Make sure the .eh_frame ends with a terminator. This avoids creating a

zero-sized .eh_frame section, which confuses the strip from our
frankenbinutils.

With this diff lld seems to be usable as the arm64 system linker.

ok patrick@, jsg@

1 files changed, 310 insertions, 1563 deletions

diff --git a/gnu/llvm/tools/lld/ELF/OutputSections.cpp b/gnu/llvm/tools/lld/ELF/OutputSections.cpp
index 50b94015f22..edcc0f186b3 100644
--- a/gnu/llvm/tools/lld/ELF/OutputSections.cpp
+++ b/gnu/llvm/tools/lld/ELF/OutputSections.cpp
@@ -11,15 +11,16 @@
 #include "Config.h"
 #include "EhFrame.h"
 #include "LinkerScript.h"
+#include "Memory.h"
 #include "Strings.h"
 #include "SymbolTable.h"
+#include "SyntheticSections.h"
 #include "Target.h"
-#include "lld/Core/Parallel.h"
+#include "Threads.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;
@@ -30,855 +31,152 @@ 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)
+OutputSectionBase::OutputSectionBase(StringRef Name, uint32_t Type,
+                                     uint64_t Flags)
     : Name(Name) {
-  memset(&Header, 0, sizeof(Elf_Shdr));
-  Header.sh_type = Type;
-  Header.sh_flags = Flags;
-  Header.sh_addralign = 1;
+  this->Type = Type;
+  this->Flags = Flags;
+  this->Addralign = 1;
 }
 
-template <class ELFT>
-void OutputSectionBase<ELFT>::writeHeaderTo(Elf_Shdr *Shdr) {
-  *Shdr = Header;
+uint32_t OutputSectionBase::getPhdrFlags() const {
+  uint32_t Ret = PF_R;
+  if (Flags & SHF_WRITE)
+    Ret |= PF_W;
+  if (Flags & SHF_EXECINSTR)
+    Ret |= PF_X;
+  return Ret;
 }
 
 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);
+void OutputSectionBase::writeHeaderTo(typename ELFT::Shdr *Shdr) {
+  Shdr->sh_entsize = Entsize;
+  Shdr->sh_addralign = Addralign;
+  Shdr->sh_type = Type;
+  Shdr->sh_offset = Offset;
+  Shdr->sh_flags = Flags;
+  Shdr->sh_info = Info;
+  Shdr->sh_link = Link;
+  Shdr->sh_addr = Addr;
+  Shdr->sh_size = Size;
+  Shdr->sh_name = ShName;
+}
+
+template <class ELFT> static uint64_t getEntsize(uint32_t Type) {
+  switch (Type) {
+  case SHT_RELA:
+    return sizeof(typename ELFT::Rela);
+  case SHT_REL:
+    return sizeof(typename ELFT::Rel);
+  case SHT_MIPS_REGINFO:
+    return sizeof(Elf_Mips_RegInfo<ELFT>);
+  case SHT_MIPS_OPTIONS:
+    return sizeof(Elf_Mips_Options<ELFT>) + sizeof(Elf_Mips_RegInfo<ELFT>);
+  case SHT_MIPS_ABIFLAGS:
+    return sizeof(Elf_Mips_ABIFlags<ELFT>);
+  default:
+    return 0;
   }
 }
 
 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;
+OutputSection<ELFT>::OutputSection(StringRef Name, uint32_t Type, uintX_t Flags)
+    : OutputSectionBase(Name, Type, Flags) {
+  this->Entsize = getEntsize<ELFT>(Type);
 }
 
-// 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))
+template <typename ELFT>
+static bool compareByFilePosition(InputSection<ELFT> *A,
+                                  InputSection<ELFT> *B) {
+  // Synthetic doesn't have link order dependecy, stable_sort will keep it last
+  if (A->kind() == InputSectionData::Synthetic ||
+      B->kind() == InputSectionData::Synthetic)
     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);
+  auto *LA = cast<InputSection<ELFT>>(A->getLinkOrderDep());
+  auto *LB = cast<InputSection<ELFT>>(B->getLinkOrderDep());
+  OutputSectionBase *AOut = LA->OutSec;
+  OutputSectionBase *BOut = LB->OutSec;
+  if (AOut != BOut)
+    return AOut->SectionIndex < BOut->SectionIndex;
+  return LA->OutSecOff < LB->OutSecOff;
 }
 
