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 std::unique_ptr<MCObjectWriter> ObjectWriter; 38 std::unique_ptr<MCAsmBackend> TAB; 39 std::unique_ptr<MCCodeEmitter> Emitter; 40 std::unique_ptr<MCAssembler> Assembler; 41 MCSection::iterator CurInsertionPoint; 42 bool EmitEHFrame; 43 bool EmitDebugFrame; 44 SmallVector<MCSymbol *, 2> PendingLabels; 45 46 virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0; 47 void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override; 48 void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override; 49 MCSymbol *EmitCFILabel() override; 50 51 protected: 52 MCObjectStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> TAB, 53 raw_pwrite_stream &OS, 54 std::unique_ptr<MCCodeEmitter> Emitter); 55 ~MCObjectStreamer(); 56 57 public: 58 /// state management 59 void reset() override; 60 61 /// Object streamers require the integrated assembler. 62 bool isIntegratedAssemblerRequired() const override { return true; } 63 64 void EmitFrames(MCAsmBackend *MAB); 65 void EmitCFISections(bool EH, bool Debug) override; 66 67 MCFragment *getCurrentFragment() const; 68 69 void insert(MCFragment *F) { 70 flushPendingLabels(F); 71 MCSection *CurSection = getCurrentSectionOnly(); 72 CurSection->getFragmentList().insert(CurInsertionPoint, F); 73 F->setParent(CurSection); 74 } 75 76 /// Get a data fragment to write into, creating a new one if the current 77 /// fragment is not a data fragment. 78 MCDataFragment *getOrCreateDataFragment(); 79 80 protected: 81 bool changeSectionImpl(MCSection *Section, const MCExpr *Subsection); 82 83 /// If any labels have been emitted but not assigned fragments, ensure that 84 /// they get assigned, either to F if possible or to a new data fragment. 85 /// Optionally, it is also possible to provide an offset \p FOffset, which 86 /// will be used as a symbol offset within the fragment. 87 void flushPendingLabels(MCFragment *F, uint64_t FOffset = 0); 88 89 public: 90 void visitUsedSymbol(const MCSymbol &Sym) override; 91 92 MCAssembler &getAssembler() { return *Assembler; } 93 94 /// \name MCStreamer Interface 95 /// @{ 96 97 void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override; 98 virtual void EmitLabel(MCSymbol *Symbol, SMLoc Loc, MCFragment *F); 99 void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override; 100 void EmitValueImpl(const MCExpr *Value, unsigned Size, 101 SMLoc Loc = SMLoc()) override; 102 void EmitULEB128Value(const MCExpr *Value) override; 103 void EmitSLEB128Value(const MCExpr *Value) override; 104 void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override; 105 void ChangeSection(MCSection *Section, const MCExpr *Subsection) override; 106 void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI, 107 bool = false) override; 108 109 /// \brief Emit an instruction to a special fragment, because this instruction 110 /// can change its size during relaxation. 111 virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &); 112 113 void EmitBundleAlignMode(unsigned AlignPow2) override; 114 void EmitBundleLock(bool AlignToEnd) override; 115 void EmitBundleUnlock() override; 116 void EmitBytes(StringRef Data) override; 117 void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 118 unsigned ValueSize = 1, 119 unsigned MaxBytesToEmit = 0) override; 120 void EmitCodeAlignment(unsigned ByteAlignment, 121 unsigned MaxBytesToEmit = 0) override; 122 void emitValueToOffset(const MCExpr *Offset, unsigned char Value, 123 SMLoc Loc) override; 124 void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 125 unsigned Column, unsigned Flags, 126 unsigned Isa, unsigned Discriminator, 127 StringRef FileName) override; 128 void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel, 129 const MCSymbol *Label, 130 unsigned PointerSize); 131 void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel, 132 const MCSymbol *Label); 133 void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line, 134 unsigned Column, bool PrologueEnd, bool IsStmt, 135 StringRef FileName, SMLoc Loc) override; 136 void EmitCVLinetableDirective(unsigned FunctionId, const MCSymbol *Begin, 137 const MCSymbol *End) override; 138 void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId, 139 unsigned SourceFileId, 140 unsigned SourceLineNum, 141 const MCSymbol *FnStartSym, 142 const MCSymbol *FnEndSym) override; 143 void EmitCVDefRangeDirective( 144 ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges, 145 StringRef FixedSizePortion) override; 146 void EmitCVStringTableDirective() override; 147 void EmitCVFileChecksumsDirective() override; 148 void EmitCVFileChecksumOffsetDirective(unsigned FileNo) override; 149 void EmitDTPRel32Value(const MCExpr *Value) override; 150 void EmitDTPRel64Value(const MCExpr *Value) override; 151 void EmitTPRel32Value(const MCExpr *Value) override; 152 void EmitTPRel64Value(const MCExpr *Value) override; 153 void EmitGPRel32Value(const MCExpr *Value) override; 154 void EmitGPRel64Value(const MCExpr *Value) override; 155 bool EmitRelocDirective(const MCExpr &Offset, StringRef Name, 156 const MCExpr *Expr, SMLoc Loc) override; 157 using MCStreamer::emitFill; 158 void emitFill(uint64_t NumBytes, uint8_t FillValue) override; 159 void emitFill(const MCExpr &NumBytes, uint64_t FillValue, 160 SMLoc Loc = SMLoc()) override; 161 void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr, 162 SMLoc Loc = SMLoc()) override; 163 void EmitFileDirective(StringRef Filename) override; 164 165 void FinishImpl() override; 166 167 /// Emit the absolute difference between two symbols if possible. 168 /// 169 /// Emit the absolute difference between \c Hi and \c Lo, as long as we can 170 /// compute it. Currently, that requires that both symbols are in the same 171 /// data fragment. Otherwise, do nothing and return \c false. 172 /// 173 /// \pre Offset of \c Hi is greater than the offset \c Lo. 174 void emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo, 175 unsigned Size) override; 176 177 bool mayHaveInstructions(MCSection &Sec) const override; 178 }; 179 180 } // end namespace llvm 181 182 #endif 183
