Index: tools/llvm-objcopy/llvm-objcopy.cpp
===================================================================
--- tools/llvm-objcopy/llvm-objcopy.cpp
+++ tools/llvm-objcopy/llvm-objcopy.cpp
@@ -340,7 +340,10 @@
 
   auto Reader = CreateReader();
   auto Obj = Reader->create();
-  auto Writer = CreateWriter(*Obj, OutputFilename);
+  StringRef Output = OutputFilename;
+  if (StripDWO && !OutputFilename.getNumOccurrences())
+    Output = InputFilename;
+  auto Writer = CreateWriter(*Obj, Output);
   HandleArgs(*Obj, *Reader);
   Writer->finalize();
   Writer->write();