[lld] r250182 - Revert r250169: "This patch implements basic variant of lazy loading for x86_x64 and for X86 targets."

Rui Ueyama via llvm-commits llvm-commits at lists.llvm.org
Tue Oct 13 09:59:32 PDT 2015


Author: ruiu
Date: Tue Oct 13 11:59:30 2015
New Revision: 250182

URL: http://llvm.org/viewvc/llvm-project?rev=250182&view=rev
Log:
Revert r250169: "This patch implements basic variant of lazy loading for x86_x64 and for X86 targets."

With this patch LLD is not able to self-host on x86-64 Linux.

Modified:
    lld/trunk/ELF/OutputSections.cpp
    lld/trunk/ELF/OutputSections.h
    lld/trunk/ELF/Symbols.h
    lld/trunk/ELF/Target.cpp
    lld/trunk/ELF/Target.h
    lld/trunk/ELF/Writer.cpp
    lld/trunk/test/elf2/plt-i686.s
    lld/trunk/test/elf2/plt.s
    lld/trunk/test/elf2/relocation-i686.s
    lld/trunk/test/elf2/relocation.s

Modified: lld/trunk/ELF/OutputSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.cpp?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.cpp (original)
+++ lld/trunk/ELF/OutputSections.cpp Tue Oct 13 11:59:30 2015
@@ -30,43 +30,6 @@ OutputSectionBase<Is64Bits>::OutputSecti
 }
 
 template <class ELFT>
-GotPltSection<ELFT>::GotPltSection()
-    : OutputSectionBase<ELFT::Is64Bits>(".got.plt", llvm::ELF::SHT_PROGBITS,
-                                        llvm::ELF::SHF_ALLOC |
-                                            llvm::ELF::SHF_WRITE) {
-  this->Header.sh_addralign = this->getAddrSize();
-  // .got.plt has 3 reserved entry
-  Entries.resize(3);
-}
-
-template <class ELFT> void GotPltSection<ELFT>::addEntry(SymbolBody *Sym) {
-  Sym->GotPltIndex = Entries.size();
-  Entries.push_back(Sym);
-}
-
-template <class ELFT> bool GotPltSection<ELFT>::empty() const {
-  return Entries.size() == 3;
-}
-
-template <class ELFT>
-typename GotPltSection<ELFT>::uintX_t
-GotPltSection<ELFT>::getEntryAddr(const SymbolBody &B) const {
-  return this->getVA() + B.GotPltIndex * this->getAddrSize();
-}
-
-template <class ELFT> void GotPltSection<ELFT>::finalize() {
-  this->Header.sh_size = Entries.size() * this->getAddrSize();
-}
-
-template <class ELFT> void GotPltSection<ELFT>::writeTo(uint8_t *Buf) {
-  for (const SymbolBody *B : Entries) {
-    if (B)
-      Target->writeGotPltEntry(Buf, Out<ELFT>::Plt->getEntryAddr(*B));
-    Buf += sizeof(uintX_t);
-  }
-}
-
-template <class ELFT>
 GotSection<ELFT>::GotSection()
     : OutputSectionBase<ELFT::Is64Bits>(".got", llvm::ELF::SHT_PROGBITS,
                                         llvm::ELF::SHF_ALLOC |
@@ -106,13 +69,10 @@ PltSection<ELFT>::PltSection()
 
 template <class ELFT> void PltSection<ELFT>::writeTo(uint8_t *Buf) {
   size_t Off = 0;
-  // First write PLT[0] entry which is special.
-  Target->writePltZeroEntry(Buf, Out<ELFT>::GotPlt->getVA(), this->getVA());
-  Off += Target->getPltZeroEntrySize();
   for (const SymbolBody *E : Entries) {
-    uint64_t Got = Out<ELFT>::GotPlt->getEntryAddr(*E);
+    uint64_t Got = Out<ELFT>::Got->getEntryAddr(*E);
     uint64_t Plt = this->getVA() + Off;
-    Target->writePltEntry(Buf + Off, Got, Plt, E->PltIndex);
+    Target->writePltEntry(Buf + Off, Got, Plt);
     Off += Target->getPltEntrySize();
   }
 }
@@ -125,20 +85,19 @@ template <class ELFT> void PltSection<EL
 template <class ELFT>
 typename PltSection<ELFT>::uintX_t
 PltSection<ELFT>::getEntryAddr(const SymbolBody &B) const {
-  return this->getVA() + Target->getPltZeroEntrySize() +
-         B.PltIndex * Target->getPltEntrySize();
+  return this->getVA() + B.PltIndex * Target->getPltEntrySize();
 }
 
 template <class ELFT>
 void PltSection<ELFT>::finalize() {
-  this->Header.sh_size =
-      Target->getPltZeroEntrySize() + Entries.size() * Target->getPltEntrySize();
+  this->Header.sh_size = Entries.size() * Target->getPltEntrySize();
 }
 
 template <class ELFT>
-RelocationSection<ELFT>::RelocationSection(StringRef Name, bool IsRela)
-    : OutputSectionBase<ELFT::Is64Bits>(Name, IsRela ? llvm::ELF::SHT_RELA
-                                                     : llvm::ELF::SHT_REL,
+RelocationSection<ELFT>::RelocationSection(bool IsRela)
+    : OutputSectionBase<ELFT::Is64Bits>(IsRela ? ".rela.dyn" : ".rel.dyn",
+                                        IsRela ? llvm::ELF::SHT_RELA
+                                               : llvm::ELF::SHT_REL,
                                         llvm::ELF::SHF_ALLOC),
       IsRela(IsRela) {
   this->Header.sh_entsize = IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel);
@@ -176,22 +135,10 @@ template <class ELFT> void RelocationSec
     }
 
