path: root/lib/MC/ELFObjectWriter.cpp

//===- lib/MC/ELFObjectWriter.cpp - ELF File Writer -------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements ELF object file writer information.
//
//===----------------------------------------------------------------------===//

#include "ELFObjectWriter.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/ADT/StringSwitch.h"

#include "../Target/Mips/MCTargetDesc/MipsFixupKinds.h"

#include <vector>
using namespace llvm;

#undef  DEBUG_TYPE
#define DEBUG_TYPE "reloc-info"

bool ELFObjectWriter::isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
  const MCFixupKindInfo &FKI =
    Asm.getBackend().getFixupKindInfo((MCFixupKind) Kind);

  return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel;
}

bool ELFObjectWriter::RelocNeedsGOT(MCSymbolRefExpr::VariantKind Variant) {
  switch (Variant) {
  default:
    return false;
  case MCSymbolRefExpr::VK_GOT:
  case MCSymbolRefExpr::VK_PLT:
  case MCSymbolRefExpr::VK_GOTPCREL:
  case MCSymbolRefExpr::VK_GOTOFF:
  case MCSymbolRefExpr::VK_TPOFF:
  case MCSymbolRefExpr::VK_TLSGD:
  case MCSymbolRefExpr::VK_GOTTPOFF:
  case MCSymbolRefExpr::VK_INDNTPOFF:
  case MCSymbolRefExpr::VK_NTPOFF:
  case MCSymbolRefExpr::VK_GOTNTPOFF:
  case MCSymbolRefExpr::VK_TLSLDM:
  case MCSymbolRefExpr::VK_DTPOFF:
  case MCSymbolRefExpr::VK_TLSLD:
    return true;
  }
}

ELFObjectWriter::~ELFObjectWriter()
{}

// Emit the ELF header.
void ELFObjectWriter::WriteHeader(uint64_t SectionDataSize,
                                  unsigned NumberOfSections) {
  // ELF Header
  // ----------
  //
  // Note
  // ----
  // emitWord method behaves differently for ELF32 and ELF64, writing
  // 4 bytes in the former and 8 in the latter.

  Write8