https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83797
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #4)
> FWIW the C front-end highlights the function name not the return type:
>
> vm.c:1:6: warning: return type of ‘main’ is not ‘int’ [-Wmain]
> void main() { }
> ^~~~
Which is now PR 89926