     if (Body && Target->relocNeedsGot(Type, *Body)) {
-      // Each symbol that needs plt relocation is placed to Plt and GotPlt,
-      // otherwise to Got.
-      // Also symbol can be placed both to Got and Plt + GotPlt, for example
-      // when we take address of function from DSO and also make a call to it.
-      // So here depending on what type of relocation is we switch from which
-      // table to take the offset from.
-      bool NeedsPlt = Target->relocNeedsPlt(Type, *Body);
-      if (NeedsPlt)
-        P->r_offset = Out<ELFT>::GotPlt->getEntryAddr(*Body);
-      else
-        P->r_offset = Out<ELFT>::Got->getEntryAddr(*Body);
+      P->r_offset = Out<ELFT>::Got->getEntryAddr(*Body);
       if (CanBePreempted)
         P->setSymbolAndType(Body->getDynamicSymbolTableIndex(),
-                            NeedsPlt ? Target->getPltReloc()
-                                     : Target->getGotReloc(),
-                            IsMips64EL);
+                            Target->getGotReloc(), IsMips64EL);
     } else {
       if (IsRela)
         Addend += static_cast<const Elf_Rela &>(RI).r_addend;
@@ -308,12 +255,6 @@ template <class ELFT> void DynamicSectio
     ++NumEntries; // DT_RELASZ / DT_RELSZ
     ++NumEntries; // DT_RELAENT / DT_RELENT
   }
-  if (Out<ELFT>::RelaPlt->hasRelocs()) {
-    ++NumEntries; // DT_JMPREL
-    ++NumEntries; // DT_PLTRELSZ
-    ++NumEntries; // DT_PLTGOT
-    ++NumEntries; // DT_PLTREL
-  }
   ++NumEntries; // DT_SYMTAB
   ++NumEntries; // DT_SYMENT
   ++NumEntries; // DT_STRTAB
@@ -382,12 +323,7 @@ template <class ELFT> void DynamicSectio
     WriteVal(IsRela ? DT_RELAENT : DT_RELENT,
              IsRela ? sizeof(Elf_Rela) : sizeof(Elf_Rel));
   }
-  if (Out<ELFT>::RelaPlt->hasRelocs()) {
-    WritePtr(DT_JMPREL, Out<ELFT>::RelaPlt->getVA());
-    WriteVal(DT_PLTRELSZ, Out<ELFT>::RelaPlt->getSize());
-    WritePtr(DT_PLTGOT, Out<ELFT>::Got->getVA());
-    WriteVal(DT_PLTREL, Out<ELFT>::RelaPlt->isRela() ? DT_RELA : DT_REL);
-  }
+
   WritePtr(DT_SYMTAB, Out<ELFT>::DynSymTab->getVA());
   WritePtr(DT_SYMENT, sizeof(Elf_Sym));
   WritePtr(DT_STRTAB, Out<ELFT>::DynStrTab->getVA());
@@ -759,11 +695,6 @@ template void OutputSectionBase<false>::
 template void OutputSectionBase<true>::writeHeaderTo<support::big>(
     ELFFile<ELFType<support::big, true>>::Elf_Shdr *SHdr);
 
-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>;

Modified: lld/trunk/ELF/OutputSections.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/OutputSections.h?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/ELF/OutputSections.h (original)
+++ lld/trunk/ELF/OutputSections.h Tue Oct 13 11:59:30 2015
@@ -117,23 +117,6 @@ private:
 };
 
 template <class ELFT>
-class GotPltSection final : public OutputSectionBase<ELFT::Is64Bits> {
-  typedef OutputSectionBase<ELFT::Is64Bits> Base;
-  typedef typename Base::uintX_t uintX_t;
-
-public:
-  GotPltSection();
-  void finalize() override;
-  void writeTo(uint8_t *Buf) override;
-  void addEntry(SymbolBody *Sym);
-  bool empty() const;
-  uintX_t getEntryAddr(const SymbolBody &B) const;
-
-private:
-  std::vector<const SymbolBody *> Entries;
-};
-
-template <class ELFT>
 class PltSection final : public OutputSectionBase<ELFT::Is64Bits> {
   typedef OutputSectionBase<ELFT::Is64Bits> Base;
   typedef typename Base::uintX_t uintX_t;
@@ -189,7 +172,7 @@ class RelocationSection final : public O
   typedef typename llvm::object::ELFFile<ELFT>::uintX_t uintX_t;
 
 public:
-  RelocationSection(StringRef Name, bool IsRela);
+  RelocationSection(bool IsRela);
   void addReloc(const DynamicReloc<ELFT> &Reloc) { Relocs.push_back(Reloc); }
   void finalize() override;
   void writeTo(uint8_t *Buf) override;
@@ -301,7 +284,6 @@ private:
 // until Writer is initialized.
 template <class ELFT> struct Out {
   static DynamicSection<ELFT> *Dynamic;
-  static GotPltSection<ELFT> *GotPlt;
   static GotSection<ELFT> *Got;
   static HashTableSection<ELFT> *HashTab;
   static InterpSection<ELFT::Is64Bits> *Interp;
@@ -310,7 +292,6 @@ template <class ELFT> struct Out {
   static uint8_t *OpdBuf;
   static PltSection<ELFT> *Plt;
   static RelocationSection<ELFT> *RelaDyn;
-  static RelocationSection<ELFT> *RelaPlt;
   static StringTableSection<ELFT::Is64Bits> *DynStrTab;
   static StringTableSection<ELFT::Is64Bits> *StrTab;
   static SymbolTableSection<ELFT> *DynSymTab;
@@ -318,7 +299,6 @@ template <class ELFT> struct Out {
 };
 
