1 //===- DerivedUser.h - Base for non-IR Users --------------------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 #ifndef LLVM_IR_DERIVEDUSER_H
10 #define LLVM_IR_DERIVEDUSER_H
12 #include "llvm/IR/User.h"
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.
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.
27 class DerivedUser : public User {
29 using DeleteValueTy = void (*)(DerivedUser *);
34 DeleteValueTy DeleteValue;
37 DerivedUser(Type *Ty, unsigned VK, Use *U, unsigned NumOps,
38 DeleteValueTy DeleteValue)
39 : User(Ty, VK, U, NumOps), DeleteValue(DeleteValue) {}
42 } // end namespace llvm
44 #endif // LLVM_IR_DERIVEDUSER_H