Move hash computation code into a separate class and file.

No functional change intended.

llvm-svn: 188028

1 files changed, 46 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DIEHash.h b/llvm/lib/CodeGen/AsmPrinter/DIEHash.h
new file mode 100644
index 00000000000..b9f811c91af
--- /dev/null
+++ b/llvm/lib/CodeGen/AsmPrinter/DIEHash.h
@@ -0,0 +1,46 @@
+//===-- 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 "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 {
+public:
+  /// \brief Initializes. The hash is default initialized.
+  DIEHash() {}
+
+  /// \brief Computes the ODR signature
+  uint64_t computeDIEODRSignature(DIE *Die);
+
+  // Helper routines to process parts of a DIE.
+ private:
+  /// \brief Adds the parent context of \param Die to the hash.
+  void addParentContext(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 Adds \param Str to the hash and includes a NULL byte.
+  void addString(StringRef Str);
+  
+private:
+  MD5 Hash;
+};
+}