MCNullStreamer.cpp revision 2c3a4641a7785da78839caf574277df9cd93b52c 
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
16using namespace llvm;
17
18namespace {
19
20  class MCNullStreamer : public MCStreamer {
21  public:
22    MCNullStreamer(MCContext &Context) : MCStreamer(Context) {}
23
24    /// @name MCStreamer Interface
25    /// @{
26
27    virtual void InitSections() {
28    }
29
30    virtual void ChangeSection(const MCSection *Section) {
31    }
32
33    virtual void EmitLabel(MCSymbol *Symbol) {
34      assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
35      assert(getCurrentSection() && "Cannot emit before setting section!");
36      Symbol->setSection(*getCurrentSection());
37    }
38    virtual void EmitDebugLabel(MCSymbol *Symbol) {
39      EmitLabel(Symbol);
40    }
41    virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
42    virtual void EmitThumbFunc(MCSymbol *Func) {}
43
44    virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
45    virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol){}
46    virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
47                                          const MCSymbol *LastLabel,
48                                          const MCSymbol *Label,
49                                          unsigned PointerSize) {}
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    virtual void EmitCOFFSecRel32(MCSymbol const *Symbol) {}
60
61    virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
62    virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
63                                  unsigned ByteAlignment) {}
64    virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
65                                       unsigned ByteAlignment) {}
66    virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
67                              uint64_t Size = 0, unsigned ByteAlignment = 0) {}
68    virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
69                                uint64_t Size, unsigned ByteAlignment) {}
70    virtual void EmitBytes(StringRef Data, unsigned AddrSpace) {}
71
72    virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
73                               unsigned AddrSpace) {}
74    virtual void EmitULEB128Value(const MCExpr *Value) {}
75    virtual void EmitSLEB128Value(const MCExpr *Value) {}
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 bool EmitValueToOffset(const MCExpr *Offset,
85                                   unsigned char Value = 0) { return false; }
86
87    virtual void EmitFileDirective(StringRef Filename) {}
88    virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
89                                        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                                       StringRef FileName) {}
96    virtual void EmitInstruction(const MCInst &Inst) {}
97
98    virtual void FinishImpl() {}
99
100    virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
101      RecordProcEnd(Frame);
102    }
103
104    /// @}
105  };
106
107}
108
109MCStreamer *llvm::createNullStreamer(MCContext &Context) {
110  return new MCNullStreamer(Context);
111}
112