When add_event_library macro was called without the INNER_LIBRARIES parameter, it reused the
value set by a previous call, since the INNER_LIBRARIES variable was not reset.
$ cmake -DEVENT__LIBRARY_TYPE=static ..
...
CMake Error:
Error evaluating generator expression:
$<TARGET_FILE_DIR:event_core_shared>
No target "event_core_shared"
Fixes: #853
Fixes: 669a53f3 ("cmake: set library names to be the same as with autotools")
libtool has VERSION_INFO [1], cmake has SOVERSION/VERSION instead
(although it has different format). Also libtool has RELEASE [2] while
cmake do not have analog yet [3], hence manual symlinks should be
created.
[1]: https://www.gnu.org/software/libtool/manual/html_node/Libtool-versioning.html
[2]: https://www.gnu.org/software/libtool/manual/html_node/Release-numbers.html
[3]: https://gitlab.kitware.com/cmake/cmake/issues/17652
Plus osx has compatibility_version/current_version dylib properties and
cmake do not have separate properties for them [4], hence manual LINK_FLAGS.
And also there INSTALL_NAME_DIR property which should be adjusted too.
[4]: https://public.kitware.com/Bug/view.php?id=4383
So after all changes, here is an example before/after for osx and linux:
# osx
# autotools
.libs/libevent_pthreads-2.2.1.dylib
.libs/libevent_pthreads.dylib -> libevent_pthreads-2.2.1.dylib
/usr/local/lib/libevent_pthreads-2.2.1.dylib (compatibility version 2.0.0, current version 2.0.0)
# cmake
# before patch
lib/libevent_pthreads.2.2.0.dylib
lib/libevent_pthreads.dylib -> libevent_pthreads.2.2.0.dylib
@rpath/libevent_pthreads.2.2.0.dylib (compatibility version 2.2.0, current version 0.0.0)
# after patch
lib/libevent_pthreads-2.2.1.dylib
lib/libevent_pthreads.dylib -> libevent_pthreads-2.2.1.dylib
/vagrant/.cmake/inst/lib/libevent_pthreads-2.2.1.dylib (compatibility version 2.0.0, current version 2.0.0)
# linux
# autotools
.libs/libevent_pthreads-2.2.so.1 -> libevent_pthreads-2.2.so.1.0.0
.libs/libevent_pthreads-2.2.so.1.0.0
.libs/libevent_pthreads.so -> libevent_pthreads-2.2.so.1.0.0
# cmake
# before patch
lib/libevent_pthreads.so -> libevent_pthreads.so.2.2.0
lib/libevent_pthreads.so.2.2.0
# after patch
lib/libevent_pthreads-2.2.so -> libevent_pthreads-2.2.so.1
lib/libevent_pthreads-2.2.so.1 -> libevent_pthreads-2.2.so.1.0.0
lib/libevent_pthreads-2.2.so.1.0.0
lib/libevent_pthreads.so -> libevent_pthreads-2.2.so.1.0.0
Closes: #838 (cherry-picked)
Closes: #760
Long time ago in [1] cmake build was forced to compile both libraries
(SHARED and STATIC), since this is how our autotools build works.
[1]: 7182c2f561570cd9ceb704623ebe9ae3608c7b43 ("cmake: build SHARED and STATIC libraries (like autoconf does)")
And there is no way to configure this (and indeed you need to do this
for MSVC for example), so let's introduce option for this --
EVENT__LIBRARY_TYPE.
Plus now we have INTERFACE libraries, that we can use internally in
libevent's cmake rules to avoid strict to _shared/_static variant of the
libraries to link with samples/tests (we prefer SHARED over STATIC for
linking).
Also bump minimal cmake required version to 3.1 by the following
reasons:
- 3.1 is required for RPATH configuration under APPLE
- 3.0 is required for add_library(INTERFACE) (did not found it in 2.8.x
documentation)
- remove extra conditions
(anyway 3.1 was release 4 years ago, so I guess that most of the systems
will have it)
On centos with cmake 2.8.12.2:
CMake Error at cmake/AddEventLibrary.cmake:92 (export):
export called with target "event_extra_shared" which requires target
"event_core_shared" that is not in the export list.
If the required target is not easy to reference in this call, consider
using the APPEND option with multiple separate calls.
But on newer cmake I guess everything is ok.
Fixes: 7182c2f561570cd9ceb704623ebe9ae3608c7b43 ("cmake: build SHARED
and STATIC libraries (like autoconf does)")
Remove next vars, since I don't think that somebody want to change it:
- bin
- lib
- include
And fix exports problem:
CMake Error: INSTALL(EXPORT "LibeventTargets") given absolute DESTINATION "/usr/lib/cmake/libevent" but the export references an installation of target "event_core_static" which has relative DESTINATION "lib".
Since they are useful for debugging, and if autotools build them then
cmamke has to do this too, to make migration more simple.
And now:
- tests: uses shared libraries (since this is upstreams one)
- other binaries: uses static libraries
This removes next private config:
- EVENT__NEED_DLLIMPORT
