From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from omta001.cacentral1.a.cloudfilter.net (omta001.cacentral1.a.cloudfilter.net [3.97.99.32]) by sourceware.org (Postfix) with ESMTPS id C53123858C83 for ; Tue, 15 Feb 2022 22:02:42 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org C53123858C83 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=SystematicSw.ab.ca Authentication-Results: sourceware.org; spf=none smtp.mailfrom=systematicsw.ab.ca Received: from shw-obgw-4004a.ext.cloudfilter.net ([10.228.9.227]) by cmsmtp with ESMTP id K1T6n4Jmk5Rf1K5uDn7MGt; Tue, 15 Feb 2022 22:02:41 +0000 Received: from [10.0.0.5] ([184.64.124.72]) by cmsmtp with ESMTP id K5uCnBZzM3exBK5uDn3sE3; Tue, 15 Feb 2022 22:02:41 +0000 X-Authority-Analysis: v=2.4 cv=d7HmdDvE c=1 sm=1 tr=0 ts=620c2301 a=oHm12aVswOWz6TMtn9zYKg==:117 a=oHm12aVswOWz6TMtn9zYKg==:17 a=IkcTkHD0fZMA:10 a=7vT8eNxyAAAA:8 a=CCpqsmhAAAAA:8 a=NEAV23lmAAAA:8 a=uYT-Tk0qkVT609LjNaIA:9 a=QEXdDO2ut3YA:10 a=Mzmg39azMnTNyelF985k:22 a=ul9cdbp4aOFLsgKbc677:22 Message-ID: Date: Tue, 15 Feb 2022 15:02:40 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.0 Reply-To: newlib@sourceware.org Subject: Re: Support non-POSIX TZ strings Content-Language: en-CA To: newlib@sourceware.org References: <758cfb47-ac13-fb88-877e-63a1d4327429@SystematicSw.ab.ca> From: Brian Inglis Organization: Systematic Software In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfGazuRTOJU0FIGW6mLYAoM8cq/zWd5v41jGlbK/QFSGYAVL5FE647gewmYuBkSTXhJ8aUSjLP/5bcdGkbK2qt/BANp1LJK+vARfznl5mIGwhyt41nAHR E5bNCJozJ+X7YI8awFopwCMYJRVqGt8fl1ieUP/FmJz3zB+HIsYrEbNvaCqLEvElcgTNYCeqtJto4B1b8ZhZs/rsSaOfBHFlTuI= X-Spam-Status: No, score=-1163.8 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, NICE_REPLY_A, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=no 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: Tue, 15 Feb 2022 22:02:44 -0000 On 2022-02-14 14:33, Jeff Johnston wrote: > On Mon, Feb 14, 2022 at 3:46 PM Brian Inglis < > Brian.Inglis@systematicsw.ab.ca> wrote: > >> On 2022-02-14 12:58, jdoubleu wrote: >>> On 22-02-14 10:10-0700, Brian Inglis wrote: >> >>>> [..] but we should start with the actual POSIX spec under TZ >> >>> Yes, that is exactly what I meant: Newlib supporting the <> (angle >>> brackets) syntax. >>> I didn't know that it was actually part of POSIX spec, since so many >>> libs actually don't implement it. >> >> Most should have by now if maintained: we should be a laggard! ;^> >> >>>> The BSD or TZcode implementations could probably be adapted [..] >> >>> It looks like the TZcode implementation by Paul Eggert uses a different >>> approach to parsing the strings, than the current implementation in >>> newlib >>> ( >> https://sourceware.org/git/?p=newlib-cygwin.git;a=blob;f=newlib/libc/time/tzset_r.c). >> >>> I'm not sure, if you want to copy the code over or use changes by e.g. >>> Earle F. Philhower from >>> https://github.com/earlephilhower/newlib-xtensa/pull/14. >>> Because of the above question, I'm not sure how to continue on this. I >>> would like to contribute myself and submit an implementation, but I'll >>> wait for feedback by other maintainers, first. >> >> Upstream sources like BSDs or TZcode official reference implementations >> are normally preferred because they are feature complete, regularly >> maintained, feature test and standards compliant, vulnerabilities >> checked, issues reported, and promptly fixed. >> >> I checked the BSDs and they seem to have adopted or adapted the TZcode >> official reference implementation, so I am not sure from where it may >> have been adopted, or whether it is original: the maintainer Jeff >> Johnson may remember. > Unfortunately, I do not remember the exact details from back then. With no > license header, it means it was written by Cygnus/Red Hat. >> I also wonder if the GMT defaults should be updated to UTC. Submitted a newlib patch which builds okay, but cannot test, as I don't have a newlib platform to run on, and Cygwin uses it's own TZ DB code base. It should accept up to 10 character abbreviations for STD and DST matching POSIX specs including anything within < > quoted content. If someone needing this could build, test, and send feedback, I'd appreciate it. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in binary units and prefixes, physical quantities in SI.]