 template <class ELFT> DynamicSection<ELFT> *Out<ELFT>::Dynamic;
-template <class ELFT> GotPltSection<ELFT> *Out<ELFT>::GotPlt;
 template <class ELFT> GotSection<ELFT> *Out<ELFT>::Got;
 template <class ELFT> HashTableSection<ELFT> *Out<ELFT>::HashTab;
 template <class ELFT> InterpSection<ELFT::Is64Bits> *Out<ELFT>::Interp;
@@ -327,7 +307,6 @@ template <class ELFT> OutputSection<ELFT
 template <class ELFT> uint8_t *Out<ELFT>::OpdBuf;
 template <class ELFT> PltSection<ELFT> *Out<ELFT>::Plt;
 template <class ELFT> RelocationSection<ELFT> *Out<ELFT>::RelaDyn;
-template <class ELFT> RelocationSection<ELFT> *Out<ELFT>::RelaPlt;
 template <class ELFT> StringTableSection<ELFT::Is64Bits> *Out<ELFT>::DynStrTab;
 template <class ELFT> StringTableSection<ELFT::Is64Bits> *Out<ELFT>::StrTab;
 template <class ELFT> SymbolTableSection<ELFT> *Out<ELFT>::DynSymTab;

Modified: lld/trunk/ELF/Symbols.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Symbols.h?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/ELF/Symbols.h (original)
+++ lld/trunk/ELF/Symbols.h Tue Oct 13 11:59:30 2015
@@ -79,10 +79,8 @@ public:
   void setDynamicSymbolTableIndex(unsigned V) { DynamicSymbolTableIndex = V; }
 
   uint32_t GotIndex = -1;
-  uint32_t GotPltIndex = -1;
   uint32_t PltIndex = -1;
   bool isInGot() const { return GotIndex != -1U; }
-  bool isInGotPlt() const { return GotPltIndex != -1U; }
   bool isInPlt() const { return PltIndex != -1U; }
 
   // A SymbolBody has a backreference to a Symbol. Originally they are

Modified: lld/trunk/ELF/Target.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.cpp?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/ELF/Target.cpp (original)
+++ lld/trunk/ELF/Target.cpp Tue Oct 13 11:59:30 2015
@@ -55,40 +55,16 @@ X86TargetInfo::X86TargetInfo() {
   PCRelReloc = R_386_PC32;
   GotReloc = R_386_GLOB_DAT;
   GotRefReloc = R_386_GOT32;
-  PltReloc = R_386_JUMP_SLOT;
-  PltEntrySize = 16;
   VAStart = 0x10000;
 }
 
-void X86TargetInfo::writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const {
-  // Skip 6 bytes of "jmpq *got(%rip)"
-  write32le(Buf, Plt + 6);
-}
-
-void X86TargetInfo::writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                      uint64_t PltEntryAddr) const {
-  const uint8_t PltData[] = {
-      0xff, 0x35, 0x00, 0x00, 0x00, 0x00, // pushq GOT+8(%rip)
-      0xff, 0x25, 0x00, 0x00, 0x00, 0x00, // jmp *GOT+16(%rip)
-      0x00, 0x00, 0x00, 0x00
-  };
-  memcpy(Buf, PltData, sizeof(PltData));
-  write32le(Buf + 2, GotEntryAddr - PltEntryAddr + 2); // GOT+8
-  write32le(Buf + 8, GotEntryAddr - PltEntryAddr + 4); // GOT+16
-}
-
 void X86TargetInfo::writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                  uint64_t PltEntryAddr, int32_t Index) const {
-  const uint8_t Inst[] = {
-      0xff, 0x25, 0x00, 0x00, 0x00, 0x00, // jmpq *got(%rip)
-      0x68, 0x00, 0x00, 0x00, 0x00,       // pushq <relocation index>
-      0xe9, 0x00, 0x00, 0x00, 0x00        // jmpq plt[0]
-  };
+                                  uint64_t PltEntryAddr) const {
+  // jmpl *val; nop; nop
+  const uint8_t Inst[] = {0xff, 0x25, 0, 0, 0, 0, 0x90, 0x90};
   memcpy(Buf, Inst, sizeof(Inst));
-
-  write32le(Buf + 2, GotEntryAddr - PltEntryAddr - 6);
-  write32le(Buf + 7, Index);
-  write32le(Buf + 12, -Index * PltEntrySize - PltZeroEntrySize - 16);
+  assert(isUInt<32>(GotEntryAddr));
+  write32le(Buf + 2, GotEntryAddr);
 }
 
 bool X86TargetInfo::relocNeedsGot(uint32_t Type, const SymbolBody &S) const {
@@ -133,9 +109,7 @@ X86_64TargetInfo::X86_64TargetInfo() {
   PCRelReloc = R_X86_64_PC32;
   GotReloc = R_X86_64_GLOB_DAT;
   GotRefReloc = R_X86_64_PC32;
-  PltReloc = R_X86_64_JUMP_SLOT;
   RelativeReloc = R_X86_64_RELATIVE;
-  PltEntrySize = 16;
 
   // On freebsd x86_64 the first page cannot be mmaped.
   // On linux that is controled by vm.mmap_min_addr. At least on some x86_64
@@ -146,35 +120,16 @@ X86_64TargetInfo::X86_64TargetInfo() {
   VAStart = 0x10000;
 }
 
