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

1 files changed, 46 insertions, 8 deletions

diff --git a/cmake/AddEventLibrary.cmake b/cmake/AddEventLibrary.cmake
index 9de4484c..12a36831 100644
--- a/cmake/AddEventLibrary.cmake
+++ b/cmake/AddEventLibrary.cmake
@@ -38,6 +38,10 @@ endmacro()
 
 # Global variables that it uses:
 # - EVENT_ABI_LIBVERSION
+# - EVENT_ABI_LIBVERSION_CURRENT
+# - EVENT_ABI_LIBVERSION_REVISION
+# - EVENT_ABI_LIBVERSION_AGE
+# - EVENT_PACKAGE_RELEASE
 # - CMAKE_THREAD_LIBS_INIT LIB_PLATFORM
 # - OPENSSL_LIBRARIES
 # - HDR_PUBLIC
@@ -87,16 +91,44 @@ macro(add_event_library LIB_NAME)
             set_event_shared_lib_flags("${LIB_NAME}" "${EVENT_SHARED_FLAGS}")
         endif()
 
-        set_target_properties("${LIB_NAME}_shared" PROPERTIES
-            OUTPUT_NAME "${LIB_NAME}"
-            CLEAN_DIRECT_OUTPUT 1)
-        set_target_properties(
-            "${LIB_NAME}_shared" PROPERTIES
-            PUBLIC_HEADER "${HDR_PUBLIC}")
+        if (WIN32)
+            set_target_properties(
+                "${LIB_NAME}_shared" PROPERTIES
+                OUTPUT_NAME "${LIB_NAME}"
+                SOVERSION ${EVENT_ABI_LIBVERSION})
+        elseif (APPLE)
+            math(EXPR COMPATIBILITY_VERSION "${EVENT_ABI_LIBVERSION_CURRENT}+1")
+            math(EXPR CURRENT_MINUS_AGE "${EVENT_ABI_LIBVERSION_CURRENT}-${EVENT_ABI_LIBVERSION_AGE}")
+            set_target_properties(
+                "${LIB_NAME}_shared" PROPERTIES
+                OUTPUT_NAME "${LIB_NAME}-${EVENT_PACKAGE_RELEASE}.${CURRENT_MINUS_AGE}"
+                INSTALL_NAME_DIR "${CMAKE_INSTALL_PREFIX}/lib"
+                LINK_FLAGS "-compatibility_version ${COMPATIBILITY_VERSION} -current_version ${COMPATIBILITY_VERSION}.${EVENT_ABI_LIBVERSION_REVISION}")
+        else()
+            math(EXPR CURRENT_MINUS_AGE "${EVENT_ABI_LIBVERSION_CURRENT}-${EVENT_ABI_LIBVERSION_AGE}")
+            set_target_properties(
+                "${LIB_NAME}_shared" PROPERTIES
+                OUTPUT_NAME "${LIB_NAME}-${EVENT_PACKAGE_RELEASE}"
+                VERSION "${CURRENT_MINUS_AGE}.${EVENT_ABI_LIBVERSION_AGE}.${EVENT_ABI_LIBVERSION_REVISION}"
+                SOVERSION "${CURRENT_MINUS_AGE}")
+        endif()
+
         set_target_properties(
             "${LIB_NAME}_shared" PROPERTIES
-            SOVERSION ${EVENT_ABI_LIBVERSION}
-        )
+            PUBLIC_HEADER "${HDR_PUBLIC}"
+            CLEAN_DIRECT_OUTPUT 1)
+
+        if (NOT WIN32)
+            set(LIB_LINK_NAME
+                "${CMAKE_SHARED_LIBRARY_PREFIX}${LIB_NAME}${CMAKE_SHARED_LIBRARY_SUFFIX}")
+
+            add_custom_command(TARGET ${LIB_NAME}_shared
+                POST_BUILD
+                COMMAND ${CMAKE_COMMAND} -E create_symlink
+                    "$<TARGET_FILE_NAME:${LIB_NAME}_shared>"
+                    "${LIB_LINK_NAME}"
+                WORKING_DIRECTORY "lib")
+        endif()
 
         list(APPEND LIBEVENT_SHARED_LIBRARIES "${LIB_NAME}_shared")
         list(APPEND ADD_EVENT_LIBRARY_TARGETS "${LIB_NAME}_shared")
@@ -117,6 +149,12 @@ macro(add_event_library LIB_NAME)
         PUBLIC_HEADER DESTINATION "include/event2"
         COMPONENT dev
     )
+    if (NOT WIN32)
+        install(FILES
+            "$<TARGET_FILE_DIR:${LIB_NAME}_shared>/${LIB_LINK_NAME}"
+            DESTINATION "lib"
+            COMPONENT lib)
+    endif()
 
     add_library(${LIB_NAME} INTERFACE)
     target_link_libraries(${LIB_NAME} INTERFACE ${ADD_EVENT_LIBRARY_INTERFACE})