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 public:
26   MCCodeEmitter(const MCCodeEmitter &) = delete;
27   MCCodeEmitter &operator=(const MCCodeEmitter &) = delete;
28   virtual ~MCCodeEmitter();
29 
30   /// Lifetime management
reset()31   virtual void reset() {}
32 
33   /// Append the prefixes of given instruction to the code buffer.
34   ///
35   /// \param Inst a single low-level machine instruction.
36   /// \param CB code buffer
emitPrefix(const MCInst & Inst,SmallVectorImpl<char> & CB,const MCSubtargetInfo & STI)37   virtual void emitPrefix(const MCInst &Inst, SmallVectorImpl<char> &CB,
38                           const MCSubtargetInfo &STI) const {}
39   /// Encode the given \p Inst to bytes and append to \p CB.
40   virtual void encodeInstruction(const MCInst &Inst, SmallVectorImpl<char> &CB,
41                                  SmallVectorImpl<MCFixup> &Fixups,
42                                  const MCSubtargetInfo &STI) const = 0;
43 };
44 
45 } // end namespace llvm
46 
47 #endif // LLVM_MC_MCCODEEMITTER_H
48