-void X86_64TargetInfo::writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const {
-  // Skip 6 bytes of "jmpq *got(%rip)"
-  write32le(Buf, Plt + 6);
-}
-
-void X86_64TargetInfo::writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                      uint64_t PltEntryAddr) const {
-  const uint8_t PltData[] = {
-      0xff, 0x35, 0x00, 0x00, 0x00, 0x00, // pushq GOT+8(%rip)
-      0xff, 0x25, 0x00, 0x00, 0x00, 0x00, // jmp *GOT+16(%rip)
-      0x0f, 0x1f, 0x40, 0x00              // nopl 0x0(rax)
-  };
-  memcpy(Buf, PltData, sizeof(PltData));
-  write32le(Buf + 2, GotEntryAddr - PltEntryAddr + 2); // GOT+8
-  write32le(Buf + 8, GotEntryAddr - PltEntryAddr + 4); // GOT+16
-}
-
 void X86_64TargetInfo::writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                     uint64_t PltEntryAddr, int32_t Index) const {
-  const uint8_t Inst[] = {
-      0xff, 0x25, 0x00, 0x00, 0x00, 0x00, // jmpq *got(%rip)
-      0x68, 0x00, 0x00, 0x00, 0x00,       // pushq <relocation index>
-      0xe9, 0x00, 0x00, 0x00, 0x00        // jmpq plt[0]
-  };
+                                     uint64_t PltEntryAddr) const {
+  // jmpq *val(%rip); nop; nop
+  const uint8_t Inst[] = {0xff, 0x25, 0, 0, 0, 0, 0x90, 0x90};
   memcpy(Buf, Inst, sizeof(Inst));
 
-  write32le(Buf + 2, GotEntryAddr - PltEntryAddr - 6);
-  write32le(Buf + 7, Index);
-  write32le(Buf + 12, -Index * PltEntrySize - PltZeroEntrySize - 16);
+  uint64_t NextPC = PltEntryAddr + 6;
+  int64_t Delta = GotEntryAddr - NextPC;
+  assert(isInt<32>(Delta));
+  write32le(Buf + 2, Delta);
 }
 
 bool X86_64TargetInfo::relocNeedsGot(uint32_t Type, const SymbolBody &S) const {
@@ -286,9 +241,7 @@ PPC64TargetInfo::PPC64TargetInfo() {
   GotReloc = R_PPC64_GLOB_DAT;
   GotRefReloc = R_PPC64_REL64;
   RelativeReloc = R_PPC64_RELATIVE;
-  // PltReloc = FIXME
   PltEntrySize = 32;
-  PltZeroEntrySize = 0; //FIXME
 
   // We need 64K pages (at least under glibc/Linux, the loader won't
   // set different permissions on a finer granularity than that).
@@ -314,12 +267,8 @@ static uint64_t getPPC64TocBase() {
   return TocVA + 0x8000;
 }
 
-
-void PPC64TargetInfo::writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const {}
-void PPC64TargetInfo::writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                       uint64_t PltEntryAddr) const {}
 void PPC64TargetInfo::writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                    uint64_t PltEntryAddr, int32_t Index) const {
+                                    uint64_t PltEntryAddr) const {
   uint64_t Off = GotEntryAddr - getPPC64TocBase();
 
   // FIXME: What we should do, in theory, is get the offset of the function
@@ -508,16 +457,11 @@ void PPC64TargetInfo::relocateOne(uint8_
 PPCTargetInfo::PPCTargetInfo() {
   // PCRelReloc = FIXME
   // GotReloc = FIXME
-  // PltReloc = FIXME
   PageSize = 65536;
   VAStart = 0x10000000;
 }
-
-void PPCTargetInfo::writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const {}
-void PPCTargetInfo::writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                      uint64_t PltEntryAddr) const {}
 void PPCTargetInfo::writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                  uint64_t PltEntryAddr, int32_t Index) const {}
+                                  uint64_t PltEntryAddr) const {}
 bool PPCTargetInfo::relocNeedsGot(uint32_t Type, const SymbolBody &S) const {
   return false;
 }
@@ -531,16 +475,10 @@ void PPCTargetInfo::relocateOne(uint8_t
 AArch64TargetInfo::AArch64TargetInfo() {
   // PCRelReloc = FIXME
   // GotReloc = FIXME
-  // PltReloc = FIXME
   VAStart = 0x400000;
 }
-
-void AArch64TargetInfo::writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const {}
-void AArch64TargetInfo::writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                          uint64_t PltEntryAddr) const {}
 void AArch64TargetInfo::writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                      uint64_t PltEntryAddr,
-                                      int32_t Index) const {}
+                                      uint64_t PltEntryAddr) const {}
 bool AArch64TargetInfo::relocNeedsGot(uint32_t Type,
                                       const SymbolBody &S) const {
   return false;
@@ -615,19 +553,12 @@ void AArch64TargetInfo::relocateOne(uint
 MipsTargetInfo::MipsTargetInfo() {
   // PCRelReloc = FIXME
   // GotReloc = FIXME
-  // PltReloc = FIXME
   PageSize = 65536;
   VAStart = 0x400000;
 }
 
-void MipsTargetInfo::writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const {}
-
-void MipsTargetInfo::writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                       uint64_t PltEntryAddr) const {}
-
 void MipsTargetInfo::writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                                   uint64_t PltEntryAddr, int32_t Index) const {
-}
+                                   uint64_t PltEntryAddr) const {}
 
 bool MipsTargetInfo::relocNeedsGot(uint32_t Type, const SymbolBody &S) const {
   return false;

