From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 06AC51F55B for ; Wed, 20 May 2020 04:28:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726463AbgETE2j (ORCPT ); Wed, 20 May 2020 00:28:39 -0400 Received: from cloud.peff.net ([104.130.231.41]:51508 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1725785AbgETE2j (ORCPT ); Wed, 20 May 2020 00:28:39 -0400 Received: (qmail 30829 invoked by uid 109); 20 May 2020 04:28:39 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Wed, 20 May 2020 04:28:39 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 17319 invoked by uid 111); 20 May 2020 04:28:40 -0000 Received: from coredump.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.2) by peff.net (qpsmtpd/0.94) with (TLS_AES_256_GCM_SHA384 encrypted) ESMTPS; Wed, 20 May 2020 00:28:40 -0400 Authentication-Results: peff.net; auth=none Date: Wed, 20 May 2020 00:28:38 -0400 From: Jeff King To: "Daniel Richard G." Cc: git@vger.kernel.org Subject: Re: Minor portability issues + fixes Message-ID: <20200520042838.GA102274@coredump.intra.peff.net> References: <7422404e-7fc8-4961-aae4-3f0adb71bb3a@www.fastmail.com> <20200519024945.GB70483@coredump.intra.peff.net> <40a42f1d-61bd-46fb-8946-5588df7b044b@www.fastmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <40a42f1d-61bd-46fb-8946-5588df7b044b@www.fastmail.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Tue, May 19, 2020 at 12:22:00AM -0400, Daniel Richard G. wrote: > > If so, then perhaps it should be added to the AIX defines in > > config.mak.uname. > > I've confirmed that this works. But would it not be safe to #include > both inttypes.h and stdint.h explicitly if both are present, rather than > cater to AIX specifically? I could see this similarly arising in, say, > an old version of Solaris. Yes, as long as we check that both are present, I think that would do the right thing. And the autoconf check could cover that. I don't think there's an easy way to have a general Makefile knob that can check which files are present, though (and we generally consider the Makefile and its knobs to be the primary mechanism; autoconf to turn those knobs is generally implemented on top). So probably we'd want something like (in this order): - NEEDS_EXPLICIT_STDINT gets passed from the Makefile into the compiler via -D, which then triggers stdint.h being included unconditionally in git-compat-util.h - optionally set that in config.mak.uname for AIX (checking uname_R since it sounds like only old versions need it) - add an autoconf rule that sets it, either strictly (when a test-program decides it's needed) or loosely (when we see that it's available at all) Even just the first one would let you build by setting the knob manually; the rest is gravy on top, if you or somebody else chooses to do it. > > I do wonder, though, if configure.ac could be extended for AIX to > > support whatever syntax the system linker uses for setting the run-path. > > I understand that you don't care either way about this feature, but this > > might be a good opportunity to fix it. > > This could be a bit complicated, I'm afraid. > > The applicable value for CC_LD_DYNPATH on AIX is "-Wl,-blibpath:". > However, have a look at the description for this option in the > ld(1) man page: OK, gross. :) I agree it's not worth going too far into this rabbit hole. I do wonder if you could just be using GNU ld along with gcc, but maybe that's not practical. You should be able to build with: make CC_LD_DYNPATH=-L as a workaround, but it would be nice if the Makefile handled this correctly. It looks like CC_LD_DYNPATH gets used in a lot of places, so I suspect we'd want a Makefile function to help out. Something like: # usage: $(call linker_lib,PATH) # Create linker args for looking for libraries in PATH at both link-time # and run-time. linker_lib = -L$1 $(if $(CC_LD_DYNPATH),$(CC_LD_DYNPATH)$1) which would allow: EXTLIBS += $(call linker_lib,$(LIBPCREDIR)/$(lib)) etc. This would be our first foray into Makefile functions, but I think we've determined that most platforms have a recent enough GNU make for it to be OK (and we already require GNU make). -Peff