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(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    }
35
36    virtual void EmitLabel(MCSymbol *Symbol) {
37      assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
38      assert(getCurrentSection() && "Cannot emit before setting section!");
39      Symbol->setSection(*getCurrentSection());
40    }
41    virtual void EmitDebugLabel(MCSymbol *Symbol) {
42      EmitLabel(Symbol);
43    }
44    virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {}
45    virtual void EmitThumbFunc(MCSymbol *Func) {}
46
47    virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
48    virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol){}
49    virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
50                                          const MCSymbol *LastLabel,
51                                          const MCSymbol *Label,
52                                          unsigned PointerSize) {}
53
54    virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute){}
55
56    virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
57
58    virtual void BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
59    virtual void EmitCOFFSymbolStorageClass(int StorageClass) {}
60    virtual void EmitCOFFSymbolType(int Type) {}
61    virtual void EndCOFFSymbolDef() {}
62    virtual void EmitCOFFSecRel32(MCSymbol const *Symbol) {}
63
64    virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
65    virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
66                                  unsigned ByteAlignment) {}
67    virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
68                                       unsigned ByteAlignment) {}
69    virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
70                              uint64_t Size = 0, unsigned ByteAlignment = 0) {}
71    virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
72                                uint64_t Size, unsigned ByteAlignment) {}
73    virtual void EmitBytes(StringRef Data, unsigned AddrSpace) {}
74
75    virtual void EmitValueImpl(const MCExpr *Value, unsigned Size,
76                               unsigned AddrSpace) {}
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
121MCStreamer *llvm::createNullStreamer(MCContext &Context) {
122  return new MCNullStreamer(Context);
123}
124