netdev - Re: [iproute PATCH v3 0/6] Big C99 style initializer rework

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Message-ID: <0a003d6f-ae2f-57cb-f3f1-1975011c7b78@cumulusnetworks.com>
Date:	Tue, 28 Jun 2016 11:37:43 -0600
From:	David Ahern <dsa@...ulusnetworks.com>
To:	Phil Sutter <phil@....cc>,
	Stephen Hemminger <shemming@...cade.com>,
	Daniel Borkmann <daniel@...earbox.net>,
	Nicolas Dichtel <nicolas.dichtel@...nd.com>,
	Julien Floret <julien.floret@...nd.com>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: [iproute PATCH v3 0/6] Big C99 style initializer rework

On 6/28/16 11:37 AM, Phil Sutter wrote:
>>> I saw these too with gcc-3.4.6 but not with 5.3.0. It appears to be a
>>> gcc bug[1]. One possible workaround is to match the brace level of the
>>> first field, but it's quite ugly: [2]. Another way might be to
>>> initialize one of the fields to zero, like so:
>>>
>>> | struct ifreq ifr = { .ifr_qlen = 0 };
>>>
>>> What do you think?
>>>
>>> Thanks, Phil
>>>
>>> [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119
>>> [2] http://nwl.cc/cgi-bin/git/gitweb.cgi?p=iproute2.git;a=commitdiff;h=a1cbf2b63c995b2f633c5b4699248ab308b201d2;hp=3809cfec65b03716d1d0360338126df4b4f3fbf6
>>
>> I am using gcc on Debian stable which is 5.3.1.
>
> Hmm. In a fresh install of Debian 8.5 I see the warnings as well, but it
> has gcc-4.9.2-10 as most recent version.
>
> Another thing I noticed: Using empty braces ('{}') instead of the
> universal zero initializer seems to work without causing warnings (at
> least unless '-pedantic' is used).

since .ifr_qlen is already referenced in that function seems like your 
suggestion above (struct ifreq ifr = { .ifr_qlen = 0 };) should be 
acceptable.