1 //===- MipsELFStreamer.h - ELF Object Output --------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This is a custom MCELFStreamer which allows us to insert some hooks before 10 // emitting data into an actual object file. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H 15 #define LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H 16 17 #include "MipsOptionRecord.h" 18 #include "llvm/ADT/SmallVector.h" 19 #include "llvm/MC/MCELFStreamer.h" 20 #include <memory> 21 22 namespace llvm { 23 24 class MCAsmBackend; 25 class MCCodeEmitter; 26 class MCContext; 27 class MCSubtargetInfo; 28 struct MCDwarfFrameInfo; 29 30 class MipsELFStreamer : public MCELFStreamer { 31 SmallVector<std::unique_ptr<MipsOptionRecord>, 8> MipsOptionRecords; 32 MipsRegInfoRecord *RegInfoRecord; 33 SmallVector<MCSymbol*, 4> Labels; 34 35 public: 36 MipsELFStreamer(MCContext &Context, std::unique_ptr<MCAsmBackend> MAB, 37 std::unique_ptr<MCObjectWriter> OW, 38 std::unique_ptr<MCCodeEmitter> Emitter); 39 40 /// Overriding this function allows us to add arbitrary behaviour before the 41 /// \p Inst is actually emitted. For example, we can inspect the operands and 42 /// gather sufficient information that allows us to reason about the register 43 /// usage for the translation unit. 44 void emitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override; 45 46 /// Overriding this function allows us to record all labels that should be 47 /// marked as microMIPS. Based on this data marking is done in 48 /// EmitInstruction. 49 void emitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override; 50 51 /// Overriding this function allows us to dismiss all labels that are 52 /// candidates for marking as microMIPS when .section directive is processed. 53 void switchSection(MCSection *Section, 54 const MCExpr *Subsection = nullptr) override; 55 56 /// Overriding these functions allows us to dismiss all labels that are 57 /// candidates for marking as microMIPS when .word/.long/.4byte etc 58 /// directives are emitted. 59 void emitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) override; 60 void emitIntValue(uint64_t Value, unsigned Size) override; 61 62 // Overriding these functions allows us to avoid recording of these labels 63 // in EmitLabel and later marking them as microMIPS. 64 void emitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override; 65 void emitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override; 66 MCSymbol *emitCFILabel() override; 67 68 /// Emits all the option records stored up until the point it's called. 69 void EmitMipsOptionRecords(); 70 71 /// Mark labels as microMIPS, if necessary for the subtarget. 72 void createPendingLabelRelocs(); 73 }; 74 75 MCELFStreamer *createMipsELFStreamer(MCContext &Context, 76 std::unique_ptr<MCAsmBackend> MAB, 77 std::unique_ptr<MCObjectWriter> OW, 78 std::unique_ptr<MCCodeEmitter> Emitter, 79 bool RelaxAll); 80 } // end namespace llvm 81 82 #endif // LLVM_LIB_TARGET_MIPS_MCTARGETDESC_MIPSELFSTREAMER_H 83