Fix for older cmake versions

Summary: Recent changes prevented it to build on KDE Neon.

Test Plan: Built it on Neon

Reviewers: #kwin, bshah, davidedmundson

Reviewed By: #kwin, bshah, davidedmundson

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D28511

CMakeLists.txt

@@ -373,7 +373,7 @@ configure_file(config-kwin.h.cmake ${CMAKE_CURRENT_BINARY_DIR}/config-kwin.h)
 ########### global ###############
 set(kwin_effects_dbus_xml ${CMAKE_CURRENT_SOURCE_DIR}/org.kde.kwin.Effects.xml)
 qt5_add_dbus_interface(effects_interface_SRCS ${kwin_effects_dbus_xml} kwineffects_interface)
-add_library(KWinEffectsInterface OBJECT ${effects_interface_SRCS})
+add_library(KWinEffectsInterface STATIC ${effects_interface_SRCS})
 target_link_libraries(KWinEffectsInterface Qt5::DBus)
 
 include_directories(BEFORE

autotests/libinput/CMakeLists.txt

@@ -1,7 +1,7 @@
 include_directories(${Libinput_INCLUDE_DIRS})
 include_directories(${UDEV_INCLUDE_DIR})
 
-add_library(LibInputTestObjects OBJECT ../../libinput/device.cpp ../../libinput/events.cpp mock_libinput.cpp)
+add_library(LibInputTestObjects STATIC ../../libinput/device.cpp ../../libinput/events.cpp mock_libinput.cpp)
 target_link_libraries(LibInputTestObjects Qt5::Test Qt5::Widgets Qt5::DBus Qt5::Gui KF5::ConfigCore)
 
 ########################################################

kcmkwin/kwinrules/CMakeLists.txt

@@ -21,7 +21,7 @@ ki18n_wrap_ui(kwinrules_SRCS ruleslist.ui detectwidget.ui editshortcut.ui rulesw
 kconfig_add_kcfg_files(kwinrules_SRCS ../../rulesettings.kcfgc)
 kconfig_add_kcfg_files(kwinrules_SRCS ../../rulebooksettingsbase.kcfgc)
 
-add_library(KWinRulesObjects OBJECT ${kwinrules_SRCS})
+add_library(KWinRulesObjects STATIC ${kwinrules_SRCS})
 
 set(kwin_kcm_rules_XCB_LIBS
     XCB::CURSOR