From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 35559 invoked by alias); 20 May 2016 10:38:12 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 35543 invoked by uid 89); 20 May 2016 10:38:11 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=Sam, H*f:sk:b21c0ab, Help X-HELO: csmail.cs.umass.edu Received: from mdc1.cs.umass.edu (HELO csmail.cs.umass.edu) (128.119.240.121) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 20 May 2016 10:38:10 +0000 Received: from [192.168.0.144] (rrcs-50-74-66-18.nyc.biz.rr.com [50.74.66.18]) by csmail.cs.umass.edu (Postfix) with ESMTPSA id 3E1C9580000F148D3A; Fri, 20 May 2016 06:38:08 -0400 (EDT) Reply-To: moss@cs.umass.edu Subject: Re: Help debugging a dll issue References: To: Sam Habiel , "cygwin@cygwin.com" From: Eliot Moss Message-ID: <3a4d2501-8845-99b6-d58b-544bff5e223f@cs.umass.edu> Date: Fri, 20 May 2016 10:38:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-05/txt/msg00221.txt.bz2 On 5/19/2016 11:28 PM, Sam Habiel wrote: > I had trouble with dlopen in Cygwin, where it did not behave intuitively. In my case, I was > dlopening libicu and friends. If you search using my name on the Cygwin mailing list, you should be > able to find out how I resolved the issue. I don't recall exactly what I did, but I think it was > that Cygwin put everything in a global namespace, and you need to dlsym NULL to grab the function > addresses. I just tried using NULL for the handle in dlsym, and I get the same result as before, and it does not change between using RTLD_LOCAL or RTLD_GLOBAL in dlopen. What I am seeing is that looking up one symbol is giving the value for a totally different one -- it's not returning an error indication. And this same wrong value is what happens if I just allow the natural linking to take place (which is what I really want to happen -- the dl calls simply help focus the issue). I will look up your previous issue, though, to see if there is something else there of use in this situation. Regards -- EM -- 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