-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 OutputSection<ELFT>::finalize() {
+  if ((this->Flags & SHF_LINK_ORDER) && !this->Sections.empty()) {
+    std::sort(Sections.begin(), Sections.end(), compareByFilePosition<ELFT>);
+    Size = 0;
+    assignOffsets();
 
-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;
+    // We must preserve the link order dependency of sections with the
+    // SHF_LINK_ORDER flag. The dependency is indicated by the sh_link field. We
+    // need to translate the InputSection sh_link to the OutputSection sh_link,
+    // all InputSections in the OutputSection have the same dependency.
+    if (auto *D = this->Sections.front()->getLinkOrderDep())
+      this->Link = D->OutSec->SectionIndex;
   }
-  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())
+  uint32_t Type = this->Type;
+  if (!Config->Relocatable || (Type != SHT_RELA && Type != SHT_REL))
     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;
+  this->Link = In<ELFT>::SymTab->OutSec->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;
+  this->Info = S->OutSec->SectionIndex;
 }
 
 template <class ELFT>
-void OutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
+void OutputSection<ELFT>::addSection(InputSectionData *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;
+  // Keep sh_entsize value of the input section to be able to perform merging
+  // later during a final linking using the generated relocatable object.
+  if (Config->Relocatable && (S->Flags & SHF_MERGE))
+    this->Entsize = S->Entsize;
 }
 
 // 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;
+  uintX_t Off = this->Size;
   for (InputSection<ELFT> *S : Sections) {
     Off = alignTo(Off, S->Alignment);
     S->OutSecOff = Off;
     Off += S->getSize();
   }
-  this->Header.sh_size = Off;
+  this->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;
+template <class ELFT>
+void OutputSection<ELFT>::sort(
+    std::function<int(InputSection<ELFT> *S)> Order) {
+  typedef std::pair<unsigned, 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});
+    V.push_back({Order(S), S});
   std::stable_sort(V.begin(), V.end(), Comp);
   Sections.clear();
   for (Pair &P : V)
     Sections.push_back(P.second);
 }
 
+// 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.
+  sort([](InputSection<ELFT> *S) { return getPriority(S->Name); });
+}
+
 // Returns true if S matches /Filename.?\.o$/.
 static bool isCrtBeginEnd(StringRef S, StringRef Filename) {
   if (!S.endswith(".o"))
@@ -921,8 +219,8 @@ static bool compCtors(const InputSection<ELFT> *A,
   bool EndB = isCrtend(B->getFile()->getName());
   if (EndA != EndB)
     return EndB;
-  StringRef X = A->getSectionName();
-  StringRef Y = B->getSectionName();
+  StringRef X = A->Name;
+  StringRef Y = B->Name;
   assert(X.startswith(".ctors") || X.startswith(".dtors"));
   assert(Y.startswith(".ctors") || Y.startswith(".dtors"));
   X = X.substr(6);
@@ -939,65 +237,50 @@ 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) {
+// Fill [Buf, Buf + Size) with Filler. Filler is written in big
+// endian order. This is used for linker script "=fillexp" command.
+void fill(uint8_t *Buf, size_t Size, uint32_t Filler) {
+  uint8_t V[4];
+  write32be(V, Filler);
   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);
+  for (; I + 4 < Size; I += 4)
+    memcpy(Buf + I, V, 4);
+  memcpy(Buf + I, V, 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);
-  }
+  Loc = Buf;
+  if (uint32_t Filler = Script<ELFT>::X->getFiller(this->Name))
+    fill(Buf, this->Size, Filler);
+
+  auto Fn = [=](InputSection<ELFT> *IS) { IS->writeTo(Buf); };
+  forEach(Sections.begin(), Sections.end(), Fn);
+
+  // Linker scripts may have BYTE()-family commands with which you
+  // can write arbitrary bytes to the output. Process them if any.
+  Script<ELFT>::X->writeDataBytes(this->Name, 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;
-}
+    : OutputSectionBase(".eh_frame", SHT_PROGBITS, SHF_ALLOC) {}
 
 // 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) {
+CieRecord *EhOutputSection<ELFT>::addCie(EhSectionPiece &Piece,
+                                         ArrayRef<RelTy> Rels) {
+  auto *Sec = cast<EhInputSection<ELFT>>(Piece.ID);
   const endianness E = ELFT::TargetEndianness;
   if (read32<E>(Piece.data().data() + 4) != 0)
-    fatal("CIE expected at beginning of .eh_frame: " + Sec->getSectionName());
+    fatal(toString(Sec) + ": CIE expected at beginning of .eh_frame");
 
