MCObjectStreamer.h revision a3863ea2dacafc925a8272ebf9884fc64bef686c 
1//===- MCObjectStreamer.h - MCStreamer Object File Interface ----*- C++ -*-===//
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#ifndef LLVM_MC_MCOBJECTSTREAMER_H
11#define LLVM_MC_MCOBJECTSTREAMER_H
12
13#include "llvm/MC/MCAssembler.h"
14#include "llvm/MC/MCStreamer.h"
15
16namespace llvm {
17class MCAssembler;
18class MCCodeEmitter;
19class MCSectionData;
20class MCExpr;
21class MCFragment;
22class MCDataFragment;
23class MCAsmBackend;
24class raw_ostream;
25
26/// \brief Streaming object file generation interface.
27///
28/// This class provides an implementation of the MCStreamer interface which is
29/// suitable for use with the assembler backend. Specific object file formats
30/// are expected to subclass this interface to implement directives specific
31/// to that file format or custom semantics expected by the object writer
32/// implementation.
33class MCObjectStreamer : public MCStreamer {
34  MCAssembler *Assembler;
35  MCSectionData *CurSectionData;
36  MCSectionData::iterator CurInsertionPoint;
37
38  virtual void EmitInstToData(const MCInst &Inst) = 0;
39  virtual void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame);
40  virtual void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame);
41
42protected:
43  MCObjectStreamer(StreamerKind Kind, MCContext &Context, MCAsmBackend &TAB,
44                   raw_ostream &_OS, MCCodeEmitter *_Emitter);
45  MCObjectStreamer(StreamerKind Kind, MCContext &Context, MCAsmBackend &TAB,
46                   raw_ostream &_OS, MCCodeEmitter *_Emitter,
47                   MCAssembler *_Assembler);
48  ~MCObjectStreamer();
49
50public:
51  /// state management
52  virtual void reset();
53
54protected:
55  MCSectionData *getCurrentSectionData() const {
56    return CurSectionData;
57  }
58
59  MCFragment *getCurrentFragment() const;
60
61  void insert(MCFragment *F) const {
62    CurSectionData->getFragmentList().insert(CurInsertionPoint, F);
63    F->setParent(CurSectionData);
64  }
65
66  /// Get a data fragment to write into, creating a new one if the current
67  /// fragment is not a data fragment.
68  MCDataFragment *getOrCreateDataFragment() const;
69
70  const MCExpr *AddValueSymbols(const MCExpr *Value);
71
72public:
73  MCAssembler &getAssembler() { return *Assembler; }
74
75  /// @name MCStreamer Interface
76  /// @{
77
78  virtual void EmitLabel(MCSymbol *Symbol);
79  virtual void EmitDebugLabel(MCSymbol *Symbol);
80  virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
81  virtual void EmitValueImpl(const MCExpr *Value, unsigned Size);
82  virtual void EmitULEB128Value(const MCExpr *Value);
83  virtual void EmitSLEB128Value(const MCExpr *Value);
84  virtual void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol);
85  virtual void ChangeSection(const MCSection *Section,
86                             const MCExpr *Subsection);
87  virtual void EmitInstruction(const MCInst &Inst);
88
89  /// \brief Emit an instruction to a special fragment, because this instruction
90  /// can change its size during relaxation.
91  virtual void EmitInstToFragment(const MCInst &Inst);
92
93  virtual void EmitBundleAlignMode(unsigned AlignPow2);
94  virtual void EmitBundleLock(bool AlignToEnd);
95  virtual void EmitBundleUnlock();
96  virtual void EmitBytes(StringRef Data);
97  virtual void EmitValueToAlignment(unsigned ByteAlignment,
98                                    int64_t Value = 0,
99                                    unsigned ValueSize = 1,
100                                    unsigned MaxBytesToEmit = 0);
101  virtual void EmitCodeAlignment(unsigned ByteAlignment,
102                                 unsigned MaxBytesToEmit = 0);
103  virtual bool EmitValueToOffset(const MCExpr *Offset, unsigned char Value);
104  virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
105                                     unsigned Column, unsigned Flags,
106                                     unsigned Isa, unsigned Discriminator,
107                                     StringRef FileName);
108  virtual void EmitDwarfAdvanceLineAddr(int64_t LineDelta,
109                                        const MCSymbol *LastLabel,
110                                        const MCSymbol *Label,
111                                        unsigned PointerSize);
112  virtual void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
113                                         const MCSymbol *Label);
114  virtual void EmitGPRel32Value(const MCExpr *Value);
115  virtual void EmitGPRel64Value(const MCExpr *Value);
116  virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue);
117  virtual void EmitZeros(uint64_t NumBytes);
118  virtual void FinishImpl();
119
120  /// @}
121
122  static bool classof(const MCStreamer *S) {
123    return S->getKind() >= SK_ELFStreamer && S->getKind() <= SK_WinCOFFStreamer;
124  }
125};
126
127} // end namespace llvm
128
129#endif
130