1 files changed, 87 insertions, 0 deletions
diff --git a/include/clang/AST/BaseSubobject.h b/include/clang/AST/BaseSubobject.h
new file mode 100644
index 0000000000000..6a036bb62cf43
--- /dev/null
+++ b/include/clang/AST/BaseSubobject.h
@@ -0,0 +1,87 @@
+//===--- BaseSubobject.h - BaseSubobject class ----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides a definition of the BaseSubobject class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_BASESUBOBJECT_H
+#define LLVM_CLANG_AST_BASESUBOBJECT_H
+
+#include "clang/AST/CharUnits.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/type_traits.h"
+
+namespace clang {
+  class CXXRecordDecl;
+
+// BaseSubobject - Uniquely identifies a direct or indirect base class. 
+// Stores both the base class decl and the offset from the most derived class to
+// the base class. Used for vtable and VTT generation.
+class BaseSubobject {
+  /// Base - The base class declaration.
+  const CXXRecordDecl *Base;
+  
+  /// BaseOffset - The offset from the most derived class to the base class.
+  CharUnits BaseOffset;
+  
+public:
+  BaseSubobject() { }
+  BaseSubobject(const CXXRecordDecl *Base, CharUnits BaseOffset)
+    : Base(Base), BaseOffset(BaseOffset) { }
+  
+  /// getBase - Returns the base class declaration.
+  const CXXRecordDecl *getBase() const { return Base; }
+
+  /// getBaseOffset - Returns the base class offset.
+  CharUnits getBaseOffset() const { return BaseOffset; }
+
+  friend bool operator==(const BaseSubobject &LHS, const BaseSubobject &RHS) {
+    return LHS.Base == RHS.Base && LHS.BaseOffset == RHS.BaseOffset;
+ }
+};
+
+} // end namespace clang
+
+namespace llvm {
+
+template<> struct DenseMapInfo<clang::BaseSubobject> {
+  static clang::BaseSubobject getEmptyKey() {
+    return clang::BaseSubobject(
+      DenseMapInfo<const clang::CXXRecordDecl *>::getEmptyKey(),
+      clang::CharUnits::fromQuantity(DenseMapInfo<int64_t>::getEmptyKey()));
+  }
+
+  static clang::BaseSubobject getTombstoneKey() {
+    return clang::BaseSubobject(
+      DenseMapInfo<const clang::CXXRecordDecl *>::getTombstoneKey(),
+      clang::CharUnits::fromQuantity(DenseMapInfo<int64_t>::getTombstoneKey()));
+  }
+
+  static unsigned getHashValue(const clang::BaseSubobject &Base) {
+    return 
+      DenseMapInfo<const clang::CXXRecordDecl *>::getHashValue(Base.getBase()) ^
+      DenseMapInfo<int64_t>::getHashValue(Base.getBaseOffset().getQuantity());
+  }
+
+  static bool isEqual(const clang::BaseSubobject &LHS, 
+                      const clang::BaseSubobject &RHS) {
+    return LHS == RHS;
+  }
+};
+
+// It's OK to treat BaseSubobject as a POD type.
+template <> struct isPodLike<clang::BaseSubobject> {
+  static const bool value = true;
+};
+
+}
+
+#endif