } + + if (DtFlags) + Add({DT_FLAGS, DtFlags}); + if (DtFlags1) + Add({DT_FLAGS_1, DtFlags1}); + + if (!Config->Entry.empty()) + Add({DT_DEBUG, (uint64_t)0}); + + bool HasVerNeed = Out<ELFT>::VerNeed->getNeedNum() != 0; + if (HasVerNeed || Out<ELFT>::VerDef) + Add({DT_VERSYM, Out<ELFT>::VerSym}); + if (Out<ELFT>::VerDef) { + Add({DT_VERDEF, Out<ELFT>::VerDef}); + Add({DT_VERDEFNUM, getVerDefNum()}); + } + if (HasVerNeed) { + Add({DT_VERNEED, Out<ELFT>::VerNeed}); + Add({DT_VERNEEDNUM, Out<ELFT>::VerNeed->getNeedNum()}); + } + + if (Config->EMachine == EM_MIPS) { + Add({DT_MIPS_RLD_VERSION, 1}); + Add({DT_MIPS_FLAGS, RHF_NOTPOT}); + Add({DT_MIPS_BASE_ADDRESS, Config->ImageBase}); + Add({DT_MIPS_SYMTABNO, Out<ELFT>::DynSymTab->getNumSymbols()}); + Add({DT_MIPS_LOCAL_GOTNO, Out<ELFT>::Got->getMipsLocalEntriesNum()}); + if (const SymbolBody *B = Out<ELFT>::Got->getMipsFirstGlobalEntry()) + Add({DT_MIPS_GOTSYM, B->DynsymIndex}); + else + Add({DT_MIPS_GOTSYM, Out<ELFT>::DynSymTab->getNumSymbols()}); + Add({DT_PLTGOT, Out<ELFT>::Got}); + if (Out<ELFT>::MipsRldMap) + Add({DT_MIPS_RLD_MAP, Out<ELFT>::MipsRldMap}); + } + + // +1 for DT_NULL + Header.sh_size = (Entries.size() + 1) * Header.sh_entsize; +} + +template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t *Buf) { + auto *P = reinterpret_cast<Elf_Dyn *>(Buf); + + for (const Entry &E : Entries) { + P->d_tag = E.Tag; + switch (E.Kind) { + case Entry::SecAddr: + P->d_un.d_ptr = E.OutSec->getVA(); + break; + case Entry::SymAddr: + P->d_un.d_ptr = E.Sym->template getVA<ELFT>(); + break; + case Entry::PlainInt: + P->d_un.d_val = E.Val; + break; + } + ++P; + } +} + +template <class ELFT> +EhFrameHeader<ELFT>::EhFrameHeader() + : OutputSectionBase<ELFT>(".eh_frame_hdr", SHT_PROGBITS, SHF_ALLOC) {} + +// .eh_frame_hdr contains a binary search table of pointers to FDEs. +// Each entry of the search table consists of two values, +// the starting PC from where FDEs covers, and the FDE's address. +// It is sorted by PC. +template <class ELFT> void EhFrameHeader<ELFT>::writeTo(uint8_t *Buf) { + const endianness E = ELFT::TargetEndianness; + + // Sort the FDE list by their PC and uniqueify. Usually there is only + // one FDE for a PC (i.e. function), but if ICF merges two functions + // into one, there can be more than one FDEs pointing to the address. + auto Less = [](const FdeData &A, const FdeData &B) { return A.Pc < B.Pc; }; + std::stable_sort(Fdes.begin(), Fdes.end(), Less); + auto Eq = [](const FdeData &A, const FdeData &B) { return A.Pc == B.Pc; }; + Fdes.erase(std::unique(Fdes.begin(), Fdes.end(), Eq), Fdes.end()); + + Buf[0] = 1; + Buf[1] = DW_EH_PE_pcrel | DW_EH_PE_sdata4; + Buf[2] = DW_EH_PE_udata4; + Buf[3] = DW_EH_PE_datarel | DW_EH_PE_sdata4; + write32<E>(Buf + 4, Out<ELFT>::EhFrame->getVA() - this->getVA() - 4); + write32<E>(Buf + 8, Fdes.size()); + Buf += 12; + + uintX_t VA = this->getVA(); + for (FdeData &Fde : Fdes) { + write32<E>(Buf, Fde.Pc - VA); + write32<E>(Buf + 4, Fde.FdeVA - VA); + Buf += 8; + } +} + +template <class ELFT> void EhFrameHeader<ELFT>::finalize() { + // .eh_frame_hdr has a 12 bytes header followed by an array of FDEs. + this->Header.sh_size = 12 + Out<ELFT>::EhFrame->NumFdes * 8; +} + +template <class ELFT> +void EhFrameHeader<ELFT>::addFde(uint32_t Pc, uint32_t FdeVA) { + Fdes.push_back({Pc, FdeVA}); +} + +template <class ELFT> +OutputSection<ELFT>::OutputSection(StringRef Name, uint32_t Type, uintX_t Flags) + : OutputSectionBase<ELFT>(Name, Type, Flags) { + if (Type == SHT_RELA) + this->Header.sh_entsize = sizeof(Elf_Rela); + else if (Type == SHT_REL) + this->Header.sh_entsize = sizeof(Elf_Rel); +} + +template <class ELFT> void OutputSection<ELFT>::finalize() { + uint32_t Type = this->Header.sh_type; + if (Type != SHT_RELA && Type != SHT_REL) + return; + this->Header.sh_link = Out<ELFT>::SymTab->SectionIndex; + // sh_info for SHT_REL[A] sections should contain the section header index of + // the section to which the relocation applies. + InputSectionBase<ELFT> *S = Sections[0]->getRelocatedSection(); + this->Header.sh_info = S->OutSec->SectionIndex; +} + +template <class ELFT> +void OutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) { + assert(C->Live); + auto *S = cast<InputSection<ELFT>>(C); + Sections.push_back(S); + S->OutSec = this; + this->updateAlignment(S->Alignment); +} + +// If an input string is in the form of "foo.N" where N is a number, +// return N. Otherwise, returns 65536, which is one greater than the +// lowest priority. +static int getPriority(StringRef S) { + size_t Pos = S.rfind('.'); + if (Pos == StringRef::npos) + return 65536; + int V; + if (S.substr(Pos + 1).getAsInteger(10, V)) + return 65536; + return V; +} + +// This function is called after we sort input sections +// and scan relocations to setup sections' offsets. +template <class ELFT> void OutputSection<ELFT>::assignOffsets() { + uintX_t Off = this->Header.sh_size; + for (InputSection<ELFT> *S : Sections) { + Off = alignTo(Off, S->Alignment); + S->OutSecOff = Off; + Off += S->getSize(); + } + this->Header.sh_size = Off; +} + +// Sorts input sections by section name suffixes, so that .foo.N comes +// before .foo.M if N < M. Used to sort .