That's what I do sometimes. To make that easier, CMake gives some convenience variables for library prefixes and suffixes if you are on multiple platforms.
Clint On Monday, November 14, 2011 01:20:29 pm David Cole wrote: > If you already know where all the libraries are, please just use the > full paths to those libraries, and do not use find_library. > > On Mon, Nov 14, 2011 at 3:15 PM, Robert Dailey <[email protected]> wrote: > > On Mon, Nov 14, 2011 at 1:59 PM, Michael Hertling <[email protected]> > > > > wrote: > >> On 11/14/2011 06:17 PM, Robert Dailey wrote: > >> > Well maybe you can tell me I'm doing this wrong then, but based on how > >> >I > >> > > >> > am > >> > currently setting up my third party libraries, it is required. > >> > > >> > So basically all third party libraries we use are not installed > >> > individually, instead we have a server on our intranet that contains > >> > precompiled versions of all libraries in a specific and consistent > >> > hierarchy. For this reason, it doesn't make sense to use > >> > find_library(), which would normally always give you absolute paths > >> > to your library files > >> > and thus link_directories() would not be needed. > >> > > >> > Instead I have a script in CMake that iterates each third party > >> > library and > >> > adds its lib link directory to a list. When done I take this whole > >> > list of > >> > link directories and pass it to link_directories() in my top level > >> > CMakeLists file, this way each and every project will include all of > >> > the third party library lib directories to have access to them. > >> > >> Instead of populating a list with the libraries' directories, you might > >> set up one variable for each library containing the latter's full path, > >> e.g. ZLIB_LIBRARY or BDB47_LIBRARY. Since you do this in the top-level > >> CMakeLists.txt, these variables propagate to subordinate CMakeLists.txt > >> files and, thus, will be known wherever they are needed in your project. > >> > >> > For each target I simply create a list of my libs, like so: > >> > > >> > set( libraries zlib libbdb47 ) > >> > >> SET(libraries ${ZLIB_LIBRARY} ${BDB47_LIBRARY}) > >> > >> > I pass each one of these to target_link_libraries() and I leave it up > >> > to the compiler to search for where to find the file in the provided > >> > link directories. > >> > >> An unrestricted use of LINK_DIRECTORIES() means asking for trouble; > >> especially with numerous directories, there's a growing probability > >> that the -L option will lure the linker into a wrong directory some > >> day. There're even situations which can't be resolved with -L/-l at > >> all: Suppose you have a directory x with liba.so and libb.so, and a > >> directory y with different versions of lib{a,b}.so. Suppose further > >> you want to link against x/liba.so and y/libb.so. How do you achieve > >> this with LINK_DIRECTORIES() and TARGET_LINK_LIBRARIES()? Reversely, > >> insisting on the use of LINK_DIRECTORIES() limits the possibilities > >> how to organize the libraries on your intranet server. IMO, these > >> are actual drawbacks. OTOH, you must know the libaries' locations > >> to use LINK_DIRECTORIES(), and the libraries must be known anyway, > >> so why not join the locations to the libraries and use full paths? > > > > Problem is, if I end up using find_library(), I will have to provide hint > > search directories for each and every single library, and there are about > > 20 of them. This to me is the same as just generating a list of > > directories and including those directly, and a lot less trouble. > > find_library() is great and I really wanted to use it for this, but to me > > the benefits of using it diminish when we are not using third party > > libraries installed in a non deterministic location. If a user installs > > the third party libraries in different locations on each of their > > machines, and different versions, it makes more sense to use it in that > > case. > > Why should I let CMake search & find a library when I already know where > > it is? Simply to get absolute paths to those libraries? If I want > > absolute paths I can think of much better ways to do > > it, preferably through string concatenation. > > Another issue is that 80% of the libraries we use do not have a > > pre-packaged Find module provided by CMake. This means I'd end up > > writing 80% of the find modules myself. This is a lot of work for no > > perceived benefit. > > With my points made and circumstances explained, can you still give me a > > good reason to use find_library? > > I understand and agree with the issues that come with using > > link_directories(), however I haven't run into those issues yet and our > > consistent organization of third party libraries on our intranet server > > are carry over from our legacy build system that I'm replacing. > > -- > > > > Powered by www.kitware.com > > > > Visit other Kitware open-source projects at > > http://www.kitware.com/opensource/opensource.html > > > > Please keep messages on-topic and check the CMake FAQ at: > > http://www.cmake.org/Wiki/CMake_FAQ > > > > Follow this link to subscribe/unsubscribe: > > http://www.cmake.org/mailman/listinfo/cmake > > -- > > Powered by www.kitware.com > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Please keep messages on-topic and check the CMake FAQ at: > http://www.cmake.org/Wiki/CMake_FAQ > > Follow this link to subscribe/unsubscribe: > http://www.cmake.org/mailman/listinfo/cmake -- Clinton Stimpson Elemental Technologies, Inc Computational Simulation Software, LLC www.csimsoft.com -- Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
