1 //===- lib/MC/MCNullStreamer.cpp - Dummy Streamer Implementation ----------===// 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 #include "llvm/MC/MCStreamer.h" 11 #include "llvm/MC/MCContext.h" 12 #include "llvm/MC/MCInst.h" 13 #include "llvm/MC/MCSectionMachO.h" 14 #include "llvm/MC/MCSymbol.h" 15 16 using namespace llvm; 17 18 namespace { 19 20 class MCNullStreamer : public MCStreamer { 21 public: 22 MCNullStreamer(MCContext &Context) : MCStreamer(SK_NullStreamer, Context) {} 23 24 /// @name MCStreamer Interface 25 /// @{ 26 27 virtual void InitToTextSection() { 28 } 29 30 virtual void InitSections() { 31 } 32 33 virtual void ChangeSection(const MCSection *Section, 34 const MCExpr *Subsection) { 35 } 36 37 virtual void EmitLabel(MCSymbol *Symbol) { 38 assert(Symbol->isUndefined() && "Cannot define a symbol twice!"); 39 assert(getCurrentSection().first &&"Cannot emit before setting section!"); 40 Symbol->setSection(*getCurrentSection().first); 41 } 42 virtual void EmitDebugLabel(MCSymbol *Symbol) { 43 EmitLabel(Symbol); 44 } 45 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {} 46 virtual void EmitThumbFunc(MCSymbol *Func) {} 47 48 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {} 49 virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol){} 50 virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta, 51 const MCSymbol *LastLabel, 52 const MCSymbol *Label, 53 unsigned PointerSize) {} 54 55 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute){} 56 57 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {} 58 59 virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {} 60 virtual void EmitCOFFSymbolStorageClass(int StorageClass) {} 61 virtual void EmitCOFFSymbolType(int Type) {} 62 virtual void EndCOFFSymbolDef() {} 63 virtual void EmitCOFFSecRel32(MCSymbol const *Symbol) {} 64 65 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {} 66 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size, 67 unsigned ByteAlignment) {} 68 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size, 69 unsigned ByteAlignment) {} 70 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0, 71 uint64_t Size = 0, unsigned ByteAlignment = 0) {} 72 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol, 73 uint64_t Size, unsigned ByteAlignment) {} 74 virtual void EmitBytes(StringRef Data) {} 75 76 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {} 77 virtual void EmitULEB128Value(const MCExpr *Value) {} 78 virtual void EmitSLEB128Value(const MCExpr *Value) {} 79 virtual void EmitGPRel32Value(const MCExpr *Value) {} 80 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0, 81 unsigned ValueSize = 1, 82 unsigned MaxBytesToEmit = 0) {} 83 84 virtual void EmitCodeAlignment(unsigned ByteAlignment, 85 unsigned MaxBytesToEmit = 0) {} 86 87 virtual bool EmitValueToOffset(const MCExpr *Offset, 88 unsigned char Value = 0) { return false; } 89 90 virtual void EmitFileDirective(StringRef Filename) {} 91 virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory, 92 StringRef Filename, unsigned CUID = 0) { 93 return false; 94 } 95 virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line, 96 unsigned Column, unsigned Flags, 97 unsigned Isa, unsigned Discriminator, 98 StringRef FileName) {} 99 virtual void EmitInstruction(const MCInst &Inst) {} 100 101 virtual void EmitBundleAlignMode(unsigned AlignPow2) {} 102 virtual void EmitBundleLock(bool AlignToEnd) {} 103 virtual void EmitBundleUnlock() {} 104 105 virtual void FinishImpl() {} 106 107 virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) { 108 RecordProcEnd(Frame); 109 } 110 111 /// @} 112 113 static bool classof(const MCStreamer *S) { 114 return S->getKind() == SK_NullStreamer; 115 } 116 117 }; 118 119 } 120 121 MCStreamer *llvm::createNullStreamer(MCContext &Context) { 122 return new MCNullStreamer(Context); 123 } 124