Modified: lld/trunk/ELF/Target.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Target.h?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/ELF/Target.h (original)
+++ lld/trunk/ELF/Target.h Tue Oct 13 11:59:30 2015
@@ -24,16 +24,11 @@ public:
   uint64_t getVAStart() const { return VAStart; }
   unsigned getPCRelReloc() const { return PCRelReloc; }
   unsigned getGotReloc() const { return GotReloc; }
-  unsigned getPltReloc() const { return PltReloc; }
   unsigned getGotRefReloc() const { return GotRefReloc; }
   unsigned getRelativeReloc() const { return RelativeReloc; }
-  unsigned getPltZeroEntrySize() const { return PltZeroEntrySize; }
   unsigned getPltEntrySize() const { return PltEntrySize; }
-  virtual void writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const = 0;
-  virtual void writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                              uint64_t PltEntryAddr) const = 0;
   virtual void writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                             uint64_t PltEntryAddr, int32_t Index) const = 0;
+                             uint64_t PltEntryAddr) const = 0;
   virtual bool isRelRelative(uint32_t Type) const;
   virtual bool relocNeedsGot(uint32_t Type, const SymbolBody &S) const = 0;
   virtual bool relocPointsToGot(uint32_t Type) const;
@@ -50,21 +45,15 @@ protected:
   unsigned PCRelReloc;
   unsigned GotRefReloc;
   unsigned GotReloc;
-  unsigned PltReloc;
   unsigned RelativeReloc;
   unsigned PltEntrySize = 8;
-  unsigned PltZeroEntrySize = 16;
-  llvm::StringRef DefaultEntry = "_start";
 };
 
 class X86TargetInfo final : public TargetInfo {
 public:
   X86TargetInfo();
-  void writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const override;
-  void writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                      uint64_t PltEntryAddr) const override;
   void writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                     uint64_t PltEntryAddr, int32_t Index) const override;
+                     uint64_t PltEntryAddr) const override;
   bool relocNeedsGot(uint32_t Type, const SymbolBody &S) const override;
   bool relocPointsToGot(uint32_t Type) const override;
   bool relocNeedsPlt(uint32_t Type, const SymbolBody &S) const override;
@@ -76,11 +65,8 @@ public:
 class X86_64TargetInfo final : public TargetInfo {
 public:
   X86_64TargetInfo();
-  void writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const override;
-  void writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                      uint64_t PltEntryAddr) const override;
   void writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                     uint64_t PltEntryAddr, int32_t Index) const override;
+                     uint64_t PltEntryAddr) const override;
   bool relocNeedsGot(uint32_t Type, const SymbolBody &S) const override;
   bool relocNeedsPlt(uint32_t Type, const SymbolBody &S) const override;
   void relocateOne(uint8_t *Buf, uint8_t *BufEnd, const void *RelP,
@@ -92,11 +78,8 @@ public:
 class PPC64TargetInfo final : public TargetInfo {
 public:
   PPC64TargetInfo();
-  void writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const override;
-  void writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                      uint64_t PltEntryAddr) const override;
   void writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                     uint64_t PltEntryAddr, int32_t Index) const override;
+                     uint64_t PltEntryAddr) const override;
   bool relocNeedsGot(uint32_t Type, const SymbolBody &S) const override;
   bool relocNeedsPlt(uint32_t Type, const SymbolBody &S) const override;
   void relocateOne(uint8_t *Buf, uint8_t *BufEnd, const void *RelP,
@@ -108,11 +91,8 @@ public:
 class PPCTargetInfo final : public TargetInfo {
 public:
   PPCTargetInfo();
-  void writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const override;
-  void writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                      uint64_t PltEntryAddr) const override;
   void writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                     uint64_t PltEntryAddr, int32_t Index) const override;
+                     uint64_t PltEntryAddr) const override;
   bool relocNeedsGot(uint32_t Type, const SymbolBody &S) const override;
   bool relocNeedsPlt(uint32_t Type, const SymbolBody &S) const override;
   void relocateOne(uint8_t *Buf, uint8_t *BufEnd, const void *RelP,
@@ -123,11 +103,8 @@ public:
 class AArch64TargetInfo final : public TargetInfo {
 public:
   AArch64TargetInfo();
-  void writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const override;
-  void writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                      uint64_t PltEntryAddr) const override;
   void writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                     uint64_t PltEntryAddr, int32_t Index) const override;
+                     uint64_t PltEntryAddr) const override;
   bool relocNeedsGot(uint32_t Type, const SymbolBody &S) const override;
   bool relocNeedsPlt(uint32_t Type, const SymbolBody &S) const override;
   void relocateOne(uint8_t *Buf, uint8_t *BufEnd, const void *RelP,
@@ -138,11 +115,8 @@ public:
 class MipsTargetInfo final : public TargetInfo {
 public:
   MipsTargetInfo();
-  void writeGotPltEntry(uint8_t *Buf, uint64_t Plt) const override;
-  void writePltZeroEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                      uint64_t PltEntryAddr) const override;
   void writePltEntry(uint8_t *Buf, uint64_t GotEntryAddr,
-                     uint64_t PltEntryAddr, int32_t Index) const override;
+                     uint64_t PltEntryAddr) const override;
   bool relocNeedsGot(uint32_t Type, const SymbolBody &S) const override;
   bool relocNeedsPlt(uint32_t Type, const SymbolBody &S) const override;
   void relocateOne(uint8_t *Buf, uint8_t *BufEnd, const void *RelP,

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Tue Oct 13 11:59:30 2015
@@ -98,8 +98,6 @@ template <class ELFT> void lld::elf2::wr
   Out<ELFT>::Bss = &Bss;
   GotSection<ELFT> Got;
   Out<ELFT>::Got = &Got;
-  GotPltSection<ELFT> GotPlt;
-  Out<ELFT>::GotPlt = &GotPlt;
   PltSection<ELFT> Plt;
   Out<ELFT>::Plt = &Plt;
   SymbolTableSection<ELFT> SymTab(*Symtab, *Out<ELFT>::StrTab);
@@ -108,11 +106,8 @@ template <class ELFT> void lld::elf2::wr
   Out<ELFT>::DynSymTab = &DynSymTab;
   HashTableSection<ELFT> HashTab;
   Out<ELFT>::HashTab = &HashTab;
-  bool IsRela = Symtab->shouldUseRela();
-  RelocationSection<ELFT> RelaDyn(IsRela ? ".rela.dyn" : ".rel.dyn", IsRela);
+  RelocationSection<ELFT> RelaDyn(Symtab->shouldUseRela());
   Out<ELFT>::RelaDyn = &RelaDyn;
-  RelocationSection<ELFT> RelaPlt(IsRela ? ".rela.plt" : ".rel.plt", IsRela);
-  Out<ELFT>::RelaPlt = &RelaPlt;
   DynamicSection<ELFT> Dynamic(*Symtab);
   Out<ELFT>::Dynamic = &Dynamic;
 
