DeclAccessPair.h revision 2fa67efeaf66a9332c30a026dc1c21bef6c33a6c 
1//===--- DeclAccessPair.h - A decl bundled with its path access -*- 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//  This file defines the DeclAccessPair class, which provides an
11//  efficient representation of a pair of a NamedDecl* and an
12//  AccessSpecifier.  Generally the access specifier gives the
13//  natural access of a declaration when named in a class, as
14//  defined in C++ [class.access.base]p1.
15//
16//===----------------------------------------------------------------------===//
17
18#ifndef LLVM_CLANG_AST_DECLACCESSPAIR_H
19#define LLVM_CLANG_AST_DECLACCESSPAIR_H
20
21#include "clang/Basic/Specifiers.h"
22#include "llvm/Support/DataTypes.h"
23
24namespace clang {
25
26class NamedDecl;
27
28/// A POD class for pairing a NamedDecl* with an access specifier.
29/// Can be put into unions.
30class DeclAccessPair {
31  NamedDecl *Ptr; // we'd use llvm::PointerUnion, but it isn't trivial
32
33  enum { Mask = 0x3 };
34
35public:
36  static DeclAccessPair make(NamedDecl *D, AccessSpecifier AS) {
37    DeclAccessPair p;
38    p.set(D, AS);
39    return p;
40  }
41
42  NamedDecl *getDecl() const {
43    return (NamedDecl*) (~Mask & (uintptr_t) Ptr);
44  }
45  AccessSpecifier getAccess() const {
46    return AccessSpecifier(Mask & (uintptr_t) Ptr);
47  }
48
49  void setDecl(NamedDecl *D) {
50    set(D, getAccess());
51  }
52  void setAccess(AccessSpecifier AS) {
53    set(getDecl(), AS);
54  }
55  void set(NamedDecl *D, AccessSpecifier AS) {
56    Ptr = reinterpret_cast<NamedDecl*>(uintptr_t(AS) |
57                                       reinterpret_cast<uintptr_t>(D));
58  }
59
60  operator NamedDecl*() const { return getDecl(); }
61  NamedDecl *operator->() const { return getDecl(); }
62};
63}
64
65// Take a moment to tell SmallVector that DeclAccessPair is POD.
66namespace llvm {
67template<typename> struct isPodLike;
68template<> struct isPodLike<clang::DeclAccessPair> {
69   static const bool value = true;
70};
71}
72
73#endif
74