1 //===-------- llvm/GlobalAlias.h - GlobalAlias class ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declaration of the GlobalAlias class, which
11 // represents a single function or variable alias in the IR.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_GLOBAL_ALIAS_H
16 #define LLVM_GLOBAL_ALIAS_H
18 #include "llvm/GlobalValue.h"
19 #include "llvm/OperandTraits.h"
26 template<typename ValueSubClass, typename ItemParentClass>
27 class SymbolTableListTraits;
29 class GlobalAlias : public GlobalValue {
30 friend class SymbolTableListTraits<GlobalAlias, Module>;
31 void operator=(const GlobalAlias &); // Do not implement
32 GlobalAlias(const GlobalAlias &); // Do not implement
34 void setParent(Module *parent);
36 GlobalAlias *Prev, *Next;
37 void setNext(GlobalAlias *N) { Next = N; }
38 void setPrev(GlobalAlias *N) { Prev = N; }
40 // getNext/Prev - Return the next or previous alias in the list.
41 GlobalAlias *getNext() { return Next; }
42 const GlobalAlias *getNext() const { return Next; }
43 GlobalAlias *getPrev() { return Prev; }
44 const GlobalAlias *getPrev() const { return Prev; }
47 // allocate space for exactly one operand
48 void *operator new(size_t s) {
49 return User::operator new(s, 1);
51 /// GlobalAlias ctor - If a parent module is specified, the alias is
52 /// automatically inserted into the end of the specified module's alias list.
53 GlobalAlias(const Type *Ty, LinkageTypes Linkage, const std::string &Name = "",
54 Constant* Aliasee = 0, Module *Parent = 0);
56 /// Provide fast operand accessors
57 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
59 /// isDeclaration - Is this global variable lacking an initializer? If so,
60 /// the global variable is defined in some other translation unit, and is thus
61 /// only a declaration here.
62 virtual bool isDeclaration() const;
64 /// removeFromParent - This method unlinks 'this' from the containing module,
65 /// but does not delete it.
67 void removeFromParent();
69 /// eraseFromParent - This method unlinks 'this' from the containing module
72 void eraseFromParent();
74 virtual void print(std::ostream &OS) const;
75 void print(std::ostream *OS) const { if (OS) print(*OS); }
77 /// set/getAliasee - These methods retrive and set alias target.
78 void setAliasee(Constant* GV);
79 const Constant* getAliasee() const {
80 return cast_or_null<Constant>(getOperand(0));
82 Constant* getAliasee() {
83 return cast_or_null<Constant>(getOperand(0));
85 /// getAliasedGlobal() - Aliasee can be either global or bitcast of
86 /// global. This method retrives the global for both aliasee flavours.
87 const GlobalValue* getAliasedGlobal() const;
89 /// resolveAliasedGlobal() - This method tries to ultimately resolve the alias
90 /// by going through the aliasing chain and trying to find the very last
91 /// global. Returns NULL if a cycle was found.
92 const GlobalValue* resolveAliasedGlobal() const;
94 // Methods for support type inquiry through isa, cast, and dyn_cast:
95 static inline bool classof(const GlobalAlias *) { return true; }
96 static inline bool classof(const Value *V) {
97 return V->getValueID() == Value::GlobalAliasVal;
102 struct OperandTraits<GlobalAlias> : FixedNumOperandTraits<1> {
105 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalAlias, Value)
107 } // End llvm namespace