From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 4273F384781A for ; Fri, 18 Mar 2022 09:26:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 4273F384781A Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647595571; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=anZEbpOkBYdigtI4o/IyMZyiNrHS49O4QLFbPDbxjHY=; b=aVavocbfywg9ce9cMa8xUDCr8fT0bDAlGYT4dJ7aR2L0R3npJs1FQTooU+vNcx2/vK6cGM SvoY1YBElcmZXIg5g2zwxmD8XgR0Cx6GzZyKPnSPJqohi1kuzFwQDcSBj+ungT8wdw5gds IJneNXXvkSWxB5dBqoNvg9B37zcnSXY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-593-sZdxsIHuMA273b9Zkn9gHw-1; Fri, 18 Mar 2022 05:26:10 -0400 X-MC-Unique: sZdxsIHuMA273b9Zkn9gHw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 67CF180005D for ; Fri, 18 Mar 2022 09:26:10 +0000 (UTC) Received: from calimero.vinschen.de (unknown [10.36.112.5]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4243A2156A31 for ; Fri, 18 Mar 2022 09:26:10 +0000 (UTC) Received: by calimero.vinschen.de (Postfix, from userid 500) id 0E153A8096F; Fri, 18 Mar 2022 10:26:09 +0100 (CET) Date: Fri, 18 Mar 2022 10:26:09 +0100 From: Corinna Vinschen To: newlib@sourceware.org Subject: Re: [PATCH v2] newlib: fix build with Reply-To: newlib@sourceware.org Mail-Followup-To: newlib@sourceware.org References: <2c68b0f8-03ad-d93d-dd35-002a66576ff8@foss.arm.com> <16551142-64aa-fdda-8f9e-7656c6b9390f@yahoo.de> <18777f5b-7e27-b0a0-5d8f-8ca0a30e07a6@yahoo.de> MIME-Version: 1.0 In-Reply-To: <18777f5b-7e27-b0a0-5d8f-8ca0a30e07a6@yahoo.de> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vinschen@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Spam-Status: No, score=-5.3 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: newlib@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Newlib mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Mar 2022 09:26:13 -0000 On Mar 18 09:30, R. Diez via Newlib wrote: > > > > It's not just about old GCC, it's about any C compiler that doesn't have > > > that builtin. > > > > Well, I guess, GTG then. > > > Let's see if I understand the situation: > > You are committing a replacement implementation of __builtin_mul_overflow() for older GCC versions and for any other compiler which does not have it. > > The only significant extra feature about that function is the detection of integer overflow. > > The implementation lives in libc/include/sys/cdefs.h , so it is > accessible not just by some special malloc code which should never > overflow because targets wouldn't have that much memory or whatever. > > The replacement implementation is known to be broken and therefore poses a risk on anybody relying on the original, documented behaviour. > > There are no mitigation measures. There is not even a comment next to the replacement implementation that states it is broken. > > And you guys are fine with that. > > Is that correct? I'm open to a better or followup patch. Corinna