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