X86TargetObjectFile.cpp

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//===-- X86TargetObjectFile.cpp - X86 Object Info -------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
 
#include "X86TargetObjectFile.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Target/TargetMachine.h"
 
using namespace llvm;
using namespace dwarf;
 
const MCExpr *X86_64MachoTargetObjectFile::getTTypeGlobalReference(
    const GlobalValue *GV, unsigned Encoding, const TargetMachine &TM,
    MachineModuleInfo *MMI, MCStreamer &Streamer) const {
 
  // On Darwin/X86-64, we can reference dwarf symbols with foo@GOTPCREL+4, which
  // is an indirect pc-relative reference.
  if ((Encoding & DW_EH_PE_indirect) && (Encoding & DW_EH_PE_pcrel)) {
    const MCSymbol *Sym = TM.getSymbol(GV);
    const MCExpr *Res =
      MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOTPCREL, getContext());
    const MCExpr *Four = MCConstantExpr::create(4, getContext());
    return MCBinaryExpr::createAdd(Res, Four, getContext());
  }
 
  return TargetLoweringObjectFileMachO::getTTypeGlobalReference(
      GV, Encoding, TM, MMI, Streamer);
}
 
MCSymbol *X86_64MachoTargetObjectFile::getCFIPersonalitySymbol(
    const GlobalValue *GV, const TargetMachine &TM,
    MachineModuleInfo *MMI) const {
  return TM.getSymbol(GV);
}
 
const MCExpr *X86_64MachoTargetObjectFile::getIndirectSymViaGOTPCRel(
    const GlobalValue *GV, const MCSymbol *Sym, const MCValue &MV,
    int64_t Offset, MachineModuleInfo *MMI, MCStreamer &Streamer) const {
  // On Darwin/X86-64, we need to use foo@GOTPCREL+4 to access the got entry
  // from a data section. In case there's an additional offset, then use
  // foo@GOTPCREL+4+<offset>.
  unsigned FinalOff = Offset+MV.getConstant()+4;
  const MCExpr *Res =
    MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOTPCREL, getContext());
  const MCExpr *Off = MCConstantExpr::create(FinalOff, getContext());
  return MCBinaryExpr::createAdd(Res, Off, getContext());
}
 
const MCExpr *X86ELFTargetObjectFile::getDebugThreadLocalSymbol(
    const MCSymbol *Sym) const {
  return MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_DTPOFF, getContext());
}
 
const MCExpr *X86ELFTargetObjectFile::getIndirectSymViaGOTPCRel(
    const GlobalValue *GV, const MCSymbol *Sym, const MCValue &MV,
    int64_t Offset, MachineModuleInfo *MMI, MCStreamer &Streamer) const {
  int64_t FinalOffset = Offset + MV.getConstant();
  const MCExpr *Res =
      MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_GOTPCREL, getContext());
  const MCExpr *Off = MCConstantExpr::create(FinalOffset, getContext());
  return MCBinaryExpr::createAdd(Res, Off, getContext());
}