GlobalAlias.h revision 7ed47a13356daed2a34cd2209a31f92552e3bdd8 
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_GLOBAL_ALIAS_H
16#define LLVM_GLOBAL_ALIAS_H
17
18#include "llvm/GlobalValue.h"
19
20namespace llvm {
21
22class Module;
23class Constant;
24class PointerType;
25template<typename ValueSubClass, typename ItemParentClass>
26  class SymbolTableListTraits;
27
28class GlobalAlias : public GlobalValue {
29  friend class SymbolTableListTraits<GlobalAlias, Module>;
30  void operator=(const GlobalAlias &);     // Do not implement
31  GlobalAlias(const GlobalAlias &);     // Do not implement
32
33  void setParent(Module *parent);
34
35  GlobalAlias *Prev, *Next;
36  void setNext(GlobalAlias *N) { Next = N; }
37  void setPrev(GlobalAlias *N) { Prev = N; }
38
39  // getNext/Prev - Return the next or previous alias in the list.
40        GlobalAlias *getNext()       { return Next; }
41  const GlobalAlias *getNext() const { return Next; }
42        GlobalAlias *getPrev()       { return Prev; }
43  const GlobalAlias *getPrev() const { return Prev; }
44
45  Use Aliasee;
46public:
47  /// GlobalAlias ctor - If a parent module is specified, the alias is
48  /// automatically inserted into the end of the specified module's alias list.
49  GlobalAlias(const Type *Ty, LinkageTypes Linkage, const std::string &Name = "",
50              Constant* Aliasee = 0, Module *Parent = 0);
51
52  /// isDeclaration - Is this global variable lacking an initializer?  If so,
53  /// the global variable is defined in some other translation unit, and is thus
54  /// only a declaration here.
55  virtual bool isDeclaration() const;
56
57  /// removeFromParent - This method unlinks 'this' from the containing module,
58  /// but does not delete it.
59  ///
60  void removeFromParent();
61
62  /// eraseFromParent - This method unlinks 'this' from the containing module
63  /// and deletes it.
64  ///
65  void eraseFromParent();
66
67  virtual void print(std::ostream &OS) const;
68  void print(std::ostream *OS) const { if (OS) print(*OS); }
69
70  /// set/getAliasee - These methods retrive and set alias target.
71  void setAliasee(Constant* GV);
72  const Constant* getAliasee() const {
73    return cast_or_null<Constant>(getOperand(0));
74  }
75  Constant* getAliasee() {
76    return cast_or_null<Constant>(getOperand(0));
77  }
78  /// getAliasedGlobal() - Aliasee can be either global or bitcast of
79  /// global. This method retrives the global for both aliasee flavours.
80  const GlobalValue* getAliasedGlobal() const;
81
82  // Methods for support type inquiry through isa, cast, and dyn_cast:
83  static inline bool classof(const GlobalAlias *) { return true; }
84  static inline bool classof(const Value *V) {
85    return V->getValueID() == Value::GlobalAliasVal;
86  }
87};
88
89} // End llvm namespace
90
91#endif
92