Home | History | Annotate | Download | only in MC 
      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 
     16 namespace llvm {
     17 class MCAssembler;
     18 class MCCodeEmitter;
     19 class MCSectionData;
     20 class MCExpr;
     21 class MCFragment;
     22 class MCDataFragment;
     23 class MCAsmBackend;
     24 class 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.
     33 class 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 
     42 protected:
     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 
     50 public:
     51   /// state management
     52   virtual void reset();
     53 
     54 protected:
     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 
     72 public:
     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