diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 99ea9af..d534ff4 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -315,6 +315,7 @@
   case SD_Dynamic:
     llvm_unreachable("temporary can't have dynamic storage duration");
   }
+  llvm_unreachable("unknown storage duration");
 }
 
 static llvm::Value *