build: simplify management of dependencies on object libraries in CMake `gtest` function

This commits changes the `gtest` function to `target_add_libraries`
library object targets `${lib}` directly instead of
`$<TARGET_OBJECTS:${lib}>`. As a consequence, the
`target_include_directories` from the object target `${lib}` are
also passed to the target to compile and including them in the caller of
`gtest` is not needed anymore.

CMakeModules/testing_cpp.cmake

@@ -92,24 +92,18 @@ endfunction()
 
 function(gtest target test_source_files linktarget)
     if (BUILD_TESTS)
+        unset(libs)
         FOREACH (lib ${linktarget})
             if (NOT ${lib} STREQUAL "")
-                get_target_property(target_type ${lib} TYPE)
-                if (target_type STREQUAL "OBJECT_LIBRARY")
-                    list(APPEND OBJECT "$<TARGET_OBJECTS:${lib}>")
-                else ()
-                    list(APPEND libs "${lib}")
-
-                endif ()
+                list(APPEND libs "${lib}")
             endif ()
         ENDFOREACH ()
 
-        add_executable(test-${target} ${test_source_files} ${OBJECT})
+        add_executable(test-${target} ${test_source_files})
 
-        if (NOT ${libs} STREQUAL "")
+        if (libs)
             target_link_libraries(test-${target} ${libs})
         endif ()
-
         target_link_libraries(test-${target} ${GTEST_LIBS} ${CMAKE_THREAD_LIBS_INIT})
 
         GET_PROPERTY(ASAPO_COMMON_IO_LIBRARIES GLOBAL PROPERTY ASAPO_COMMON_IO_LIBRARIES)

common/cpp/src/data_structs/CMakeLists.txt

@@ -17,5 +17,4 @@ target_include_directories(${TARGET_NAME} PUBLIC ${ASAPO_CXX_COMMON_INCLUDE_DIR}
 set(TEST_SOURCE_FILES ../../unittests/data_structs/test_data_structs.cpp)
 
 set(TEST_LIBRARIES "${TARGET_NAME};json_parser;system_io")
-include_directories(${ASAPO_CXX_COMMON_INCLUDE_DIR})
 gtest(${TARGET_NAME} "${TEST_SOURCE_FILES}" "${TEST_LIBRARIES}")

common/cpp/src/database/CMakeLists.txt

@@ -26,6 +26,4 @@ target_compile_definitions (${TARGET_NAME} PRIVATE "${MONGOC_STATIC_DEFINITIONS}
 set(TEST_SOURCE_FILES ../../unittests/database/test_encoding.cpp)
 
 set(TEST_LIBRARIES "${TARGET_NAME}")
-
-include_directories(${ASAPO_CXX_COMMON_INCLUDE_DIR})
 gtest(${TARGET_NAME} "${TEST_SOURCE_FILES}" "${TEST_LIBRARIES}" "nocov")

common/cpp/src/json_parser/CMakeLists.txt

@@ -8,8 +8,8 @@ set(SOURCE_FILES
 ################################
 
 add_library(${TARGET_NAME} OBJECT ${SOURCE_FILES})
-target_include_directories(${TARGET_NAME} PUBLIC ${ASAPO_CXX_COMMON_INCLUDE_DIR}
-        ${CMAKE_SOURCE_DIR}/3d_party/rapidjson/include)
+target_include_directories(${TARGET_NAME} PUBLIC ${ASAPO_CXX_COMMON_INCLUDE_DIR})
+target_include_directories(${TARGET_NAME} SYSTEM PUBLIC ${CMAKE_SOURCE_DIR}/3d_party/rapidjson/include)
 
 ################################
 # Testing
@@ -19,7 +19,4 @@ target_include_directories(${TARGET_NAME} PUBLIC ${ASAPO_CXX_COMMON_INCLUDE_DIR}
 set(TEST_SOURCE_FILES ../../unittests/json_parser/test_json_parser.cpp)
 
 set(TEST_LIBRARIES "${TARGET_NAME};system_io")
-include_directories(${ASAPO_CXX_COMMON_INCLUDE_DIR})
-include_directories(SYSTEM ${CMAKE_SOURCE_DIR}/3d_party/rapidjson/include)
-
 gtest(${TARGET_NAME} "${TEST_SOURCE_FILES}" "${TEST_LIBRARIES}")

common/cpp/src/logger/CMakeLists.txt

@@ -22,6 +22,4 @@ set(TEST_SOURCE_FILES ../../unittests/logger/test_logger.cpp
 link_libraries(CURL::libcurl ${CMAKE_THREAD_LIBS_INIT})
 
 set(TEST_LIBRARIES "${TARGET_NAME};curl_http_client;system_io")
-include_directories(${ASAPO_CXX_COMMON_INCLUDE_DIR})
-include_directories(SYSTEM ${CMAKE_SOURCE_DIR}/3d_party/spd_log/include)
 gtest(${TARGET_NAME} "${TEST_SOURCE_FILES}" "${TEST_LIBRARIES}")

common/cpp/src/request/CMakeLists.txt

@@ -21,5 +21,4 @@ set(TEST_SOURCE_FILES ../../unittests/request/test_request_pool.cpp
 link_libraries(CURL::libcurl ${CMAKE_THREAD_LIBS_INIT} )
 
 set(TEST_LIBRARIES "${TARGET_NAME};system_io;logger;curl_http_client")
-include_directories(${ASAPO_CXX_COMMON_INCLUDE_DIR})
 gtest(${TARGET_NAME} "${TEST_SOURCE_FILES}" "${TEST_LIBRARIES}")