cmake add_subdirectory 命令的执行顺序

Question

我的 cmake 配置中存在依赖性问题。当我从项目的根目录开始构建时，它总是报错。当我在使用 LibCalcBin 的地方禁用 add_subdirectory(application) 时，它会成功构建 library。然后，我可以构建 application。

为什么 cmake 不先构建 library 然后再构建 application，正如我在 add_subdirectory 命令的顺序中指定的那样。有什么办法可以解决这个问题吗？谢谢。

错误

Please set them or make sure they are set and tested correctly in the CMake files:
LibCalcBin
    linked by target "run" in directory ...

./CMakeList.txt（根目录）

cmake_minimum_required(VERSION 3.3)
project(DLLAbstract)

# specify where to put executable
SET(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)

# specify where to put binaries
SET(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)

# compile and build library
add_subdirectory(library)

# compile and build application
add_subdirectory(application)

./图书馆

set(src LibCalc.cpp Calculator.cpp)

add_definitions(-DDLL_EXPORT)

add_library(LibCalc SHARED ${src})

./申请

set(Src main.cpp)

find_path(LibCalcHeader
    NAMES 
        LibCalc.hpp
    PATHS 
        ${PROJECT_SOURCE_DIR}/library
)

find_library(LibCalcBin
    NAMES 
        LibCalc
    PATHS 
        ${PROJECT_SOURCE_DIR}/bin/Debug
        ${PROJECT_SOURCE_DIR}/bin/Release
        ${PROJECT_SOURCE_DIR}/bin
)

include_directories(${LibCalcHeader})

add_executable(run ${Src})

target_link_libraries(run ${LibCalcBin})

Answer 1

find_library 命令用于查找不属于您的项目的库。对于由 add_library 命令创建的库，不需要特殊处理，您可以在 target_link_libraries 调用中使用目标名称：

target_link_libraries(run LibCalc)

cmake add_subdirectory 命令的执行顺序

cmake order of execution of add_subdirectory command

dependencies

cmake

错误

./CMakeList.txt（根目录）

./图书馆

./申请