@@ -192,8 +187,8 @@ void Writer<ELFT>::scanRelocs(
         if (Body->isInPlt())
           continue;
         Out<ELFT>::Plt->addEntry(Body);
-        Out<ELFT>::GotPlt->addEntry(Body);
-      } else if (Target->relocNeedsGot(Type, *Body)) {
+      }
+      if (Target->relocNeedsGot(Type, *Body)) {
         if (Body->isInGot())
           continue;
         Out<ELFT>::Got->addEntry(Body);
@@ -205,10 +200,7 @@ void Writer<ELFT>::scanRelocs(
       continue;
     if (CBP)
       Body->setUsedInDynamicReloc();
-    if (Body && Target->relocNeedsPlt(Type, *Body))
-      Out<ELFT>::RelaPlt->addReloc({ C, RI });
-    else
-      Out<ELFT>::RelaDyn->addReloc({ C, RI });
+    Out<ELFT>::RelaDyn->addReloc({C, RI});
   }
 }
 
@@ -455,13 +447,9 @@ template <class ELFT> void Writer<ELFT>:
     OutputSections.push_back(Out<ELFT>::DynStrTab);
     if (Out<ELFT>::RelaDyn->hasRelocs())
       OutputSections.push_back(Out<ELFT>::RelaDyn);
-    if (Out<ELFT>::RelaPlt->hasRelocs())
-      OutputSections.push_back(Out<ELFT>::RelaPlt);
   }
   if (!Out<ELFT>::Got->empty())
     OutputSections.push_back(Out<ELFT>::Got);
-  if (!Out<ELFT>::GotPlt->empty())
-    OutputSections.push_back(Out<ELFT>::GotPlt);
   if (!Out<ELFT>::Plt->empty())
     OutputSections.push_back(Out<ELFT>::Plt);
 

Modified: lld/trunk/test/elf2/plt-i686.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf2/plt-i686.s?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/test/elf2/plt-i686.s (original)
+++ lld/trunk/test/elf2/plt-i686.s Tue Oct 13 11:59:30 2015
@@ -14,62 +14,41 @@
 // CHECK-NEXT: ]
 // CHECK-NEXT: Address: 0x11010
 // CHECK-NEXT: Offset:
-// CHECK-NEXT: Size: 48
+// CHECK-NEXT: Size: 16
 // CHECK-NEXT: Link: 0
 // CHECK-NEXT: Info: 0
 // CHECK-NEXT: AddressAlignment: 16
 
-// CHECK:      Name: .got.plt
-// CHECK-NEXT: Type: SHT_PROGBITS
-// CHECK-NEXT: Flags [
-// CHECK-NEXT:   SHF_ALLOC
-// CHECK-NEXT:   SHF_WRITE
-// CHECK-NEXT: ]
-// CHECK-NEXT: Address: 0x12058
-// CHECK-NEXT: Offset: 0x2058
-// CHECK-NEXT: Size: 20
-// CHECK-NEXT: Link: 0
-// CHECK-NEXT: Info: 0
-// CHECK-NEXT: AddressAlignment: 4
-// CHECK-NEXT: EntrySize: 0
-
 // CHECK:      Relocations [
-// CHECK-NEXT:   Section ({{.*}}) .rel.plt {
-// CHECK-NEXT:     0x12064 R_386_JUMP_SLOT bar 0x0
-// CHECK-NEXT:     0x12068 R_386_JUMP_SLOT zed 0x0
+// CHECK-NEXT:   Section ({{.*}}) .rel.dyn {
+// CHECK-NEXT:     0x12050 R_386_GLOB_DAT bar 0x0
+// CHECK-NEXT:     0x12054 R_386_GLOB_DAT zed 0x0
 // CHECK-NEXT:   }
 // CHECK-NEXT: ]
 
 // Unfortunately FileCheck can't do math, so we have to check for explicit
 // values:
 
-// 16 is the size of PLT[0]
-// (0x11010 + 16) - (0x11000 + 1) - 4 = 27
-// (0x11010 + 16) - (0x11005 + 1) - 4 = 22
-// (0x11020 + 16) - (0x1100a + 1) - 4 = 33
+// 0x11010 - (0x11000 + 1) - 4 = 11
+// 0x11010 - (0x11005 + 1) - 4 = 2
+// 0x11018 - (0x1100a + 1) - 4 = 9
 
