1 //===- MCELFStreamer.h - MCStreamer ELF 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_MCELFSTREAMER_H
11 #define LLVM_MC_MCELFSTREAMER_H
12 
13 #include "llvm/ADT/SmallPtrSet.h"
14 #include "llvm/MC/MCDirectives.h"
15 #include "llvm/MC/MCObjectStreamer.h"
16 #include "llvm/MC/SectionKind.h"
17 #include "llvm/Support/DataTypes.h"
18 
19 namespace llvm {
20 class MCAsmBackend;
21 class MCAssembler;
22 class MCCodeEmitter;
23 class MCExpr;
24 class MCInst;
25 class raw_ostream;
26 
27 class MCELFStreamer : public MCObjectStreamer {
28 public:
MCELFStreamer(MCContext & Context,MCAsmBackend & TAB,raw_pwrite_stream & OS,MCCodeEmitter * Emitter)29   MCELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_pwrite_stream &OS,
30                 MCCodeEmitter *Emitter)
31       : MCObjectStreamer(Context, TAB, OS, Emitter), SeenIdent(false) {}
32 
33   ~MCELFStreamer() override;
34 
35   /// state management
reset()36   void reset() override {
37     SeenIdent = false;
38     BundleGroups.clear();
39     MCObjectStreamer::reset();
40   }
41 
42   /// \name MCStreamer Interface
43   /// @{
44 
45   void InitSections(bool NoExecStack) override;
46   void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
47   void EmitLabel(MCSymbol *Symbol) override;
48   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
49   void EmitThumbFunc(MCSymbol *Func) override;
50   void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
51   bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
52   void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) override;
53   void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
54                         unsigned ByteAlignment) override;
55   void BeginCOFFSymbolDef(const MCSymbol *Symbol) override;
56   void EmitCOFFSymbolStorageClass(int StorageClass) override;
57   void EmitCOFFSymbolType(int Type) override;
58   void EndCOFFSymbolDef() override;
59 
60   void emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) override;
61 
62   void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
63                              unsigned ByteAlignment) override;
64 
65   void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
66                     uint64_t Size = 0, unsigned ByteAlignment = 0) override;
67   void EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
68                       unsigned ByteAlignment = 0) override;
69   void EmitValueImpl(const MCExpr *Value, unsigned Size,
70                      SMLoc Loc = SMLoc()) override;
71 
72   void EmitFileDirective(StringRef Filename) override;
73 
74   void EmitIdent(StringRef IdentString) override;
75 
76   void EmitValueToAlignment(unsigned, int64_t, unsigned, unsigned) override;
77 
78   void FinishImpl() override;
79 
80   void EmitBundleAlignMode(unsigned AlignPow2) override;
81   void EmitBundleLock(bool AlignToEnd) override;
82   void EmitBundleUnlock() override;
83 
84 private:
85   bool isBundleLocked() const;
86   void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &) override;
87   void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo &) override;
88 
89   void fixSymbolsInTLSFixups(const MCExpr *expr);
90 
91   /// \brief Merge the content of the fragment \p EF into the fragment \p DF.
92   void mergeFragment(MCDataFragment *, MCDataFragment *);
93 
94   bool SeenIdent;
95 
96   /// BundleGroups - The stack of fragments holding the bundle-locked
97   /// instructions.
98   llvm::SmallVector<MCDataFragment *, 4> BundleGroups;
99 };
100 
101 MCELFStreamer *createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
102                                     raw_pwrite_stream &OS,
103                                     MCCodeEmitter *Emitter, bool RelaxAll,
104                                     bool IsThumb);
105 
106 } // end namespace llvm
107 
108 #endif
109