From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 128564 invoked by alias); 26 Oct 2018 15:08:15 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 128554 invoked by uid 89); 26 Oct 2018 15:08:15 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.7 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=Force, HX-Received:f241 X-HELO: mail-vs1-f65.google.com Received: from mail-vs1-f65.google.com (HELO mail-vs1-f65.google.com) (209.85.217.65) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 26 Oct 2018 15:08:13 +0000 Received: by mail-vs1-f65.google.com with SMTP id j20so989432vso.8 for ; Fri, 26 Oct 2018 08:08:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=dW+cqQNL3gnrQCe9bkTfxLJn1zPl8DfuMvgEqqCVY+Q=; b=IqCXob+yh9MH/cdsP5CR5xnv4asOfGea24HEx/8FLf6NMLBKR0p3yrlI5RaeMLIGIV Ep0zym0VrNKWugA5A23aA1v3fdq9q0rTK9ApLEUmx2jfr6QYmEnahSehqnoGAcHMob+7 QJqdZQUvwkV9sKWNLhBbXT7muMcSpX/3LSaUo= MIME-Version: 1.0 References: <20181011133518.17258-1-christophe.lyon@st.com> <20181011133518.17258-4-christophe.lyon@st.com> <26314d4c-d0cf-05c0-9460-e1df2a6147cd@arm.com> <13da7741-e438-25bc-2825-1aebd79a4767@arm.com> <20181023145716.GK5205@gate.crashing.org> In-Reply-To: <20181023145716.GK5205@gate.crashing.org> From: Christophe Lyon Date: Fri, 26 Oct 2018 15:33:00 -0000 Message-ID: Subject: Re: [ARM/FDPIC v3 03/21] [ARM] FDPIC: Force FDPIC related options unless -mno-fdpic is provided To: Segher Boessenkool Cc: Richard Earnshaw , christophe lyon St , gcc Patches Content-Type: text/plain; charset="UTF-8" X-IsSubscribed: yes X-SW-Source: 2018-10/txt/msg01713.txt.bz2 On Tue, 23 Oct 2018 at 17:14, Segher Boessenkool wrote: > > On Tue, Oct 23, 2018 at 02:58:21PM +0100, Richard Earnshaw (lists) wrote: > > On 15/10/2018 11:10, Christophe Lyon wrote: > > > Do you mean to also make -mfdpic non-existent/rejected when GCC is not > > > configured > > > for arm-uclinuxfdpiceabi? > > > > Ideally doesn't exist, so that it doesn't show up in things like --help > > when it doesn't work. > > > > > How to achieve that? > > > > Good question, I'm not sure, off hand. It might be possible to make the > > config machinery add additional opt files, but it's not something I've > > tried. You might want to try adding an additional opt file to > > extra_options for fdpic targets. > > That should work yes. You could look at how 476.opt is added for powerpc, > it is a comparable situation. > Thanks, I got it to work. Now back to Richard's original question: > I think this needs to be resolved. Either -mfdpic works everywhere, or > the option should only be available when configured for -mfdpic. It's not that -mfdpic does not work everywhere, rather it is not sufficient to use it alone: it should be used along with fpic/fPIC/fpie/fPIE depending on the use case. In practice I don't know if we want to be able to use -mfdpic with a arm-linux-gnueabi toolchain, or if we are ok to have to use two different toolchains when we want to make tests/compare code generation in both cases. The 1st option means I should improve the documentation patch. For the 2nd one, I have patches in progress (which also imply reworking the doc since the option would not also be available) Christophe > > Segher