1 files changed, 2 insertions, 0 deletions
diff --git a/llvm/tools/llvm-diff/DiffLog.h b/llvm/tools/llvm-diff/DiffLog.h
index 8eb53ffffcc..cfdeec89d9e 100644
--- a/llvm/tools/llvm-diff/DiffLog.h
+++ b/llvm/tools/llvm-diff/DiffLog.h
@@ -40,6 +40,8 @@ namespace llvm {
   public:
     LogBuilder(Consumer &c, StringRef Format)
       : consumer(c), Format(Format) {}
+    // Relying on RVO, not actually copyable.
+    LogBuilder(const LogBuilder&);
 
     LogBuilder &operator<<(Value *V) {
       Arguments.push_back(V);