https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77434
--- Comment #7 from Bernd Edlinger <bernd.edlinger at hotmail dot de> --- (In reply to jos...@codesourcery.com from comment #6) > On Thu, 1 Sep 2016, bernd.edlinger at hotmail dot de wrote: > > > + warning_at (location, 0, > > + "?: expression using integer constants in boolean > > context"); > > This should of course be enabled by some -W option (new or existing, and > enabled by -Wall in any case); warnings without an option to control them > should be avoided. sure. It is only an experiment so far. But it feels quite right. The location info is not optimal: at the closing parenthesis. I am not sure how to name the warning, and if there is a better way to tell the user what's wrong with the code.