1//===-------- llvm/GlobalAlias.h - GlobalAlias class ------------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains the declaration of the GlobalAlias class, which
11// represents a single function or variable alias in the IR.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_IR_GLOBALALIAS_H
16#define LLVM_IR_GLOBALALIAS_H
17
18#include "llvm/ADT/ilist_node.h"
19#include "llvm/IR/GlobalIndirectSymbol.h"
20#include "llvm/IR/Value.h"
21
22namespace llvm {
23
24class Twine;
25class Module;
26template <typename ValueSubClass> class SymbolTableListTraits;
27
28class GlobalAlias : public GlobalIndirectSymbol,
29 public ilist_node<GlobalAlias> {
30 friend class SymbolTableListTraits<GlobalAlias>;
31
32 GlobalAlias(Type *Ty, unsigned AddressSpace, LinkageTypes Linkage,
33 const Twine &Name, Constant *Aliasee, Module *Parent);
34
35public:
36 GlobalAlias(const GlobalAlias &) = delete;
37 GlobalAlias &operator=(const GlobalAlias &) = delete;
38
39 /// If a parent module is specified, the alias is automatically inserted into
40 /// the end of the specified module's alias list.
41 static GlobalAlias *create(Type *Ty, unsigned AddressSpace,
42 LinkageTypes Linkage, const Twine &Name,
43 Constant *Aliasee, Module *Parent);
44
45 // Without the Aliasee.
46 static GlobalAlias *create(Type *Ty, unsigned AddressSpace,
47 LinkageTypes Linkage, const Twine &Name,
48 Module *Parent);
49
50 // The module is taken from the Aliasee.
51 static GlobalAlias *create(Type *Ty, unsigned AddressSpace,
52 LinkageTypes Linkage, const Twine &Name,
53 GlobalValue *Aliasee);
54
55 // Type, Parent and AddressSpace taken from the Aliasee.
56 static GlobalAlias *create(LinkageTypes Linkage, const Twine &Name,
57 GlobalValue *Aliasee);
58
59 // Linkage, Type, Parent and AddressSpace taken from the Aliasee.
60 static GlobalAlias *create(const Twine &Name, GlobalValue *Aliasee);
61
62 void copyAttributesFrom(const GlobalValue *Src) {
63 GlobalValue::copyAttributesFrom(Src);
64 }
65
66 /// removeFromParent - This method unlinks 'this' from the containing module,
67 /// but does not delete it.
68 ///
69 void removeFromParent();
70
71 /// eraseFromParent - This method unlinks 'this' from the containing module
72 /// and deletes it.
73 ///
74 void eraseFromParent();
75
76 /// These methods retrieve and set alias target.
77 void setAliasee(Constant *Aliasee);
78 const Constant *getAliasee() const {
79 return getIndirectSymbol();
80 }
81 Constant *getAliasee() {
82 return getIndirectSymbol();
83 }
84
85 static bool isValidLinkage(LinkageTypes L) {
86 return isExternalLinkage(L) || isLocalLinkage(L) ||
87 isWeakLinkage(L) || isLinkOnceLinkage(L);
88 }
89
90 // Methods for support type inquiry through isa, cast, and dyn_cast:
91 static bool classof(const Value *V) {
92 return V->getValueID() == Value::GlobalAliasVal;
93 }
94};
95
96} // end namespace llvm
97
98#endif // LLVM_IR_GLOBALALIAS_H
99