[Bug preprocessor/33305] We should warn about empty macro arguments

[Andrew Pinski]

On 5 Sep 2007 09:24:09 -0000, manu at gcc dot gnu dot org
<gcc-bugzilla@gcc.gnu.org> wrote:
> There was talking about creating a -Wundefined flag that warns about undefined
> behaviour (PR30334). Would this fit in there? (-pedantic is not supposed to
> warn about undefined constructions as far as I know).

There are two different undefined behaviors, one at runtime and one at
compile time.  This belongs to the latter which means we can
diagnostic this if we want (and can do it with -pedantic in fact).

-- Pinski