//===- lib/MC/MCObjectWriter.cpp - MCObjectWriter implementation ----------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSymbol.h"

using namespace llvm;

MCObjectWriter::~MCObjectWriter() {
}

bool
MCObjectWriter::IsSymbolRefDifferenceFullyResolved(const MCAssembler &Asm,
                                                   const MCSymbolRefExpr *A,
                                                   const MCSymbolRefExpr *B,
                                                   bool InSet) const {
  // Modified symbol references cannot be resolved.
  if (A->getKind() != MCSymbolRefExpr::VK_None ||
      B->getKind() != MCSymbolRefExpr::VK_None)
    return false;

  const MCSymbol &SA = A->getSymbol();
  const MCSymbol &SB = B->getSymbol();
  if (SA.AliasedSymbol().isUndefined() || SB.AliasedSymbol().isUndefined())
    return false;

  const MCSymbolData &DataA = Asm.getSymbolData(SA);
  const MCSymbolData &DataB = Asm.getSymbolData(SB);
  if(!DataA.getFragment() || !DataB.getFragment())
    return false;

  return IsSymbolRefDifferenceFullyResolvedImpl(Asm, DataA,
                                                *DataB.getFragment(),
                                                InSet,
                                                false);
}

bool
MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
                                                      const MCSymbolData &DataA,
                                                      const MCFragment &FB,
                                                      bool InSet,
                                                      bool IsPCRel) const {
  const MCSection &SecA = DataA.getSymbol().AliasedSymbol().getSection();
  const MCSection &SecB = FB.getParent()->getSection();
  // On ELF and COFF  A - B is absolute if A and B are in the same section.
  return &SecA == &SecB;
}