1 files changed, 72 insertions, 0 deletions
diff --git a/include/clang/AST/DeclAccessPair.h b/include/clang/AST/DeclAccessPair.h
new file mode 100644
index 0000000000..7ecd8f8bcd
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+++ b/include/clang/AST/DeclAccessPair.h
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+//===--- DeclAccessPair.h - A decl bundled with its path access -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the DeclAccessPair class, which provides an
+//  efficient representation of a pair of a NamedDecl* and an
+//  AccessSpecifier.  Generally the access specifier gives the
+//  natural access of a declaration when named in a class, as
+//  defined in C++ [class.access.base]p1.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_DECLACCESSPAIR_H
+#define LLVM_CLANG_AST_DECLACCESSPAIR_H
+
+#include "clang/Basic/Specifiers.h"
+
+namespace clang {
+
+class NamedDecl;
+
+/// A POD class for pairing a NamedDecl* with an access specifier.
+/// Can be put into unions.
+class DeclAccessPair {
+  NamedDecl *Ptr; // we'd use llvm::PointerUnion, but it isn't trivial
+
+  enum { Mask = 0x3 };
+
+public:
+  static DeclAccessPair make(NamedDecl *D, AccessSpecifier AS) {
+    DeclAccessPair p;
+    p.set(D, AS);
+    return p;
+  }
+
+  NamedDecl *getDecl() const {
+    return (NamedDecl*) (~Mask & (uintptr_t) Ptr);
+  }
+  AccessSpecifier getAccess() const {
+    return AccessSpecifier(Mask & (uintptr_t) Ptr);
+  }
+
+  void setDecl(NamedDecl *D) {
+    set(D, getAccess());
+  }
+  void setAccess(AccessSpecifier AS) {
+    set(getDecl(), AS);
+  }
+  void set(NamedDecl *D, AccessSpecifier AS) {
+    Ptr = reinterpret_cast<NamedDecl*>(uintptr_t(AS) |
+                                       reinterpret_cast<uintptr_t>(D));
+  }
+
+  operator NamedDecl*() const { return getDecl(); }
+  NamedDecl *operator->() const { return getDecl(); }
+};
+}
+
+// Take a moment to tell SmallVector that DeclAccessPair is POD.
+namespace llvm {
+template<typename> struct isPodLike;
+template<> struct isPodLike<clang::DeclAccessPair> {
+   static const bool value = true;
+};
+}
+
+#endif