include/llvm/IR/GlobalIFunc.h

   1 //===-------- llvm/GlobalIFunc.h - GlobalIFunc 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 /// \brief
  10 /// This file contains the declaration of the GlobalIFunc class, which
  11 /// represents a single indirect function in the IR. Indirect function uses
  12 /// ELF symbol type extension to mark that the address of a declaration should
  13 /// be resolved at runtime by calling a resolver function.
  14 ///
  15 //===----------------------------------------------------------------------===//
  16
  17 #ifndef LLVM_IR_GLOBALIFUNC_H
  18 #define LLVM_IR_GLOBALIFUNC_H
  19
  20 #include "llvm/ADT/ilist_node.h"
  21 #include "llvm/IR/GlobalIndirectSymbol.h"
  22 #include "llvm/IR/Value.h"
  23
  24 namespace llvm {
  25
  26 class Twine;
  27 class Module;
  28
  29 // Traits class for using GlobalIFunc in symbol table in Module.
  30 template <typename ValueSubClass> class SymbolTableListTraits;
  31
  32 class GlobalIFunc final : public GlobalIndirectSymbol,
  33                           public ilist_node<GlobalIFunc> {
  34   friend class SymbolTableListTraits<GlobalIFunc>;
  35
  36   GlobalIFunc(Type *Ty, unsigned AddressSpace, LinkageTypes Linkage,
  37               const Twine &Name, Constant *Resolver, Module *Parent);
  38
  39 public:
  40   GlobalIFunc(const GlobalIFunc &) = delete;
  41   GlobalIFunc &operator=(const GlobalIFunc &) = delete;
  42
  43   /// If a parent module is specified, the ifunc is automatically inserted into
  44   /// the end of the specified module's ifunc list.
  45   static GlobalIFunc *create(Type *Ty, unsigned AddressSpace,
  46                              LinkageTypes Linkage, const Twine &Name,
  47                              Constant *Resolver, Module *Parent);
  48
  49   void copyAttributesFrom(const GlobalIFunc *Src) {
  50     GlobalValue::copyAttributesFrom(Src);
  51   }
  52
  53   /// This method unlinks 'this' from the containing module, but does not
  54   /// delete it.
  55   void removeFromParent();
  56
  57   /// This method unlinks 'this' from the containing module and deletes it.
  58   void eraseFromParent();
  59
  60   /// These methods retrieve and set ifunc resolver function.
  61   void setResolver(Constant *Resolver) {
  62     setIndirectSymbol(Resolver);
  63   }
  64   const Constant *getResolver() const {
  65     return getIndirectSymbol();
  66   }
  67   Constant *getResolver() {
  68     return getIndirectSymbol();
  69   }
  70
  71   // Methods for support type inquiry through isa, cast, and dyn_cast:
  72   static bool classof(const Value *V) {
  73     return V->getValueID() == Value::GlobalIFuncVal;
  74   }
  75 };
  76
  77 } // end namespace llvm
  78
  79 #endif // LLVM_IR_GLOBALIFUNC_H