1//===- DerivedUser.h - Base for non-IR Users --------------------*- 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_IR_DERIVEDUSER_H 10#define LLVM_IR_DERIVEDUSER_H 11 12#include "llvm/IR/User.h" 13 14namespace llvm { 15 16class Type; 17class Use; 18 19/// Extension point for the Value hierarchy. All classes outside of lib/IR 20/// that wish to inherit from User should instead inherit from DerivedUser 21/// instead. Inheriting from this class is discouraged. 22/// 23/// Generally speaking, Value is the base of a closed class hierarchy 24/// that can't be extended by code outside of lib/IR. This class creates a 25/// loophole that allows classes outside of lib/IR to extend User to leverage 26/// its use/def list machinery. 27class DerivedUser : public User { 28protected: 29 using DeleteValueTy = void (*)(DerivedUser *); 30 31private: 32 friend class Value; 33 34 DeleteValueTy DeleteValue; 35 36public: 37 DerivedUser(Type *Ty, unsigned VK, Use *U, unsigned NumOps, 38 DeleteValueTy DeleteValue) 39 : User(Ty, VK, U, NumOps), DeleteValue(DeleteValue) {} 40}; 41 42} // end namespace llvm 43 44#endif // LLVM_IR_DERIVEDUSER_H 45