Index: cfe-7.0.0rc1.src/lib/Driver/ToolChains/Gnu.cpp
===================================================================
--- cfe-7.0.0rc1.src.orig/lib/Driver/ToolChains/Gnu.cpp
+++ cfe-7.0.0rc1.src/lib/Driver/ToolChains/Gnu.cpp
@@ -1596,7 +1596,8 @@ Generic_GCC::GCCVersion Generic_GCC::GCC
       MinorStr = MinorStr.slice(0, EndNumber);
     }
   }
-  if (MinorStr.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0)
+  if (!MinorStr.str().empty() && 
+      (MinorStr.getAsInteger(10, GoodVersion.Minor) || GoodVersion.Minor < 0))
     return BadVersion;
   GoodVersion.MinorStr = MinorStr.str();