This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: C++ PATCH to suppress bogus -Wunused warning for parameter packs (PR c++/68965)
- From: Marek Polacek <polacek at redhat dot com>
- To: Jason Merrill <jason at redhat dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 13 Jan 2016 23:52:00 +0100
- Subject: Re: C++ PATCH to suppress bogus -Wunused warning for parameter packs (PR c++/68965)
- Authentication-results: sourceware.org; auth=none
- References: <20160113165022 dot GK25528 at redhat dot com> <5696B497 dot 1010005 at redhat dot com>
On Wed, Jan 13, 2016 at 03:33:27PM -0500, Jason Merrill wrote:
> On 01/13/2016 11:50 AM, Marek Polacek wrote:
> >So to quash that -Wunused-parameter warning, I decided to set TREE_USED at the
> >place where we create those #xs parameters.
>
> Won't that cause false negatives when the parameter pack is never mentioned
> in the function?
You mean that e.g. for
auto fn = [](auto&&... xs)
{
};
int
main ()
{
fn (1, 2, 3);
}
we won't print
z.cc:1:24: warning: unused parameter 'xs' [-Wunused-parameter]
anymore? Unfortunately, we don't print that even without the patch :(.
Marek