LLVM  10.0.0svn
DerivedUser.h
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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 
14 namespace llvm {
15 
16 class Type;
17 class 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.
27 class DerivedUser : public User {
28 protected:
29  using DeleteValueTy = void (*)(DerivedUser *);
30 
31 private:
32  friend class Value;
33 
34  DeleteValueTy DeleteValue;
35 
36 public:
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
DerivedUser(Type *Ty, unsigned VK, Use *U, unsigned NumOps, DeleteValueTy DeleteValue)
Definition: DerivedUser.h:37
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Extension point for the Value hierarchy.
Definition: DerivedUser.h:27
void(*)(DerivedUser *) DeleteValueTy
Definition: DerivedUser.h:29
A Use represents the edge between a Value definition and its users.
Definition: Use.h:55
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
LLVM Value Representation.
Definition: Value.h:74