1//===-------- llvm/GlobalAlias.h - GlobalAlias class ------------*- C++ -*-===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8// 9// This file contains the declaration of the GlobalAlias class, which 10// represents a single function or variable alias in the IR. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_IR_GLOBALALIAS_H 15#define LLVM_IR_GLOBALALIAS_H 16 17#include "llvm/ADT/ilist_node.h" 18#include "llvm/IR/GlobalValue.h" 19#include "llvm/IR/OperandTraits.h" 20#include "llvm/IR/Value.h" 21 22namespace llvm { 23 24class Twine; 25class Module; 26template <typename ValueSubClass, typename... Args> class SymbolTableListTraits; 27 28class GlobalAlias : public GlobalValue, public ilist_node<GlobalAlias> { 29 friend class SymbolTableListTraits<GlobalAlias>; 30 31 GlobalAlias(Type *Ty, unsigned AddressSpace, LinkageTypes Linkage, 32 const Twine &Name, Constant *Aliasee, Module *Parent); 33 34public: 35 GlobalAlias(const GlobalAlias &) = delete; 36 GlobalAlias &operator=(const GlobalAlias &) = delete; 37 38 /// If a parent module is specified, the alias is automatically inserted into 39 /// the end of the specified module's alias list. 40 static GlobalAlias *create(Type *Ty, unsigned AddressSpace, 41 LinkageTypes Linkage, const Twine &Name, 42 Constant *Aliasee, Module *Parent); 43 44 // Without the Aliasee. 45 static GlobalAlias *create(Type *Ty, unsigned AddressSpace, 46 LinkageTypes Linkage, const Twine &Name, 47 Module *Parent); 48 49 // The module is taken from the Aliasee. 50 static GlobalAlias *create(Type *Ty, unsigned AddressSpace, 51 LinkageTypes Linkage, const Twine &Name, 52 GlobalValue *Aliasee); 53 54 // Type, Parent and AddressSpace taken from the Aliasee. 55 static GlobalAlias *create(LinkageTypes Linkage, const Twine &Name, 56 GlobalValue *Aliasee); 57 58 // Linkage, Type, Parent and AddressSpace taken from the Aliasee. 59 static GlobalAlias *create(const Twine &Name, GlobalValue *Aliasee); 60 61 // allocate space for exactly one operand 62 void *operator new(size_t S) { return User::operator new(S, 1); } 63 void operator delete(void *Ptr) { User::operator delete(Ptr); } 64 65 /// Provide fast operand accessors 66 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant); 67 68 void copyAttributesFrom(const GlobalAlias *Src) { 69 GlobalValue::copyAttributesFrom(Src); 70 } 71 72 /// removeFromParent - This method unlinks 'this' from the containing module, 73 /// but does not delete it. 74 /// 75 void removeFromParent(); 76 77 /// eraseFromParent - This method unlinks 'this' from the containing module 78 /// and deletes it. 79 /// 80 void eraseFromParent(); 81 82 /// These methods retrieve and set alias target. 83 void setAliasee(Constant *Aliasee); 84 const Constant *getAliasee() const { 85 return static_cast<Constant *>(Op<0>().get()); 86 } 87 Constant *getAliasee() { return static_cast<Constant *>(Op<0>().get()); } 88 89 const GlobalObject *getAliaseeObject() const; 90 GlobalObject *getAliaseeObject() { 91 return const_cast<GlobalObject *>( 92 static_cast<const GlobalAlias *>(this)->getAliaseeObject()); 93 } 94 95 static bool isValidLinkage(LinkageTypes L) { 96 return isExternalLinkage(L) || isLocalLinkage(L) || isWeakLinkage(L) || 97 isLinkOnceLinkage(L) || isAvailableExternallyLinkage(L); 98 } 99 100 // Methods for support type inquiry through isa, cast, and dyn_cast: 101 static bool classof(const Value *V) { 102 return V->getValueID() == Value::GlobalAliasVal; 103 } 104}; 105 106template <> 107struct OperandTraits<GlobalAlias> 108 : public FixedNumOperandTraits<GlobalAlias, 1> {}; 109 110DEFINE_TRANSPARENT_OPERAND_ACCESSORS(GlobalAlias, Constant) 111 112} // end namespace llvm 113 114#endif // LLVM_IR_GLOBALALIAS_H 115