From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sam Ravnborg Subject: Re: [PATCH] Use __unused0 instead of __unused for user visible struct member names Date: Wed, 4 Jan 2012 14:35:22 +0100 Message-ID: <20120104133522.GA7147@merkur.ravnborg.org> References: <20120102024418.GA10483@gaara.hadrons.org> <20120102202243.GA31103@elie.hsd1.il.comcast.net> <20120103065659.GA32216@merkur.ravnborg.org> <20120104081414.GA29745@gaara.hadrons.org> <4F0431F4.4050303@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4F0431F4.4050303-AlSwsSmVLrQ@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Michal Marek Cc: Guillem Jover , Jonathan Nieder , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kbuild-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org On Wed, Jan 04, 2012 at 12:03:16PM +0100, Michal Marek wrote: > On 4.1.2012 09:14, Guillem Jover wrote: > > On Tue, 2012-01-03 at 07:56:59 +0100, Sam Ravnborg wrote: > >> On Mon, Jan 02, 2012 at 02:22:43PM -0600, Jonathan Nieder wrote: > >>> Guillem Jover wrote: > >>>> On BSD systems __unused has traditionally been defined to mean the > >>>> equivalent of gcc's __attribute__((__unused__)), some parts of the > >>>> Linux tree use that convention too (e.g. perf). The problem comes when > >>>> defining such macro while trying to build unmodified source code with > >>>> BSD origins on systems with Linux headers. > >>>> > >>>> Rename the user visible struct members from __unused to __unused0 to > >>>> not cause compilation failures due to that macro, which should not be > >>>> a problem as those members are supposed to be private anyway. > >> > >> ^__ is reserved for libc internal stuff and there is no reason to > >> name the unused/padding members "__unused". > >> So one or a set of patches that rename them all to something more > >> sensible would be fine. > > > > On a quick glance, I've found other functionally similar struct > > member names present on the tree: > > > > __unused __unusedN __reserved __reservedN __reserved_N __resN > > __pad __padN __flr_pad __ifi_pad __tcpm_padN __tcpct_padN > > > > Do you mean you'd like to see patch(es) to rename all those? I'd not > > mind providing them, although my immediate concern right now is just > > regarding __unused. > > __.* and _[A-Z].* are reserved for the implementation. Unfortunately, > both the kernel userspace headers and the libc are part of the > implementation, so there needs to be some common sense applied to avoid > clashes. IMO renaming __unused to __unused0 on the basis that some > headers define __unused to __attribute__((__unused__)) makes sense, but > blindly renaming any occurence of double underscore helps little. Agree on Michael on this. Sam