   SymbolBody *Personality = nullptr;
-  if (const RelTy *Rel = getReloc(Piece.InputOff, Piece.size(), Rels))
-    Personality = &Sec->getFile()->getRelocTargetSym(*Rel);
+  unsigned FirstRelI = Piece.FirstRelocation;
+  if (FirstRelI != (unsigned)-1)
+    Personality = &Sec->getFile()->getRelocTargetSym(Rels[FirstRelI]);
 
   // Search for an existing CIE by CIE contents/relocation target pair.
   CieRecord *Cie = &CieMap[{Piece.data(), Personality}];
@@ -1014,13 +297,14 @@ CieRecord *EhOutputSection<ELFT>::addCie(SectionPiece &Piece,
 // 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);
+bool EhOutputSection<ELFT>::isFdeLive(EhSectionPiece &Piece,
+                                      ArrayRef<RelTy> Rels) {
+  auto *Sec = cast<EhInputSection<ELFT>>(Piece.ID);
+  unsigned FirstRelI = Piece.FirstRelocation;
+  if (FirstRelI == (unsigned)-1)
+    fatal(toString(Sec) + ": FDE doesn't reference another section");
+  const RelTy &Rel = Rels[FirstRelI];
+  SymbolBody &B = Sec->getFile()->getRelocTargetSym(Rel);
   auto *D = dyn_cast<DefinedRegular<ELFT>>(&B);
   if (!D || !D->Section)
     return false;
@@ -1039,7 +323,7 @@ void EhOutputSection<ELFT>::addSectionAux(EhInputSection<ELFT> *Sec,
   const endianness E = ELFT::TargetEndianness;
 
   DenseMap<size_t, CieRecord *> OffsetToCie;
-  for (SectionPiece &Piece : Sec->Pieces) {
+  for (EhSectionPiece &Piece : Sec->Pieces) {
     // The empty record is the end marker.
     if (Piece.size() == 4)
       return;
@@ -1047,16 +331,16 @@ void EhOutputSection<ELFT>::addSectionAux(EhInputSection<ELFT> *Sec,
     size_t Offset = Piece.InputOff;
     uint32_t ID = read32<E>(Piece.data().data() + 4);
     if (ID == 0) {
-      OffsetToCie[Offset] = addCie(Piece, Sec, Rels);
+      OffsetToCie[Offset] = addCie(Piece, Rels);
       continue;
     }
 
     uint32_t CieOffset = Offset + 4 - ID;
     CieRecord *Cie = OffsetToCie[CieOffset];
     if (!Cie)
-      fatal("invalid CIE reference");
+      fatal(toString(Sec) + ": invalid CIE reference");
 
-    if (!isFdeLive(Piece, Sec, Rels))
+    if (!isFdeLive(Piece, Rels))
       continue;
     Cie->FdePieces.push_back(&Piece);
     NumFdes++;
@@ -1064,7 +348,7 @@ void EhOutputSection<ELFT>::addSectionAux(EhInputSection<ELFT> *Sec,
 }
 
 template <class ELFT>
-void EhOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
+void EhOutputSection<ELFT>::addSection(InputSectionData *C) {
   auto *Sec = cast<EhInputSection<ELFT>>(C);
   Sec->OutSec = this;
   this->updateAlignment(Sec->Alignment);
@@ -1077,12 +361,11 @@ void EhOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
   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));
+  if (Sec->NumRelocations) {
+    if (Sec->AreRelocsRela)
+      addSectionAux(Sec, Sec->relas());
     else
-      addSectionAux(Sec, Obj.rels(RelSec));
+      addSectionAux(Sec, Sec->rels());
     return;
   }
   addSectionAux(Sec, makeArrayRef<Elf_Rela>(nullptr, nullptr));
@@ -1098,7 +381,7 @@ static void writeCieFde(uint8_t *Buf, ArrayRef<uint8_t> D) {
 }
 
 template <class ELFT> void EhOutputSection<ELFT>::finalize() {
-  if (this->Header.sh_size)
+  if (this->Size)
     return; // Already finalized.
 
