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 /// If a parent module is specified, the alias is automatically inserted into
42 /// the end of the specified module's alias list.
43 GlobalAlias(Type *Ty, LinkageTypes Linkage, const Twine &Name = "",
44 Constant* Aliasee = nullptr, Module *Parent = nullptr,
45 unsigned AddressSpace = 0);
47 /// Provide fast operand accessors
48 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
50 /// removeFromParent - This method unlinks 'this' from the containing module,
51 /// but does not delete it.
53 void removeFromParent() override;
55 /// eraseFromParent - This method unlinks 'this' from the containing module
58 void eraseFromParent() override;
60 /// set/getAliasee - These methods retrive and set alias target.
61 void setAliasee(Constant *GV);
62 const Constant *getAliasee() const {
65 Constant *getAliasee() {
69 /// This method tries to ultimately resolve the alias by going through the
70 /// aliasing chain and trying to find the very last global. Returns NULL if a
72 GlobalObject *getAliasedGlobal();
73 const GlobalObject *getAliasedGlobal() const {
74 return const_cast<GlobalAlias *>(this)->getAliasedGlobal();
77 static bool isValidLinkage(LinkageTypes L) {
78 return isExternalLinkage(L) || isLocalLinkage(L) ||
79 isWeakLinkage(L) || isLinkOnceLinkage(L);
82 // Methods for support type inquiry through isa, cast, and dyn_cast:
83 static inline bool classof(const Value *V) {
84 return V->getValueID() == Value::GlobalAliasVal;
89 struct OperandTraits<GlobalAlias> :
90 public FixedNumOperandTraits<GlobalAlias, 1> {
93 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalAlias, Constant)
95 } // End llvm namespace