From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mr6.vodafonemail.de (mr6.vodafonemail.de [145.253.228.166]) by sourceware.org (Postfix) with ESMTPS id E0CE93858D33 for ; Mon, 28 Aug 2023 11:27:32 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org E0CE93858D33 Authentication-Results: sourceware.org; dmarc=pass (p=quarantine dis=none) header.from=arcor.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=arcor.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arcor.de; s=vfde-mb-mr2-21dec; t=1693222051; bh=FdjLizokGrfeTIP+a+JcIaSeTce/8pZc8s+sNX86ybw=; h=Date:From:To:Subject:In-Reply-To:References:Message-ID: Content-Type:From; b=G9pD0HiOWDl/teIf2U1/L3cFsCy93vzYU1H3nALK0Vt3li433oVHSw6R43haQz6cr BYtRmtaW/T3wAsQ9e03P6l3fMESZCIvRmQDjuHMPqP6benlz5ZtcC6cCr6f40HP/pN J2vaSLzaAruAlaDgwgA374P3QLvTupu4yzzvtfyU= Received: from smtp.vodafone.de (unknown [10.0.0.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by mr6.vodafonemail.de (Postfix) with ESMTPS id 4RZ7ZW4VrBz1y4K; Mon, 28 Aug 2023 11:27:31 +0000 (UTC) Received: from [127.0.0.1] (dynamic-046-114-167-030.46.114.pool.telefonica.de [46.114.167.30]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp.vodafone.de (Postfix) with ESMTPSA id 4RZ7Z46Z4hz9s3v; Mon, 28 Aug 2023 11:27:05 +0000 (UTC) Date: Mon, 28 Aug 2023 11:26:58 +0000 From: Richard To: debian-68k@lists.debian.org, Geert Uytterhoeven , James Le Cuirot CC: Finn Thain , John Paul Adrian Glaubitz , libc-help@sourceware.org, debian-68k , linux-m68k Subject: Re: Tuple and changes for m68k with -malign-int In-Reply-To: References: <10cbcb8a65639f88e7eeb503fd02df172bc46a07.camel@physik.fu-berlin.de> <80a52487-3105-ed5b-a1eb-ec1a0689ef21@linux-m68k.org> <751c83150533b701d66ac24c8fe81863cf5eab98.camel@aura-online.co.uk> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-purgate-type: clean X-purgate: clean X-purgate-size: 1609 X-purgate-ID: 155817::1693222047-4BFF8816-F4D88D58/0/0 X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On August 28, 2023 7:00:07 AM UTC, Geert Uytterhoeven wrote: >On Sun, Aug 27, 2023 at 11:36=E2=80=AFAM James Le Cuirot > wrote: >> On Sun, 2023-08-27 at 10:46 +1000, Finn Thain wrote: >> > Moreover, why is it that only a few developers have a problem with ma= king >> > explicit their decisions regarding alignment of shorts? What actual p= ain >> > does it cause them to accept a patch to make their struct layouts pla= in? >> >> Some projects do accept patches=2E Yann Collet was even kind enough to = fix this >> in zstd themselves=2E On the other hand, we have had to fight to stop P= ython >> from dropping m68k support entirely=2E The real problem is the effort r= equired >> to produce these patches=2E I haven't been able to wrap my head around = this so >> far, but I would still like to learn=2E I could see myself eventually f= ixing >> mold, but LLVM feels like a very tall order=2E > >Perhaps we need a new compiler warning: "hole in structure due to >non-natural alignment, please consider adding explicit padding"? Sounds reasonable but I am afraid in 99% of cases this would be completely= irrelevant and not break anything so the acceptance would be pretty low=2E= =20 The problem arises only when people start doing "strange" things with such= structs=2E Can we define strange things in a better way? It appears to me = all modern c standards somewhat lack an attribute to mark a struct as being= "special use" and thus emit more warnings and avoid some kinds of trickery= =2E Richard