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:date:from:to:subject:message-id:mime-version :content-type; q=dns; s=default; b=xf59YaYJPo21lHvArHwDGJ2lY6iRA opSUdz4qaXKmBEYToAKgnxFYgO8q4mdL3vtpNviifYqcpMzwP8J6Z0+twA/o46SJ WkbkPM2z7J6vdUrs4LZefc9z+Rso7T72kKRHlnv120PkmSUOIDiHPdVD7Mqedvxc xrm0yvpoLEKKgo= 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:date:from:to:subject:message-id:mime-version :content-type; s=default; bh=0PpVWtQj3iuXdr7kynaFB+Q5GiU=; b=Xqt bLtzgXx02uuuVpJj/Ke7Le2P6wZPAQtOyH0h0Y1BerkpDtwlAnmWVRBX4ayOAdmz CgC3xAuBM24Rr780jM60JCLvske/mZeeLwvmyZzaH9t6zXnkwMZi9wvK1J/tJR9K ljIXlllbgXUFtu5s1nrR6AeBACVtR8kEvzCOYTCg= Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , 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-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.3 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy=strawberry, sk:portabl, resembling, Sincerely X-HELO: karasik.eu.org Date: Fri, 3 Jun 2016 18:14:19 +0200 From: Dmitry Karasik To: cygwin AT cygwin DOT com Subject: bug: configuration problem in perl with gcc libs Message-ID: <20160603161419.GA5300@karasik2> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Note-from-DJ: This may be spam Hello, I'd like to report a configuration bug in perl. The problem arises when a 3-rd party module tries to build an extension using perl configuration with a gcc-specific library. Generally perl extensions don't have a way to specify library to link with directly, they do that through ExtUtils::MakeMaker, the standard tool for that. Which in turn tries to resolve '-llibname' using its own compile-time-configured internal list of lib paths. Everything works so far libraries are found in perl's libpth (see by running 'perl -V:libpth') which is /usr/lib on my machine. The problem arises when I need to link together with libgomp, which is not found there, being a gcc-version-specific library. For example, the following minimal Makefile.PL configure script use ExtUtils::MakeMaker; WriteMakefile(NAME => 'foo', LIBS => '-lgomp'); will emit a warning Warning (mostly harmless): No library found for -lgomp and removes -lgomp from the linker command, resulting in perl extension not being able to compile. The problem is confirmed, when, if I edit perl configuration file /usr/lib/perl5/5.22/i686-cygwin-threads-64int/Config.pm, everything works: ldlibpthname => 'PATH', - libpth => '/usr/lib', + libpth => '/usr/lib /usr/lib/gcc/i686-pc-cygwin/5.3.0', osname => 'cygwin', I believe perl needs to be built with the properly set/found libpth in advance. The diff below is the closest thing resembling a patch for the perl source package I could come with: --- Configure.0 2016-06-03 17:45:43.102008000 +0200 +++ Configure 2016-06-03 17:46:10.077558700 +0200 @@ -4948,6 +4948,16 @@ *) libpth="$libpth $j";; esac fi + # add gcc-specific libpath + if echo "$i" | grep -q "/usr/lib/gcc/"; then + j="`$echo $i|$sed 's,/include$,,'`" + if $test -d $j; then + case " $libpth " in + *" $j "*) ;; + *) libpth="$libpth $j";; + esac + fi + fi done libpth="`$echo $libpth|$sed 's/^ //'`" for xxx in $libpth $loclibpth $plibpth $glibpth; do The idea for the patch is taken from strawberry perl, which has the gcc libpath included in configuration. I couldn't find though exactly how they manage to include the path, during the configuration or when building, but it seems they somehow add it explicitly, using a custom tool for the MinGW perl build: https://github.com/StrawberryPerl/Perl-Dist-Strawberry/blob/master/share/portable/portable.perl.32#L60-L65 Hopefully this makes sense. -- Sincerely, Dmitry Karasik -- 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