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 #include <vector>
19 
20 namespace llvm {
21 class MCAsmBackend;
22 class MCAssembler;
23 class MCCodeEmitter;
24 class MCExpr;
25 class MCInst;
26 class raw_ostream;
27 
28 class MCELFStreamer : public MCObjectStreamer {
29 public:
MCELFStreamer(MCContext & Context,MCAsmBackend & TAB,raw_pwrite_stream & OS,MCCodeEmitter * Emitter)30   MCELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_pwrite_stream &OS,
31                 MCCodeEmitter *Emitter)
32       : MCObjectStreamer(Context, TAB, OS, Emitter), SeenIdent(false) {}
33 
34   ~MCELFStreamer() override;
35 
36   /// state management
reset()37   void reset() override {
38     SeenIdent = false;
39     BundleGroups.clear();
40     MCObjectStreamer::reset();
41   }
42 
43   /// \name MCStreamer Interface
44   /// @{
45 
46   void InitSections(bool NoExecStack) override;
47   void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
48   void EmitLabel(MCSymbol *Symbol) override;
49   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
50   void EmitThumbFunc(MCSymbol *Func) override;
51   void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
52   bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
53   void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) override;
54   void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
55                         unsigned ByteAlignment) override;
56   void BeginCOFFSymbolDef(const MCSymbol *Symbol) override;
57   void EmitCOFFSymbolStorageClass(int StorageClass) override;
58   void EmitCOFFSymbolType(int Type) override;
59   void EndCOFFSymbolDef() override;
60 
61   void emitELFSize(MCSymbolELF *Symbol, const MCExpr *Value) override;
62 
63   void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
64                              unsigned ByteAlignment) override;
65 
66   void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
67                     uint64_t Size = 0, unsigned ByteAlignment = 0) override;
68   void EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
69                       unsigned ByteAlignment = 0) override;
70   void EmitValueImpl(const MCExpr *Value, unsigned Size,
71                      SMLoc Loc = SMLoc()) override;
72 
73   void EmitFileDirective(StringRef Filename) override;
74 
75   void EmitIdent(StringRef IdentString) override;
76 
77   void EmitValueToAlignment(unsigned, int64_t, unsigned, unsigned) override;
78 
79   void FinishImpl() override;
80 
81   void EmitBundleAlignMode(unsigned AlignPow2) override;
82   void EmitBundleLock(bool AlignToEnd) override;
83   void EmitBundleUnlock() override;
84 
85 private:
86   bool isBundleLocked() const;
87   void EmitInstToFragment(const MCInst &Inst, const MCSubtargetInfo &) override;
88   void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo &) override;
89 
90   void fixSymbolsInTLSFixups(const MCExpr *expr);
91 
92   /// \brief Merge the content of the fragment \p EF into the fragment \p DF.
93   void mergeFragment(MCDataFragment *, MCDataFragment *);
94 
95   bool SeenIdent;
96 
97   /// BundleGroups - The stack of fragments holding the bundle-locked
98   /// instructions.
99   llvm::SmallVector<MCDataFragment *, 4> BundleGroups;
100 };
101 
102 MCELFStreamer *createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
103                                     raw_pwrite_stream &OS,
104                                     MCCodeEmitter *Emitter, bool RelaxAll,
105                                     bool IsThumb);
106 
107 } // end namespace llvm
108 
109 #endif
110