| delorie.com/archives/browse.cgi | search |
| X-Recipient: | archive-cygwin AT delorie DOT com |
| DomainKey-Signature: | a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id |
| :list-unsubscribe:list-subscribe:list-archive:list-post | |
| :list-help:sender:reply-to:subject:to:references:from:message-id | |
| :date:mime-version:in-reply-to:content-type | |
| :content-transfer-encoding; q=dns; s=default; b=vhMuVJD0oNB/iSBE | |
| Kedz+Rny11wa/eyTB8tqS0Alwc2LVMs+Qr6VKtDL0hdXmR5la6U1jjrG9P0X0KVJ | |
| olzGKo3NpnrnEbkYZUvyiTYX+bDHWIGRPp3lcZh1jTdD9K35U4VDcm00hAQyb139 | |
| PiKAI2shP9mPN1uA5RU+RVOCC4E= | |
| 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:reply-to:subject:to:references:from:message-id | |
| :date:mime-version:in-reply-to:content-type | |
| :content-transfer-encoding; s=default; bh=7ZtUGnrMkHCWVrXrleldzG | |
| zF448=; b=XRvhe+jxlW+fYTMvx1md2in2jMYKbrlu2N1iy9Ev7HMDlhA0VCgEeD | |
| JyMXCcjg7byOlntIVO7qmhOd5rwTGkU8jk5TjNkb35FBG7GVvHRABwueHlJ5lmWs | |
| E8JQZtwanWbD2S6ZPiAiYEGy/k8Rx5lBkRg5SvcfqGXv2VtdDZK+s= | |
| Mailing-List: | contact cygwin-help AT cygwin DOT com; run by ezmlm |
| List-Id: | <cygwin.cygwin.com> |
| List-Subscribe: | <mailto:cygwin-subscribe AT cygwin DOT com> |
| List-Archive: | <http://sourceware.org/ml/cygwin/> |
| List-Post: | <mailto:cygwin AT cygwin DOT com> |
| List-Help: | <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs> |
| Sender: | cygwin-owner AT cygwin DOT com |
| Mail-Followup-To: | cygwin AT cygwin DOT com |
| Delivered-To: | mailing list cygwin AT cygwin DOT com |
| Authentication-Results: | sourceware.org; auth=none |
| X-Spam-SWARE-Status: | No, score=-3.4 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 spammy= |
| X-HELO: | smtp-out-no.shaw.ca |
| Reply-To: | Brian DOT Inglis AT SystematicSw DOT ab DOT ca |
| Subject: | Re: bug: cygwin-devel v3.0.2-1 socket.h does not #define MSG_EOR per the POSIX standard |
| To: | cygwin AT cygwin DOT com |
| References: | <0873126E9D101A4A983DE738F4346DBC9114A8F3 AT NAWESPSCXM03V DOT nadsuswe DOT nads DOT navy DOT mil> <20190424164358 DOT GG30041 AT calimero DOT vinschen DOT de> <4e01e86d-83c9-5855-c4a5-29f5375dc2dc AT cs DOT umass DOT edu> <a1cb4f3e-ae07-26c2-aa7f-695f2a178961 AT t-online DOT de> <f73771ca-780c-cde3-2edc-08bb60b1c261 AT redhat DOT com> |
| From: | Brian Inglis <Brian DOT Inglis AT SystematicSw DOT ab DOT ca> |
| Openpgp: | preference=signencrypt |
| Message-ID: | <3a646fc6-82cb-1980-cc85-75cd4db6f3a0@SystematicSw.ab.ca> |
| Date: | Thu, 25 Apr 2019 09:28:36 -0600 |
| User-Agent: | Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 |
| MIME-Version: | 1.0 |
| In-Reply-To: | <f73771ca-780c-cde3-2edc-08bb60b1c261@redhat.com> |
| X-IsSubscribed: | yes |
On 2019-04-24 14:50, Eric Blake wrote: > On 4/24/19 3:36 PM, Hans-Bernhard Bröker wrote: >> Am 24.04.2019 um 19:54 schrieb Eliot Moss: >>> On 4/24/2019 12:43 PM, Corinna Vinschen wrote: >> >>>> Since MSG_EOR isn't implemented in the underlying transport layer, >>>> there's no way to implement it in userspace. That's why it's not >>>> defined in Cygwin's headers. If you have an idea how to implement >>>> this in plain userspace, feel free to provide patches. >>> >>> I don't have a direct interest in this issue, but I do have a wondering. >>> If Cygwin fails to define an error code -- even if the error cannot >>> actually happen under Cygwin -- isn't that a problem when trying to >>> compile imported software? >> > > Well, MSG_EOR is not an error, but we can certainly do better than not > defining it at all. My suggestion for the least-cost implementation: > > - add a define for MSG_EOR to a non-zero value that is bitwise distinct > from other required MSG_ values > - return EOPNOTSUPP on attempts to use the flag in > send()/sendmsg()/sendto() (POSIX permits that failure for protocols that > don't support it - and none of Cygwin's protocols support it) > - optionally, document that MSG_EOR will never be set in the results > returned by recvmsg() (POSIX says it will only be set on protocols that > support it - and none of Cygwin's protocols support it) > > This will at least let software compile that attempts to use it, and > hopefully that software is robust to the fact that send() may reject the > flag and that recvmsg() cannot reliably report use of that flag. > >> >> Either way, as Standardese goes, this is sufficiently unclear that it >> IMHO calls for a defect report to the governing body of this standard. > > You're welcome to do so: > http://austingroupbugs.net/main_page.php > > although I personally thought POSIX was clear enough that MSG_EOR is > required to be defined, even if only so that it can trigger send() > errors showing that it is unsupported. Would it be allowed and valid to #define MSG_EOR 0 to simplify lack of support? -- 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. -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
| webmaster | delorie software privacy |
| Copyright © 2019 by DJ Delorie | Updated Jul 2019 |