replace object libraries with unity object libraries

CMake/cotire.cmake

@@ -2884,6 +2884,16 @@ function (cotire_setup_pch_target _languages _configurations _target)
 	endif()
 endfunction()
 
+function (cotire_filter_object_libraries _target _objectLibrariesVar)
+	set (_objectLibraries "")
+	foreach (_source ${ARGN})
+		if (_source MATCHES "^\\$<TARGET_OBJECTS:.+>$")
+			list (APPEND _objectLibraries "${_source}")
+		endif()
+	endforeach()
+	set (${_objectLibrariesVar} ${_objectLibraries} PARENT_SCOPE)
+endfunction()
+
 function (cotire_collect_unity_target_sources _target _languages _unityTargetSourcesVar)
 	get_target_property(_targetSourceFiles ${_target} SOURCES)
 	set (_unityTargetSources ${_targetSourceFiles})
@@ -2902,6 +2912,15 @@ function (cotire_collect_unity_target_sources _target _languages _unityTargetSou
 			list (APPEND _unityTargetSources ${_unityFiles})
 		endif()
 	endforeach()
+	get_target_property(_linkLibrariesStrategy ${_target} COTIRE_UNITY_LINK_LIBRARIES_INIT)
+	if ("${_linkLibrariesStrategy}" MATCHES "^COPY_UNITY$")
+		cotire_filter_object_libraries(${_target} _objectLibraries ${_targetSourceFiles})
+		if (_objectLibraries)
+			cotire_map_libraries("${_linkLibrariesStrategy}" _unityObjectLibraries ${_objectLibraries})
+			list (REMOVE_ITEM _unityTargetSources ${_objectLibraries})
+			list (APPEND _unityTargetSources ${_unityObjectLibraries})
+		endif()
+	endif()
 	set (${_unityTargetSourcesVar} ${_unityTargetSources} PARENT_SCOPE)
 endfunction()
 
@@ -3178,9 +3197,15 @@ function (cotire_map_libraries _strategy _mappedLibrariesVar)
 		if (_library MATCHES "^\\$<LINK_ONLY:(.+)>$")
 			set (_libraryName "${CMAKE_MATCH_1}")
 			set (_linkOnly TRUE)
+			set (_objectLibrary FALSE)
+		elseif (_library MATCHES "^\\$<TARGET_OBJECTS:(.+)>$")
+			set (_libraryName "${CMAKE_MATCH_1}")
+			set (_linkOnly FALSE)
+			set (_objectLibrary TRUE)
 		else()
 			set (_libraryName "${_library}")
 			set (_linkOnly FALSE)
+			set (_objectLibrary FALSE)
 		endif()
 		if ("${_strategy}" MATCHES "COPY_UNITY")
 			cotire_is_target_supported(${_libraryName} _isSupported)
@@ -3190,6 +3215,8 @@ function (cotire_map_libraries _strategy _mappedLibrariesVar)
 				if (TARGET "${_libraryUnityTargetName}")
 					if (_linkOnly)
 						list (APPEND _mappedLibraries "$<LINK_ONLY:${_libraryUnityTargetName}>")
+					elseif (_objectLibrary)
+						list (APPEND _mappedLibraries "$<TARGET_OBJECTS:${_libraryUnityTargetName}>")
 					else()
 						list (APPEND _mappedLibraries "${_libraryUnityTargetName}")
 					endif()