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 #include "llvm/OperandTraits.h" 20 #include "llvm/ADT/ilist_node.h" 21 #include "llvm/ADT/Twine.h" 22 23 namespace llvm { 24 25 class Module; 26 template<typename ValueSubClass, typename ItemParentClass> 27 class SymbolTableListTraits; 28 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 33 34 void setParent(Module *parent); 35 36 public: 37 // allocate space for exactly one operand new(size_t s)38 void *operator new(size_t s) { 39 return User::operator new(s, 1); 40 } 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(Type *Ty, LinkageTypes Linkage, const Twine &Name = "", 44 Constant* Aliasee = 0, Module *Parent = 0); 45 46 /// Provide fast operand accessors 47 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant); 48 49 /// removeFromParent - This method unlinks 'this' from the containing module, 50 /// but does not delete it. 51 /// 52 virtual void removeFromParent(); 53 54 /// eraseFromParent - This method unlinks 'this' from the containing module 55 /// and deletes it. 56 /// 57 virtual void eraseFromParent(); 58 59 /// set/getAliasee - These methods retrive and set alias target. 60 void setAliasee(Constant *GV); getAliasee()61 const Constant *getAliasee() const { 62 return getOperand(0); 63 } getAliasee()64 Constant *getAliasee() { 65 return getOperand(0); 66 } 67 /// getAliasedGlobal() - Aliasee can be either global or bitcast of 68 /// global. This method retrives the global for both aliasee flavours. 69 const GlobalValue *getAliasedGlobal() const; 70 71 /// resolveAliasedGlobal() - This method tries to ultimately resolve the alias 72 /// by going through the aliasing chain and trying to find the very last 73 /// global. Returns NULL if a cycle was found. If stopOnWeak is false, then 74 /// the whole chain aliasing chain is traversed, otherwise - only strong 75 /// aliases. 76 const GlobalValue *resolveAliasedGlobal(bool stopOnWeak = true) const; 77 78 // Methods for support type inquiry through isa, cast, and dyn_cast: classof(const GlobalAlias *)79 static inline bool classof(const GlobalAlias *) { return true; } classof(const Value * V)80 static inline bool classof(const Value *V) { 81 return V->getValueID() == Value::GlobalAliasVal; 82 } 83 }; 84 85 template <> 86 struct OperandTraits<GlobalAlias> : 87 public FixedNumOperandTraits<GlobalAlias, 1> { 88 }; 89 90 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalAlias, Constant) 91 92 } // End llvm namespace 93 94 #endif 95