The Cray system requires static libraries, so all symbols are defined during the linking process.
Leaving out the LINKER_LANGUAGE CXX statement, CMake sees all the source files as C files, uses the C linker and I get undefined symbol errors. Manually linking with the C++ linker but excluding the -lstdc++ flag generates an executable. I really just need CMake to use the C++ linker without adding that flag. Thanks, Lucas Pettey, PhD HPCMP PETTT EQM CTA Lead ERDC-DSRC OnSite Vicksburg, MS 512-297-9833 Mobile (preferred) 601-634-2980 Office lucas.pet...@engilitycorp.com ________________________________________ From: Dan Liew [d...@su-root.co.uk] Sent: Friday, May 22, 2015 7:19 AM To: Pettey, Lucas @ EngilityCorp Cc: cmake@cmake.org Subject: Re: [CMake] (no subject) Hi, On 21 May 2015 at 23:00, <lucas.pet...@engilitycorp.com> wrote: > Hello, > > I am trying to compile a code written in C, but using an external library > that contains C++ functions. I am on a Cray system and everything works if I > manually link with the cray CC wrapper. When I change the linker language > with this command: > > set_property(TARGET adh PROPERTY LINKER_LANGUAGE CXX) > > CMake is using the CC wrapper, but adding -lstdc++ to the link line. This > causes an error. Can anyone tell me how to not get this added library? Why are you telling CMake that the linker language is C++ in the target you are building is C code? The C code you are compiling be must calling into extern "C" functions in the external library you mention which means the linker (at compile time) should not need to know about C++ at all. At runtime the linker needs to know that your external library depends on C++ but you don't need to be concerned with this because when your external library was built those dependencies end up in the shared library. E.g. ``` $ readelf -d /usr/lib/libboost_program_options.so ... Tag Type Name/Value ... 0x0000000000000001 (NEEDED) Shared library: [libstdc++.so.6] ... ``` Does your target build if you just leave LINKER_LANGUAGE alone (i.e. set C)? I would expect that it would. Thanks, Dan. -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/cmake
