Home | History | Annotate | Download | only in MC 
      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