include/llvm/IR/GlobalAlias.h

   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/GlobalIndirectSymbol.h"
  19 #include "llvm/IR/Value.h"
  20
  21 namespace llvm {
  22
  23 class Twine;
  24 class Module;
  25 template <typename ValueSubClass> class SymbolTableListTraits;
  26
  27 class GlobalAlias : public GlobalIndirectSymbol,
  28                     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
  34 public:
  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   /// removeFromParent - This method unlinks 'this' from the containing module,
  62   /// but does not delete it.
  63   ///
  64   void removeFromParent();
  65
  66   /// eraseFromParent - This method unlinks 'this' from the containing module
  67   /// and deletes it.
  68   ///
  69   void eraseFromParent();
  70
  71   /// These methods retrieve and set alias target.
  72   void setAliasee(Constant *Aliasee);
  73   const Constant *getAliasee() const {
  74     return getIndirectSymbol();
  75   }
  76   Constant *getAliasee() {
  77     return getIndirectSymbol();
  78   }
  79
  80   static bool isValidLinkage(LinkageTypes L) {
  81     return isExternalLinkage(L) || isLocalLinkage(L) ||
  82       isWeakLinkage(L) || isLinkOnceLinkage(L);
  83   }
  84
  85   // Methods for support type inquiry through isa, cast, and dyn_cast:
  86   static bool classof(const Value *V) {
  87     return V->getValueID() == Value::GlobalAliasVal;
  88   }
  89 };
  90
  91 } // end namespace llvm
  92
  93 #endif // LLVM_IR_GLOBALALIAS_H