My project involves a set of plugin libraries. Those libraries get loaded
dynamically at runtime, e.g. by calling dlopen(). The user can install them to
any location they want, so the directory won't necessarily be in the library
path. I can safely assume, though, that they'll all be in the same directory.
Sometimes, one plugin directly depends on another plugin, and uses symbols
defined in it. That means that when I dlopen() the first plugin, it needs to
locate the second one (which is in the same directory) or loading will fail.
On Linux, this seems to "just work". Presumably this is because the directory
containing a library is one of the default locations searched for other
libraries it depends on?
On Mac OS it doesn't work. It can be made to work, though, by using
install_name_tool to specify @loader_path as the location of the dependent
library. I'm trying to get my CMake script to do this. I've added the
following line:
INSTALL(CODE "EXECUTE_PROCESS(COMMAND install_name_tool -change
libOpenMMOpenCL.dylib @loader_path/libOpenMMOpenCL.dylib
${CMAKE_INSTALL_PREFIX}/lib/plugins/libOpenMMRPMDOpenCL.dylib)")
This appears to execute correctly. To verify that it worked, I add the
following line immediately after that:
INSTALL(CODE "EXECUTE_PROCESS(COMMAND otool -L
${CMAKE_INSTALL_PREFIX}/lib/plugins/libOpenMMRPMDOpenCL.dylib)")
So I first run install_name_tool to edit the path in the library, then run
otool to print out the changed path. That verifies that yes, the library
really does contain the right path.
But at some later point in the build process, it's getting changed back again.
I don't know where or why, but once the build finishes running, otool shows
that the @loader_path/ prefix has been removed again. How can I prevent this
from happening?
I haven't even begun looking into how to make things work on Windows, but if
anyone has suggestions on that, I'll be very grateful for those too!
Peter
--
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
