https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64185
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to zaz from comment #4)
> > > this:
> > > struct PascalString
> > > {
> > > int length;
> > > char data[0];
> > > };
> > > And then just allocate necessary memory block and able access to something
> > > like:
> > > ps.data[100] - if allocated block have enough size.
> >
> > This structure will always work. It is only the case where the array field
> > is not at the end of the structure which is where it is undefined.
>
> So why it not work in this case:
> struct PascalString
> {
> int length;
> char data[0];
> char the_padding[1024];
> };
Because that is what the C standard say. And also the above code is invalid C.
