1 //===-------- MipsELFStreamer.h - ELF Object Output -----------------------===// 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 // This is a custom MCELFStreamer which allows us to insert some hooks before 11 // emitting data into an actual object file. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H 16 #define LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H 17 18 #include "MipsOptionRecord.h" 19 #include "llvm/ADT/SmallVector.h" 20 #include "llvm/MC/MCELFStreamer.h" 21 #include <memory> 22 23 namespace llvm { 24 class MCAsmBackend; 25 class MCCodeEmitter; 26 class MCContext; 27 class MCSubtargetInfo; 28 29 class MipsELFStreamer : public MCELFStreamer { 30 SmallVector<std::unique_ptr<MipsOptionRecord>, 8> MipsOptionRecords; 31 MipsRegInfoRecord *RegInfoRecord; 32 SmallVector<MCSymbol*, 4> Labels; 33 34 35 public: 36 MipsELFStreamer(MCContext &Context, MCAsmBackend &MAB, raw_pwrite_stream &OS, 37 MCCodeEmitter *Emitter) 38 : MCELFStreamer(Context, MAB, OS, Emitter) { 39 40 RegInfoRecord = new MipsRegInfoRecord(this, Context); 41 MipsOptionRecords.push_back( 42 std::unique_ptr<MipsRegInfoRecord>(RegInfoRecord)); 43 } 44 45 /// Overriding this function allows us to add arbitrary behaviour before the 46 /// \p Inst is actually emitted. For example, we can inspect the operands and 47 /// gather sufficient information that allows us to reason about the register 48 /// usage for the translation unit. 49 void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override; 50 51 /// Overriding this function allows us to record all labels that should be 52 /// marked as microMIPS. Based on this data marking is done in 53 /// EmitInstruction. 54 void EmitLabel(MCSymbol *Symbol) override; 55 56 /// Overriding this function allows us to dismiss all labels that are 57 /// candidates for marking as microMIPS when .section directive is processed. 58 void SwitchSection(MCSection *Section, 59 const MCExpr *Subsection = nullptr) override; 60 61 /// Overriding this function allows us to dismiss all labels that are 62 /// candidates for marking as microMIPS when .word directive is emitted. 63 void EmitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override; 64 65 /// Emits all the option records stored up until the point it's called. 66 void EmitMipsOptionRecords(); 67 68 /// Mark labels as microMIPS, if necessary for the subtarget. 69 void createPendingLabelRelocs(); 70 }; 71 72 MCELFStreamer *createMipsELFStreamer(MCContext &Context, MCAsmBackend &MAB, 73 raw_pwrite_stream &OS, 74 MCCodeEmitter *Emitter, bool RelaxAll); 75 } // namespace llvm. 76 #endif 77
