[Bug c/7652] -Wswitch-break : Warn if a switch case falls through

["michael.chapman at cortus dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=7652

--- Comment #33 from Michael Chapman <michael.chapman at cortus dot com> ---
(In reply to Florian Weimer from comment #30)
> (In reply to Manuel LÃpez-IbÃÃez from comment #29)
> 
> > I like the previous suggestion of using "goto LABEL;". In fact, the warning
> > message could explicitly say "use %<goto %D;%> to silence this warning".
> 
> Does this mean that you propose a GCC extension which allows to write this?
> 
>      goto 5;
>    case 5:
> 
> I'm not sure if the extension is worth it, and it creates another source of
> errors/unclarities if another switch branch is inserted before "case 5:". 
> It looks like fall-through, but it isn't one because the case labels aren't
> aligned.

Why an extension? What is wrong with:-

        goto case_5;
      case 5: case_5:
         ....