{init,fini}_array.N sections. +// We want to keep the original order if the priorities are the same +// because the compiler keeps the original initialization order in a +// translation unit and we need to respect that. +// For more detail, read the section of the GCC's manual about init_priority. +template <class ELFT> void OutputSection<ELFT>::sortInitFini() { + // Sort sections by priority. + typedef std::pair<int, InputSection<ELFT> *> Pair; + auto Comp = [](const Pair &A, const Pair &B) { return A.first < B.first; }; + + std::vector<Pair> V; + for (InputSection<ELFT> *S : Sections) + V.push_back({getPriority(S->getSectionName()), S}); + std::stable_sort(V.begin(), V.end(), Comp); + Sections.clear(); + for (Pair &P : V) + Sections.push_back(P.second); +} + +// Returns true if S matches /Filename.?\.o$/. +static bool isCrtBeginEnd(StringRef S, StringRef Filename) { + if (!S.endswith(".o")) + return false; + S = S.drop_back(2); + if (S.endswith(Filename)) + return true; + return !S.empty() && S.drop_back().endswith(Filename); +} + +static bool isCrtbegin(StringRef S) { return isCrtBeginEnd(S, "crtbegin"); } +static bool isCrtend(StringRef S) { return isCrtBeginEnd(S, "crtend"); } + +// .ctors and .dtors are sorted by this priority from highest to lowest. +// +// 1. The section was contained in crtbegin (crtbegin contains +// some sentinel value in its .ctors and .dtors so that the runtime +// can find the beginning of the sections.) +// +// 2. The section has an optional priority value in the form of ".ctors.N" +// or ".dtors.N" where N is a number. Unlike .{init,fini}_array, +// they are compared as string rather than number. +// +// 3. The section is just ".ctors" or ".dtors". +// +// 4. The section was contained in crtend, which contains an end marker. +// +// In an ideal world, we don't need this function because .init_array and +// .ctors are duplicate features (and .init_array is newer.) However, there +// are too many real-world use cases of .ctors, so we had no choice to +// support that with this rather ad-hoc semantics. +template <class ELFT> +static bool compCtors(const InputSection<ELFT> *A, + const InputSection<ELFT> *B) { + bool BeginA = isCrtbegin(A->getFile()->getName()); + bool BeginB = isCrtbegin(B->getFile()->getName()); + if (BeginA != BeginB) + return BeginA; + bool EndA = isCrtend(A->getFile()->getName()); + bool EndB = isCrtend(B->getFile()->getName()); + if (EndA != EndB) + return EndB; + StringRef X = A->getSectionName(); + StringRef Y = B->getSectionName(); + assert(X.startswith(".ctors") || X.startswith(".dtors")); + assert(Y.startswith(".ctors") || Y.startswith(".dtors")); + X = X.substr(6); + Y = Y.substr(6); + if (X.empty() && Y.empty()) + return false; + return X < Y; +} + +// Sorts input sections by the special rules for .ctors and .dtors. +// Unfortunately, the rules are different from the one for .{init,fini}_array. +// Read the comment above. +template <class ELFT> void OutputSection<ELFT>::sortCtorsDtors() { + std::stable_sort(Sections.begin(), Sections.end(), compCtors<ELFT>); +} + +static void fill(uint8_t *Buf, size_t Size, ArrayRef<uint8_t> A) { + size_t I = 0; + for (; I + A.size() < Size; I += A.size()) + memcpy(Buf + I, A.data(), A.size()); + memcpy(Buf + I, A.data(), Size - I); +} + +template <class ELFT> void OutputSection<ELFT>::writeTo(uint8_t *Buf) { + ArrayRef<uint8_t> Filler = Script<ELFT>::X->getFiller(this->Name); + if (!Filler.empty()) + fill(Buf, this->getSize(), Filler); + if (Config->Threads) { + parallel_for_each(Sections.begin(), Sections.end(), + [=](InputSection<ELFT> *C) { C->writeTo(Buf); }); + } else { + for (InputSection<ELFT> *C : Sections) + C->writeTo(Buf); + } +} + +template <class ELFT> +EhOutputSection<ELFT>::EhOutputSection() + : OutputSectionBase<ELFT>(".eh_frame", SHT_PROGBITS, SHF_ALLOC) {} + +// Returns the first relocation that points to a region +// between Begin and Begin+Size. +template <class IntTy, class RelTy> +static const RelTy *getReloc(IntTy Begin, IntTy Size, ArrayRef<RelTy> &Rels) { + for (auto I = Rels.begin(), E = Rels.end(); I != E; ++I) { + if (I->r_offset < Begin) + continue; + + // Truncate Rels for fast access. That means we expect that the + // relocations are sorted and we are looking up symbols in + // sequential order. It is naturally satisfied for .eh_frame. + Rels = Rels.slice(I - Rels.begin()); + if (I->r_offset < Begin + Size) + return I; + return nullptr; + } + Rels = ArrayRef<RelTy>(); + return nullptr; +} + +// Search for an existing CIE record or create a new one. +// CIE records from input object files are uniquified by their contents +// and where their relocations point to. +template <class ELFT> +template <class RelTy> +CieRecord *EhOutputSection<ELFT>::addCie(SectionPiece &Piece, + EhInputSection<ELFT> *Sec, + ArrayRef<RelTy> &Rels) { + const endianness E = ELFT::TargetEndianness; + if (read32<E>(Piece.data().data() + 4) != 0) + fatal("CIE expected at beginning of .eh_frame: " + Sec->getSectionName()); + + SymbolBody *Personality = nullptr; + if (const RelTy *Rel = getReloc(Piece.InputOff, Piece.size(), Rels)) + Personality = &Sec->getFile()->getRelocTargetSym(*Rel); + + // Search for an existing CIE by CIE contents/relocation target pair. + CieRecord *Cie = &CieMap[{Piece.data(), Personality}]; + + // If not found, create a new one. + if (Cie->Piece == nullptr) { + Cie->Piece = &Piece; + Cies.push_back(Cie); + } + return Cie; +} + +// There is one FDE per function. Returns true if a given FDE +// points to a live function. +template <class ELFT> +template <class RelTy> +bool EhOutputSection<ELFT>::isFdeLive(SectionPiece &Piece, + EhInputSection<ELFT> *Sec, + ArrayRef<RelTy> &Rels) { + const RelTy *Rel = getReloc(Piece.InputOff, Piece.size(), Rels); + if (!Rel) + fatal("FDE doesn't reference another section"); + SymbolBody &B = Sec->getFile()->getRelocTargetSym(*Rel); + auto *D = dyn_cast<DefinedRegular<ELFT>>(&B); + if (!D || !D->Section) + return false; + InputSectionBase<ELFT> *Target = D->Section->Repl; + return Target && Target->Live; +} + +// .eh_frame is a sequence of CIE or FDE records. In general, there +// is one CIE record per input object file which is followed by +// a list of FDEs. This function searches an existing CIE or create a new +// one and associates FDEs to the CIE. +template <class ELFT> +template <class RelTy> +void EhOutputSection<ELFT>::addSectionAux(EhInputSection<ELFT> *Sec, + ArrayRef<RelTy> Rels) { + const endianness E = ELFT::TargetEndianness; + + DenseMap<size_t, CieRecord *> OffsetToCie; + for (SectionPiece &Piece : Sec->Pieces) { + // The empty record is the end marker. + if (Piece.size() == 4) + return; + + size_t Offset = Piece.InputOff; + uint32_t ID = read32<E>(Piece.data().data() + 4); + if (ID == 0) { + OffsetToCie[Offset] = addCie(Piece, Sec, Rels); + continue; + } + + uint32_t CieOffset = Offset + 4 - ID; + CieRecord *Cie = OffsetToCie[CieOffset]; + if (!Cie) + fatal("invalid CIE reference"); + + if (!isFdeLive(Piece, Sec, Rels)) + continue; + Cie->FdePieces.push_back(&Piece); + NumFdes++; + } +} + +template <class ELFT> +void EhOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) { + auto *Sec = cast<EhInputSection<ELFT>>(C); + Sec->OutSec = this; + this->updateAlignment(Sec->Alignment); + Sections.push_back(Sec); + + // .eh_frame is a sequence of CIE or FDE records. This function + // splits it into pieces so that we can call + // SplitInputSection::getSectionPiece on the section. + Sec->split(); + if (Sec->Pieces.empty()) + return; + + if (const Elf_Shdr *RelSec = Sec->RelocSection) { + ELFFile<ELFT> &Obj = Sec->getFile()->getObj(); + if (RelSec->sh_type == SHT_RELA) + addSectionAux(Sec, Obj.relas(RelSec)); + else + addSectionAux(Sec, Obj.rels(RelSec)); + return; + } + addSectionAux(Sec, makeArrayRef<Elf_Rela>(nullptr, nullptr)); +} + +template <class ELFT> +static void writeCieFde(uint8_t *Buf, ArrayRef<uint8_t> D) { + memcpy(Buf, D.data(), D.size()); + + // Fix the size field. -4 since size does not include the size field itself. + const endianness E = ELFT::TargetEndianness; + write32<E>(Buf, alignTo(D.size(), sizeof(typename ELFT::uint)) - 4); +} + +template <class ELFT> void EhOutputSection<ELFT>::finalize() { + if (this->Header.sh_size) + return; // Already finalized. + + size_t Off = 0; + for (CieRecord *Cie : Cies) { + Cie->Piece->OutputOff = Off; + Off += alignTo(Cie->Piece->size(), sizeof(uintX_t)); + + for (SectionPiece *Fde : Cie->FdePieces) { + Fde->OutputOff = Off; + Off += alignTo(Fde->size(), sizeof(uintX_t)); + } + } + this->Header.sh_size = Off; +} + +template <class ELFT> static uint64_t readFdeAddr(uint8_t *Buf, int Size) { + const endianness E = ELFT::TargetEndianness; + switch (Size) { + case DW_EH_PE_udata2: + return read16<E>(Buf); + case DW_EH_PE_udata4: + return read32<E>(Buf); + case DW_EH_PE_udata8: + return read64<E>(Buf); + case DW_EH_PE_absptr: + if (ELFT::Is64Bits) + return read64<E>(Buf); + return read32<E>(Buf); + } + fatal("unknown FDE size encoding"); +} + +// Returns the VA to which a given FDE (on a mmap'ed buffer) is applied to. +// We need it to create .eh_frame_hdr section. +template <class ELFT> +typename ELFT::uint EhOutputSection<ELFT>::getFdePc(uint8_t *Buf, size_t FdeOff, + uint8_t Enc) { + // The starting address to which this FDE applies is + // stored at FDE + 8 byte. + size_t Off = FdeOff + 8; + uint64_t Addr = readFdeAddr<ELFT>(Buf + Off, Enc & 0x7); + if ((Enc & 0x70) == DW_EH_PE_absptr) + return Addr; + if ((Enc & 0x70) == DW_EH_PE_pcrel) + return Addr + this->getVA() + Off; + fatal("unknown FDE size relative encoding"); +} + +template <class ELFT> void EhOutputSection<ELFT>::writeTo(uint8_t *Buf) { + const endianness E = ELFT::TargetEndianness; + for (CieRecord *Cie : Cies) { + size_t CieOffset = Cie->Piece->OutputOff; + writeCieFde<ELFT>(Buf + CieOffset, Cie->Piece->data()); + + for (SectionPiece *Fde : Cie->FdePieces) { + size_t Off = Fde->OutputOff; + writeCieFde<ELFT>(Buf + Off, Fde->data()); + + // FDE's second word should have the offset to an associated CIE. + // Write it. + write32<E>(Buf + Off + 4, Off + 4 - CieOffset); + } + } + + for (EhInputSection<ELFT> *S : Sections) + S->relocate(Buf, nullptr); + + // Construct .eh_frame_hdr. .eh_frame_hdr is a binary search table + // to get a FDE from an address to which FDE is applied. So here + // we obtain two addresses and pass them to EhFrameHdr object. + if (Out<ELFT>::EhFrameHdr) { + for (CieRecord *Cie : Cies) { + uint8_t Enc = getFdeEncoding<ELFT>(Cie->Piece->data()); + for (SectionPiece *Fde : Cie->FdePieces) { + uintX_t Pc = getFdePc(Buf, Fde->OutputOff, Enc); + uintX_t FdeVA = this->getVA() + Fde->OutputOff; + Out<ELFT>::EhFrameHdr->addFde(Pc, FdeVA); + } + } + } +} + +template <class ELFT> +MergeOutputSection<ELFT>::MergeOutputSection(StringRef Name, uint32_t Type, + uintX_t Flags, uintX_t Alignment) + : OutputSectionBase<ELFT>(Name, Type, Flags), + Builder(StringTableBuilder::RAW, Alignment) {} + +template <class ELFT> void MergeOutputSection<ELFT>::writeTo(uint8_t *Buf) { + if (shouldTailMerge()) { + StringRef Data = Builder.data(); + memcpy(Buf, Data.data(), Data.size()); + return; + } + for (const std::pair<CachedHash<StringRef>, size_t> &P : Builder.getMap()) { + StringRef Data = P.first.Val; + memcpy(Buf + P.second, Data.data(), Data.size()); + } +} + +static StringRef toStringRef(ArrayRef<uint8_t> A) { + return {(const char *)A.data(), A.size()}; +} + +template <class ELFT> +void MergeOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) { + auto *Sec = cast<MergeInputSection<ELFT>>(C); + Sec->OutSec = this; + this->updateAlignment(Sec->Alignment); + this->Header.sh_entsize = Sec->getSectionHdr()->sh_entsize; + Sections.push_back(Sec); + + bool IsString = this->Header.sh_flags & SHF_STRINGS; + + for (SectionPiece &Piece : Sec->Pieces) { + if (!Piece.Live) + continue; + uintX_t OutputOffset = Builder.add(toStringRef(Piece.data())); + if (!IsString || !shouldTailMerge()) + Piece.OutputOff = OutputOffset; + } +} + +template <class ELFT> +unsigned MergeOutputSection<ELFT>::getOffset(StringRef Val) { + return Builder.getOffset(Val); +} + +template <class ELFT> bool MergeOutputSection<ELFT>::shouldTailMerge() const { + return Config->Optimize >= 2 && this->Header.sh_flags & SHF_STRINGS; +} + +template <class ELFT> void MergeOutputSection<ELFT>::finalize() { + if (shouldTailMerge()) + Builder.finalize(); + this->Header.sh_size = Builder.getSize(); +} + +template <class ELFT> void MergeOutputSection<ELFT>::finalizePieces() { + for (MergeInputSection<ELFT> *Sec : Sections) + Sec->finalizePieces(); +} + +template <class ELFT> +StringTableSection<ELFT>::StringTableSection(StringRef Name, bool Dynamic) + : OutputSectionBase<ELFT>(Name, SHT_STRTAB, + Dynamic ? (uintX_t)SHF_ALLOC : 0), + Dynamic(Dynamic) {} + +// Adds a string to the string table. If HashIt is true we hash and check for +// duplicates. It is optional because the name of global symbols are already +// uniqued and hashing them again has a big cost for a small value: uniquing +// them with some other string that happens to be the same. +template <class ELFT> +unsigned StringTableSection<ELFT>::addString(StringRef S, bool HashIt) { + if (HashIt) { + auto R = StringMap.insert(std::make_pair(S, Size)); + if (!R.second) + return R.first->second; + } + unsigned Ret = Size; + Size += S.size() + 1; + Strings.push_back(S); + return Ret; +} + +template <class ELFT> void StringTableSection<ELFT>::writeTo(uint8_t *Buf) { + // ELF string tables start with NUL byte, so advance the pointer by one. + ++Buf; + for (StringRef S : Strings) { + memcpy(Buf, S.data(), S.size()); + Buf += S.size() + 1; + } +} + +template <class ELFT> +typename ELFT::uint DynamicReloc<ELFT>::getOffset() const { + if (OutputSec) + return OutputSec->getVA() + OffsetInSec; + return InputSec->OutSec->getVA() + InputSec->getOffset(OffsetInSec); +} + +template <class ELFT> +typename ELFT::uint DynamicReloc<ELFT>::getAddend() const { + if (UseSymVA) + return Sym->getVA<ELFT>(Addend); + return Addend; +} + +template <class ELFT> uint32_t DynamicReloc<ELFT>::getSymIndex() const { + if (Sym && !UseSymVA) + return Sym->DynsymIndex; + return 0; +} + +template <class ELFT> +SymbolTableSection<ELFT>::SymbolTableSection( + StringTableSection<ELFT> &StrTabSec) + : OutputSectionBase<ELFT>(StrTabSec.isDynamic() ? ".dynsym" : ".symtab", + StrTabSec.isDynamic() ? SHT_DYNSYM : SHT_SYMTAB, + StrTabSec.isDynamic() ? (uintX_t)SHF_ALLOC : 0), + StrTabSec(StrTabSec) { + this->Header.sh_entsize = sizeof(Elf_Sym); + this->Header.sh_addralign = sizeof(uintX_t); +} + +// Orders symbols according to their positions in the GOT, +// in compliance with MIPS ABI rules. +// See "Global Offset Table" in Chapter 5 in the following document +// for detailed description: +// ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/mipsabi.pdf +static bool sortMipsSymbols(const std::pair<SymbolBody *, unsigned> &L, + const std::pair<SymbolBody *, unsigned> &R) { + // Sort entries related to non-local preemptible symbols by GOT indexes. + // All other entries go to the first part of GOT in arbitrary order. + bool LIsInLocalGot = !L.first->IsInGlobalMipsGot; + bool RIsInLocalGot = !R.first->IsInGlobalMipsGot; + if (LIsInLocalGot || RIsInLocalGot) + return !RIsInLocalGot; + return L.first->GotIndex < R.first->GotIndex; +} + +static uint8_t getSymbolBinding(SymbolBody *Body) { + Symbol *S = Body->symbol(); + uint8_t Visibility = S->Visibility; + if (Visibility != STV_DEFAULT && Visibility != STV_PROTECTED) + return STB_LOCAL; + if (Config->NoGnuUnique && S->Binding == STB_GNU_UNIQUE) + return STB_GLOBAL; + return S->Binding; +} + +template <class ELFT> void SymbolTableSection<ELFT>::finalize() { + if (this->Header.sh_size) + return; // Already finalized. + + this->Header.sh_size = getNumSymbols() * sizeof(Elf_Sym); + this->Header.sh_link = StrTabSec.SectionIndex; + this->Header.sh_info = NumLocals + 1; + + if (Config->Relocatable) { + size_t