Fix MSVC 'not all control paths return a value' warning

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@320297 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Driver/ToolChains/Darwin.cpp b/lib/Driver/ToolChains/Darwin.cpp
index f4ed52838df9c3014ff578bfecae1b57270c53e0..28efa86538edf59f8c93a70cf2e2e382e3367125 100644 (file)
--- a/lib/Driver/ToolChains/Darwin.cpp
+++ b/lib/Driver/ToolChains/Darwin.cpp
@@ -1230,6 +1230,7 @@ struct DarwinPlatform {
     case DeploymentTargetEnv:
       return (llvm::Twine(EnvVarName) + "=" + OSVersion).str();
     }
+    llvm_unreachable("Unsupported Darwin Source Kind");
   }
 
   static DarwinPlatform createOSVersionArg(DarwinPlatformKind Platform,