Index: lib/Driver/ToolChain.cpp
===================================================================
--- lib/Driver/ToolChain.cpp
+++ lib/Driver/ToolChain.cpp
@@ -646,6 +646,8 @@
   switch (Type) {
   case ToolChain::CST_Libcxx:
     CmdArgs.push_back("-lc++");
+    if (GetRuntimeLibType(Args) == ToolChain::RLT_CompilerRT)
+        CmdArgs.push_back("-lunwind");
     break;
 
   case ToolChain::CST_Libstdcxx: