1//===-------- llvm/GlobalAlias.h - GlobalAlias class ------------*- 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// This file contains the declaration of the GlobalAlias class, which
10// represents a single function or variable alias in the IR.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_IR_GLOBALALIAS_H
15#define LLVM_IR_GLOBALALIAS_H
16
17#include "llvm/ADT/ilist_node.h"
18#include "llvm/IR/GlobalIndirectSymbol.h"
19#include "llvm/IR/Value.h"
20
21namespace llvm {
22
23class Twine;
24class Module;
25template <typename ValueSubClass> class SymbolTableListTraits;
26
27class GlobalAlias : public GlobalIndirectSymbol,
28 public ilist_node<GlobalAlias> {
29 friend class SymbolTableListTraits<GlobalAlias>;
30
31 GlobalAlias(Type *Ty, unsigned AddressSpace, LinkageTypes Linkage,
32 const Twine &Name, Constant *Aliasee, Module *Parent);
33
34public:
35 GlobalAlias(const GlobalAlias &) = delete;
36 GlobalAlias &operator=(const GlobalAlias &) = delete;
37
38 /// If a parent module is specified, the alias is automatically inserted into
39 /// the end of the specified module's alias list.
40 static GlobalAlias *create(Type *Ty, unsigned AddressSpace,
41 LinkageTypes Linkage, const Twine &Name,
42 Constant *Aliasee, Module *Parent);
43
44 // Without the Aliasee.
45 static GlobalAlias *create(Type *Ty, unsigned AddressSpace,
46 LinkageTypes Linkage, const Twine &Name,
47 Module *Parent);
48
49 // The module is taken from the Aliasee.
50 static GlobalAlias *create(Type *Ty, unsigned AddressSpace,
51 LinkageTypes Linkage, const Twine &Name,
52 GlobalValue *Aliasee);
53
54 // Type, Parent and AddressSpace taken from the Aliasee.
55 static GlobalAlias *create(LinkageTypes Linkage, const Twine &Name,
56 GlobalValue *Aliasee);
57
58 // Linkage, Type, Parent and AddressSpace taken from the Aliasee.
59 static GlobalAlias *create(const Twine &Name, GlobalValue *Aliasee);
60
61 /// removeFromParent - This method unlinks 'this' from the containing module,
62 /// but does not delete it.
63 ///
64 void removeFromParent();
65
66 /// eraseFromParent - This method unlinks 'this' from the containing module
67 /// and deletes it.
68 ///
69 void eraseFromParent();
70
71 /// These methods retrieve and set alias target.
72 void setAliasee(Constant *Aliasee);
73 const Constant *getAliasee() const {
74 return getIndirectSymbol();
75 }
76 Constant *getAliasee() {
77 return getIndirectSymbol();
78 }
79
80 static bool isValidLinkage(LinkageTypes L) {
81 return isExternalLinkage(L) || isLocalLinkage(L) ||
82 isWeakLinkage(L) || isLinkOnceLinkage(L);
83 }
84
85 // Methods for support type inquiry through isa, cast, and dyn_cast:
86 static bool classof(const Value *V) {
87 return V->getValueID() == Value::GlobalAliasVal;
88 }
89};
90
91} // end namespace llvm
92
93#endif // LLVM_IR_GLOBALALIAS_H
94