1 //===- llvm/MC/MCCodeEmitter.h - Instruction Encoding -----------*- 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 #ifndef LLVM_MC_MCCODEEMITTER_H 10 #define LLVM_MC_MCCODEEMITTER_H 11 12 namespace llvm { 13 14 class MCFixup; 15 class MCInst; 16 class MCSubtargetInfo; 17 class raw_ostream; 18 template<typename T> class SmallVectorImpl; 19 20 /// MCCodeEmitter - Generic instruction encoding interface. 21 class MCCodeEmitter { 22 protected: // Can only create subclasses. 23 MCCodeEmitter(); 24 25 /// EncodeInstruction - Encode the given \p Inst to bytes on the output stream 26 /// \p OS. Allows for an implementation of encodeInstruction that uses streams 27 /// instead of a SmallVector. 28 virtual void encodeInstruction(const MCInst &Inst, raw_ostream &OS, 29 SmallVectorImpl<MCFixup> &Fixups, 30 const MCSubtargetInfo &STI) const {} 31 32 public: 33 MCCodeEmitter(const MCCodeEmitter &) = delete; 34 MCCodeEmitter &operator=(const MCCodeEmitter &) = delete; 35 virtual ~MCCodeEmitter(); 36 37 /// Lifetime management 38 virtual void reset() {} 39 40 /// Append the prefixes of given instruction to the code buffer. 41 /// 42 /// \param Inst a single low-level machine instruction. 43 /// \param CB code buffer 44 virtual void emitPrefix(const MCInst &Inst, SmallVectorImpl<char> &CB, 45 const MCSubtargetInfo &STI) const {} 46 /// EncodeInstruction - Encode the given \p Inst to bytes and append to \p CB. 47 virtual void encodeInstruction(const MCInst &Inst, SmallVectorImpl<char> &CB, 48 SmallVectorImpl<MCFixup> &Fixups, 49 const MCSubtargetInfo &STI) const; 50 }; 51 52 } // end namespace llvm 53 54 #endif // LLVM_MC_MCCODEEMITTER_H 55