MCNullStreamer.cpp revision 263508 
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, 0) {}
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      AssignSection(Symbol, 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 bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute){
56      return true;
57    }
58
59    virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
60
61    virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
62    virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
63    virtual void EmitCOFFSymbolType(int Type) {}
64    virtual void EndCOFFSymbolDef() {}
65    virtual void EmitCOFFSecRel32(MCSymbol const *Symbol) {}
66
67    virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
68    virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
69                                  unsigned ByteAlignment) {}
70    virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
71                                       unsigned ByteAlignment) {}
72    virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
73                              uint64_t Size = 0, unsigned ByteAlignment = 0) {}
74    virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
75                                uint64_t Size, unsigned ByteAlignment) {}
76    virtual void EmitBytes(StringRef Data) {}
77
78    virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {}
79    virtual void EmitULEB128Value(const MCExpr *Value) {}
80    virtual void EmitSLEB128Value(const MCExpr *Value) {}
81    virtual void EmitGPRel32Value(const MCExpr *Value) {}
82    virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
83                                      unsigned ValueSize = 1,
84                                      unsigned MaxBytesToEmit = 0) {}
85
86    virtual void EmitCodeAlignment(unsigned ByteAlignment,
87                                   unsigned MaxBytesToEmit = 0) {}
88
89    virtual bool EmitValueToOffset(const MCExpr *Offset,
90                                   unsigned char Value = 0) { return false; }
91
92    virtual void EmitFileDirective(StringRef Filename) {}
93    virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
94                                        StringRef Filename, unsigned CUID = 0) {
95      return false;
96    }
97    virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
98                                       unsigned Column, unsigned Flags,
99                                       unsigned Isa, unsigned Discriminator,
100                                       StringRef FileName) {}
101    virtual void EmitInstruction(const MCInst &Inst) {}
102
103    virtual void EmitBundleAlignMode(unsigned AlignPow2) {}
104    virtual void EmitBundleLock(bool AlignToEnd) {}
105    virtual void EmitBundleUnlock() {}
106
107    virtual void FinishImpl() {}
108
109    virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
110      RecordProcEnd(Frame);
111    }
112  };
113
114}
115
116MCStreamer *llvm::createNullStreamer(MCContext &Context) {
117  return new MCNullStreamer(Context);
118}
119