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 MCSubtargetInfo;
21class MCExpr;
22class MCFragment;
23class MCDataFragment;
24class MCAsmBackend;
25class raw_ostream;
26
27/// \brief Streaming object file generation interface.
28///
29/// This class provides an implementation of the MCStreamer interface which is
30/// suitable for use with the assembler backend. Specific object file formats
31/// are expected to subclass this interface to implement directives specific
32/// to that file format or custom semantics expected by the object writer
33/// implementation.
34class MCObjectStreamer : public MCStreamer {
35  MCAssembler *Assembler;
36  MCSectionData *CurSectionData;
37  MCSectionData::iterator CurInsertionPoint;
38  bool EmitEHFrame;
39  bool EmitDebugFrame;
40
41  virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo&) = 0;
42  void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
43  void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
44
45protected:
46  MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &_OS,
47                   MCCodeEmitter *_Emitter);
48  MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &_OS,
49                   MCCodeEmitter *_Emitter, MCAssembler *_Assembler);
50  ~MCObjectStreamer();
51
52public:
53  /// state management
54  void reset() override;
55
56  /// Object streamers require the integrated assembler.
57  bool isIntegratedAssemblerRequired() const override { return true; }
58
59  MCSymbolData &getOrCreateSymbolData(const MCSymbol *Symbol) {
60    return getAssembler().getOrCreateSymbolData(*Symbol);
61  }
62  void EmitFrames(MCAsmBackend *MAB);
63  void EmitCFISections(bool EH, bool Debug) override;
64
65protected:
66  MCSectionData *getCurrentSectionData() const {
67    return CurSectionData;
68  }
69
70  MCFragment *getCurrentFragment() const;
71
72  void insert(MCFragment *F) const {
73    CurSectionData->getFragmentList().insert(CurInsertionPoint, F);
74    F->setParent(CurSectionData);
75  }
76
77  /// Get a data fragment to write into, creating a new one if the current
78  /// fragment is not a data fragment.
79  MCDataFragment *getOrCreateDataFragment() const;
80
81public:
82  void visitUsedSymbol(const MCSymbol &Sym) override;
83
84  MCAssembler &getAssembler() { return *Assembler; }
85
86  /// @name MCStreamer Interface
87  /// @{
88
89  void EmitLabel(MCSymbol *Symbol) override;
90  void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
91  void EmitValueImpl(const MCExpr *Value, unsigned Size,
92                     const SMLoc &Loc = SMLoc()) override;
93  void EmitULEB128Value(const MCExpr *Value) override;
94  void EmitSLEB128Value(const MCExpr *Value) override;
95  void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
96  void ChangeSection(const MCSection *Section,
97                     const MCExpr *Subsection) override;
98  void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo& STI) override;
99
100  /// \brief Emit an instruction to a special fragment, because this instruction
101  /// can change its size during relaxation.
102  virtual void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &);
103
104  void EmitBundleAlignMode(unsigned AlignPow2) override;
105  void EmitBundleLock(bool AlignToEnd) override;
106  void EmitBundleUnlock() override;
107  void EmitBytes(StringRef Data) override;
108  void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
109                            unsigned ValueSize = 1,
110                            unsigned MaxBytesToEmit = 0) override;
111  void EmitCodeAlignment(unsigned ByteAlignment,
112                         unsigned MaxBytesToEmit = 0) override;
113  bool EmitValueToOffset(const MCExpr *Offset, unsigned char Value) override;
114  void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
115                             unsigned Column, unsigned Flags,
116                             unsigned Isa, unsigned Discriminator,
117                             StringRef FileName) override;
118  void EmitDwarfAdvanceLineAddr(int64_t LineDelta, const MCSymbol *LastLabel,
119                                const MCSymbol *Label,
120                                unsigned PointerSize);
121  void EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
122                                 const MCSymbol *Label);
123  void EmitGPRel32Value(const MCExpr *Value) override;
124  void EmitGPRel64Value(const MCExpr *Value) override;
125  void EmitFill(uint64_t NumBytes, uint8_t FillValue) override;
126  void EmitZeros(uint64_t NumBytes) override;
127  void FinishImpl() override;
128
129  virtual bool mayHaveInstructions() const {
130    return getCurrentSectionData()->hasInstructions();
131  }
132};
133
134} // end namespace llvm
135
136#endif
137