1//===-------- llvm/GlobalIFunc.h - GlobalIFunc class ------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9///
10/// \brief
11/// This file contains the declaration of the GlobalIFunc class, which
12/// represents a single indirect function in the IR. Indirect function uses
13/// ELF symbol type extension to mark that the address of a declaration should
14/// be resolved at runtime by calling a resolver function.
15///
16//===----------------------------------------------------------------------===//
17
18#ifndef LLVM_IR_GLOBALIFUNC_H
19#define LLVM_IR_GLOBALIFUNC_H
20
21#include "llvm/ADT/ilist_node.h"
22#include "llvm/IR/GlobalIndirectSymbol.h"
23#include "llvm/IR/Value.h"
24
25namespace llvm {
26
27class Twine;
28class Module;
29
30// Traits class for using GlobalIFunc in symbol table in Module.
31template <typename ValueSubClass> class SymbolTableListTraits;
32
33class GlobalIFunc final : public GlobalIndirectSymbol,
34                          public ilist_node<GlobalIFunc> {
35  friend class SymbolTableListTraits<GlobalIFunc>;
36
37  GlobalIFunc(Type *Ty, unsigned AddressSpace, LinkageTypes Linkage,
38              const Twine &Name, Constant *Resolver, Module *Parent);
39
40public:
41  GlobalIFunc(const GlobalIFunc &) = delete;
42  GlobalIFunc &operator=(const GlobalIFunc &) = delete;
43
44  /// If a parent module is specified, the ifunc is automatically inserted into
45  /// the end of the specified module's ifunc list.
46  static GlobalIFunc *create(Type *Ty, unsigned AddressSpace,
47                             LinkageTypes Linkage, const Twine &Name,
48                             Constant *Resolver, Module *Parent);
49
50  void copyAttributesFrom(const GlobalIFunc *Src) {
51    GlobalValue::copyAttributesFrom(Src);
52  }
53
54  /// This method unlinks 'this' from the containing module, but does not
55  /// delete it.
56  void removeFromParent();
57
58  /// This method unlinks 'this' from the containing module and deletes it.
59  void eraseFromParent();
60
61  /// These methods retrieve and set ifunc resolver function.
62  void setResolver(Constant *Resolver) {
63    setIndirectSymbol(Resolver);
64  }
65  const Constant *getResolver() const {
66    return getIndirectSymbol();
67  }
68  Constant *getResolver() {
69    return getIndirectSymbol();
70  }
71
72  // Methods for support type inquiry through isa, cast, and dyn_cast:
73  static bool classof(const Value *V) {
74    return V->getValueID() == Value::GlobalIFuncVal;
75  }
76};
77
78} // end namespace llvm
79
80#endif // LLVM_IR_GLOBALIFUNC_H
81