Question

我试图链接到我使用CMake构建的静态库，并具有一个子目录结构。看起来像这样（->代表目录）：

Root
| - CMakeLists.txt
| -> First
|    | - CMakeLists.txt
|    | -> Object
|    |    | - object.cpp object.hpp
|    |
| -> Second
|    | - CMakeLists.txt
|    | - secondObject.hpp secondObject.cpp
|    |
| -> Third
|    | - CMakeLists.txt
|    | - thirdObject.hpp thirdObject.cpp 
|    |
| -> Main
     | - CMakeLists.txt
     | - main.cpp

在Root的cmake文件中：

cmake_minimum_required(VERSION 3.0)
project(Main)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)

include_directories(First)
include_directories(Second)
include_directories(Third)

add_subdirectory(First)
add_subdirectory(Second)
add_subdirectory(Third)
add_subdirectory(Main)

在First的cmake文件中：

project(First)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)

add_library(First STATIC Object/object.cpp Object/object.hpp)
add_dependencies(First Second Third)

target_link_libraries( First Second Third)

第二个和第三个相似，但是第二个仅取决于第三个，而第三个则完全不依赖任何东西。当我尝试将其与Main的cmake文件链接时，就会出现问题：

project(Main)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
set(Main First Second Third)

add_executable(Main main.cpp)
target_link_libraries(Main First Second Third)

当我从构建文件夹运行cmake ..时，它会经历得很开心，并且不会抱怨。但是，当我在GUI中点击make或Generate for Windows时，我会抱怨object.hpp: No such file or directory。我将此包含在main.cpp中。很明显，我可以将其更改为#include <Object/object.hpp>，但是我觉得这违反了链接到库的目的。（也许这是错误的想法）。

我还遇到了类似的问题，在类似这样的其他结构中，在object.cpp这样的文件中，即使#include "Object/object.hpp"与object.hpp。

如何正确地将Project Main链接到Project First，这样我就不必object.cpp？还是这是唯一的方法？还是我走错路了？

Answer 1

对我来说，CMakeLists.txt的以下解决方案是可行的。我还认为您只需在顶级目录中调用一次add_project。

添加额外的依赖项似乎是多余的，因为CMake用target_link_libraries指出了这一点。我能够运行CMake并构建项目，但是除main.cpp之外的文件都是空的。

这是我的CMakeLists.txt

First / CMakeLists.txt

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)    
add_library(First STATIC Object/object.cpp Object/object.hpp)    
target_link_libraries( First Second Third)

Second / CMakeLists.txt

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
add_library(Second STATIC secondObject.cpp secondObject.hpp)
target_link_libraries( Second Third)

第三/CMakeLists.txt

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
add_library(Third STATIC thirdObject.cpp thirdObject.hpp)

CMakeLists.txt

cmake_minimum_required(VERSION 3.0)
project(Main)

set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)

include_directories(First)
include_directories(Second)
include_directories(Third)

add_subdirectory(First)
add_subdirectory(Second)
add_subdirectory(Third)
add_subdirectory(Main)

如何正确链接到子目录中的静态库？

1 个答案: