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"
20 #include "llvm/ADT/ilist_node.h"
27 template<typename ValueSubClass, typename ItemParentClass>
28 class SymbolTableListTraits;
30 class GlobalAlias : public GlobalValue, public ilist_node<GlobalAlias> {
31 friend class SymbolTableListTraits<GlobalAlias, Module>;
32 void operator=(const GlobalAlias &); // Do not implement
33 GlobalAlias(const GlobalAlias &); // Do not implement
35 void setParent(Module *parent);
38 // allocate space for exactly one operand
39 void *operator new(size_t s) {
40 return User::operator new(s, 1);
42 /// GlobalAlias ctor - If a parent module is specified, the alias is
43 /// automatically inserted into the end of the specified module's alias list.
44 GlobalAlias(const Type *Ty, LinkageTypes Linkage, const std::string &Name = "",
45 Constant* Aliasee = 0, Module *Parent = 0);
47 /// Provide fast operand accessors
48 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
50 /// isDeclaration - Is this global variable lacking an initializer? If so,
51 /// the global variable is defined in some other translation unit, and is thus
52 /// only a declaration here.
53 virtual bool isDeclaration() const;
55 /// removeFromParent - This method unlinks 'this' from the containing module,
56 /// but does not delete it.
58 void removeFromParent();
60 /// eraseFromParent - This method unlinks 'this' from the containing module
63 void eraseFromParent();
65 virtual void print(std::ostream &OS) const;
66 void print(std::ostream *OS) const { if (OS) print(*OS); }
68 /// set/getAliasee - These methods retrive and set alias target.
69 void setAliasee(Constant* GV);
70 const Constant* getAliasee() const {
71 return cast_or_null<Constant>(getOperand(0));
73 Constant* getAliasee() {
74 return cast_or_null<Constant>(getOperand(0));
76 /// getAliasedGlobal() - Aliasee can be either global or bitcast of
77 /// global. This method retrives the global for both aliasee flavours.
78 const GlobalValue* getAliasedGlobal() const;
80 /// resolveAliasedGlobal() - This method tries to ultimately resolve the alias
81 /// by going through the aliasing chain and trying to find the very last
82 /// global. Returns NULL if a cycle was found.
83 const GlobalValue* resolveAliasedGlobal() const;
85 // Methods for support type inquiry through isa, cast, and dyn_cast:
86 static inline bool classof(const GlobalAlias *) { return true; }
87 static inline bool classof(const Value *V) {
88 return V->getValueID() == Value::GlobalAliasVal;
93 struct OperandTraits<GlobalAlias> : FixedNumOperandTraits<1> {
96 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalAlias, Value)
98 } // End llvm namespace