cmake调用第三方库

代码依赖

自己写的工程，非第三方工程

• 工程目录

├── 3rdparty
│   └── jsoncpp
│       ├── include
│       └── src
├── build
├── CMakeLists.txt
└── main.cpp

• CMakeLists.txt

cmake_minimum_required(VERSION 3.11)

project(cmake_3rd)
set(CMAKE_CXX_STANDARD 17)

set(SRC_MAIN main.cpp)

include_directories(${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/jsoncpp/include)

aux_source_directory(${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/jsoncpp/src jsoncpp)
add_executable(main ${SRC_MAIN} ${jsoncpp})

• main.cpp

#include <iostream>
#include "json/json.h"

int main(int argc, char const *argv[])
{
    Json::Value json;
    json["name"] = "wiki";
    json["age"] = 18;
    std::cout << json.toStyledString() << std::endl;
    return 0;
}

引入他人的第三方代码库，独立的库

• 工程目录

├── 3rdparty
│   └── jsoncpp
│       ├── CMakeLists.txt
│       ├── include
│       └── src
├── build
├── CMakeLists.txt
└── main.cpp

• 3rdparty/jsoncpp/CMakeLists.txt

project(jsoncpp)
aux_source_directory(./src SRC_JSONCPP)
add_library(jsoncpp ${SRC_JSONCPP})

• CMakeLists.txt

cmake_minimum_required(VERSION 3.11)

project(cmake_3rd)

set(CMAKE_CXX_STANDARD 17)

set(SRC_MAIN main.cpp)

include_directories(${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/jsoncpp/include)

add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/jsoncpp)

add_executable(main ${SRC_MAIN})
target_link_libraries(main jsoncpp)

目标文件依赖

jsoncpp工程，生成lib库

• 过程目录

├── build
├── CMakeLists.txt
├── include
│   └── json
│       ├── allocator.h
│       ├── assertions.h
│       ├── autolink.h
│       ├── config.h
│       ├── features.h
│       ├── forwards.h
│       ├── json.h
│       ├── reader.h
│       ├── value.h
│       ├── version.h
│       └── writer.h
└── src
    ├── json_reader.cpp
    ├── json_tool.h
    ├── json_value.cpp
    ├── json_valueiterator.inl
    ├── json_writer.cpp
    └── version.h.in

• CMakeLists.txt

cmake_minimum_required(VERSION 3.11)
project(jsoncpp)

include_directories(${PROJECT_SOURCE_DIR}/include)
aux_source_directory(./src SRC_JSONCPP)
add_library(lib_jsoncpp_static STATIC ${SRC_JSONCPP})
add_library(lib_jsoncpp_dynamic SHARED ${SRC_JSONCPP})

set_target_properties(lib_jsoncpp_static PROPERTIES OUTPUT_NAME "jsoncpp")
set_target_properties(lib_jsoncpp_dynamic PROPERTIES OUTPUT_NAME "jsoncpp")

set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/lib)

将jsoncpp/build/lib文件夹拷贝到使用者目录（main.cpp所在目录的build目录下）

main.cpp工程

• 工程目录

├── 3rdparty
│   └── jsoncpp
│       └── include
├── build
│   ├── lib
│   │   ├── libjsoncpp.a
│   │   └── libjsoncpp.so
├── CMakeLists.txt
└── main.cpp

• 方法1：CMakeLists.txt

cmake_minimum_required(VERSION 3.11)

project(cmake_3rd)

set(CMAKE_CXX_STANDARD 17)

set(SRC_MAIN main.cpp)

include_directories(${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/jsoncpp/include)

link_directories(${PROJECT_BINARY_DIR}/lib)
add_executable(main ${SRC_MAIN})
target_link_libraries(main libjsoncpp.a)

​ - link_directories：执行后可以链接该目录下的多个库文件

• 方法2：CMakeLists.txt

cmake_minimum_required(VERSION 3.11)

project(cmake_3rd)

set(CMAKE_CXX_STANDARD 17)

set(SRC_MAIN main.cpp)

include_directories(${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/jsoncpp/include)

add_executable(main ${SRC_MAIN})
find_library(lib_jsoncpp NAMES libjsoncpp.so PATHS ${PROJECT_BINARY_DIR}/lib)
target_link_libraries(main ${lib_jsoncpp})

​ - find_library:执行后，只能使用该库（如果工程需要链接其他目标，则需要再次find_library）

find_package

• 工程目录

├── build
├── CMakeLists.txt
└── main.cpp

• CMakeLists.txt

cmake_minimum_required(VERSION 3.11)

project(cmake_3rd)

set(CMAKE_CXX_STANDARD 17)

set(SRC_MAIN main.cpp)

find_package(Boost COMPONENTS atomic REQUIRED)

if (Boost_FOUND)
    message("Boost_INCLUDE_DIRS = ${Boost_INCLUDE_DIRS}")
    message("Boost_LIBRARIES = ${Boost_LIBRARIES}")
    message("Boost_VERSION = ${Boost_VERSION}")

    include_directories(${Boost_INCLUDE_DIRS})

    add_executable(main ${SRC_MAIN})
    target_link_libraries(main ${Boost_LIBRARIES})
endif()

• main.cpp

#include <iostream>
#include "boost/atomic.hpp"

int main(int argc, char const *argv[])
{
    boost::atomic_bool b = true;
    std::cout << b << std::endl;
    return 0;
}

fetchContent

CPM

git submodule