[ELF][MIPS] Move MIPS GOT header generation to the GotSection

MIPS is the only target requires GOT header. We already have MIPS
specific code in the `GotSection` class, so move MIPS GOT header
generation there and delete redundant stuff like `GotHeaderEntriesNum`
field and `writeGotHeader` method.

Differential Revision: http://reviews.llvm.org/D19465

llvm-svn: 267460

1 files changed, 0 insertions, 25 deletions

diff --git a/lld/ELF/Target.cpp b/lld/ELF/Target.cpp
index 31d72bbc0e1..bc846a03cb4 100644
--- a/lld/ELF/Target.cpp
+++ b/lld/ELF/Target.cpp
@@ -179,7 +179,6 @@ public:
   void writePltZero(uint8_t *Buf) const override;
   void writePlt(uint8_t *Buf, uint64_t GotEntryAddr, uint64_t PltEntryAddr,
                 int32_t Index, unsigned RelOff) const override;
-  void writeGotHeader(uint8_t *Buf) const override;
   void writeThunk(uint8_t *Buf, uint64_t S) const override;
   bool needsThunk(uint32_t Type, const InputFile &File,
                   const SymbolBody &S) const override;
@@ -1294,7 +1293,6 @@ RelExpr AMDGPUTargetInfo::getRelExpr(uint32_t Type, const SymbolBody &S) const {
 }
 
 template <class ELFT> MipsTargetInfo<ELFT>::MipsTargetInfo() {
-  GotHeaderEntriesNum = 2;
   GotPltHeaderEntriesNum = 2;
   PageSize = 65536;
   PltEntrySize = 16;
@@ -1353,29 +1351,6 @@ uint32_t MipsTargetInfo<ELFT>::getDynRel(uint32_t Type) const {
 }
 
 template <class ELFT>
-void MipsTargetInfo<ELFT>::writeGotHeader(uint8_t *Buf) const {
-  typedef typename ELFT::Off Elf_Off;
-  typedef typename ELFT::uint uintX_t;
-
-  // 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<Elf_Off *>(Buf);
-  P[1] = uintX_t(1) << (ELFT::Is64Bits ? 63 : 31);
-}
-
-template <class ELFT>
 void MipsTargetInfo<ELFT>::writeGotPlt(uint8_t *Buf, uint64_t Plt) const {
   write32<ELFT::TargetEndianness>(Buf, Out<ELFT>::Plt->getVA());
 }