1 //===- MCObjectStreamer.h - MCStreamer Object File Interface ----*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_MC_MCOBJECTSTREAMER_H 11 #define LLVM_MC_MCOBJECTSTREAMER_H 12 13 #include "llvm/ADT/SmallVector.h" 14 #include "llvm/MC/MCAssembler.h" 15 #include "llvm/MC/MCStreamer.h" 16 17 namespace llvm { 18 class MCAssembler; 19 class MCCodeEmitter; 20 class MCSectionData; 21 class MCSubtargetInfo; 22 class MCExpr; 23 class MCFragment; 24 class MCDataFragment; 25 class MCAsmBackend; 26 class raw_ostream; 27 28 /// \brief Streaming object file generation interface. 29 /// 30 /// This class provides an implementation of the MCStreamer interface which is 31 /// suitable for use with the assembler backend. Specific object file formats 32 /// are expected to subclass this interface to implement directives specific 33 /// to that file format or custom semantics expected by the object writer 34 /// implementation. 35 class MCObjectStreamer : public MCStreamer { 36 MCAssembler *Assembler; 37 MCSectionData *CurSectionData; 38 MCSectionData::iterator CurInsertionPoint; 39 bool EmitEHFrame; 40 bool EmitDebugFrame; 41 SmallVector<MCSymbolData *, 2> PendingLabels; 42 43 virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0; 44 void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override; 45 void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override; 46 47 // If any labels have been emitted but not assigned fragments, ensure that 48 // they get assigned, either to F if possible or to a new data fragment. 49 void flushPendingLabels(MCFragment *F); 50 51 protected: 52 MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &_OS, 53 MCCodeEmitter *_Emitter); 54 MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &_OS, 55 MCCodeEmitter *_Emitter, MCAssembler *_Assembler); 56 ~MCObjectStreamer(); 57 58 public: 59 /// state management 60 void reset() override; 61 62 /// Object streamers require the integrated assembler. isIntegratedAssemblerRequired()63 bool isIntegratedAssemblerRequired() const override { return true; } 64 getOrCreateSymbolData(const MCSymbol * Symbol)65 MCSymbolData &getOrCreateSymbolData(const MCSymbol *Symbol) { 66 return getAssembler().getOrCreateSymbolData(*Symbol); 67 } 68 void EmitFrames(MCAsmBackend *MAB); 69 void EmitCFISections(bool EH, bool Debug) override; 70 71 protected: getCurrentSectionData()72 MCSectionData *getCurrentSectionData() const { 73 return CurSectionData; 74 } 75 76 MCFragment *getCurrentFragment() const; 77 insert(MCFragment * F)78 void insert(MCFragment *F) { 79 flushPendingLabels(F); 80 CurSectionData->getFragmentList().insert(CurInsertionPoint, F); 81 F->setParent(CurSectionData); 82 } 83 84 /// Get a data fragment to write into, creating a new one if the current 85 /// fragment is not a data fragment. 86 MCDataFragment *getOrCreateDataFragment(); 87 88 public: 89 void visitUsedSymbol(const MCSymbol &Sym) override; 90 getAssembler()91 MCAssembler &getAssembler() { return *Assembler; } 92 93 /// @name MCStreamer Interface 94 /// @{ 95 96 void EmitLabel(MCSymbol *Symbol) override; 97 void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override; 98 void EmitValueImpl(const MCExpr *Value, unsigned Size, 99 const SMLoc &Loc = SMLoc()) override; 100 void EmitULEB128Value(const MCExpr *Value) override; 101 void EmitSLEB128Value(const MCExpr *Value) override; 102 void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override; 103 void ChangeSection(const MCSection *Section, 104 const MCExpr *Subsection) override; 105 void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo& STI) override; 106 107 /// \brief Emit an instruction to a special fragment, because this instruction 108 /// can change its size during relaxation. 109 virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &); 110 111 void EmitBundleAlignMode(unsigned AlignPow2) override; 112 void EmitBundleLock(bool AlignToEnd) override; 113 void EmitBundleUnlock() override; 114 void EmitBytes(StringRef Data) override; 115 void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 116 unsigned ValueSize = 1, 117 unsigned MaxBytesToEmit = 0) override; 118 void EmitCodeAlignment(unsigned ByteAlignment, 119 unsigned MaxBytesToEmit = 0) override; 120 bool EmitValueToOffset(const MCExpr *Offset, unsigned char Value) override; 121 void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 122 unsigned Column, unsigned Flags, 123 unsigned Isa, unsigned Discriminator, 124 StringRef FileName) override; 125 void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, 126 const MCSymbol *Label, 127 unsigned PointerSize); 128 void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, 129 const MCSymbol *Label); 130 void EmitGPRel32Value(const MCExpr *Value) override; 131 void EmitGPRel64Value(const MCExpr *Value) override; 132 void EmitFill(uint64_t NumBytes, uint8_t FillValue) override; 133 void EmitZeros(uint64_t NumBytes) override; 134 void FinishImpl() override; 135 mayHaveInstructions()136 bool mayHaveInstructions() const override { 137 return getCurrentSectionData()->hasInstructions(); 138 } 139 }; 140 141 } // end namespace llvm 142 143 #endif 144