c++ - 在子目录中使用target_sources()命令时进行单元测试(qtest)的项目结构

Question

首先，我知道这个论坛中有非常相似的问题。但是，没有人能真正回答我的具体情况。
我有以下项目结构:

|---Project_Root
    |---CMakeLists.txt
    |---build
    |---src
    |   |---CMakeLists.txt
    |   |---many .cpp and .h files in multiple subfolders with a different CMakeLists.txt 
    |---tests
    |   |---CMakeLists.txt
    |   |---many .cpp files

在Project_Root / CMakeLists.txt中:

cmake_minimum_required(VERSION 3.5)

set(SRC_DIR src)

project(
        Project
        LANGUAGES CXX
        )

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

add_executable(${PROJECT_NAME} "")
target_include_directories(${PROJECT_NAME} PRIVATE ${SRC_DIR})
add_subdirectory(${SRC_DIR})

在src文件夹和CMakeLists.txt子文件夹中:

cmake_minimum_required(VERSION 3.5)

set(SRC_FILES
    Source1.cpp
    )

set(HEADER_FILES
    Source1.hpp
    )
target_sources(${PROJECT_NAME}
        PRIVATE
        ${CMAKE_CURRENT_SOURCE_DIR}/${SRC_FILES}
        ${CMAKE_CURRENT_SOURCE_DIR}/${HEADER_FILES}
        )

现在在测试子文件夹中:

project(Test LANGUAGES CXX)

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
enable_testing()

add_executable(Test tst_test.cpp)
add_test(NAME Test COMMAND Test)

target_link_libraries(Test PRIVATE Qt5::Test)

在上面的CMakeLists.txt中，我想将主项目包括为静态库。例如，我可以在根CMakeLists.txt中添加一个新的库目标(例如 Project_Lib)，然后再次使用以下命令:

target_sources(Project_Lib
        PRIVATE
        ${CMAKE_CURRENT_SOURCE_DIR}/${SRC_FILES}
        ${CMAKE_CURRENT_SOURCE_DIR}/${HEADER_FILES}
        )

在所有子文件夹中。
但是有没有一种更优雅的方法，而不必修改子文件夹中的所有CMakeLists.txt？例如，是否有办法从 Project目标中提取源文件，以便可以将其重新用于制作 Project_Lib目标？

Answer 1

如您所述，您可以将新的静态库目标设置为Project_Lib。利用您通过使用项目名称(${PROJECT_NAME})参数化了目标名称这一事实，因此您实际上不必更改子文件夹中的所有CMakeLists.txt文件。只需更改项目名称。
正如我所评论的，只需从静态库中排除main.cpp文件中的，然后将其添加到单独的可执行目标中即可。
在Project_Root / CMakeLists.txt中:

cmake_minimum_required(VERSION 3.5)

set(SRC_DIR src)

# Change the project name, as now the static library is the primary target.
project(
        Project_Lib
        LANGUAGES CXX
        )

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# Create the static library target, whose sources are populated in subdirectories.
add_library(${PROJECT_NAME} STATIC)
target_include_directories(${PROJECT_NAME} PRIVATE ${SRC_DIR})
# The only modification necessary in the subdirectories is to *exclude* the 
# main.cpp file from the target_sources for the static library.
add_subdirectory(${SRC_DIR})

# Add *only* the main.cpp file to the executable target.
add_executable(Project_Exe src/main.cpp)
# Link the static library target to the executable.
target_link_libraries(Project_Exe PRIVATE ${PROJECT_NAME})

在tests / CMakeLists.txt中:

...
# Link the static library to your Test executable also.
target_link_libraries(Test PRIVATE Project_Lib Qt5::Test)