MCObjectWriter.cpp

//===- lib/MC/MCObjectWriter.cpp - MCObjectWriter implementation ----------===//
//
// 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 "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFragment.h"
#include "llvm/MC/MCSymbol.h"
namespace llvm {
class MCSection;
}

using namespace llvm;

MCObjectWriter::~MCObjectWriter() = default;

void MCObjectWriter::reset() {
  FileNames.clear();
  AddrsigSyms.clear();
  EmitAddrsigSection = false;
  SubsectionsViaSymbols = false;
  CGProfile.clear();
}

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();
  assert(!SA.isUndefined() && !SB.isUndefined());
  MCFragment *FB = SB.getFragment();
  if (!FB || !SA.getFragment())
    return false;

  return isSymbolRefDifferenceFullyResolvedImpl(Asm, SA, *FB, InSet, /*IsPCRel=*/false);
}

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

void MCObjectWriter::addFileName(MCAssembler &Asm, StringRef FileName) {
  FileNames.emplace_back(std::string(FileName), Asm.Symbols.size());
}