From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <52FCDF56.3060408@kernel.dk> Date: Thu, 13 Feb 2014 08:05:58 -0700 From: Jens Axboe MIME-Version: 1.0 Subject: Re: [PATCH] Fix g++ warning about void* used in arithmetic References: <1392229542-14083-1-git-send-email-d.gollub@telekom.de> <52FC45E9.3090101@kernel.dk> <20140213071357.36e92383@marvin> In-Reply-To: <20140213071357.36e92383@marvin> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit To: Daniel Gollub Cc: fio@vger.kernel.org, Daniel Gollub List-ID: On 02/12/2014 11:13 PM, Daniel Gollub wrote: > Hi Jens, > > On Wed, 12 Feb 2014 21:11:21 -0700, Jens Axboe wrote: >> On 2014-02-12 11:25, Daniel Gollub wrote: >>> ../parse.h: In function ‘void* td_var(thread_options*, fio_option*, >>> unsigned int)’: ../parse.h:110:10: warning: pointer of type ‘void >>> *’ used in arithmetic [-Wpointer-arith] ../parse.h:112:9: warning: >>> pointer of type ‘void *’ used in arithmetic [-Wpointer-arith] >> >> I bet there are a lot of these, or other similar code that would >> prevent compiling with g++. I'm dubious of the value add here. Fio is >> written in C, after all. >> > > I should have mentioned this in the commit message: this is required to > compile an external ionengine written in C++. I do not try to compile > entire fio with g++. If I include fio.h in the external ioengine, > parse.h gets included by fio.h or so and causes this g++ warning. > > This was the last warning (which just got introduced 2 days > ago) when fio.h gets included by an external engine build with g++. > > So the value here is to build external ioengines against libraries/APIs > which are only available in C++. In my case against an internal library > of CEPH. I guessed as much last night, so I did end up applying your patches. -- Jens Axboe