1 //===- MCObjectStreamer.h - MCStreamer Object File Interface ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_MC_MCOBJECTSTREAMER_H
11 #define LLVM_MC_MCOBJECTSTREAMER_H
13 #include "llvm/MC/MCAssembler.h"
14 #include "llvm/MC/MCStreamer.h"
20 class MCSubtargetInfo;
27 /// \brief Streaming object file generation interface.
29 /// This class provides an implementation of the MCStreamer interface which is
30 /// suitable for use with the assembler backend. Specific object file formats
31 /// are expected to subclass this interface to implement directives specific
32 /// to that file format or custom semantics expected by the object writer
34 class MCObjectStreamer : public MCStreamer {
35 MCAssembler *Assembler;
36 MCSectionData *CurSectionData;
37 MCSectionData::iterator CurInsertionPoint;
41 virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0;
42 void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
43 void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
46 MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &_OS,
47 MCCodeEmitter *_Emitter);
48 MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &_OS,
49 MCCodeEmitter *_Emitter, MCAssembler *_Assembler);
54 void reset() override;
56 /// Object streamers require the integrated assembler.
57 bool isIntegratedAssemblerRequired() const override { return true; }
59 MCSymbolData &getOrCreateSymbolData(const MCSymbol *Symbol) {
60 return getAssembler().getOrCreateSymbolData(*Symbol);
62 void EmitFrames(MCAsmBackend *MAB);
63 void EmitCFISections(bool EH, bool Debug) override;
66 MCSectionData *getCurrentSectionData() const {
67 return CurSectionData;
70 MCFragment *getCurrentFragment() const;
72 void insert(MCFragment *F) const {
73 CurSectionData->getFragmentList().insert(CurInsertionPoint, F);
74 F->setParent(CurSectionData);
77 /// Get a data fragment to write into, creating a new one if the current
78 /// fragment is not a data fragment.
79 MCDataFragment *getOrCreateDataFragment() const;
82 void visitUsedSymbol(const MCSymbol &Sym) override;
84 MCAssembler &getAssembler() { return *Assembler; }
86 /// @name MCStreamer Interface
89 void EmitLabel(MCSymbol *Symbol) override;
90 void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
91 void EmitValueImpl(const MCExpr *Value, unsigned Size,
92 const SMLoc &Loc = SMLoc()) override;
93 void EmitULEB128Value(const MCExpr *Value) override;
94 void EmitSLEB128Value(const MCExpr *Value) override;
95 void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
96 void ChangeSection(const MCSection *Section,
97 const MCExpr *Subsection) override;
98 void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo& STI) override;
100 /// \brief Emit an instruction to a special fragment, because this instruction
101 /// can change its size during relaxation.
102 virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &);
104 void EmitBundleAlignMode(unsigned AlignPow2) override;
105 void EmitBundleLock(bool AlignToEnd) override;
106 void EmitBundleUnlock() override;
107 void EmitBytes(StringRef Data) override;
108 void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
109 unsigned ValueSize = 1,
110 unsigned MaxBytesToEmit = 0) override;
111 void EmitCodeAlignment(unsigned ByteAlignment,
112 unsigned MaxBytesToEmit = 0) override;
113 bool EmitValueToOffset(const MCExpr *Offset, unsigned char Value) override;
114 void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
115 unsigned Column, unsigned Flags,
116 unsigned Isa, unsigned Discriminator,
117 StringRef FileName) override;
118 void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel,
119 const MCSymbol *Label,
120 unsigned PointerSize);
121 void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
122 const MCSymbol *Label);
123 void EmitGPRel32Value(const MCExpr *Value) override;
124 void EmitGPRel64Value(const MCExpr *Value) override;
125 void EmitFill(uint64_t NumBytes, uint8_t FillValue) override;
126 void EmitZeros(uint64_t NumBytes) override;
127 void FinishImpl() override;
129 virtual bool mayHaveInstructions() const {
130 return getCurrentSectionData()->hasInstructions();
134 } // end namespace llvm