cmake: include lockstep_scheduler test

This makes sure we add the lockstep_scheduler_test even if the
ENABLE_LOCKSTEP_SCHEDULER is not set to yes. This means the
lockstep_scheduler is not used for SITL but the CMakeLists.txt file
still used and the test added.

platforms/posix/src/CMakeLists.txt

@@ -31,9 +31,8 @@
 #
 ############################################################################
 
-if (ENABLE_LOCKSTEP_SCHEDULER)
-	add_subdirectory(lockstep_scheduler)
-endif()
 
 add_subdirectory(px4_daemon)
 add_subdirectory(px4_layer)
+
+add_subdirectory(lockstep_scheduler)

platforms/posix/src/lockstep_scheduler/CMakeLists.txt

 cmake_minimum_required(VERSION 2.8.12)
 
-if(NOT PROJECT_NAME STREQUAL "px4")
+# We want to test the lockstep schedule even if it is not used otherwise.
+add_library(lockstep_scheduler
+	src/lockstep_scheduler.cpp
+)
 
-	project(lockstep_scheduler)
+target_include_directories(lockstep_scheduler
+	PUBLIC
+	${CMAKE_CURRENT_SOURCE_DIR}/include
+)
 
-	set (CMAKE_CXX_STANDARD 11)
-
-	add_definitions(-DUNIT_TESTS)
-
-	add_library(lockstep_scheduler
-		src/lockstep_scheduler.cpp
-	)
-
-	target_include_directories(lockstep_scheduler
-		PUBLIC
-			$<INSTALL_INTERFACE:include>
-			$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-		PRIVATE
-			${CMAKE_CURRENT_SOURCE_DIR}/src
-	)
-
-	target_link_libraries(lockstep_scheduler
-		pthread
-	)
-
-	target_compile_options(lockstep_scheduler PRIVATE -Wall -Wextra -Werror -O2)
-
-	add_subdirectory(test)
-
-else()
-
-	add_library(lockstep_scheduler
-		src/lockstep_scheduler.cpp
-	)
-	target_include_directories(lockstep_scheduler
-		PUBLIC
-		${CMAKE_CURRENT_SOURCE_DIR}/include
-	)
-
-endif()
+px4_add_gtest(SRC test/src/lockstep_scheduler_test.cpp LINKLIBS lockstep_scheduler)