Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===- MCELFStreamer.h - MCStreamer ELF Object File Interface ---*- C++ -*-===//

//

// 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

//

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

#ifndef LLVM_MC_MCELFSTREAMER_H

#define LLVM_MC_MCELFSTREAMER_H

#include "llvm/ADT/SmallVector.h"

#include "llvm/MC/MCDirectives.h"

#include "llvm/MC/MCObjectStreamer.h"

namespace llvm {

class MCContext;

class MCDataFragment;

class MCFragment;

class MCObjectWriter;

class MCSection;

class MCSubtargetInfo;

class MCSymbol;

class MCSymbolRefExpr;

class MCAsmBackend;

class MCCodeEmitter;

class MCExpr;

class MCInst;

class MCELFStreamer : public MCObjectStreamer {

public:

  MCELFStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,

                std::unique_ptr<MCObjectWriter> OW,

                std::unique_ptr<MCCodeEmitter> Emitter);

  ~MCELFStreamer() override = default;

  /// state management

  void reset() override {

    SeenIdent = false;

    BundleGroups.clear();

    MCObjectStreamer::reset();

  }

  /// \name MCStreamer Interface

  /// @{

  void initSections(bool NoExecStack, const MCSubtargetInfo &STI) override;

  void changeSection(MCSection *Section, const MCExpr *Subsection) override;

  void emitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;

  void emitLabelAtPos(MCSymbol *Symbol, SMLoc Loc, MCFragment *F,

                      uint64_t Offset) override;

  void emitAssemblerFlag(MCAssemblerFlag Flag) override;

  void emitThumbFunc(MCSymbol *Func) override;

  void emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;

  bool emitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;

  void emitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) override;

  void emitCommonSymbol(MCSymbol *Symbol, uint64_t Size,

                        Align ByteAlignment) override;

  void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;

  void emitELFSymverDirective(const MCSymbol *OriginalSym, StringRef Name,

                              bool KeepOriginalSym) override;

  void emitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,

                             Align ByteAlignment) override;

  void emitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,

                    uint64_t Size = 0, Align ByteAlignment = Align(1),

                    SMLoc L = SMLoc()) override;

  void emitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,

                      Align ByteAlignment = Align(1)) override;

  void emitValueImpl(const MCExpr *Value, unsigned Size,

                     SMLoc Loc = SMLoc()) override;

  void emitIdent(StringRef IdentString) override;

  void emitValueToAlignment(Align, int64_t, unsigned, unsigned) override;

  void emitCGProfileEntry(const MCSymbolRefExpr *From,

                          const MCSymbolRefExpr *To, uint64_t Count) override;

  void finishImpl() override;

  void emitBundleAlignMode(Align Alignment) override;

  void emitBundleLock(bool AlignToEnd) override;

  void emitBundleUnlock() override;

  /// ELF object attributes section emission support

  struct AttributeItem {

    // This structure holds all attributes, accounting for their string /

    // numeric value, so we can later emit them in declaration order, keeping

    // all in the same vector.

    enum {

      HiddenAttribute = 0,

      NumericAttribute,

      TextAttribute,

      NumericAndTextAttributes

    } Type;

    unsigned Tag;

    unsigned IntValue;

    std::string StringValue;

  };

  // Attributes that are added and managed entirely by target.

  SmallVector<AttributeItem, 64> Contents;

  void setAttributeItem(unsigned Attribute, unsigned Value,

                        bool OverwriteExisting);

  void setAttributeItem(unsigned Attribute, StringRef Value,

                        bool OverwriteExisting);

  void setAttributeItems(unsigned Attribute, unsigned IntValue,

                         StringRef StringValue, bool OverwriteExisting);

  void emitAttributesSection(StringRef Vendor, const Twine &Section,

                             unsigned Type, MCSection *&AttributeSection) {

    createAttributesSection(Vendor, Section, Type, AttributeSection, Contents);

  }

private:

  AttributeItem *getAttributeItem(unsigned Attribute);

  size_t calculateContentSize(SmallVector<AttributeItem, 64> &AttrsVec);

  void createAttributesSection(StringRef Vendor, const Twine &Section,

                               unsigned Type, MCSection *&AttributeSection,

                               SmallVector<AttributeItem, 64> &AttrsVec);

  // GNU attributes that will get emitted at the end of the asm file.

  SmallVector<AttributeItem, 64> GNUAttributes;

public:

  void emitGNUAttribute(unsigned Tag, unsigned Value) override {

    AttributeItem Item = {AttributeItem::NumericAttribute, Tag, Value,

                          std::string(StringRef(""))};

    GNUAttributes.push_back(Item);

  }

private:

  bool isBundleLocked() const;

  void emitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &) override;

  void emitInstToData(const MCInst &Inst, const MCSubtargetInfo &) override;

  void fixSymbolsInTLSFixups(const MCExpr *expr);

  void finalizeCGProfileEntry(const MCSymbolRefExpr *&S, uint64_t Offset);

  void finalizeCGProfile();

  /// Merge the content of the fragment \p EF into the fragment \p DF.

  void mergeFragment(MCDataFragment *, MCDataFragment *);

  bool SeenIdent = false;

  /// BundleGroups - The stack of fragments holding the bundle-locked

  /// instructions.

  SmallVector<MCDataFragment *, 4> BundleGroups;

};

MCELFStreamer *createARMELFStreamer(MCContext &Context,

                                    std::unique_ptr<MCAsmBackend> TAB,

                                    std::unique_ptr<MCObjectWriter> OW,

                                    std::unique_ptr<MCCodeEmitter> Emitter,

                                    bool RelaxAll, bool IsThumb, bool IsAndroid);

} // end namespace llvm

#endif // LLVM_MC_MCELFSTREAMER_H