On Sat, 2013-04-06 at 12:59 -0400, Tom Lane wrote:
> The reason I'm thinking it's a good idea is that it would expose any
> remaining places where we have nominally var-length arrays embedded in
> larger structs. Now that I've seen the failures with gcc 4.8.0, I'm
> quite worried that there might be some more declarations like that
> which we've not identified yet, but that by chance aren't causing
> obvious failures today.
Here is a rough patch that replaces almost all occurrences of
something[1] in a struct with FLEXIBLE_ARRAY_MEMBER. It crashes left
and right (because of sizeof issues, probably), but at least so far the
compiler hasn't complained about any flexible-array members not at the
end of the struct, which is what it did last time. So the answer to
your concern so far is negative.
Completing this patch will be quite a bit more debugging work. Some
kind of electric fence for palloc would be helpful.