The default warnings set contains -Wswitch-default, which gives a warning if a switch lacks a default case. Therefore, -Wswitch is useless, because (assuming authors fix all warnings) there will already be a default label. In order to catch missing enumeration cases, -Wswitch-enum is needed.
(If on the other hand it's thought that warning when all enumeration cases are not covered is excessive, -Wswitch should be added to the .spec files to signal this intent, even thought currently it will have no effect.)
--