On Friday, August 28, 2015 08:23:47 Nico Schlömer wrote:
> Hi everyone,
>
> I'm curious about when CMake decides to link a library by its absolute path
> and when it links using the `-l*` syntax. I came across this for the very
> simple test problem
> ```
> cmake_minimum_required(VERSION 3.0)
>
> project(mytest)
>
> find_package(ZLIB REQUIRED)
> find_package(netCDF REQUIRED)
>
> add_executable(mytest main.cpp)
> target_link_libraries(
> mytest
> ${ZLIB_LIBRARIES}
> ${netCDF_LIBRARIES}
> )
> ```
> The resulting link line is
> ```
> /usr/bin/c++ CMakeFiles/mytest.dir/main.cpp.o -o mytest -rdynamic
> -lz /usr/lib/x86_64-linux-gnu/libnetcdf.so.7.3.0
> ```
> so ZLIB is linked with `-lz`, netCDF with the full absolute path.
>
> Seems inconsistent? (ZLIB by the way is found through CMake's
> FindZLIB.cmake, netCDF by their own export files.)
>
> So far, I had been under the impression that `-l*` defeats the purpose of
> CMake a little bit as it asks the linker to search in the system's paths
> for a libz.so, something CMake has already done.
>
> A little clarification here would be great.
it uses -l if the full path is not know or if the full path is one of the
system library dirs (like e.g. /usr/lib/ or the, IIRC, $LIBRARY_PATH env.var)
Alex
--
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
