From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/13670 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: (OT?) Re: [musl] Symbol versioning approximation trips on compat symbols Date: Mon, 28 Jan 2019 10:34:39 -0500 Message-ID: <20190128153439.GC23599@brightrain.aerifal.cx> References: <87r2d5evvi.fsf@oldenburg2.str.redhat.com> <20190124014340.GV23599@brightrain.aerifal.cx> <20190124110931.GU21289@port70.net> <87sgxi718r.fsf@oldenburg2.str.redhat.com> <20190127040424.GA23599@brightrain.aerifal.cx> <20190127093650.GB30123@example.net> <87bm41xpce.fsf@oldenburg2.str.redhat.com> <20190128130813.GC30123@example.net> <20190128152244.GA28581@voyager> Reply-To: musl@lists.openwall.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="210916"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.5.21 (2010-09-15) To: musl@lists.openwall.com Original-X-From: musl-return-13686-gllmg-musl=m.gmane.org@lists.openwall.com Mon Jan 28 16:34:54 2019 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.89) (envelope-from ) id 1go8w2-000slO-8y for gllmg-musl@m.gmane.org; Mon, 28 Jan 2019 16:34:54 +0100 Original-Received: (qmail 3678 invoked by uid 550); 28 Jan 2019 15:34:52 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 3660 invoked from network); 28 Jan 2019 15:34:51 -0000 Content-Disposition: inline In-Reply-To: <20190128152244.GA28581@voyager> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:13670 Archived-At: On Mon, Jan 28, 2019 at 04:22:45PM +0100, Markus Wichmann wrote: > On Mon, Jan 28, 2019 at 02:08:13PM +0100, u-uy74@aetey.se wrote: > > If there is a feature which is hard or impossible to test for, like > > symbol versioning, it means that the applications may _have_ to rely on > > an explicit build flag telling whether to use it. > > Why is symbol versioning hard to test for, again? You make a library > containing two versions of the same function, one returns one, the other > two. The one that returns one is the default symbol. The test > application tries to link against the version that returns two. If that > works, symbol versioning is supported. That's not a test for symbol versioning. At best that's a test for an odd sort of bug under the assumption that symbol versioning is basically supported. If you're trying to identify the current situation with musl, what you'd instead need to be testing for is failure to resolve a *non-default* version at runtime when that's what should happen according to the symbol versioning rules. The key here is that this is a runtime test, making it invalid in the eyes of a large portion of the community (myself included) who consider a test that can't work when cross-compiling to be an invalid configure-time test. Rich