//===- MCSection.h - Machine Code Sections ----------------------*- C++ -*-===//

//

//                     The LLVM Compiler Infrastructure

//

// This file is distributed under the University of Illinois Open Source

// License. See LICENSE.TXT for details.

//

//===----------------------------------------------------------------------===//

//

// This file declares the MCSection class.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_MC_MCSECTION_H

#define LLVM_MC_MCSECTION_H

#include "llvm/ADT/SmallVector.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/ADT/ilist.h"

#include "llvm/ADT/ilist_node.h"

#include "llvm/MC/MCFragment.h"

#include "llvm/MC/SectionKind.h"

#include "llvm/Support/Compiler.h"

namespace llvm_ks {

class MCAsmInfo;

class MCAssembler;

class MCContext;

class MCExpr;

class MCFragment;

class MCSection;

class MCSymbol;

class raw_ostream;

template<>

struct ilist_node_traits<MCFragment> {

  MCFragment *createNode(const MCFragment &V);

  static void deleteNode(MCFragment *V);

  void addNodeToList(MCFragment *) {}

  void removeNodeFromList(MCFragment *) {}

  void transferNodesFromList(ilist_node_traits &    /*SrcTraits*/,

                             ilist_iterator<MCFragment> /*first*/,

                             ilist_iterator<MCFragment> /*last*/) {}

};

/// Instances of this class represent a uniqued identifier for a section in the

/// current translation unit.  The MCContext class uniques and creates these.

class MCSection {

public:

  enum SectionVariant { SV_COFF = 0, SV_ELF, SV_MachO };

  /// \brief Express the state of bundle locked groups while emitting code.

  enum BundleLockStateType {

    NotBundleLocked,

    BundleLocked,

    BundleLockedAlignToEnd

  };

  typedef iplist<MCFragment> FragmentListType;

  typedef FragmentListType::const_iterator const_iterator;

  typedef FragmentListType::iterator iterator;

  typedef FragmentListType::const_reverse_iterator const_reverse_iterator;

  typedef FragmentListType::reverse_iterator reverse_iterator;

private:

  MCSection(const MCSection &) = delete;

  void operator=(const MCSection &) = delete;

  MCSymbol *Begin;

  MCSymbol *End = nullptr;

  /// The alignment requirement of this section.

  unsigned Alignment = 1;

  /// The section index in the assemblers section list.

  unsigned Ordinal = 0;

  /// The index of this section in the layout order.

  unsigned LayoutOrder;

  /// \brief Keeping track of bundle-locked state.

  BundleLockStateType BundleLockState = NotBundleLocked;

  /// \brief Current nesting depth of bundle_lock directives.

  unsigned BundleLockNestingDepth = 0;

  /// \brief We've seen a bundle_lock directive but not its first instruction

  /// yet.

  unsigned BundleGroupBeforeFirstInst : 1;

  /// Whether this section has had instructions emitted into it.

  unsigned HasInstructions : 1;

  unsigned IsRegistered : 1;

  MCDummyFragment DummyFragment;

  FragmentListType Fragments;

  /// Mapping from subsection number to insertion point for subsection numbers

  /// below that number.

  SmallVector<std::pair<unsigned, MCFragment *>, 1> SubsectionFragmentMap;

protected:

  MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin);

  SectionVariant Variant;

  SectionKind Kind;

  ~MCSection();

public:

  SectionKind getKind() const { return Kind; }

  SectionVariant getVariant() const { return Variant; }

  MCSymbol *getBeginSymbol() { return Begin; }

  const MCSymbol *getBeginSymbol() const {

    return const_cast<MCSection *>(this)->getBeginSymbol();

  }

  void setBeginSymbol(MCSymbol *Sym) {

    assert(!Begin);

    Begin = Sym;

  }

  MCSymbol *getEndSymbol(MCContext &Ctx);

  bool hasEnded() const;

  unsigned getAlignment() const { return Alignment; }

  void setAlignment(unsigned Value) { Alignment = Value; }

  unsigned getOrdinal() const { return Ordinal; }

  void setOrdinal(unsigned Value) { Ordinal = Value; }

  unsigned getLayoutOrder() const { return LayoutOrder; }

  void setLayoutOrder(unsigned Value) { LayoutOrder = Value; }

  BundleLockStateType getBundleLockState() const { return BundleLockState; }

  void setBundleLockState(BundleLockStateType NewState);

  bool isBundleLocked() const { return BundleLockState != NotBundleLocked; }

  bool isBundleGroupBeforeFirstInst() const {

    return BundleGroupBeforeFirstInst;

  }

  void setBundleGroupBeforeFirstInst(bool IsFirst) {

    BundleGroupBeforeFirstInst = IsFirst;

  }

  bool hasInstructions() const { return HasInstructions; }

  void setHasInstructions(bool Value) { HasInstructions = Value; }

  bool isRegistered() const { return IsRegistered; }

  void setIsRegistered(bool Value) { IsRegistered = Value; }

  MCSection::FragmentListType &getFragmentList() { return Fragments; }

  const MCSection::FragmentListType &getFragmentList() const {

    return const_cast<MCSection *>(this)->getFragmentList();

  }

  /// Support for MCFragment::getNextNode().

  static FragmentListType MCSection::*getSublistAccess(MCFragment *) {

    return &MCSection::Fragments;

  }

  const MCDummyFragment &getDummyFragment() const { return DummyFragment; }

  MCDummyFragment &getDummyFragment() { return DummyFragment; }

  MCSection::iterator begin();

  MCSection::const_iterator begin() const {

    return const_cast<MCSection *>(this)->begin();

  }

  MCSection::iterator end();

  MCSection::const_iterator end() const {

    return const_cast<MCSection *>(this)->end();

  }

  MCSection::reverse_iterator rbegin();

  MCSection::const_reverse_iterator rbegin() const {

    return const_cast<MCSection *>(this)->rbegin();

  }

  MCSection::reverse_iterator rend();

  MCSection::const_reverse_iterator rend() const {

    return const_cast<MCSection *>(this)->rend();

  }

  MCSection::iterator getSubsectionInsertionPoint(unsigned Subsection);

  void dump();

  virtual void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,

                                    const MCExpr *Subsection) const = 0;

  /// Return true if a .align directive should use "optimized nops" to fill

  /// instead of 0s.

  virtual bool UseCodeAlign() const = 0;

  /// Check whether this section is "virtual", that is has no actual object

  /// file contents.

  virtual bool isVirtualSection() const = 0;

};

} // end namespace llvm_ks

#endif