llvm-mirror/lib/MC/MCSection.cpp

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

#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;

//===----------------------------------------------------------------------===//
// MCSection
//===----------------------------------------------------------------------===//

MCSection::MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
    : Begin(Begin), HasInstructions(false), Data(*this), Variant(V), Kind(K) {}

MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) {
  if (!End)
    End = Ctx.createTempSymbol("sec_end", true);
  return End;
}

bool MCSection::hasEnded() const { return End && End->isInSection(); }

MCSection::~MCSection() {
}

void MCSection::setBundleLockState(BundleLockStateType NewState) {
  if (NewState == NotBundleLocked) {
    if (BundleLockNestingDepth == 0) {
      report_fatal_error("Mismatched bundle_lock/unlock directives");
    }
    if (--BundleLockNestingDepth == 0) {
      BundleLockState = NotBundleLocked;
    }
    return;
  }

  // If any of the directives is an align_to_end directive, the whole nested
  // group is align_to_end. So don't downgrade from align_to_end to just locked.
  if (BundleLockState != BundleLockedAlignToEnd) {
    BundleLockState = NewState;
  }
  ++BundleLockNestingDepth;
}

MCSectionData::iterator
MCSection::getSubsectionInsertionPoint(unsigned Subsection) {
  if (Subsection == 0 && Data.SubsectionFragmentMap.empty())
    return end();

  SmallVectorImpl<std::pair<unsigned, MCFragment *>>::iterator MI =
      std::lower_bound(Data.SubsectionFragmentMap.begin(),
                       Data.SubsectionFragmentMap.end(),
                       std::make_pair(Subsection, (MCFragment *)nullptr));
  bool ExactMatch = false;
  if (MI != Data.SubsectionFragmentMap.end()) {
    ExactMatch = MI->first == Subsection;
    if (ExactMatch)
      ++MI;
  }
  MCSectionData::iterator IP;
  if (MI == Data.SubsectionFragmentMap.end())
    IP = end();
  else
    IP = MI->second;
  if (!ExactMatch && Subsection != 0) {
    // The GNU as documentation claims that subsections have an alignment of 4,
    // although this appears not to be the case.
    MCFragment *F = new MCDataFragment();
    Data.SubsectionFragmentMap.insert(MI, std::make_pair(Subsection, F));
    getFragmentList().insert(IP, F);
    F->setParent(this);
  }

  return IP;
}

MCSectionData::iterator MCSection::begin() { return Data.begin(); }

MCSectionData::iterator MCSection::end() { return Data.end(); }

MCSectionData::reverse_iterator MCSection::rbegin() { return Data.rbegin(); }

MCSectionData::FragmentListType &MCSection::getFragmentList() {
  return Data.getFragmentList();
}

MCSectionData::iterator MCSectionData::begin() { return Fragments.begin(); }

MCSectionData::iterator MCSectionData::end() { return Fragments.end(); }

MCSectionData::reverse_iterator MCSectionData::rbegin() {
  return Fragments.rbegin();
}

MCSectionData::reverse_iterator MCSectionData::rend() {
  return Fragments.rend();
}