DeclAccessPair.h revision 207619 
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
23namespace clang {
24
25class NamedDecl;
26
27/// A POD class for pairing a NamedDecl* with an access specifier.
28/// Can be put into unions.
29class DeclAccessPair {
30  NamedDecl *Ptr; // we'd use llvm::PointerUnion, but it isn't trivial
31
32  enum { Mask = 0x3 };
33
34public:
35  static DeclAccessPair make(NamedDecl *D, AccessSpecifier AS) {
36    DeclAccessPair p;
37    p.set(D, AS);
38    return p;
39  }
40
41  NamedDecl *getDecl() const {
42    return (NamedDecl*) (~Mask & (uintptr_t) Ptr);
43  }
44  AccessSpecifier getAccess() const {
45    return AccessSpecifier(Mask & (uintptr_t) Ptr);
46  }
47
48  void setDecl(NamedDecl *D) {
49    set(D, getAccess());
50  }
51  void setAccess(AccessSpecifier AS) {
52    set(getDecl(), AS);
53  }
54  void set(NamedDecl *D, AccessSpecifier AS) {
55    Ptr = reinterpret_cast<NamedDecl*>(uintptr_t(AS) |
56                                       reinterpret_cast<uintptr_t>(D));
57  }
58
59  operator NamedDecl*() const { return getDecl(); }
60  NamedDecl *operator->() const { return getDecl(); }
61};
62}
63
64// Take a moment to tell SmallVector that DeclAccessPair is POD.
65namespace llvm {
66template<typename> struct isPodLike;
67template<> struct isPodLike<clang::DeclAccessPair> {
68   static const bool value = true;
69};
70}
71
72#endif
73