devel <dev001@pas-world.com> writes:
> I see that GCC do not warning something like this:
>
> {
> x++;
>
> char var[10];
> int hello;
>
> if ()
> {
> }
> ...
>
> }
>
> or similar.
>
> Why GCC do not advise about this?
Because it is permitted by the C99 standard. GCC permits it in C90
mode as an extension. In C90 mode you will get a warning if you use
-pedantic.
Ian