CMakeLists.txt

# 为什么不指定 cmake_minimum_required 会导致下面在 project 处出错？
cmake_minimum_required(VERSION 3.10)

project(hellocmake VERSION 3.1.4 LANGUAGES CXX C)

# 如何让构建类型默认为 Release？
#set(CMAKE_BUILD_TYPE Release)

if (NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE Release)
endif()

# 这样设置 C++14 的方式对吗？请改正
# set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} "-std=c++14")
set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS ON)
# （可选）使用 ccache 加速编译
find_program(CCACHE_PROGRAM ccache)
if (CCACHE_PROGRAM)
    message(STATUS "Found CCache: ${CCACHE_PROGRAM}")
    set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ${CCACHE_PROGRAM})
    set_property(GLOBAL PROPERTY RULE_LAUNCH_LINK ${CCACHE_PROGRAM})
else()
    message("CCache not found")
endif()

# legacy/CMakeLists.txt 和 mylib/CMakeLists.txt 里还有问题哦！
add_subdirectory(legacy)
add_subdirectory(mylib)

# 这样需要一个个写出所有文件很麻烦，请改成自动批量添加源文件
# set(main_sources "src/main.cpp" "src/other.cpp" "src/dummy.cpp" "src/veryusefulfile.cpp")
file(GLOB_RECURSE main_sources CONFIGURE_DEPENDS src/*.cpp )  
add_executable(main ${main_sources})

target_link_libraries(main PRIVATE mylib)

# 请改为项目的正确版本（用变量来获取）
# target_compile_definitions(main PRIVATE HELLOCMAKE_VERSION="233.33.33")
target_compile_definitions(main PRIVATE HELLOCMAKE_VERSION=${PROJECT_VERSION})
# （可选）添加 run 作为伪目标方便命令行调用