path: root/include/llvm/MC/MCAssembler.h

//===- MCAssembler.h - Object File Generation -------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_MC_MCASSEMBLER_H
#define LLVM_MC_MCASSEMBLER_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/ilist.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/DataTypes.h"
#include <vector> // FIXME: Shouldn't be needed.

namespace llvm {
class raw_ostream;
class MCAsmLayout;
class MCAssembler;
class MCContext;
class MCCodeEmitter;
class MCExpr;
class MCFragment;
class MCObjectWriter;
class MCSection;
class MCSectionData;
class MCSymbol;
class MCSymbolData;
class MCValue;
class MCAsmBackend;

class MCFragment : public ilist_node<MCFragment> {
  friend class MCAsmLayout;

  MCFragment(const MCFragment&) LLVM_DELETED_FUNCTION;
  void operator=(const MCFragment&) LLVM_DELETED_FUNCTION;

public:
  enum FragmentType {
    FT_Align,
    FT_Data,
    FT_CompactEncodedInst,
    FT_Fill,
    FT_Relaxable,
    FT_Org,
    FT_Dwarf,
    FT_DwarfFrame,
    FT_LEB
  };

private:
  FragmentType Kind;

  /// Parent - The data for the section this fragment is in.
  MCSectionData *Parent;

  /// Atom - The atom this fragment is in, as represented by it's defining
  /// symbol. Atom's are only used by backends which set
  /// \see MCAsmBackend::hasReliableSymbolDifference().
  MCSymbolData *Atom;

  /// @name Assembler Backend Data
  /// @{
  //
  // FIXME: This could all be kept private to the assembler implementation.

  /// Offset - The offset of this fragment in its section. This is ~0 until
  /// initialized.
  uint64_t Offset;

  /// LayoutOrder - The layout order of this fragment.
  unsigned LayoutOrder;

  /// @}

protected:
  MCFragment(FragmentType _Kind, MCSectionData *_Parent = 0);

public:
  // Only for sentinel.
  MCFragment();
  virtual ~MCFragment();

  FragmentType getKind() const { return Kind; }

  MCSectionData *getParent() const { return Parent; }
  void setParent(MCSectionData *Value) { Parent = Value; }

  MCSymbolData *getAtom() const { return Atom; }
  void setAtom(MCSymbolData *Value) { Atom = Value; }

  unsigned getLayoutOrder() const { return LayoutOrder; }
  void setLayoutOrder(unsigned Value) { LayoutOrder = Value; }

  /// \brief Does this fragment have instructions emitted into it? By default
  /// this is false, but specific fragment types may set it to true.
  virtual bool hasInstructions() const { return false; }

  /// \brief Should this fragment be placed at the end of an aligned bundle?
  virtual bool alignToBundleEnd() const { return false; }
  virtual void setAlignToBundleEnd(bool V) { }

  /// \brief Get the padding size that must be inserted before this fragment.
  /// Used for bundling. By default, no padding is inserted.
  /// Note that padding size is restricted to 8 bits. This is an optimization
  /// to reduce the amount of space used for each fragment. In practice, larger
  /// padding should never be required.
  virtual uint8_t getBundlePadding() const {
    return 0;
  }

  /// \brief Set the padding size for this fragment. By default it's a no-op,
  /// and only some fragments have a meaningful implementation.
  virtual void setBundlePadding(uint8_t N) {
  }

  void dump();
};

/// Interface implemented by fragments that contain encoded instructions and/or
/// data.
///
class MCEncodedFragment : public MCFragment {
  virtual void anchor();

  uint8_t BundlePadding;
public:
  MCEncodedFragment(MCFragment::FragmentType FType, MCSectionData *SD = 0)
    : MCFragment(FType, SD), BundlePadding(0)
  {
  }
  virtual ~MCEncodedFragment();

  virtual