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_IR_GLOBALALIAS_H
16 #define LLVM_IR_GLOBALALIAS_H
18 #include "llvm/ADT/Twine.h"
19 #include "llvm/ADT/ilist_node.h"
20 #include "llvm/IR/GlobalValue.h"
21 #include "llvm/IR/OperandTraits.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 &) LLVM_DELETED_FUNCTION;
32 GlobalAlias(const GlobalAlias &) LLVM_DELETED_FUNCTION;
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(Type *Ty, LinkageTypes Linkage, const Twine &Name = "",
44 Constant* Aliasee = 0, Module *Parent = 0);
46 /// Provide fast operand accessors
47 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
49 /// removeFromParent - This method unlinks 'this' from the containing module,
50 /// but does not delete it.
52 virtual void removeFromParent();
54 /// eraseFromParent - This method unlinks 'this' from the containing module
57 virtual void eraseFromParent();
59 /// set/getAliasee - These methods retrive and set alias target.
60 void setAliasee(Constant *GV);
61 const Constant *getAliasee() const {
64 Constant *getAliasee() {
67 /// getAliasedGlobal() - Aliasee can be either global or bitcast of
68 /// global. This method retrives the global for both aliasee flavours.
69 GlobalValue *getAliasedGlobal();
70 const GlobalValue *getAliasedGlobal() const {
71 return const_cast<GlobalAlias *>(this)->getAliasedGlobal();
74 /// resolveAliasedGlobal() - This method tries to ultimately resolve the alias
75 /// by going through the aliasing chain and trying to find the very last
76 /// global. Returns NULL if a cycle was found. If stopOnWeak is false, then
77 /// the whole chain aliasing chain is traversed, otherwise - only strong
79 GlobalValue *resolveAliasedGlobal(bool stopOnWeak = true);
80 const GlobalValue *resolveAliasedGlobal(bool stopOnWeak = true) const {
81 return const_cast<GlobalAlias *>(this)->resolveAliasedGlobal(stopOnWeak);
84 // Methods for support type inquiry through isa, cast, and dyn_cast:
85 static inline bool classof(const Value *V) {
86 return V->getValueID() == Value::GlobalAliasVal;
91 struct OperandTraits<GlobalAlias> :
92 public FixedNumOperandTraits<GlobalAlias, 1> {
95 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalAlias, Constant)
97 } // End llvm namespace