MCNullStreamer.cpp revision f410608271b6318bfc9e26c0d199f185d5a89ccb 
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 ChangeSection(const MCSection *Section) {
32    }
33
34    virtual void EmitLabel(MCSymbol *Symbol) {
35      assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
36      assert(getCurrentSection() && "Cannot emit before setting section!");
37      Symbol->setSection(*getCurrentSection());
38    }
39
40    virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
41    virtual void EmitThumbFunc(MCSymbol *Func) {}
42
43    virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
44    virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol){}
45    virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
46                                          const MCSymbol *LastLabel,
47                                          const MCSymbol *Label) {}
48
49    virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute){}
50
51    virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
52
53    virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
54    virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
55    virtual void EmitCOFFSymbolType(int Type) {}
56    virtual void EndCOFFSymbolDef() {}
57    virtual void EmitCOFFSecRel32(MCSymbol const *Symbol) {}
58
59    virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
60    virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
61                                  unsigned ByteAlignment) {}
62    virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {}
63
64    virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
65                              unsigned Size = 0, unsigned ByteAlignment = 0) {}
66    virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
67                                uint64_t Size, unsigned ByteAlignment) {}
68    virtual void EmitBytes(StringRef Data, unsigned AddrSpace) {}
69
70    virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
71                               bool isPCRel, unsigned AddrSpace) {}
72    virtual void EmitULEB128Value(const MCExpr *Value,
73                                  unsigned AddrSpace = 0) {}
74    virtual void EmitSLEB128Value(const MCExpr *Value,
75                                  unsigned AddrSpace = 0) {}
76    virtual void EmitGPRel32Value(const MCExpr *Value) {}
77    virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
78                                      unsigned ValueSize = 1,
79                                      unsigned MaxBytesToEmit = 0) {}
80
81    virtual void EmitCodeAlignment(unsigned ByteAlignment,
82                                   unsigned MaxBytesToEmit = 0) {}
83
84    virtual void EmitValueToOffset(const MCExpr *Offset,
85                                   unsigned char Value = 0) {}
86
87    virtual void EmitFileDirective(StringRef Filename) {}
88    virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename) {
89      return false;
90    }
91    virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
92                                       unsigned Column, unsigned Flags,
93                                       unsigned Isa, unsigned Discriminator) {}
94    virtual void EmitInstruction(const MCInst &Inst) {}
95
96    virtual void Finish() {}
97
98    /// @}
99  };
100
101}
102
103MCStreamer *llvm::createNullStreamer(MCContext &Context) {
104  return new MCNullStreamer(Context);
105}
106