MCNullStreamer.cpp revision f7fd4aa2610f46467369de07f3ec669561d79be0 
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
12#include "llvm/MC/MCContext.h"
13#include "llvm/MC/MCInst.h"
14#include "llvm/MC/MCSectionMachO.h"
15#include "llvm/MC/MCSymbol.h"
16
17using namespace llvm;
18
19namespace {
20
21  class MCNullStreamer : public MCStreamer {
22  public:
23    MCNullStreamer(MCContext &Context) : MCStreamer(Context) {}
24
25    /// @name MCStreamer Interface
26    /// @{
27
28    virtual void InitSections() {
29    }
30
31    virtual void SwitchSection(const MCSection *Section) {
32      PrevSection = CurSection;
33      CurSection = Section;
34    }
35
36    virtual void EmitLabel(MCSymbol *Symbol) {
37      assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
38      assert(CurSection && "Cannot emit before setting section!");
39      Symbol->setSection(*CurSection);
40    }
41
42    virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
43    virtual void EmitThumbFunc(MCSymbol *Func) {}
44
45    virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
46    virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol){}
47    virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
48                                          const MCSymbol *LastLabel,
49                                          const MCSymbol *Label) {}
50
51    virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute){}
52
53    virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
54
55    virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
56    virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
57    virtual void EmitCOFFSymbolType(int Type) {}
58    virtual void EndCOFFSymbolDef() {}
59
60    virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
61    virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
62                                  unsigned ByteAlignment) {}
63    virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {}
64
65    virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
66                              unsigned Size = 0, unsigned ByteAlignment = 0) {}
67    virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
68                                uint64_t Size, unsigned ByteAlignment) {}
69    virtual void EmitBytes(StringRef Data, unsigned AddrSpace) {}
70
71    virtual void EmitValue(const MCExpr *Value, unsigned Size,
72                           unsigned AddrSpace) {}
73    virtual void EmitULEB128Value(const MCExpr *Value,
74                                  unsigned AddrSpace = 0) {}
75    virtual void EmitSLEB128Value(const MCExpr *Value,
76                                  unsigned AddrSpace = 0) {}
77    virtual void EmitGPRel32Value(const MCExpr *Value) {}
78    virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
79                                      unsigned ValueSize = 1,
80                                      unsigned MaxBytesToEmit = 0) {}
81
82    virtual void EmitCodeAlignment(unsigned ByteAlignment,
83                                   unsigned MaxBytesToEmit = 0) {}
84
85    virtual void EmitValueToOffset(const MCExpr *Offset,
86                                   unsigned char Value = 0) {}
87
88    virtual void EmitFileDirective(StringRef Filename) {}
89    virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename) {
90      return false;
91    }
92    virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
93                                       unsigned Column, unsigned Flags,
94                                       unsigned Isa, unsigned Discriminator) {}
95    virtual void EmitInstruction(const MCInst &Inst) {}
96
97    virtual void Finish() {}
98
99    /// @}
100  };
101
102}
103
104MCStreamer *llvm::createNullStreamer(MCContext &Context) {
105  return new MCNullStreamer(Context);
106}
107