C++包管理利器CPM
C++包管理利器CPM
一、介绍
CPM.cmake is a cross-platform CMake script that adds dependency management capabilities to CMake. It’s built as a thin wrapper around CMake’s FetchContent module that adds version control, caching, a simple API and more.
CPM.cmake是一个与CMake配合使用的C++包管理工具，更准确说是依赖管理，它主要用于简化C++项目中对第三方依赖引入的复杂性。 通过使用CPM，开发者可以更轻松地将所需的第三方库集成到他们的项目中，而无需手动下载、配置和管理这些库。CPM提供了一个简洁的语法，使开发者能够以声明式的方式指定项目所需的依赖项，并自动处理其下载、构建和安装过程。这样，开发者可以更专注于项目本身的开发，而不必花费过多时间和精力来处理依赖项的繁琐细节。总之，CPM的出现大大简化了C++项目的依赖管理工作，提高了开发效率。
总结：包管理、依赖管理、跨平台、轻量化、即插即用、语法简单
二、CPM语法
CPMAddPackage(
NAME # The unique name of the dependency (should be the exported target's name)
VERSION # The minimum version of the dependency (optional, defaults to 0)
OPTIONS # Configuration options passed to the dependency (optional)
DOWNLOAD_ONLY # If set, the project is downloaded, but not configured (optional)
[...] # Origin parameters forwarded to FetchContent_Declare, see below
)
- […] 指定第三方依赖的源位置（支持Github, Gitlab, 和指定URL）
- 提供GIT_REPOSITORY、GIT_REPOSITORY、GIT_TAG 或者直接提供URL
指定URL示例
CPMAddPackage("https://example.com/my-package-1.2.3.zip")
CPMAddPackage("https://example.com/my-package-1.2.3.zip#MD5=68e20f674a48be38d60e129f600faf7d")
CPMAddPackage("https://example.com/[email protected]")
指定版本用@version, 比如[email protected]
指定tag用#tag，比如xxx#1.2.1
针对github，可以简写成gh:user/[email protected]
针对gitlab, 可以简写成gl:user/[email protected]
jsoncpp 引入示例
CPMAddPackage(
NAME jsoncpp
GITHUB_REPOSITORY open-source-parsers/jsoncpp
GIT_TAG 1.9.5
OPTIONS "JSONCPP_WITH_TESTS OFF"
)
# 简化
CPMAddPackage("gh:open-source-parsers/jsoncpp#1.9.5")
特别说明
在调用CPMAddPackage之后，将在本地作用域中定义以下变量，其中
比如：
jsoncpp_SOURCE_DIR
jsoncpp_BINARY_DIR
jsoncpp_ADDED
三、工程引入
1、CPM.cmake引入
手动下载引入
直接下载CPM.cmake脚本（假定下载到/your_project_path/cmake/CPM.cmake），然后在CMakeLists.txt中include即可。
# CMakeLists.txt
include(your_project_path/cmake/CPM.cmake)
自动下载引入
直接在CMakeLists.txt中使用 file 指令自动下载，然后include。
# CMakeLists.txt
# download CPM.cmake
file(
DOWNLOAD
https://github.com/cpm-cmake/CPM.cmake/releases/download/v0.38.7/CPM.cmake
${CMAKE_CURRENT_BINARY_DIR}/cmake/CPM.cmake
)
include(${CMAKE_CURRENT_BINARY_DIR}/cmake/CPM.cmake)
2、 测试代码
工程目录
.
├── CMakeLists.txt
└── main.cpp
CMakeLists.txt
cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
project(jsontest)
# download CPM.cmake
file(
DOWNLOAD
https://github.com/cpm-cmake/CPM.cmake/releases/download/v0.38.7/CPM.cmake
${CMAKE_CURRENT_BINARY_DIR}/cmake/CPM.cmake
)
include(${CMAKE_CURRENT_BINARY_DIR}/cmake/CPM.cmake)
# ---- Dependencies ----
CPMAddPackage("gh:nlohmann/[email protected]")
CPMAddPackage(
NAME jsoncpp
GITHUB_REPOSITORY open-source-parsers/jsoncpp
GIT_TAG 1.9.5
OPTIONS "JSONCPP_WITH_TESTS OFF"
)
# CPMAddPackage("gh:open-source-parsers/jsoncpp#1.9.5")
# ---- Executable ----
add_executable(jsontest main.cpp)
target_link_libraries(jsontest nlohmann_json jsoncpp_lib)
main.cpp
#include
#include
#include
int main() {
auto j = nlohmann::json::parse(R"({"happy": true, "pi": 3.141})");
std::cout << "test nlohman_json: " << j.dump(2) << std::endl;
Json::Value root;
root["action"] = "run";
root["number"] = 1;
Json::FastWriter writer;
std::cout << "test jsoncpp: " << writer.write(root) << std::endl;
return 0;
}
cmake构建
cmake -B build
cmake --build build
运行
./build/bin/jsontest
test nlohman_json: {
"happy": true,
"pi": 3.141
}
test jsoncpp: {"action":"run","number":1}
四、参考
1. CPM: https://github.com/cpm-cmake/CPM.cmake
2. CPM: An Awesome Dependency Manager for C++ with CMake: https://medium.com/swlh/cpm-an-awesome-dependency-manager-for-c-with-cmake-3c53f4376766
3. FetchContent: https://cmake.org/cmake/help/latest/module/FetchContent.html