I = NumLocals; + for (const std::pair<SymbolBody *, size_t> &P : Symbols) + P.first->DynsymIndex = ++I; + return; + } + + if (!StrTabSec.isDynamic()) { + std::stable_sort(Symbols.begin(), Symbols.end(), + [](const std::pair<SymbolBody *, unsigned> &L, + const std::pair<SymbolBody *, unsigned> &R) { + return getSymbolBinding(L.first) == STB_LOCAL && + getSymbolBinding(R.first) != STB_LOCAL; + }); + return; + } + if (Out<ELFT>::GnuHashTab) + // NB: It also sorts Symbols to meet the GNU hash table requirements. + Out<ELFT>::GnuHashTab->addSymbols(Symbols); + else if (Config->EMachine == EM_MIPS) + std::stable_sort(Symbols.begin(), Symbols.end(), sortMipsSymbols); + size_t I = 0; + for (const std::pair<SymbolBody *, size_t> &P : Symbols) + P.first->DynsymIndex = ++I; +} + +template <class ELFT> +void SymbolTableSection<ELFT>::addSymbol(SymbolBody *B) { + Symbols.push_back({B, StrTabSec.addString(B->getName(), false)}); +} + +template <class ELFT> void SymbolTableSection<ELFT>::writeTo(uint8_t *Buf) { + Buf += sizeof(Elf_Sym); + + // All symbols with STB_LOCAL binding precede the weak and global symbols. + // .dynsym only contains global symbols. + if (!Config->DiscardAll && !StrTabSec.isDynamic()) + writeLocalSymbols(Buf); + + writeGlobalSymbols(Buf); +} + +template <class ELFT> +void SymbolTableSection<ELFT>::writeLocalSymbols(uint8_t *&Buf) { + // Iterate over all input object files to copy their local symbols + // to the output symbol table pointed by Buf. + for (const std::unique_ptr<ObjectFile<ELFT>> &File : + Symtab<ELFT>::X->getObjectFiles()) { + for (const std::pair<const DefinedRegular<ELFT> *, size_t> &P : + File->KeptLocalSyms) { + const DefinedRegular<ELFT> &Body = *P.first; + InputSectionBase<ELFT> *Section = Body.Section; + auto *ESym = reinterpret_cast<Elf_Sym *>(Buf); + + if (!Section) { + ESym->st_shndx = SHN_ABS; + ESym->st_value = Body.Value; + } else { + const OutputSectionBase<ELFT> *OutSec = Section->OutSec; + ESym->st_shndx = OutSec->SectionIndex; + ESym->st_value = OutSec->getVA() + Section->getOffset(Body); + } + ESym->st_name = P.second; + ESym->st_size = Body.template getSize<ELFT>(); + ESym->setBindingAndType(STB_LOCAL, Body.Type); + Buf += sizeof(*ESym); + } + } +} + +template <class ELFT> +void SymbolTableSection<ELFT>::writeGlobalSymbols(uint8_t *Buf) { + // Write the internal symbol table contents to the output symbol table + // pointed by Buf. + auto *ESym = reinterpret_cast<Elf_Sym *>(Buf); + for (const std::pair<SymbolBody *, size_t> &P : Symbols) { + SymbolBody *Body = P.first; + size_t StrOff = P.second; + + uint8_t Type = Body->Type; + uintX_t Size = Body->getSize<ELFT>(); + + ESym->setBindingAndType(getSymbolBinding(Body), Type); + ESym->st_size = Size; + ESym->st_name = StrOff; + ESym->setVisibility(Body->symbol()->Visibility); + ESym->st_value = Body->getVA<ELFT>(); + + if (const OutputSectionBase<ELFT> *OutSec = getOutputSection(Body)) + ESym->st_shndx = OutSec->SectionIndex; + else if (isa<DefinedRegular<ELFT>>(Body)) + ESym->st_shndx = SHN_ABS; + + // On MIPS we need to mark symbol which has a PLT entry and requires pointer + // equality by STO_MIPS_PLT flag. That is necessary to help dynamic linker + // distinguish such symbols and MIPS lazy-binding stubs. + // https://sourceware.org/ml/binutils/2008-07/txt00000.txt + if (Config->EMachine == EM_MIPS && Body->isInPlt() && + Body->NeedsCopyOrPltAddr) + ESym->st_other |= STO_MIPS_PLT; + ++ESym; + } +} + +template <class ELFT> +const OutputSectionBase<ELFT> * +SymbolTableSection<ELFT>::getOutputSection(SymbolBody *Sym) { + switch (Sym->kind()) { + case SymbolBody::DefinedSyntheticKind: + return cast<DefinedSynthetic<ELFT>>(Sym)->Section; + case SymbolBody::DefinedRegularKind: { + auto &D = cast<DefinedRegular<ELFT>>(*Sym); + if (D.Section) + return D.Section->OutSec; + break; + } + case SymbolBody::DefinedCommonKind: + return Out<ELFT>::Bss; + case SymbolBody::SharedKind: + if (cast<SharedSymbol<ELFT>>(Sym)->needsCopy()) + return Out<ELFT>::Bss; + break; + case SymbolBody::UndefinedKind: + case SymbolBody::LazyArchiveKind: + case SymbolBody::LazyObjectKind: + break; + case SymbolBody::DefinedBitcodeKind: + llvm_unreachable("should have been replaced"); + } + return nullptr; +} + +template <class ELFT> +VersionDefinitionSection<ELFT>::VersionDefinitionSection() + : OutputSectionBase<ELFT>(".gnu.version_d", SHT_GNU_verdef, SHF_ALLOC) { + this->Header.sh_addralign = sizeof(uint32_t); +} + +static StringRef getFileDefName() { + if (!Config->SoName.empty()) + return Config->SoName; + return Config->OutputFile; +} + +template <class ELFT> void VersionDefinitionSection<ELFT>::finalize() { + FileDefNameOff = Out<ELFT>::DynStrTab->addString(getFileDefName()); + for (VersionDefinition &V : Config->VersionDefinitions) + V.NameOff = Out<ELFT>::DynStrTab->addString(V.Name); + + this->Header.sh_size = + (sizeof(Elf_Verdef) + sizeof(Elf_Verdaux)) * getVerDefNum(); + this->Header.sh_link = Out<ELFT>::DynStrTab->SectionIndex; + + // sh_info should be set to the number of definitions. This fact is missed in + // documentation, but confirmed by binutils community: + // https://sourceware.org/ml/binutils/2014-11/msg00355.html + this->Header.sh_info = getVerDefNum(); +} + +template <class ELFT> +void VersionDefinitionSection<ELFT>::writeOne(uint8_t *Buf, uint32_t Index, + StringRef Name, size_t NameOff) { + auto *Verdef = reinterpret_cast<Elf_Verdef *>(Buf); + Verdef->vd_version = 1; + Verdef->vd_cnt = 1; + Verdef->vd_aux = sizeof(Elf_Verdef); + Verdef->vd_next = sizeof(Elf_Verdef) + sizeof(Elf_Verdaux); + Verdef->vd_flags = (Index == 1 ? VER_FLG_BASE : 0); + Verdef->vd_ndx = Index; + Verdef->vd_hash = hashSysv(Name); + + auto *Verdaux = reinterpret_cast<Elf_Verdaux *>(Buf + sizeof(Elf_Verdef)); + Verdaux->vda_name = NameOff; + Verdaux->vda_next = 0; +} + +template <class ELFT> +void VersionDefinitionSection<ELFT>::writeTo(uint8_t *Buf) { + writeOne(Buf, 1, getFileDefName(), FileDefNameOff); + + for (VersionDefinition &V : Config->VersionDefinitions) { + Buf += sizeof(Elf_Verdef) + sizeof(Elf_Verdaux); + writeOne(Buf, V.Id, V.Name, V.NameOff); + } + + // Need to terminate the last version definition. + Elf_Verdef *Verdef = reinterpret_cast<Elf_Verdef *>(Buf); + Verdef->vd_next = 0; +} + +template <class ELFT> +VersionTableSection<ELFT>::VersionTableSection() + : OutputSectionBase<ELFT>(".gnu.version", SHT_GNU_versym, SHF_ALLOC) { + this->Header.sh_addralign = sizeof(uint16_t); +} + +template <class ELFT> void VersionTableSection<ELFT>::finalize() { + this->Header.sh_size = + sizeof(Elf_Versym) * (Out<ELFT>::DynSymTab->getSymbols().size() + 1); + this->Header.sh_entsize = sizeof(Elf_Versym); + // At the moment of june 2016 GNU docs does not mention that sh_link field + // should be set, but Sun docs do. Also readelf relies on this field. + this->Header.sh_link = Out<ELFT>::DynSymTab->SectionIndex; +} + +template <class ELFT> void VersionTableSection<ELFT>::writeTo(uint8_t *Buf) { + auto *OutVersym = reinterpret_cast<Elf_Versym *>(Buf) + 1; + for (const std::pair<SymbolBody *, size_t> &P : + Out<ELFT>::DynSymTab->getSymbols()) { + OutVersym->vs_index = P.first->symbol()->VersionId; + ++OutVersym; + } +} + +template <class ELFT> +VersionNeedSection<ELFT>::VersionNeedSection() + : OutputSectionBase<ELFT>(".gnu.version_r", SHT_GNU_verneed, SHF_ALLOC) { + this->Header.sh_addralign = sizeof(uint32_t); + + // Identifiers in verneed section start at 2 because 0 and 1 are reserved + // for VER_NDX_LOCAL and VER_NDX_GLOBAL. + // First identifiers are reserved by verdef section if it exist. + NextIndex = getVerDefNum() + 1; +} + +template <class ELFT> +void VersionNeedSection<ELFT>::addSymbol(SharedSymbol<ELFT> *SS) { + if (!SS->Verdef) { + SS->symbol()->VersionId = VER_NDX_GLOBAL; + return; + } + SharedFile<ELFT> *F = SS->file(); + // If we don't already know that we need an Elf_Verneed for this DSO, prepare + // to create one by adding it to our needed list and creating a dynstr entry + // for the soname. + if (F->VerdefMap.empty()) + Needed.push_back({F, Out<ELFT>::DynStrTab->addString(F->getSoName())}); + typename SharedFile<ELFT>::NeededVer &NV = F->VerdefMap[SS->Verdef]; + // If we don't already know that we need an Elf_Vernaux for this Elf_Verdef, + // prepare to create one by allocating a version identifier and creating a + // dynstr entry for the version name. + if (NV.Index == 0) { + NV.StrTab = Out<ELFT>::DynStrTab->addString( + SS->file()->getStringTable().data() + SS->Verdef->getAux()->vda_name); + NV.Index = NextIndex++; + } + SS->symbol()->VersionId = NV.Index; +} + +template <class ELFT> void VersionNeedSection<ELFT>::writeTo(uint8_t *Buf) { + // The Elf_Verneeds need to appear first, followed by the Elf_Vernauxs. + auto *Verneed = reinterpret_cast<Elf_Verneed *>(Buf); + auto *Vernaux = reinterpret_cast<Elf_Vernaux *>(Verneed + Needed.size()); + + for (std::pair<SharedFile<ELFT> *, size_t> &P : Needed) { + // Create an Elf_Verneed for this DSO. + Verneed->vn_version = 1; + Verneed->vn_cnt = P.first->VerdefMap.size(); + Verneed->vn_file = P.second; + Verneed->vn_aux = + reinterpret_cast<char *>(Vernaux) - reinterpret_cast<char *>(Verneed); + Verneed->vn_next = sizeof(Elf_Verneed); + ++Verneed; + + // Create the Elf_Vernauxs for this Elf_Verneed. The loop iterates over + // VerdefMap, which will only contain references to needed version + // definitions. Each Elf_Vernaux is based on the information contained in + // the Elf_Verdef in the source DSO. This loop iterates over a std::map of + // pointers, but is deterministic because the pointers refer to Elf_Verdef + // data structures within a single input file. + for (auto &NV : P.first->VerdefMap) { + Vernaux->vna_hash = NV.first->vd_hash; + Vernaux->vna_flags = 0; + Vernaux->vna_other = NV.second.Index; + Vernaux->vna_name = NV.second.StrTab; + Vernaux->vna_next = sizeof(Elf_Vernaux); + ++Vernaux; + } + + Vernaux[-1].vna_next = 0; + } + Verneed[-1].vn_next = 0; +} + +template <class ELFT> void VersionNeedSection<ELFT>::finalize() { + this->Header.sh_link = Out<ELFT>::DynStrTab->SectionIndex; + this->Header.sh_info = Needed.size(); + unsigned Size = Needed.size() * sizeof(Elf_Verneed); + for (std::pair<SharedFile<ELFT> *, size_t> &P : Needed) + Size += P.first->VerdefMap.size() * sizeof(Elf_Vernaux); + this->Header.sh_size = Size; +} + +template <class ELFT> +BuildIdSection<ELFT>::BuildIdSection(size_t HashSize) + : OutputSectionBase<ELFT>(".note.gnu.build-id", SHT_NOTE, SHF_ALLOC), + HashSize(HashSize) { + // 16 bytes for the note section header. + this->Header.sh_size = 16 + HashSize; +} + +template <class ELFT> void BuildIdSection<ELFT>::writeTo(uint8_t *Buf) { + const endianness E = ELFT::TargetEndianness; + write32<E>(Buf, 4); // Name size + write32<E>(Buf + 4, HashSize); // Content size + write32<E>(Buf + 8, NT_GNU_BUILD_ID); // Type + memcpy(Buf + 12, "GNU", 4); // Name string + HashBuf = Buf + 16; +} + +template <class ELFT> +void BuildIdFnv1<ELFT>::writeBuildId(ArrayRef<ArrayRef<uint8_t>> Bufs) { + const endianness E = ELFT::TargetEndianness; + + // 64-bit FNV-1 hash + uint64_t Hash = 0xcbf29ce484222325; + for (ArrayRef<uint8_t> Buf : Bufs) { + for (uint8_t B : Buf) { + Hash *= 0x100000001b3; + Hash ^= B; + } + } + write64<E>(this->HashBuf, Hash); +} + +template <class ELFT> +void BuildIdMd5<ELFT>::writeBuildId(ArrayRef<ArrayRef<uint8_t>> Bufs) { + MD5 Hash; + for (ArrayRef<uint8_t> Buf : Bufs) + Hash.update(Buf); + MD5::MD5Result Res; + Hash.final(Res); + memcpy(this->HashBuf, Res, 16); +} + +template <class ELFT> +void BuildIdSha1<ELFT>::writeBuildId(ArrayRef<ArrayRef<uint8_t>> Bufs) { + SHA1 Hash; + for (ArrayRef<uint8_t> Buf : Bufs) + Hash.update(Buf); + memcpy(this->HashBuf, Hash.final().data(), 20); +} + +template <class ELFT> +BuildIdHexstring<ELFT>::BuildIdHexstring() + : BuildIdSection<ELFT>(Config->BuildIdVector.size()) {} + +template <class ELFT> +void BuildIdHexstring<ELFT>::writeBuildId(ArrayRef<ArrayRef<uint8_t>> Bufs) { + memcpy(this->HashBuf, Config->BuildIdVector.data(), + Config->BuildIdVector.size()); +} + +template <class ELFT> +MipsReginfoOutputSection<ELFT>::MipsReginfoOutputSection() + : OutputSectionBase<ELFT>(".reginfo", SHT_MIPS_REGINFO, SHF_ALLOC) { + this->Header.sh_addralign = 4; + this->Header.sh_entsize = sizeof(Elf_Mips_RegInfo); + this->Header.sh_size = sizeof(Elf_Mips_RegInfo); +} + +template <class ELFT> +void MipsReginfoOutputSection<ELFT>::writeTo(uint8_t *Buf) { + auto *R = reinterpret_cast<Elf_Mips_RegInfo *>(Buf); + R->ri_gp_value = Out<ELFT>::Got->getVA() + MipsGPOffset; + R->ri_gprmask = GprMask; +} + +template <class ELFT> +void MipsReginfoOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) { + // Copy input object file's .reginfo gprmask to output. + auto *S = cast<MipsReginfoInputSection<ELFT>>(C); + GprMask |= S->Reginfo->ri_gprmask; + S->OutSec = this; +} + +template <class ELFT> +MipsOptionsOutputSection<ELFT>::MipsOptionsOutputSection() + : OutputSectionBase<ELFT>(".MIPS.options", SHT_MIPS_OPTIONS, + SHF_ALLOC | SHF_MIPS_NOSTRIP) { + this->Header.sh_addralign = 8; + this->Header.sh_entsize = 1; + this->Header.sh_size = sizeof(Elf_Mips_Options) + sizeof(Elf_Mips_RegInfo); +} + +template <class ELFT> +void MipsOptionsOutputSection<ELFT>::writeTo(uint8_t *Buf) { + auto *Opt = reinterpret_cast<Elf_Mips_Options *>(Buf); + Opt->kind = ODK_REGINFO; + Opt->size = this->Header.sh_size; + Opt->section = 0; + Opt->info = 0; + auto *Reg = reinterpret_cast<Elf_Mips_RegInfo *>(Buf + sizeof(*Opt)); + Reg->ri_gp_value = Out<ELFT>::Got->getVA() + MipsGPOffset; + Reg->ri_gprmask = GprMask; +} + +template <class ELFT> +void MipsOptionsOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) { + auto *S = cast<MipsOptionsInputSection<ELFT>>(C); + if (S->Reginfo) + GprMask |= S->Reginfo->ri_gprmask; + S->OutSec = this; +} + +template <class ELFT> +std::pair<OutputSectionBase<ELFT> *, bool> +OutputSectionFactory<ELFT>::create(InputSectionBase<ELFT> *C, + StringRef OutsecName) { + SectionKey<ELFT::Is64Bits> Key = createKey(C, OutsecName); + OutputSectionBase<ELFT> *&Sec = Map[Key]; + if (Sec) + return {Sec, false}; + + switch (C->SectionKind) { + case InputSectionBase<ELFT>::Regular: + Sec = new OutputSection<ELFT>(Key.Name, Key.Type, Key.Flags); + break; + case InputSectionBase<ELFT>::EHFrame: + return {Out<ELFT>::EhFrame, false}; + case InputSectionBase<ELFT>::Merge: + Sec = new MergeOutputSection<ELFT>(Key.Name, Key.Type, Key.Flags, + Key.Alignment); + break; + case InputSectionBase<ELFT>::MipsReginfo: + Sec = new MipsReginfoOutputSection<ELFT>(); + break; + case InputSectionBase<ELFT>::MipsOptions: + Sec = new MipsOptionsOutputSection<ELFT>(); + break; + } + return {Sec, true}; +} + +template <class ELFT> +OutputSectionBase<ELFT> *OutputSectionFactory<ELFT>::lookup(StringRef Name, + uint32_t Type, + uintX_t Flags) { + return Map.lookup({Name, Type, Flags, 0}); +} + +template <class ELFT> +SectionKey<ELFT::Is64Bits> +OutputSectionFactory<ELFT>::createKey(InputSectionBase<ELFT> *C, + StringRef OutsecName) { + const Elf_Shdr *H = C->getSectionHdr(); + uintX_t Flags = H->sh_flags & ~SHF_GROUP & ~SHF_COMPRESSED; + + // For SHF_MERGE we create different output sections for each alignment. + // This makes each output section simple and keeps a single level mapping from + // input to output. + uintX_t Alignment = 0; + if (isa<MergeInputSection<ELFT>>(C)) + Alignment = std::max(H->sh_addralign, H->sh_entsize); + + uint32_t Type = H->sh_type; + return SectionKey<ELFT::Is64Bits>{OutsecName, Type, Flags, Alignment}; +} + +template <bool Is64Bits> +typename lld::elf::SectionKey<Is64Bits> +DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::getEmptyKey() { + return SectionKey<Is64Bits>{DenseMapInfo<StringRef>::getEmptyKey(), 0, 0, 0}; +} + +template <bool Is64Bits> +typename