--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/CodeGen/AsmPrinter/DIEHash.h	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,147 @@
+//===-- llvm/CodeGen/DIEHash.h - Dwarf Hashing Framework -------*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for DWARF4 hashing of DIEs.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DIE.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/Support/MD5.h"
+
+namespace llvm {
+
+class CompileUnit;
+
+/// \brief An object containing the capability of hashing and adding hash
+/// attributes onto a DIE.
+class DIEHash {
+  // The entry for a particular attribute.
+  struct AttrEntry {
+    const DIEValue *Val;
+    const DIEAbbrevData *Desc;
+  };
+
+  // Collection of all attributes used in hashing a particular DIE.
+  struct DIEAttrs {
+    AttrEntry DW_AT_name;
+    AttrEntry DW_AT_accessibility;
+    AttrEntry DW_AT_address_class;
+    AttrEntry DW_AT_allocated;
+    AttrEntry DW_AT_artificial;
+    AttrEntry DW_AT_associated;
+    AttrEntry DW_AT_binary_scale;
+    AttrEntry DW_AT_bit_offset;
+    AttrEntry DW_AT_bit_size;
+    AttrEntry DW_AT_bit_stride;
+    AttrEntry DW_AT_byte_size;
+    AttrEntry DW_AT_byte_stride;
+    AttrEntry DW_AT_const_expr;
+    AttrEntry DW_AT_const_value;
+    AttrEntry DW_AT_containing_type;
+    AttrEntry DW_AT_count;
+    AttrEntry DW_AT_data_bit_offset;
+    AttrEntry DW_AT_data_location;
+    AttrEntry DW_AT_data_member_location;
+    AttrEntry DW_AT_decimal_scale;
+    AttrEntry DW_AT_decimal_sign;
+    AttrEntry DW_AT_default_value;
+    AttrEntry DW_AT_digit_count;
+    AttrEntry DW_AT_discr;
+    AttrEntry DW_AT_discr_list;
+    AttrEntry DW_AT_discr_value;
+    AttrEntry DW_AT_encoding;
+    AttrEntry DW_AT_enum_class;
+    AttrEntry DW_AT_endianity;
+    AttrEntry DW_AT_explicit;
+    AttrEntry DW_AT_is_optional;
+    AttrEntry DW_AT_location;
+    AttrEntry DW_AT_lower_bound;
+    AttrEntry DW_AT_mutable;
+    AttrEntry DW_AT_ordering;
+    AttrEntry DW_AT_picture_string;
+    AttrEntry DW_AT_prototyped;
+    AttrEntry DW_AT_small;
+    AttrEntry DW_AT_segment;
+    AttrEntry DW_AT_string_length;
+    AttrEntry DW_AT_threads_scaled;
+    AttrEntry DW_AT_upper_bound;
+    AttrEntry DW_AT_use_location;
+    AttrEntry DW_AT_use_UTF8;
+    AttrEntry DW_AT_variable_parameter;
+    AttrEntry DW_AT_virtuality;
+    AttrEntry DW_AT_visibility;
+    AttrEntry DW_AT_vtable_elem_location;
+    AttrEntry DW_AT_type;
+
+    // Insert any additional ones here...
+  };
+
+public:
+  /// \brief Computes the ODR signature.
+  uint64_t computeDIEODRSignature(const DIE &Die);
+
+  /// \brief Computes the CU signature.
+  uint64_t computeCUSignature(const DIE &Die);
+
+  /// \brief Computes the type signature.
+  uint64_t computeTypeSignature(const DIE &Die);
+
+  // Helper routines to process parts of a DIE.
+private:
+  /// \brief Adds the parent context of \param Die to the hash.
+  void addParentContext(const DIE &Die);
+
+  /// \brief Adds the attributes of \param Die to the hash.
+  void addAttributes(const DIE &Die);
+
+  /// \brief Computes the full DWARF4 7.27 hash of the DIE.
+  void computeHash(const DIE &Die);
+
+  // Routines that add DIEValues to the hash.
+private:
+  /// \brief Encodes and adds \param Value to the hash as a ULEB128.
+  void addULEB128(uint64_t Value);
+
+  /// \brief Encodes and adds \param Value to the hash as a SLEB128.
+  void addSLEB128(int64_t Value);
+
+  /// \brief Adds \param Str to the hash and includes a NULL byte.
+  void addString(StringRef Str);
+
+  /// \brief Collects the attributes of DIE \param Die into the \param Attrs
+  /// structure.
+  void collectAttributes(const DIE &Die, DIEAttrs &Attrs);
+
+  /// \brief Hashes the attributes in \param Attrs in order.
+  void hashAttributes(const DIEAttrs &Attrs, dwarf::Tag Tag);
+
+  /// \brief Hashes an individual attribute.
+  void hashAttribute(AttrEntry Attr, dwarf::Tag Tag);
+
+  /// \brief Hashes an attribute that refers to another DIE.
+  void hashDIEEntry(dwarf::Attribute Attribute, dwarf::Tag Tag,
+                    const DIE &Entry);
+
+  /// \brief Hashes a reference to a named type in such a way that is
+  /// independent of whether that type is described by a declaration or a
+  /// definition.
+  void hashShallowTypeReference(dwarf::Attribute Attribute, const DIE &Entry,
+                                StringRef Name);
+
+  /// \brief Hashes a reference to a previously referenced type DIE.
+  void hashRepeatedTypeReference(dwarf::Attribute Attribute, unsigned DieNumber);
+
+  void hashNestedType(const DIE &Die, StringRef Name);
+
+private:
+  MD5 Hash;
+  DenseMap<const DIE *, unsigned> Numbering;
+};
+}