cmake find_package说明

CMake中find_package功能演示

find_package可以被用来在系统中自动查找配置构建工程所需的程序库。在linux和unix类系统下这个命令尤其有用。CMake自带的模块文件里有大半是对各种常见开源库的find_package支持，支持库的种类非常多。

find_package(Qt5Widgets)，find_package(Qt4 COMPONENTS QTCORE QTGUI QTOPENGL QTSVG)返回之后

就会有变量Qt5Widgets_FOUND，Qt5Widgets_INCLUDE_DIRS相应的变量生效。

然后就可以在CMakeLists.txt里面使用上述的变量了。类似如下：

 INCLUDE_DIRECTORIES(${QT_INCLUDES})
 INCLUDE_DIRECTORIES(${Qt5Widgets_INCLUDE_DIRS})
 INCLUDE_DIRECTORIES(${Qt5Svg_INCLUDE_DIRS})
 INCLUDE_DIRECTORIES(${Qt5OpenGL_INCLUDE_DIRS})
 INCLUDE_DIRECTORIES(${Qt5Concurrent_INCLUDE_DIRS})

if(Qt5Widgets_FOUND)

message(STATUS ${Qt5Widgets_INCLUDE_DIRS})
   #qt5
else()
 find_package(Qt4 REQUIRED)  #qt4
 include(${QT_USE_FILE})
endif()

例子：

cmake_minimum_required(VERSION 2.6 FATAL_ERROR)

project(hello)

set(Boost_USE_STATIC_LIBS ON)
set(Boost_USE_MULTITHREAD ON)

#查找boost库中python的bind库
#REQUIRED表示如果没有找到，cmake会停止处理，并报告一个错误.
find_package( Boost 1.35 REQUIRED
COMPONENTS python)

#找到Boost后，变量Boost_INCLUDE_DIRS中将包括指定boost库头文件的查找路径.
#变量Boost_LIBRARY_DIRS中将包含指定boost库的.a或.so文件的所在目录的路径.
include_directories(${Boost_INCLUDE_DIRS})
link_directories(${Boost_LIBRARY_DIRS})

find_package(PythonLibs 2.5 REQUIRED)

add_library(hello SHARED
hello.cpp)

include_directories(${PYTHON_INCLUDE_PATH})

target_link_libraries(hello
debug ${Boost_PYTHON_LIBRARY_DEBUG}
optimized ${Boost_PYTHON_LIBRARY_RELEASE}
)

target_link_libraries(hello
debug ${PYTHON_DEBUG_LIBRARIES}
optimized ${PYTHON_LIBRARIES}
)