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"
26 template<typename ValueSubClass, typename ItemParentClass>
27 class SymbolTableListTraits;
29 class GlobalAlias : public GlobalValue, public ilist_node<GlobalAlias> {
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);
37 // allocate space for exactly one operand
38 void *operator new(size_t s) {
39 return User::operator new(s, 1);
41 /// GlobalAlias ctor - If a parent module is specified, the alias is
42 /// automatically inserted into the end of the specified module's alias list.
43 GlobalAlias(const Type *Ty, LinkageTypes Linkage, const std::string &Name = "",
44 Constant* Aliasee = 0, Module *Parent = 0);
46 /// Provide fast operand accessors
47 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
49 /// isDeclaration - Is this global variable lacking an initializer? If so,
50 /// the global variable is defined in some other translation unit, and is thus
51 /// only a declaration here.
52 virtual bool isDeclaration() const;
54 /// removeFromParent - This method unlinks 'this' from the containing module,
55 /// but does not delete it.
57 virtual void removeFromParent();
59 /// eraseFromParent - This method unlinks 'this' from the containing module
62 virtual void eraseFromParent();
64 /// set/getAliasee - These methods retrive and set alias target.
65 void setAliasee(Constant* GV);
66 const Constant* getAliasee() const {
67 return cast_or_null<Constant>(getOperand(0));
69 Constant* getAliasee() {
70 return cast_or_null<Constant>(getOperand(0));
72 /// getAliasedGlobal() - Aliasee can be either global or bitcast of
73 /// global. This method retrives the global for both aliasee flavours.
74 const GlobalValue* getAliasedGlobal() const;
76 /// resolveAliasedGlobal() - This method tries to ultimately resolve the alias
77 /// by going through the aliasing chain and trying to find the very last
78 /// global. Returns NULL if a cycle was found. If stopOnWeak is false, then
79 /// the whole chain aliasing chain is traversed, otherwise - only strong
81 const GlobalValue* resolveAliasedGlobal(bool stopOnWeak = true) const;
83 // Methods for support type inquiry through isa, cast, and dyn_cast:
84 static inline bool classof(const GlobalAlias *) { return true; }
85 static inline bool classof(const Value *V) {
86 return V->getValueID() == Value::GlobalAliasVal;
91 struct OperandTraits<GlobalAlias> : FixedNumOperandTraits<1> {
94 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalAlias, Value)
96 } // End llvm namespace