   size_t Off = 0;
@@ -1106,12 +389,12 @@ template <class ELFT> void EhOutputSection<ELFT>::finalize() {
     Cie->Piece->OutputOff = Off;
     Off += alignTo(Cie->Piece->size(), sizeof(uintX_t));
 
-    for (SectionPiece *Fde : Cie->FdePieces) {
+    for (EhSectionPiece *Fde : Cie->FdePieces) {
       Fde->OutputOff = Off;
       Off += alignTo(Fde->size(), sizeof(uintX_t));
     }
   }
-  this->Header.sh_size = Off;
+  this->Size = Off + 4;
 }
 
 template <class ELFT> static uint64_t readFdeAddr(uint8_t *Buf, int Size) {
@@ -1143,7 +426,7 @@ typename ELFT::uint EhOutputSection<ELFT>::getFdePc(uint8_t *Buf, size_t FdeOff,
   if ((Enc & 0x70) == DW_EH_PE_absptr)
     return Addr;
   if ((Enc & 0x70) == DW_EH_PE_pcrel)
-    return Addr + this->getVA() + Off;
+    return Addr + this->Addr + Off;
   fatal("unknown FDE size relative encoding");
 }
 
@@ -1153,7 +436,7 @@ template <class ELFT> void EhOutputSection<ELFT>::writeTo(uint8_t *Buf) {
     size_t CieOffset = Cie->Piece->OutputOff;
     writeCieFde<ELFT>(Buf + CieOffset, Cie->Piece->data());
 
-    for (SectionPiece *Fde : Cie->FdePieces) {
+    for (EhSectionPiece *Fde : Cie->FdePieces) {
       size_t Off = Fde->OutputOff;
       writeCieFde<ELFT>(Buf + Off, Fde->data());
 
@@ -1169,13 +452,13 @@ template <class ELFT> void EhOutputSection<ELFT>::writeTo(uint8_t *Buf) {
   // 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) {
+  if (In<ELFT>::EhFrameHdr) {
     for (CieRecord *Cie : Cies) {
-      uint8_t Enc = getFdeEncoding<ELFT>(Cie->Piece->data());
+      uint8_t Enc = getFdeEncoding<ELFT>(Cie->Piece);
       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);
+        uintX_t FdeVA = this->Addr + Fde->OutputOff;
+        In<ELFT>::EhFrameHdr->addFde(Pc, FdeVA);
       }
     }
   }
@@ -1184,703 +467,227 @@ template <class ELFT> void EhOutputSection<ELFT>::writeTo(uint8_t *Buf) {
 template <class ELFT>
 MergeOutputSection<ELFT>::MergeOutputSection(StringRef Name, uint32_t Type,
                                              uintX_t Flags, uintX_t Alignment)
-    : OutputSectionBase<ELFT>(Name, Type, Flags),
+    : OutputSectionBase(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()};
+  Builder.write(Buf);
 }
 
 template <class ELFT>
-void MergeOutputSection<ELFT>::addSection(InputSectionBase<ELFT> *C) {
+void MergeOutputSection<ELFT>::addSection(InputSectionData *C) {
   auto *Sec = cast<MergeInputSection<ELFT>>(C);
   Sec->OutSec = this;
   this->updateAlignment(Sec->Alignment);
-  this->Header.sh_entsize = Sec->getSectionHdr()->sh_entsize;
+  this->Entsize = Sec->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;
+  return (this->Flags & SHF_STRINGS) && Config->Optimize >= 2;
 }
 
-template <class ELFT> void MergeOutputSection<ELFT>::finalize() {
-  if (shouldTailMerge())
-    Builder.finalize();
-  this->Header.sh_size = Builder.getSize();
-}
-
-template <class ELFT> void MergeOutputSection<ELFT>::finalizePieces() {
+template <class ELFT> void MergeOutputSection<ELFT>::finalizeTailMerge() {
+  // Add all string pieces to the string table builder to create section
+  // contents.
   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;
-}
+    for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
+      if (Sec->Pieces[I].Live)
+        Builder.add(Sec->getData(I));
 
-template <class ELFT>
-VersionTableSection<ELFT>::VersionTableSection()
-    : OutputSectionBase<ELFT>(".gnu.version", SHT_GNU_versym, SHF_ALLOC) {
-  this->Header.sh_addralign = sizeof(uint16_t);
-}
+  // Fix the string table content. After this, the contents will never change.
+  Builder.finalize();
+  this->Size = Builder.getSize();
 