 // DISASM:      _start:
-// DISASM-NEXT:   11000:  e9 1b 00 00 00  jmp  27
-// DISASM-NEXT:   11005:  e9 16 00 00 00  jmp  22
-// DISASM-NEXT:   1100a:  e9 21 00 00 00  jmp  33
-
-// 0x12064 - 0x11020 - 6 = 4158
-// 0x12068 - 0x11030 - 6 = 4146
-// 0x11010 - 0x1102b - 5 = -32
-// 0x11010 - 0x1103b - 5 = -48
+// DISASM-NEXT:   11000:  e9 0b 00 00 00  jmp  11
+// DISASM-NEXT:   11005:  e9 06 00 00 00  jmp  6
+// DISASM-NEXT:   1100a:  e9 09 00 00 00  jmp  9
+
+// 0x12050 = 73808
+// 0x12054 = 73812
+
 // DISASM:      Disassembly of section .plt:
 // DISASM-NEXT: .plt:
-// DISASM-NEXT:   11010:  ff 35 4a 10 00 00 pushl 4170
-// DISASM-NEXT:   11016:  ff 25 4c 10 00 00 jmpl *4172
-// DISASM-NEXT:   1101c:  00 00  addb %al, (%eax)
-// DISASM-NEXT:   1101e:  00 00  addb %al, (%eax)
-// DISASM-NEXT:   11020:  ff 25 3e 10 00 00 jmpl *4158
-// DISASM-NEXT:   11026:  68 00 00 00 00 pushl $0
-// DISASM-NEXT:   1102b:  e9 e0 ff ff ff jmp -32
-// DISASM-NEXT:   11030:  ff 25 32 10 00 00 jmpl *4146
-// DISASM-NEXT:   11036:  68 01 00 00 00 pushl $1
-// DISASM-NEXT:   1103b:  e9 d0 ff ff ff jmp -48
-
+// DISASM-NEXT:   11010:  ff 25 {{.*}}       jmpl *73808
+// DISASM-NEXT:   11016:  90                 nop
+// DISASM-NEXT:   11017:  90                 nop
+// DISASM-NEXT:   11018:  ff 25 {{.*}}       jmpl *73812
+// DISASM-NEXT:   1101e:  90                 nop
+// DISASM-NEXT:   1101f:  90                 nop
 
 .global _start
 _start:

Modified: lld/trunk/test/elf2/plt.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf2/plt.s?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/test/elf2/plt.s (original)
+++ lld/trunk/test/elf2/plt.s Tue Oct 13 11:59:30 2015
@@ -14,49 +14,42 @@
 // CHECK-NEXT: ]
 // CHECK-NEXT: Address: 0x1020
 // CHECK-NEXT: Offset:
-// CHECK-NEXT: Size: 64
+// CHECK-NEXT: Size: 24
 // CHECK-NEXT: Link: 0
 // CHECK-NEXT: Info: 0
 // CHECK-NEXT: AddressAlignment: 16
 
 // CHECK:      Relocations [
-// CHECK-NEXT:   Section ({{.*}}) .rela.plt {
-// CHECK-NEXT:     0x20C8 R_X86_64_JUMP_SLOT bar 0x0
-// CHECK-NEXT:     0x20D0 R_X86_64_JUMP_SLOT zed 0x0
-// CHECK-NEXT:     0x20D8 R_X86_64_JUMP_SLOT _start 0x0
+// CHECK-NEXT:   Section ({{.*}}) .rela.dyn {
+// CHECK-NEXT:     0x20A0 R_X86_64_GLOB_DAT bar 0x0
+// CHECK-NEXT:     0x20A8 R_X86_64_GLOB_DAT zed 0x0
+// CHECK-NEXT:     0x20B0 R_X86_64_GLOB_DAT _start 0x0
 // CHECK-NEXT:   }
 // CHECK-NEXT: ]
 
 // Unfortunately FileCheck can't do math, so we have to check for explicit
 // values:
 
-// 0x1030 - (0x1000 + 5) = 43
-// 0x1030 - (0x1005 + 5) = 38
-// 0x1040 - (0x100a + 5) = 49
+// 0x11020 - (0x11000 + 1) - 4 = 27
+// 0x11020 - (0x11005 + 1) - 4 = 22
+// 0x11028 - (0x1100a + 1) - 4 = 25
 
 // DISASM:      _start:
-// DISASM-NEXT:   1000:  e9 {{.*}}       jmp  43
-// DISASM-NEXT:   1005:  e9 {{.*}}       jmp  38
-// DISASM-NEXT:   100a:  e9 {{.*}}       jmp  49
+// DISASM-NEXT:   1000:  e9 {{.*}}       jmp  27
+// DISASM-NEXT:   1005:  e9 {{.*}}       jmp  22
+// DISASM-NEXT:   100a:  e9 {{.*}}       jmp  25
 
-// 0x20C8 - 0x1036  = 4242
-// 0x20D0 - 0x1046  = 4234
+// 0x120A0 - 0x11026  = 4218
+// 0x120A8 - 0x1102e  = 4218
 
 // DISASM:      Disassembly of section .plt:
 // DISASM-NEXT: .plt:
-// DISASM-NEXT:   1020:  ff 35 92 10 00 00  pushq 4242(%rip)
-// DISASM-NEXT:   1026:  ff 25 94 10 00 00  jmpq *4244(%rip)
-// DISASM-NEXT:   102c:  0f 1f 40 00        nopl (%rax)
-// DISASM-NEXT:   1030:  ff 25 92 10 00 00  jmpq *4242(%rip)
-// DISASM-NEXT:   1036:  68 00 00 00 00     pushq $0
-// DISASM-NEXT:   103b:  e9 e0 ff ff ff     jmp -32 <bar+1020>
-// DISASM-NEXT:   1040:  ff 25 8a 10 00 00  jmpq *4234(%rip)
-// DISASM-NEXT:   1046:  68 01 00 00 00     pushq $1
-// DISASM-NEXT:   104b:  e9 d0 ff ff ff     jmp -48 <bar+1020>
-// DISASM-NEXT:   1050:  ff 25 82 10 00 00  jmpq *4226(%rip)
-// DISASM-NEXT:   1056:  68 02 00 00 00     pushq $2
-// DISASM-NEXT:   105b:  e9 c0 ff ff ff     jmp -64 <bar+1020>
-
+// DISASM-NEXT:   1020:  ff 25 {{.*}}       jmpq *4218(%rip)
+// DISASM-NEXT:   1026:  90                 nop
+// DISASM-NEXT:   1027:  90                 nop
+// DISASM-NEXT:   1028:  ff 25 {{.*}}       jmpq *4218(%rip)
+// DISASM-NEXT:   102e:  90                 nop
+// DISASM-NEXT:   102f:  90                 nop
 
