From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Horman Subject: Re: [PATCH v3] compat: merge compat library into EAL Date: Thu, 7 Feb 2019 09:34:26 -0500 Message-ID: <20190207143426.GA23613@hmswarspite.think-freely.org> References: <20190110111104.56464-1-bruce.richardson@intel.com> <20190206110130.55135-1-bruce.richardson@intel.com> <20190206122254.GA16887@hmswarspite.think-freely.org> <20190206141744.GA236864@bricha3-MOBL.ger.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@dpdk.org, stable@dpdk.org, David Marchand , Anatoly Burakov To: Bruce Richardson Return-path: Content-Disposition: inline In-Reply-To: <20190206141744.GA236864@bricha3-MOBL.ger.corp.intel.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Wed, Feb 06, 2019 at 02:17:45PM +0000, Bruce Richardson wrote: > On Wed, Feb 06, 2019 at 07:22:54AM -0500, Neil Horman wrote: > > On Wed, Feb 06, 2019 at 11:01:30AM +0000, Bruce Richardson wrote: > > > Since compat library is only a single header, we can easily move it into > > > the EAL common headers instead of tracking it separately. The downside of > > > this is that it becomes a little more difficult to have any libs that are > > > built before EAL depend on it. Thankfully, this is not a major problem as > > > the only library which uses rte_compat.h and is built before EAL (kvargs) > > > already has the path to the compat.h header file explicitly called out as > > > an include path. > > > > > > However, to ensure that we don't hit problems later with this, we can add > > > EAL common headers folder to the global include list in the meson build > > > which means that all common headers can be safely used by all libraries, no > > > matter what their build order. > > > > > This assumes that the compat lib will always just be a header though, no? Will > > this work in the event that someone wants to add some compatibility code that > > requires its own C compilation unit? > > > > No, it probably won't work, you'll hit an issue with any libraries that > don't depend on EAL and need that functionality. The question is whether > this is likely to be an issue in the future for us. I'd say the possiblity > is fairly remote, but I'm open to input on it. > Im afraid I don't have any more visibility on that than anyone else. The fact that it hasn't been needed yet is likely a good sign, but I am concerned at the notion that this change enjoins us from having that flexibility. > > > As a side-effect, this patch also fixes an issue with building on BSD using > > > meson, due to compat lib no longer needing to be listed as a dependency. > > > > > Can you elaborate here a bit please? listing a lib as a dependency seems like a > > fundamental function of a build system, was there a bug with meson in this > > capacity? > > > > It was a bug in DPDK. There was already a dependency on the compat > library from libeal from linux, but not from BSD, so when a further > dependency was added globally, the BSD build broke, but the linux one > didn't. > Do you have a link to the breakage details? I'd like to look at it to see if there is a way around this without enjoining us from adding compat C files in the future. Thanks Neil > /Bruce >