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/MCSection.h" 16 #include "llvm/MC/MCStreamer.h" 17 18 namespace llvm { 19 class MCAssembler; 20 class MCCodeEmitter; 21 class MCSubtargetInfo; 22 class MCExpr; 23 class MCFragment; 24 class MCDataFragment; 25 class MCAsmBackend; 26 class raw_ostream; 27 class raw_pwrite_stream; 28 29 /// \brief Streaming object file generation interface. 30 /// 31 /// This class provides an implementation of the MCStreamer interface which is 32 /// suitable for use with the assembler backend. Specific object file formats 33 /// are expected to subclass this interface to implement directives specific 34 /// to that file format or custom semantics expected by the object writer 35 /// implementation. 36 class MCObjectStreamer : public MCStreamer { 37 MCAssembler *Assembler; 38 MCSection::iterator CurInsertionPoint; 39 bool EmitEHFrame; 40 bool EmitDebugFrame; 41 SmallVector<MCSymbol *, 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 protected: 48 MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, raw_pwrite_stream &OS, 49 MCCodeEmitter *Emitter); 50 ~MCObjectStreamer() override; 51 52 public: 53 /// state management 54 void reset() override; 55 56 /// Object streamers require the integrated assembler. 57 bool isIntegratedAssemblerRequired() const override { return true; } 58 59 void EmitFrames(MCAsmBackend *MAB); 60 void EmitCFISections(bool EH, bool Debug) override; 61 62 MCFragment *getCurrentFragment() const; 63 64 void insert(MCFragment *F) { 65 flushPendingLabels(F); 66 MCSection *CurSection = getCurrentSectionOnly(); 67 CurSection->getFragmentList().insert(CurInsertionPoint, F); 68 F->setParent(CurSection); 69 } 70 71 /// Get a data fragment to write into, creating a new one if the current 72 /// fragment is not a data fragment. 73 MCDataFragment *getOrCreateDataFragment(); 74 75 protected: 76 bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection); 77 78 /// If any labels have been emitted but not assigned fragments, ensure that 79 /// they get assigned, either to F if possible or to a new data fragment. 80 /// Optionally, it is also possible to provide an offset \p FOffset, which 81 /// will be used as a symbol offset within the fragment. 82 void flushPendingLabels(MCFragment *F, uint64_t FOffset = 0); 83 84 public: 85 void visitUsedSymbol(const MCSymbol &Sym) override; 86 87 MCAssembler &getAssembler() { return *Assembler; } 88 89 /// \name MCStreamer Interface 90 /// @{ 91 92 void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override; 93 virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F); 94 void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override; 95 void EmitValueImpl(const MCExpr *Value, unsigned Size, 96 SMLoc Loc = SMLoc()) override; 97 void EmitULEB128Value(const MCExpr *Value) override; 98 void EmitSLEB128Value(const MCExpr *Value) override; 99 void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override; 100 void ChangeSection(MCSection *Section, const MCExpr *Subsection) override; 101 void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI, 102 bool = false) override; 103 104 /// \brief Emit an instruction to a special fragment, because this instruction 105 /// can change its size during relaxation. 106 virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &); 107 108 void EmitBundleAlignMode(unsigned AlignPow2) override; 109 void EmitBundleLock(bool AlignToEnd) override; 110 void EmitBundleUnlock() override; 111 void EmitBytes(StringRef Data) override; 112 void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 113 unsigned ValueSize = 1, 114 unsigned MaxBytesToEmit = 0) override; 115 void EmitCodeAlignment(unsigned ByteAlignment, 116 unsigned MaxBytesToEmit = 0) override; 117 void emitValueToOffset(const MCExpr *Offset, unsigned char Value, 118 SMLoc Loc) override; 119 void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 120 unsigned Column, unsigned Flags, 121 unsigned Isa, unsigned Discriminator, 122 StringRef FileName) override; 123 void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, 124 const MCSymbol *Label, 125 unsigned PointerSize); 126 void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, 127 const MCSymbol *Label); 128 void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line, 129 unsigned Column, bool PrologueEnd, bool IsStmt, 130 StringRef FileName, SMLoc Loc) override; 131 void EmitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin, 132 const MCSymbol *End) override; 133 void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId, 134 unsigned SourceFileId, 135 unsigned SourceLineNum, 136 const MCSymbol *FnStartSym, 137 const MCSymbol *FnEndSym) override; 138 void EmitCVDefRangeDirective( 139 ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges, 140 StringRef FixedSizePortion) override; 141 void EmitCVStringTableDirective() override; 142 void EmitCVFileChecksumsDirective() override; 143 void EmitDTPRel32Value(const MCExpr *Value) override; 144 void EmitDTPRel64Value(const MCExpr *Value) override; 145 void EmitTPRel32Value(const MCExpr *Value) override; 146 void EmitTPRel64Value(const MCExpr *Value) override; 147 void EmitGPRel32Value(const MCExpr *Value) override; 148 void EmitGPRel64Value(const MCExpr *Value) override; 149 bool EmitRelocDirective(const MCExpr &Offset, StringRef Name, 150 const MCExpr *Expr, SMLoc Loc) override; 151 using MCStreamer::emitFill; 152 void emitFill(uint64_t NumBytes, uint8_t FillValue) override; 153 void emitFill(const MCExpr &NumBytes, uint64_t FillValue, 154 SMLoc Loc = SMLoc()) override; 155 void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr, 156 SMLoc Loc = SMLoc()) override; 157 void EmitFileDirective(StringRef Filename) override; 158 159 void FinishImpl() override; 160 161 /// Emit the absolute difference between two symbols if possible. 162 /// 163 /// Emit the absolute difference between \c Hi and \c Lo, as long as we can 164 /// compute it. Currently, that requires that both symbols are in the same 165 /// data fragment. Otherwise, do nothing and return \c false. 166 /// 167 /// \pre Offset of \c Hi is greater than the offset \c Lo. 168 void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo, 169 unsigned Size) override; 170 171 bool mayHaveInstructions(MCSection &Sec) const override; 172 }; 173 174 } // end namespace llvm 175 176 #endif 177
