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=-8.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_MED,USER_IN_DEF_DKIM_WL autolearn=ham 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 C9ADEC433F4 for ; Tue, 28 Aug 2018 23:01:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F20F20868 for ; Tue, 28 Aug 2018 23:01:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FsdoKy5O" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4F20F20868 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727725AbeH2Cy7 (ORCPT ); Tue, 28 Aug 2018 22:54:59 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:46941 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727067AbeH2Cy7 (ORCPT ); Tue, 28 Aug 2018 22:54:59 -0400 Received: by mail-pg1-f195.google.com with SMTP id b129-v6so1406744pga.13 for ; Tue, 28 Aug 2018 16:01:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bE9wJ9fEKlFzXrt1nBEEL+L9t4J/pFX7OB46Vh8MtIc=; b=FsdoKy5OoI0YgLR/VrTG8WN2fCMsmI02bV79cuQfti0KWxpJSwWnqPti6xj2AG4tVK zsjIpFUj47RTKlpNwYeflQOmLkwJxSrrkB75y32vfQtY9KHgalvdZpt26YlWtAd4OCMX BucUTNNSSRrJTIUtxRHNxKHXRL+MIrbMA+7jqpG97bsoVO/YvBP9Mz1TvbZ4dgv9DHNk IRJJ3BjpK1SOBiIYN1uyD/VtN4AAw9vkmuBvhLIvpqKvdJyevOh4G1sKG95UA7xgA8GP peDujpJ68cKVUs2v8KZMOV3dwmAiJhStw/u2+Nv86h87fAGJUiyuyAbA/IjbROgv0brj BqYg== 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=bE9wJ9fEKlFzXrt1nBEEL+L9t4J/pFX7OB46Vh8MtIc=; b=qyNmzNkyOweUemtB0c31LxT4g5+Y280+azbNqjma57og3FL1WmD4am33oSrH4etno2 wIezgqRhFcqLX866hXgoi/oMPc1bbZR980CNR/l966a0Ebq7k1PNu4x0z3mHZnEsZgZ5 TRZEGOIqOkFFe0GqUKp1o+dP/J/NiGz3YibFv1i0f1P/83dJIzJSciDxeJI4oUGwUdnV 6pwii4s2Ej73Fkn8k52f2cExpprgLR5O9VppOycyK2jYSb+9amzIbzLDUCSSEgigRNMh kgKa+RzocgBr8c2hrlGiPrVWAHewdDtNSmu2xgM0Dqga660kIAi+ALSlTmlyDPPnIgRL Hz5A== X-Gm-Message-State: APzg51BfRQk3w5N/wvpXItInt9rzZB5jp1VaXFShQJapx0hwiWogauhv PkzlTKk27IC2Jm52d2eMPT7+i5fnlKiRpueGyBcIgA== X-Google-Smtp-Source: ANB0VdaSPfimA2ObvMKOH2TRLRjMOosusUnqqYzMk+RfsiLyL7ovS9tnM8n2SPqv11JYpZMfIt/69KNQv2vDTeKVSr0= X-Received: by 2002:a63:1e11:: with SMTP id e17-v6mr3225377pge.225.1535497266867; Tue, 28 Aug 2018 16:01:06 -0700 (PDT) MIME-Version: 1.0 References: <1535220989-27645-1-git-send-email-yamada.masahiro@socionext.com> <84cf6ae0-97c8-6b73-ca86-b3d3b3daba5b@pobox.com> <8d5cf8c6-556a-96a1-610d-c92355783a9f@pobox.com> In-Reply-To: <8d5cf8c6-556a-96a1-610d-c92355783a9f@pobox.com> From: Nick Desaulniers Date: Tue, 28 Aug 2018 16:00:55 -0700 Message-ID: Subject: Re: [PATCH v2] compiler.h: give up __compiletime_assert_fallback() To: daniel.santos@pobox.com Cc: Masahiro Yamada , Linus Torvalds , Kees Cook , sparse@chrisli.org, linux-sparse@vger.kernel.org, LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 27, 2018 at 1:42 PM Daniel Santos wrote: > > Hello Nick, > > On 08/27/2018 03:09 PM, Nick Desaulniers wrote: > >>> Let's give up __compiletime_assert_fallback(). This commit does not > >>> change the current behavior since it just rips off the useless code. > >> Clang is not the only target audience of > >> __compiletime_assert_fallback(). Instead of ripping out something that > >> may benefit builds with gcc 4.2 and earlier, why not override its > > Note that with commit cafa0010cd51 ("Raise the minimum required gcc > > version to 4.6") that gcc < 4.6 is irrelevant. > > Ah, I guess I'm not keeping up, that's wonderful news! Considering that > I guess I would be OK with its removal, but I still think it would be > better if a similar mechanism to break the Clang build could be found. I'm consulting with our best language lawyers to see what combinations of _Static_assert and __builtin_constant_p would do the trick.