Re: gcc 4.6 -Wunused-but-set-variable

On ons, 2011-06-15 at 19:28 -0400, Tom Lane wrote:
> Peter Eisentraut <peter_e(at)gmx(dot)net> writes:
> > I couldn't see a way good way of programming around this (perhaps in the
> > second case, but it would get uselessly ugly), so perhaps just marking
> > the variables as potentially unused would be appropriate? See patch.
>
> Of course this would break not only on non-gcc compilers, but old
> versions of gcc. I'd suggest a macro (cf PERL_UNUSED_DECL) and some
> version checks at the site of the macro declaration (perhaps the ones
> emitted by bison for its use of this construct will do).

Non-GCC compilers would be fine, because we define away __attribute__
there anyway, but on GCC itself, you're right, the "unused" attribute is
a bit more recent than ancient.

Actually, casting to void, which is the convention we already use
elsewhere, works for this, so done that way.