lld::elf::SectionKey<Is64Bits> +DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::getTombstoneKey() { + return SectionKey<Is64Bits>{DenseMapInfo<StringRef>::getTombstoneKey(), 0, 0, + 0}; +} + +template <bool Is64Bits> +unsigned +DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::getHashValue(const Key &Val) { + return hash_combine(Val.Name, Val.Type, Val.Flags, Val.Alignment); +} + +template <bool Is64Bits> +bool DenseMapInfo<lld::elf::SectionKey<Is64Bits>>::isEqual(const Key &LHS, + const Key &RHS) { + return DenseMapInfo<StringRef>::isEqual(LHS.Name, RHS.Name) && + LHS.Type == RHS.Type && LHS.Flags == RHS.Flags && + LHS.Alignment == RHS.Alignment; +} + +namespace llvm { +template struct DenseMapInfo<SectionKey<true>>; +template struct DenseMapInfo<SectionKey<false>>; +} + +namespace lld { +namespace elf { +template class OutputSectionBase<ELF32LE>; +template class OutputSectionBase<ELF32BE>; +template class OutputSectionBase<ELF64LE>; +template class OutputSectionBase<ELF64BE>; + +template class EhFrameHeader<ELF32LE>; +template class EhFrameHeader<ELF32BE>; +template class EhFrameHeader<ELF64LE>; +template class EhFrameHeader<ELF64BE>; + +template class GotPltSection<ELF32LE>; +template class GotPltSection<ELF32BE>; +template class GotPltSection<ELF64LE>; +template class GotPltSection<ELF64BE>; + +template class GotSection<ELF32LE>; +template class GotSection<ELF32BE>; +template class GotSection<ELF64LE>; +template class GotSection<ELF64BE>; + +template class PltSection<ELF32LE>; +template class PltSection<ELF32BE>; +template class PltSection<ELF64LE>; +template class PltSection<ELF64BE>; + +template class RelocationSection<ELF32LE>; +template class RelocationSection<ELF32BE>; +template class RelocationSection<ELF64LE>; +template class RelocationSection<ELF64BE>; + +template class InterpSection<ELF32LE>; +template class InterpSection<ELF32BE>; +template class InterpSection<ELF64LE>; +template class InterpSection<ELF64BE>; + +template class GnuHashTableSection<ELF32LE>; +template class GnuHashTableSection<ELF32BE>; +template class GnuHashTableSection<ELF64LE>; +template class GnuHashTableSection<ELF64BE>; + +template class HashTableSection<ELF32LE>; +template class HashTableSection<ELF32BE>; +template class HashTableSection<ELF64LE>; +template class HashTableSection<ELF64BE>; + +template class DynamicSection<ELF32LE>; +template class DynamicSection<ELF32BE>; +template class DynamicSection<ELF64LE>; +template class DynamicSection<ELF64BE>; + +template class OutputSection<ELF32LE>; +template class OutputSection<ELF32BE>; +template class OutputSection<ELF64LE>; +template class OutputSection<ELF64BE>; + +template class EhOutputSection<ELF32LE>; +template class EhOutputSection<ELF32BE>; +template class EhOutputSection<ELF64LE>; +template class EhOutputSection<ELF64BE>; + +template class MipsReginfoOutputSection<ELF32LE>; +template class MipsReginfoOutputSection<ELF32BE>; +template class MipsReginfoOutputSection<ELF64LE>; +template class MipsReginfoOutputSection<ELF64BE>; + +template class MipsOptionsOutputSection<ELF32LE>; +template class MipsOptionsOutputSection<ELF32BE>; +template class MipsOptionsOutputSection<ELF64LE>; +template class MipsOptionsOutputSection<ELF64BE>; + +template class MergeOutputSection<ELF32LE>; +template class MergeOutputSection<ELF32BE>; +template class MergeOutputSection<ELF64LE>; +template class MergeOutputSection<ELF64BE>; + +template class StringTableSection<ELF32LE>; +template class StringTableSection<ELF32BE>; +template class StringTableSection<ELF64LE>; +template class StringTableSection<ELF64BE>; + +template class SymbolTableSection<ELF32LE>; +template class SymbolTableSection<ELF32BE>; +template class SymbolTableSection<ELF64LE>; +template class SymbolTableSection<ELF64BE>; + +template class VersionTableSection<ELF32LE>; +template class VersionTableSection<ELF32BE>; +template class VersionTableSection<ELF64LE>; +template class VersionTableSection<ELF64BE>; + +template class VersionNeedSection<ELF32LE>; +template class VersionNeedSection<ELF32BE>; +template class VersionNeedSection<ELF64LE>; +template class VersionNeedSection<ELF64BE>; + +template class VersionDefinitionSection<ELF32LE>; +template class VersionDefinitionSection<ELF32BE>; +template class VersionDefinitionSection<ELF64LE>; +template class VersionDefinitionSection<ELF64BE>; + +template class BuildIdSection<ELF32LE>; +template class BuildIdSection<ELF32BE>; +template class BuildIdSection<ELF64LE>; +template class BuildIdSection<ELF64BE>; + +template class BuildIdFnv1<ELF32LE>; +template class BuildIdFnv1<ELF32BE>; +template class BuildIdFnv1<ELF64LE>; +template class BuildIdFnv1<ELF64BE>; + +template class BuildIdMd5<ELF32LE>; +template class BuildIdMd5<ELF32BE>; +template class BuildIdMd5<ELF64LE>; +template class BuildIdMd5<ELF64BE>; + +template class BuildIdSha1<ELF32LE>; +template class BuildIdSha1<ELF32BE>; +template class BuildIdSha1<ELF64LE>; +template class BuildIdSha1<ELF64BE>; + +template class BuildIdHexstring<ELF32LE>; +template class BuildIdHexstring<ELF32BE>; +template class BuildIdHexstring<ELF64LE>; +template class BuildIdHexstring<ELF64BE>; + +template class OutputSectionFactory<ELF32LE>; +template class OutputSectionFactory<ELF32BE>; +template class OutputSectionFactory<ELF64LE>; +template class OutputSectionFactory<ELF64BE>; +} +} |