Share the common code of ComputeHash(Selector Sel) instead of keeping 2 copies in PCHReader and PCHWriter.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111629 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/Serialization/ASTCommon.cpp b/lib/Serialization/ASTCommon.cpp
new file mode 100644
index 0000000000..0eaf7a5610
--- /dev/null
+++ b/lib/Serialization/ASTCommon.cpp
@@ -0,0 +1,29 @@
+//===--- ASTCommon.cpp - Common stuff for ASTReader/ASTWriter----*- 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 common functions that both ASTReader and ASTWriter use.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ASTCommon.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "llvm/ADT/StringExtras.h"
+
+using namespace clang;
+
+unsigned serialization::ComputeHash(Selector Sel) {
+  unsigned N = Sel.getNumArgs();
+  if (N == 0)
+    ++N;
+  unsigned R = 5381;
+  for (unsigned I = 0; I != N; ++I)
+    if (IdentifierInfo *II = Sel.getIdentifierInfoForSlot(I))
+      R = llvm::HashString(II->getName(), R);
+  return R;
+}