<HTML><BODY><div><div>It seems I know where is my fault (it is was very obvious) but I can’t understand how can I link external library to clang.</div><div> </div><div>In the folder <strong>/home/../usr/lib/llvm-10/lib</strong> I have a file called <strong>libomp.so.5</strong> (as I understood it is a library of version 5)<strong> </strong>and I strongly believe that I need to link this library when parsing commands to clang++:</div><div> </div><div><em>$ clang++ -fopenmp foo.cxx -I/home/../usr/lib/llvm-10/include/openmp/ -L/home/../usr/lib/llvm-10/lib libomp.so.5</em></div><div> </div><div>gives me error:</div><div><strong>clang-5.0: error: no such file or directory: 'libomp.so.5'</strong></div><div> </div><div>How to link <strong>libomp.so.5 </strong>? Can’t find it in google yet</div><div> </div><div> </div><blockquote style="border-left:1px solid #0857A6; margin:10px; padding:0 0 0 10px;">Среда, 23 декабря 2020, 2:33 +03:00 от Johannes Doerfert <johannesdoerfert@gmail.com>:<br> <div id=""><div class="js-helper js-readmsg-msg"><div><div id="style_16086800320105937383_BODY">I think libomp is still on version 5.0, (I know, I know).<br>It is not coupled to LLVM wrt. version numbers.<br><br>Last time I checked, LLVM build for debian (and Ububuntu)<br>came bundled with the OpenMP runtimes (for the host). That<br>means you should not need libomp-5-dev but just clang-10.<br>libomp-5-dev is useful if you *don't* want clang but still<br>target libomp, which is the LLVM OpenMP host runtime, from<br>gcc, thus use it as a replacement of libgomp.<br><br>All that said, doesn't `clang-10 -fopenmp ...` "just work"?<br><br>~ Johannes<br><br><br>On 12/22/20 5:28 PM, Керим Хемраев wrote:<div class="mail-quote-collapse">> Hi Johannes,<br>><br>> Thank you for response<br>><br>> It seems that I don’t have libthread. Moreover it is highly likely that omp.h and libomp.so that I used to provide as parameters to clang are not shipped with clang 5 :)<br>><br>> I think I should now forget about xeus-cling for a while and simply build the code with latest (or any) version of clang with OpenMP.<br>><br>> I’ve tried to do the following:<br>> $ sudo apt-get install clang-10<br>> $ sudo apt-get install libomp-5-dev<br>><br>> Now I want to find where are these packages were installed:<br>> $ find /usr -iname clang-10<br>> /usr/lib/llvm-10/bin/clang-10<br>> /usr/lib/cmake/clang-10<br>> /usr/share/doc/clang-10<br>> /usr/share/bash-completion/completions/clang-10<br>> /usr/share/lintian/overrides/clang-10<br>> /usr/bin/clang-10<br>><br>> $ find /usr -iname libomp-10-dev<br>> /usr/share/doc/libomp-10-dev<br>><br>> So I’m afraid that libomp-10-dev contains only some docs and there is no library libomp-10-dev.so (or something)<br>><br>> Could you please guide me how to properly install clang with OpenMP that I could build my test script?<br>><br>> I’m on Ubuntu 20.04, x64<br>> $ cat /etc/lsb-release<br>> DISTRIB_ID=Ubuntu<br>> DISTRIB_RELEASE=20.04<br>> DISTRIB_CODENAME=focal<br>> DISTRIB_DESCRIPTION="Ubuntu 20.04.1 LTS"<br>><br>>> Среда, 23 декабря 2020, 0:48 +03:00 от Johannes Doerfert <<a href="/compose?To=johannesdoerfert@gmail.com">johannesdoerfert@gmail.com</a>>:<br>>><br>>> Hi Kerim,<br>>><br>>> I tried to help below. Looking at xeus-cling I did not immediately see<br>>> why clang 5 is<br>>> required. If this doesn't work as described below, I might spend time<br>>> trying to get it<br>>> to run with clang 11 ;)<br>>><br>>> On 12/22/20 1:57 PM, Керим Хемраев via cfe-dev wrote:<br>>>> Hi,<br>>>><br>>>> I’m struggling with compiling simple OpenMP program with clang 5.0.0.<br>>>> Here is the code (foo.cxx):<br>>>><br>>>> #include "omp.h"<br>>>> #include <stdio.h><br>>>> int main ( void ) {<br>>>> #pragma omp parallel<br>>>> printf ( "thread %d \n " , omp_get_thread_num ());<br>>>> }<br>>>><br>>>> As I use clang as part of xeus-cling my clang installation is inside conda packages:<br>>>> $ which clang<br>>>> /home/tasik/miniconda3/envs/cling/bin/clang<br>>>><br>>>> As this clang package does’t have omp.h I provide additional directories to find omp.h and libomp.so<br>>>> To compile the code I use the command:<br>>>> $ clang -fopenmp -I/home/../usr/lib/llvm-10/include/openmp/ -L/home/../usr/lib/llvm-10/lib foo.cxx<br>>>><br>>>> And I get errors:<br>>>> /usr/bin/ld: cannot find /lib64/libpthread.so.0<br>>>> /usr/bin/ld: cannot find /usr/lib64/libpthread_nonshared.a<br>>>> clang-5.0: error: linker command failed with exit code 1 (use -v to see invocation)<br>>> The error basically means clang looks for the libthread libraries and<br>>> cannot find them.<br>>> Check on you system where they are and provide the path via -L to clang.<br>>> That might allow<br>>> you to proceed. That said, I don't think you are able to mix clang 5 and<br>>> llvm 10 as you<br>>> do now. The headers and libraries clang might pick up need to be<br>>> consistent (with the clang<br>>> version). At least, you need to make sure `omp.h` and `libomp.so` are<br>>> the ones shipped with<br>>> clang 5.<br>>><br>>> ~ Johannes<br>>><br>>><br>>>> I really need some help to undertand how to work with clang 5.0.0 OpenMP<br>>>> And I think that it is difficult to update clang’s version as xeus-cling requires mentioned 5.0.0 version...<br>>>><br>>>><br>>>> With respect,<br>>>> kerim<br>>>><br>>>> _______________________________________________<br>>>> cfe-dev mailing list<br>>>> <a href="/compose?To=cfe%2ddev@lists.llvm.org">cfe-dev@lists.llvm.org</a><br>>>> <a href="https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev" target="_blank">https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev</a><br>><br>><br>> С уважением,<br>> Керим Хемраев<br>> <a href="/compose?To=kerim.khemraev@mail.ru">kerim.khemraev@mail.ru</a><br>></div></div></div></div></div></blockquote> <div> </div><div data-signature-widget="container"><div data-signature-widget="content"><div>С уважением,<br>Керим Хемраев<br>kerim.khemraev@mail.ru</div></div></div><div> </div></div></BODY></HTML>