From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFCCBC2BA19 for ; Mon, 13 Apr 2020 09:42:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A74A320575 for ; Mon, 13 Apr 2020 09:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727997AbgDMJmR (ORCPT ); Mon, 13 Apr 2020 05:42:17 -0400 Received: from mail-ot1-f66.google.com ([209.85.210.66]:37901 "EHLO mail-ot1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727968AbgDMJmR (ORCPT ); Mon, 13 Apr 2020 05:42:17 -0400 Received: by mail-ot1-f66.google.com with SMTP id n8so3113575otk.5 for ; Mon, 13 Apr 2020 02:42:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=v8aq/FuPwdfAQWITkndPNdXLCQMI0Uz44m4744u3ai4=; b=e8MWmIvffsgFgONI2ocB1U8er/9MavEdqpWi0Ip0RYUpJy/GWT4U/+ScjQ0L8W5N1u +LaTNZ5FQmh8Vc3bFYWxtyTo4XH4jY0oMJaaYarbB02j7Dw6oEEwFLLxaRXx/uBOSRDO CEXu8EYnUv9skZYIPkImO1c0zT3cTDRkPxWMr2USZ6uopJuo3q+PTwMrbHGYofORx0sP SguAKY0GgK+Lphv+19wfNhGqpGv+6ZgDeRlOLxll2vuy2xgjK35xyKDyxJ7KTBmw5+Qt RmG7RcpPhu9ofqbO4wrZv2NWHDVNx2CK6HqIA/zI6UpGL9I6ik3bcaykhh/FdxFw3gVC Tllw== X-Gm-Message-State: AGi0PuZIFLSF8lPp3aGyG3Sl/6Vg7fm18qLYgTOW0qKdwsGXmxOnnqII 1tCMO9tRUIOI2sX5pAajl7eey64olnHQb7Kk/wWfbg== X-Google-Smtp-Source: APiQypL3rZy+S2NEwD2obVDuFID5t23VflRUbI8BQMJskGZ042gJ3CHlyuIFfcwcoG7u9dPPE1wAflOblHdE94zZqxU= X-Received: by 2002:a9d:6299:: with SMTP id x25mr8619321otk.107.1586770936007; Mon, 13 Apr 2020 02:42:16 -0700 (PDT) MIME-Version: 1.0 References: <238ea76c-fa8e-0134-667b-3864938d9a78@landley.net> <7a9ada44-e0d4-6743-3819-92dc44f3f156@landley.net> <29e2cf8a-35fa-b24a-bce2-84e05e54d4c5@landley.net> In-Reply-To: <29e2cf8a-35fa-b24a-bce2-84e05e54d4c5@landley.net> From: Geert Uytterhoeven Date: Mon, 13 Apr 2020 11:42:04 +0200 Message-ID: Subject: Re: GCC?, was Re: Running m68k on qemu with external initramfs? To: Rob Landley Cc: Finn Thain , John Paul Adrian Glaubitz , "Linux/m68k" , Laurent Vivier Content-Type: text/plain; charset="UTF-8" Sender: linux-m68k-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org Hi Rob, On Mon, Apr 13, 2020 at 11:37 AM Rob Landley wrote: > On 4/13/20 2:07 AM, Rob Landley wrote: > >> It would be great to have a minimal reproducer from toysh. Getting that > >> from the python build looks hard, even with creduce. > >> https://embed.cs.utah.edu/creduce/ > > > > Oh it's not hard, it's just tedious. > > Did you know that if you disable optimizations you can get _more_ warnings? > > _disabling_ the gcse optimization triggered one of those "may be used > uninitialized but is a false positive 99% of the time" which in this case, > turned out to have a path that could trigger in a function I added last week, > which which was called in an else case 5 lines down. (Yes, when it DIDN'T > segfault, it gave me the warning.) It's indeed a pity. I looked into each and every one of them when I could still compile the kernel with gcc 4.1, to find the few cases that were real bugs... Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds