find_package 总结

本文参考：“轻松搞定CMake”系列之find_package用法详解

原理

find_package 即在指定目录CMAKE_MODULE_PATH 或 CMAKE_PREFIX_PATH查找对应的cmake文件。

find 模式

Module模式(默认)：查询Findxxx.cmake配置文件, 在CMAKE_MODULE_PATH 目录
Config模式：查询xxxConfig.cmake or <lower-case-package-name>-config.cmake配置文件，在xxx_DIR 或 CMAKE_PREFIX_PATH目录

如果Module模式失败则自动转入Config模式。如果Config失败，则find_package 失败。

Config模式路径查找顺序

名为<PackageName>_DIR的CMake变量或环境变量路径(默认为空)
名为CMAKE_PREFIX_PATH、CMAKE_FRAMEWORK_PATH、CMAKE_APPBUNDLE_PATH的CMake变量或环境变量路径
PATH环境变量路径

findxxx.cmake配置文件大众规则（规则、变量自定义）

xxx_FOUND:BOOL 类型，如果成功则为true
xxx_INCLUDES: 模块的头文件位置
xxx_LIBRARIES:库文件位置

demo展示(add)

findadd.cmake or addConfig.cmake

message("Find add:"  $ENV{path})
message("PROJECT_SOURCE_DIR:"${PROJECT_SOURCE_DIR})
#find headers
find_path(add_INCLUDESNAMES add.h PATHS ${PROJECT_SOURCE_DIR}/add ${PROJECT_SOURCE_DIR}/add1)#find lib
find_library(add_LIBRARIES NAMES add.libPATHS ${PROJECT_SOURCE_DIR}/add/lib ${PROJECT_SOURCE_DIR}/add1/lib)message("add_INCLUDES="${add_INCLUDES})
message("add_LIBRARIES="${add_LIBRARIES})if(add_LIBRARIES AND add_LIBRARIES)set(add_FOUND TRUE)
endif()message("add_FOUND:"${add_FOUND})

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)project(mylib)#module 模式
set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake/)#config模式
set(add_DIR ${PROJECT_SOURCE_DIR}/cmake/)
message("CMAKE_MODULE_PATH=" ${CMAKE_MODULE_PATH})
find_package(add)if(add_FOUND)
message("add package find")
else(add_FOUND)
message("add package not find")
endif(add_FOUND)