Fixed an offset calculation error.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@56242 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/Rewrite/RewriteRope.cpp b/lib/Rewrite/RewriteRope.cpp
index 0a4dc85968..61cb02b9a5 100644
--- a/lib/Rewrite/RewriteRope.cpp
+++ b/lib/Rewrite/RewriteRope.cpp
@@ -792,7 +792,7 @@ RopePiece RewriteRope::MakeRopeString(const char *Start, const char *End) {
   if (AllocBuffer && --AllocBuffer->RefCount == 0)
     delete [] (char*)AllocBuffer;
   
-  unsigned AllocSize = sizeof(RopeRefCountString)-1+AllocChunkSize;
+  unsigned AllocSize = offsetof(RopeRefCountString, Data) + AllocChunkSize;
   AllocBuffer = reinterpret_cast<RopeRefCountString *>(new char[AllocSize]);
   AllocBuffer->RefCount = 0;
   memcpy(AllocBuffer->Data, Start, Len);