From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 2D0791F462 for ; Mon, 29 Jul 2019 23:12:20 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:cc:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; q=dns; s=default; b=amu+OyE/k0qv2Jyb yrX3ZxqJO5UDxIv3w8ZPAYQdPlNSeVwQC/rkaZAXqAyjZGtEKnNhkOFOHvxAuyJg 2TUy26Z9zyucOpTtDaSUdONQxd1lPURZ8HmqqDNgSgoZV3rx069s6qHHSoePWOmg 7DDB2FXdj7G+oXr3m/A7agHrQjU= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:subject:to:cc:references:from:message-id:date :mime-version:in-reply-to:content-type :content-transfer-encoding; s=default; bh=USZmMlmYQWrLDtkBLAk/qt 4gIdM=; b=j55bRAmSUamvF3eOnC38GylypiI5dkrwAmBJtQRVjK8enhnyHSkgZq ORe0b1e2NHBrnTYCZV6Gx67DOG1tFzTzL1/Muhypk2YcjoQuBv1QEkGxYE7vSRXO IbeUXBojugUv488v4avdc5d9EcAD4a5U2F9R55M9L7dX2AahJ7c1I= Received: (qmail 115068 invoked by alias); 29 Jul 2019 23:12:17 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 114938 invoked by uid 89); 29 Jul 2019 23:12:17 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: zimbra.cs.ucla.edu Subject: Re: Accelerating Y2038 glibc fixes To: Joseph Myers , Adhemerval Zanella Cc: libc-alpha@sourceware.org References: <20190712072103.D3DBC24003A@gemini.denx.de> <874l3mjgi6.fsf@oldenburg2.str.redhat.com> <20190716145216.1C7CE240085@gemini.denx.de> <875zo0911b.fsf@oldenburg2.str.redhat.com> <20190717160021.75EB224003E@gemini.denx.de> <87h87k7ilf.fsf@oldenburg2.str.redhat.com> <20190717181811.5902cd5e@jawa> <43e70b10-c1a1-ca79-b596-60616c8f5ad6@linaro.org> From: Paul Eggert Message-ID: Date: Mon, 29 Jul 2019 18:12:08 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit On 7/29/19 4:08 PM, Joseph Myers wrote: >> What it would require is to add compat implementations with a different >> type, time32_t for instance. Something like: > That seems much harder to implement through incremental development, > whereas with _TIME_BITS=64 things can readily be implemented incrementally I worry that this puts the incremental cart before the incremental horse, at least for portable applications. If we take the _TIME_BITS=64 approach, portable applications should add the equivalent of "#define _TIME_BITS 64" to their config.h files or ihatever, because they should be Y2038-safe. But if glibc development is incremental so that some time_t uses are glitchy when _TIME_BITS=64, these applications will have problems. Conversely, if glibc doesn't publicize the time_t changes until they're ready (which I think is the intent), the _TIME_BITS=32 approach would be less hassle overall for portable applications; they won't have to change their source code.