From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <sourceware-bugzilla@sourceware.org>
Received: by sourceware.org (Postfix, from userid 48)
 id F19FB385DC23; Wed, 15 Apr 2020 13:56:33 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org F19FB385DC23
From: "mark at klomp dot org" <sourceware-bugzilla@sourceware.org>
To: elfutils-devel@sourceware.org
Subject: [Bug general/24498] 0.176: isn't LTO ready
Date: Wed, 15 Apr 2020 13:56:33 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: elfutils
X-Bugzilla-Component: general
X-Bugzilla-Version: unspecified
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: mark at klomp dot org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: unassigned at sourceware dot org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-24498-10460-XKSkI8dLPa@http.sourceware.org/bugzilla/>
In-Reply-To: <bug-24498-10460@http.sourceware.org/bugzilla/>
References: <bug-24498-10460@http.sourceware.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://sourceware.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: elfutils-devel@sourceware.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Elfutils-devel mailing list <elfutils-devel.sourceware.org>
List-Unsubscribe: <http://sourceware.org/mailman/options/elfutils-devel>,
 <mailto:elfutils-devel-request@sourceware.org?subject=unsubscribe>
List-Archive: <https://sourceware.org/pipermail/elfutils-devel/>
List-Help: <mailto:elfutils-devel-request@sourceware.org?subject=help>
List-Subscribe: <http://sourceware.org/mailman/listinfo/elfutils-devel>,
 <mailto:elfutils-devel-request@sourceware.org?subject=subscribe>
X-List-Received-Date: Wed, 15 Apr 2020 13:56:34 -0000

https://sourceware.org/bugzilla/show_bug.cgi?id=3D24498

--- Comment #13 from Mark Wielaard <mark at klomp dot org> ---
(In reply to Martin Li=C5=A1ka from comment #11)
> (In reply to kloczek from comment #10)
> > > I would add a configure option --enable-lto that will append -flto to=
 {C,LD}FLAGS.
> >=20
> > Please don't do that.
> >=20
> > LTO can be driven using only env variable.
> >=20
> > % CFLAGS=3D"<clto_cflags>" LDFLAGS=3D"<lto_ldflags>" ./configure
>=20
> Works for me.

Sorry, but what are the clto_cflags and lto_ldflags precisely?
And we now (also) have some c++ code for the debuginfod server, which I ass=
ume
needs some CXXFLAGS too?

> > Please use KISS principle and do not implement something which can be
> > already done other way *without* touching existing code.
> >=20
> > PS. Changing {C,LD}FLAGS is not only part of using LTO. You need to pas=
s NM,
> > RANLIB and AR env variables.
>=20
> Not necessarily. Typical Linux systems, like openSUSE, utilize auto-loadi=
ng
> mechanism of LTO plugins:

On Fedora32 that doesn't seem to work with:

$ CFLAGS=3D"-O2 -g -flto" CXXFLAGS=3D"-O2 -g -flto" LDFLAGS=3D"-flto" ./con=
figure
--enable-maintainer-mode
$ make
[...]
ar: elf_version.o: plugin needed to handle lto object
ranlib libelf.a
ranlib: libelf.a(elf_version.o): plugin needed to handle lto object

Am I using the wrong flags?
Or are the default ar and ranlib tools not build with the correct flags?

--=20
You are receiving this mail because:
You are on the CC list for the bug.=