From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1GUjPC-0007Qe-Q0 for garchives@archives.gentoo.org; Tue, 03 Oct 2006 12:29:51 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.8/8.13.6) with SMTP id k93CSvlG032041; Tue, 3 Oct 2006 12:28:57 GMT Received: from outmail.freedom2surf.net (outmail1.freedom2surf.net [194.106.33.237]) by robin.gentoo.org (8.13.8/8.13.6) with ESMTP id k93CR1Lt027018 for ; Tue, 3 Oct 2006 12:27:02 GMT Received: from snowdrop.home (unknown [62.6.163.66]) by outmail.freedom2surf.net (Postfix) with ESMTP id D81FC52441 for ; Tue, 3 Oct 2006 13:27:01 +0100 (BST) Date: Tue, 3 Oct 2006 13:26:56 +0100 From: Ciaran McCreesh To: gentoo-dev@lists.gentoo.org Subject: Re: [gentoo-dev] [RFC] CFLAGS paragraph for the GWN Message-ID: <20061003132656.79e67731@snowdrop.home> In-Reply-To: <4521B54A.5010507@bouton.name> References: <4521B54A.5010507@bouton.name> X-Mailer: Sylpheed-Claws 2.4.0 (GTK+ 2.8.20; i686-pc-linux-gnu) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-dev@gentoo.org Reply-to: gentoo-dev@lists.gentoo.org Mime-Version: 1.0 Content-Type: multipart/signed; boundary=Sig_rAt1gjZqvPDGgi0H5XHtTva; protocol="application/pgp-signature"; micalg=PGP-SHA1 X-Archives-Salt: 615f2219-b718-488f-b681-bf29394c4353 X-Archives-Hash: 50cbb0b3d81d320755edf52bb94cf8ee --Sig_rAt1gjZqvPDGgi0H5XHtTva Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Tue, 03 Oct 2006 02:56:42 +0200 Lionel Bouton wrote: | Being able to tune the CFLAGS is part of one of the core principles of | Gentoo: let the user be in control. What? No it isn't. |
  • nss_ldap stopped working with -ffast-math (reported to | break many packages changing with the actual gcc version)
    • Uh, -ffast-math has never been and will never be a safe thing to stick in CFLAGS. |
  • -fvisibility-inlines-hidden still breaks some code
    • Ditto. In C++, inlining is a *guideline* that the compiler can and will ignore as it sees fit. Only code specifically designed to use this flag should specify it, and even then it can still lead to failures because of the non-guaranteed nature of inlining. |
  • if you used gcc-4.0, -ftree-loop-linear now breaks in | gcc-4.1(at least with mesa)
    • Users shouldn't be sticking that in CFLAGS anyway. |
  • again for gcc-4.0 users, -ftree-vectorize is known to be | broken in gcc-4.1 (at least for x86 and ppc, amd64 users seem to be | safe)
    • Or that. |
  • -fforce-addr and -fweb break regularly on x86 with | video libraries or graphic processing apps which use hand-optimised | ASM
    • Or that. | Users with unsupported CFLAGS (see the CFLAGS matrix for | example) might want to return to safe CFLAGS (see Safe CFLAGS) if recent | updates caused them stability problems. On the other hand, more | adventurous users might want to experiment with CFLAGS that didn't | work properly with gcc-3.4.6... As always, the user is in control. Linking to that is a very bad idea. The wiki is in control of the minority ricer fringe. GWN shouldn't be advocating this kind of thing at all. Here's a better paragraph:

    We would like to remind you that using anything beyond -O2 -fomit-frame-pointer -march/-mcpu/-mtune in CFLAGS or CXXLFAGS (and -mieee, -mabi etc on selected archs that tell you to do this), and using anything at all in LDFLAGS or ASFLAGS, is pointless and will lead to a broken system. Your penis length is not proportional to the size of your CFLAGS.

    --=20 Ciaran McCreesh Mail : ciaranm at ciaranm.org Web : http://ciaranm.org/ as-needed is broken : http://ciaranm.org/show_post.pl?post_id=3D13 --Sig_rAt1gjZqvPDGgi0H5XHtTva Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) iD8DBQFFIlcU96zL6DUtXhERAtHlAJ0VI1wLhaHYjmX63plFN/di1HdB/QCg2r6Y zvWv0BniXXQ6HVFptWg2kTE= =TapB -----END PGP SIGNATURE----- --Sig_rAt1gjZqvPDGgi0H5XHtTva-- -- gentoo-dev@gentoo.org mailing list