-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;
+  // finalize() fixed tail-optimized strings, so we can now get
+  // offsets of strings. Get an offset for each string and save it
+  // to a corresponding StringPiece for easy access.
+  for (MergeInputSection<ELFT> *Sec : Sections)
+    for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
+      if (Sec->Pieces[I].Live)
+        Sec->Pieces[I].OutputOff = Builder.getOffset(Sec->getData(I));
 }
 
-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 MergeOutputSection<ELFT>::finalizeNoTailMerge() {
+  // Add all string pieces to the string table builder to create section
+  // contents. Because we are not tail-optimizing, offsets of strings are
+  // fixed when they are added to the builder (string table builder contains
+  // a hash table from strings to offsets).
+  for (MergeInputSection<ELFT> *Sec : Sections)
+    for (size_t I = 0, E = Sec->Pieces.size(); I != E; ++I)
+      if (Sec->Pieces[I].Live)
+        Sec->Pieces[I].OutputOff = Builder.add(Sec->getData(I));
 
-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);
+  Builder.finalizeInOrder();
+  this->Size = Builder.getSize();
 }
 
-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> void MergeOutputSection<ELFT>::finalize() {
+  if (shouldTailMerge())
+    finalizeTailMerge();
+  else
+    finalizeNoTailMerge();
 }
 
 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());
+static typename ELFT::uint getOutFlags(InputSectionBase<ELFT> *S) {
+  return S->Flags & ~SHF_GROUP & ~SHF_COMPRESSED;
 }
 
-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);
-}
+namespace llvm {
+template <> struct DenseMapInfo<lld::elf::SectionKey> {
+  static lld::elf::SectionKey getEmptyKey();
+  static lld::elf::SectionKey getTombstoneKey();
+  static unsigned getHashValue(const lld::elf::SectionKey &Val);
+  static bool isEqual(const lld::elf::SectionKey &LHS,
+                      const lld::elf::SectionKey &RHS);
+};
+}
+
+template <class ELFT>
+static SectionKey createKey(InputSectionBase<ELFT> *C, StringRef OutsecName) {
+  //  The ELF spec just says
+  // ----------------------------------------------------------------
+  // In the first phase, input sections that match in name, type and
+  // attribute flags should be concatenated into single sections.
+  // ----------------------------------------------------------------
+  //
+  // However, it is clear that at least some flags have to be ignored for
+  // section merging. At the very least SHF_GROUP and SHF_COMPRESSED have to be
+  // ignored. We should not have two output .text sections just because one was
+  // in a group and another was not for example.
+  //
+  // It also seems that that wording was a late addition and didn't get the
+  // necessary scrutiny.
+  //
+  // Merging sections with different flags is expected by some users. One
+  // reason is that if one file has
+  //
+  // int *const bar __attribute__((section(".foo"))) = (int *)0;
+  //
+  // gcc with -fPIC will produce a read only .foo section. But if another
+  // file has
+  //
+  // int zed;
+  // int *const bar __attribute__((section(".foo"))) = (int *)&zed;
+  //
+  // gcc with -fPIC will produce a read write section.
+  //
+  // Last but not least, when using linker script the merge rules are forced by
+  // the script. Unfortunately, linker scripts are name based. This means that
+  // expressions like *(.foo*) can refer to multiple input sections with
+  // different flags. We cannot put them in different output sections or we
+  // would produce wrong results for
+  //
+  // start = .; *(.foo.*) end = .; *(.bar)
+  //
+  // and a mapping of .foo1 and .bar1 to one section and .foo2 and .bar2 to
+  // another. The problem is that there is no way to layout those output
+  // sections such that the .foo sections are the only thing between the start
+  // and end symbols.
+  //
+  // Given the above issues, we instead merge sections by name and error on
+  // incompatible types and flags.
+  //
+  // The exception being SHF_MERGE, where we create different output sections
+  // for each alignment. This makes each output section simple. In case of
+  // relocatable object generation we do not try to perform merging and treat
+  // SHF_MERGE sections as regular ones, but also create different output
+  // sections for them to allow merging at final linking stage.
+  //
+  // Fortunately, creating symbols in the middle of a merge section is not
+  // supported by bfd or gold, so the SHF_MERGE exception should not cause
+  // problems with most linker scripts.
 
