From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Date: Tue, 9 Dec 2014 08:51:34 +0100 Subject: [Buildroot] [PATCH] ltrace: disable elfutils unwinding when libunwind is used In-Reply-To: <20141209060247.GJ2440@tarshish> References: <8b0ae63676267c7fb215344ddb2ef959eaaf165d.1417763393.git.baruch@tkos.co.il> <20141207220014.1d0dede0@free-electrons.com> <20141209060247.GJ2440@tarshish> Message-ID: <20141209085134.1b2051b9@free-electrons.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: buildroot@busybox.net Dear Baruch Siach, On Tue, 9 Dec 2014 08:02:47 +0200, Baruch Siach wrote: > > While I agree with the analysis, I don't agree with the proposed fix: > > ltrace selects elfutils unconditionally (see Config.in), so it is quite > > weird to see ltrace not using it in the end. So I believe the Config.in > > *and* ltrace dependencies should be updated to reflect the fact that > > either unwind or elfutils can be used. > > It turns out that --with-elfutils=no is a misnomer. ltrace depends on libelf > regardless of --with-elfutils, so we must have elfutils both in Config.in and > in LTRACE_DEPENDENCIES. The only effect of --with-elfutils is on unwinding > back-end. Quoting configure.ac: > > AS_HELP_STRING([--with-elfutils], [Use elfutils libdwfl unwinding support]), > > I'll send a revised version of this patch with a better commit log, and a > comment in the code explaining this weirdness. Aah, ok. Indeed very confusing. Thanks for clarifying this and posting an updated version with more details! Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com