 .global _start
 _start:

Modified: lld/trunk/test/elf2/relocation-i686.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf2/relocation-i686.s?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/test/elf2/relocation-i686.s (original)
+++ lld/trunk/test/elf2/relocation-i686.s Tue Oct 13 11:59:30 2015
@@ -47,7 +47,7 @@ movl bar at GOT, %eax
 // ADDR-NEXT: ]
 // ADDR-NEXT: Address: 0x11030
 // ADDR-NEXT: Offset: 0x1030
-// ADDR-NEXT: Size: 32
+// ADDR-NEXT: Size: 8
 
 // ADDR:      Name: .got
 // ADDR-NEXT: Type: SHT_PROGBITS
@@ -55,25 +55,24 @@ movl bar at GOT, %eax
 // ADDR-NEXT:   SHF_ALLOC
 // ADDR-NEXT:   SHF_WRITE
 // ADDR-NEXT: ]
-// ADDR-NEXT: Address: 0x12070
+// ADDR-NEXT: Address: 0x12050
 
 .section .R_386_GOTPC,"ax", at progbits
 R_386_GOTPC:
  movl $_GLOBAL_OFFSET_TABLE_, %eax
 
-// 0x12070 - 0x11014 = 4188
+// 0x12050 - 0x11014 = 4156
 
 // CHECK:      Disassembly of section .R_386_GOTPC:
 // CHECK-NEXT: R_386_GOTPC:
-// CHECK-NEXT:   11014:  {{.*}} movl  $4188, %eax
+// CHECK-NEXT:   11014:  {{.*}} movl  $4156, %eax
 
 .section .dynamic_reloc, "ax", at progbits
  call bar
-// (0x11030 + 16) - (0x11019 + 5) = 34
-// 16 - is a size of PLT[0]
+// 0x11030 - (0x11019 + 5) = 18
 // CHECK:      Disassembly of section .dynamic_reloc:
 // CHECK-NEXT: .dynamic_reloc:
-// CHECK-NEXT:   11019:  e8 22 00 00 00 calll 34
+// CHECK-NEXT:   11019:  e8 12 00 00 00 calll 18
 
 .section .R_386_GOT32,"ax", at progbits
 .global R_386_GOT32

Modified: lld/trunk/test/elf2/relocation.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf2/relocation.s?rev=250182&r1=250181&r2=250182&view=diff
==============================================================================
--- lld/trunk/test/elf2/relocation.s (original)
+++ lld/trunk/test/elf2/relocation.s Tue Oct 13 11:59:30 2015
@@ -14,39 +14,23 @@
 // SEC-NEXT: ]
 // SEC-NEXT: Address: 0x11020
 // SEC-NEXT: Offset: 0x1020
-// SEC-NEXT: Size: 32
+// SEC-NEXT: Size: 8
 
-// SEC:        Name: .got
+// SEC:         Name: .got
 // SEC-NEXT:   Type: SHT_PROGBITS
 // SEC-NEXT:   Flags [
 // SEC-NEXT:     SHF_ALLOC
 // SEC-NEXT:     SHF_WRITE
 // SEC-NEXT:   ]
-// SEC-NEXT:   Address: 0x120E0
+// SEC-NEXT:   Address: 0x120A0
 // SEC-NEXT:   Offset:
-// SEC-NEXT:   Size: 8
+// SEC-NEXT:   Size: 16
 // SEC-NEXT:   Link: 0
 // SEC-NEXT:   Info: 0
 // SEC-NEXT:   AddressAlignment: 8
 // SEC-NEXT:   EntrySize: 0
 // SEC-NEXT: }
 
-// SEC:        Name: .got.plt
-// SEC-NEXT:   Type: SHT_PROGBITS
-// SEC-NEXT:   Flags [
-// SEC-NEXT:     SHF_ALLOC
-// SEC-NEXT:     SHF_WRITE
-// SEC-NEXT:   ]
-// SEC-NEXT:   Address: 0x120E8
-// SEC-NEXT:   Offset: 0x20E8
-// SEC-NEXT:   Size: 32
-// SEC-NEXT:   Link: 0
-// SEC-NEXT:   Info: 0
-// SEC-NEXT:   AddressAlignment: 8
-// SEC-NEXT:   EntrySize: 0
-// SEC-NEXT:   }
-
-
 .section       .text,"ax", at progbits,unique,1
 .global _start
 _start:
@@ -91,11 +75,10 @@ R_X86_64_32S:
 .global R_X86_64_PC32
 R_X86_64_PC32:
  call bar
-// (0x11020 + 16) - (0x11017 + 5) = 20
-// 16 - is a size of PLT[0]
+// 0x11020 - (0x11017 + 5) = 4
 // CHECK:      Disassembly of section .R_X86_64_PC32:
 // CHECK-NEXT: R_X86_64_PC32:
-// CHECK-NEXT:  11017:   e8 14 00 00 00  callq  20
+// CHECK-NEXT:  11017:   e8 04 00 00 00  callq  4
 
 .section .R_X86_64_64,"a", at progbits
 .global R_X86_64_64
@@ -110,7 +93,7 @@ R_X86_64_64:
 R_X86_64_GOTPCREL:
  .long zed at gotpcrel
 
-// 0x120E0 - 0x10160 = 8064
-// 8064 = 0x801f0000   in little endian
+// 0x120A8 - 0x10160 = 8008
+// 8008 = 0x481f0000   in little endian
 // CHECK:      Contents of section .R_X86_64_GOTPCREL
-// CHECK-NEXT:   10160 801f0000
+// CHECK-NEXT:   10160 481f0000




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