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diff --git a/lib/CodeGen/CGRecordLayoutBuilder.h b/lib/CodeGen/CGRecordLayoutBuilder.h
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+++ b/lib/CodeGen/CGRecordLayoutBuilder.h
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+//===--- CGRecordLayoutBuilder.h - Record builder helper --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This is a helper class used to build CGRecordLayout objects and LLVM types.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CODEGEN_CGRECORDLAYOUTBUILDER_H
+#define CLANG_CODEGEN_CGRECORDLAYOUTBUILDER_H
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/DataTypes.h"
+#include <vector>
+
+namespace llvm {
+  class Type;
+}
+
+namespace clang {
+  class FieldDecl;
+  class RecordDecl;
+
+namespace CodeGen {
+  class CGRecordLayout;
+  class CodeGenTypes;
+
+class CGRecordLayoutBuilder {
+  CodeGenTypes &Types;
+
+  /// Packed - Whether the resulting LLVM struct will be packed or not.
+  bool Packed;
+
+  /// ContainsMemberPointer - Whether one of the fields is a member pointer
+  /// or is a struct that contains a member pointer.
+  bool ContainsMemberPointer;
+
+  /// Alignment - Contains the alignment of the RecordDecl.
+  unsigned Alignment;
+
+  /// AlignmentAsLLVMStruct - Will contain the maximum alignment of all the
+  /// LLVM types.
+  unsigned AlignmentAsLLVMStruct;
+
+  /// BitsAvailableInLastField - If a bit field spans only part of a LLVM field,
+  /// this will have the number of bits still available in the field.
+  char BitsAvailableInLastField;
+
+  /// NextFieldOffsetInBytes - Holds the next field offset in bytes.
+  uint64_t NextFieldOffsetInBytes;
+
+  /// FieldTypes - Holds the LLVM types that the struct is created from.
+  std::vector<const llvm::Type *> FieldTypes;
+
+  /// LLVMFieldInfo - Holds a field and its corresponding LLVM field number.
+  typedef std::pair<const FieldDecl *, unsigned> LLVMFieldInfo;
+  llvm::SmallVector<LLVMFieldInfo, 16> LLVMFields;
+
+  /// LLVMBitFieldInfo - Holds location and size information about a bit field.
+  struct LLVMBitFieldInfo {
+    LLVMBitFieldInfo(const FieldDecl *FD, unsigned FieldNo, unsigned Start,
+                     unsigned Size)
+      : FD(FD), FieldNo(FieldNo), Start(Start), Size(Size) { }
+
+    const FieldDecl *FD;
+
+    unsigned FieldNo;
+    unsigned Start;
+    unsigned Size;
+  };
+  llvm::SmallVector<LLVMBitFieldInfo, 16> LLVMBitFields;
+
+  CGRecordLayoutBuilder(CodeGenTypes &Types)
+    : Types(Types), Packed(false), ContainsMemberPointer(false)
+    , Alignment(0), AlignmentAsLLVMStruct(1)
+    , BitsAvailableInLastField(0), NextFieldOffsetInBytes(0) { }
+
+  /// Layout - Will layout a RecordDecl.
+  void Layout(const RecordDecl *D);
+
+  /// LayoutUnion - Will layout a union RecordDecl.
+  void LayoutUnion(const RecordDecl *D);
+
+  /// LayoutField - try to layout all fields in the record decl.
+  /// Returns false if the operation failed because the struct is not packed.
+  bool LayoutFields(const RecordDecl *D);
+
+  /// LayoutField - layout a single field. Returns false if the operation failed
+  /// because the current struct is not packed.
+  bool LayoutField(const FieldDecl *D, uint64_t FieldOffset);
+
+  /// LayoutBitField - layout a single bit field.
+  void LayoutBitField(const FieldDecl *D, uint64_t FieldOffset);
+
+  /// AppendField - Appends a field with the given offset and type.
+  void AppendField(uint64_t FieldOffsetInBytes, const llvm::Type *FieldTy);
+
+  /// AppendPadding - Appends enough padding bytes so that the total struct
+  /// size matches the alignment of the passed in type.
+  void AppendPadding(uint64_t FieldOffsetInBytes, const llvm::Type *FieldTy);
+
+  /// AppendPadding - Appends enough padding bytes so that the total
+  /// struct size is a multiple of the field alignment.
+  void AppendPadding(uint64_t FieldOffsetInBytes, unsigned FieldAlignment);
+
+  /// AppendBytes - Append a given number of bytes to the record.
+  void AppendBytes(uint64_t NumBytes);
+
+  /// AppendTailPadding - Append enough tail padding so that the type will have
+  /// the passed size.
+  void AppendTailPadding(uint64_t RecordSize);
+
+  unsigned getTypeAlignment(const llvm::Type *Ty) const;
+  uint64_t getTypeSizeInBytes(const llvm::Type *Ty) const;
+
+  /// CheckForMemberPointer - Check if the field contains a member pointer.
+  void CheckForMemberPointer(const FieldDecl *FD);
+
+public:
+  /// ComputeLayout - Return the right record layout for a given record decl.
+  static CGRecordLayout *ComputeLayout(CodeGenTypes &Types,
+                                       const RecordDecl *D);
+};
+
+} // end namespace CodeGen
+} // end namespace clang
+
+
+#endif