-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;
-}
+  typedef typename ELFT::uint uintX_t;
+  uintX_t Flags = C->Flags & (SHF_MERGE | SHF_STRINGS);
 
-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;
-}
+  uintX_t Alignment = 0;
+  if (isa<MergeInputSection<ELFT>>(C) ||
+      (Config->Relocatable && (C->Flags & SHF_MERGE)))
+    Alignment = std::max<uintX_t>(C->Alignment, C->Entsize);
 
-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);
+  return SectionKey{OutsecName, Flags, Alignment};
 }
 
-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> OutputSectionFactory<ELFT>::OutputSectionFactory() {}
 
-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> OutputSectionFactory<ELFT>::~OutputSectionFactory() {}
 
 template <class ELFT>
-std::pair<OutputSectionBase<ELFT> *, bool>
+std::pair<OutputSectionBase *, bool>
 OutputSectionFactory<ELFT>::create(InputSectionBase<ELFT> *C,
                                    StringRef OutsecName) {
-  SectionKey<ELFT::Is64Bits> Key = createKey(C, OutsecName);
-  OutputSectionBase<ELFT> *&Sec = Map[Key];
-  if (Sec)
+  SectionKey Key = createKey(C, OutsecName);
+  return create(Key, C);
+}
+
+static uint64_t getIncompatibleFlags(uint64_t Flags) {
+  return Flags & (SHF_ALLOC | SHF_TLS);
+}
+
+template <class ELFT>
+std::pair<OutputSectionBase *, bool>
+OutputSectionFactory<ELFT>::create(const SectionKey &Key,
+                                   InputSectionBase<ELFT> *C) {
+  uintX_t Flags = getOutFlags(C);
+  OutputSectionBase *&Sec = Map[Key];
+  if (Sec) {
+    if (getIncompatibleFlags(Sec->Flags) != getIncompatibleFlags(C->Flags))
+      error("Section has flags incompatible with others with the same name " +
+            toString(C));
+    // Convert notbits to progbits if they are mixed. This happens is some
+    // linker scripts.
+    if (Sec->Type == SHT_NOBITS && C->Type == SHT_PROGBITS)
+      Sec->Type = SHT_PROGBITS;
+    if (Sec->Type != C->Type &&
+        !(Sec->Type == SHT_PROGBITS && C->Type == SHT_NOBITS))
+      error("Section has different type from others with the same name " +
+            toString(C));
+    Sec->Flags |= Flags;
     return {Sec, false};
+  }
 
-  switch (C->SectionKind) {
+  uint32_t Type = C->Type;
+  switch (C->kind()) {
   case InputSectionBase<ELFT>::Regular:
-    Sec = new OutputSection<ELFT>(Key.Name, Key.Type, Key.Flags);
+  case InputSectionBase<ELFT>::Synthetic:
+    Sec = make<OutputSection<ELFT>>(Key.Name, Type, 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>();
+    Sec = make<MergeOutputSection<ELFT>>(Key.Name, Type, Flags, Key.Alignment);
     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});
+SectionKey DenseMapInfo<SectionKey>::getEmptyKey() {
+  return SectionKey{DenseMapInfo<StringRef>::getEmptyKey(), 0, 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};
+SectionKey DenseMapInfo<SectionKey>::getTombstoneKey() {
+  return SectionKey{DenseMapInfo<StringRef>::getTombstoneKey(), 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};
+unsigned DenseMapInfo<SectionKey>::getHashValue(const SectionKey &Val) {
+  return hash_combine(Val.Name, Val.Flags, Val.Alignment);
 }
 
-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) {
+bool DenseMapInfo<SectionKey>::isEqual(const SectionKey &LHS,
+                                       const SectionKey &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>>;
+         LHS.Flags == RHS.Flags && LHS.Alignment == RHS.Alignment;
 }
 
 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 void OutputSectionBase::writeHeaderTo<ELF32LE>(ELF32LE::Shdr *Shdr);
+template void OutputSectionBase::writeHeaderTo<ELF32BE>(ELF32BE::Shdr *Shdr);
+template void OutputSectionBase::writeHeaderTo<ELF64LE>(ELF64LE::Shdr *Shdr);
+template void OutputSectionBase::writeHeaderTo<ELF64BE>(ELF64BE::Shdr *Shdr);
 
 template class OutputSection<ELF32LE>;
 template class OutputSection<ELF32BE>;
@@ -1892,71 +699,11 @@ 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>;