CMakeLists.txt基本指令介绍
背景
CMakeLists.txt是编译源包的过程中catkin所依据的文件，里面包含了所需要编译的包的编译器、名称、依赖、路径等等信息。为了便于大家新建一个代码后在ROS编译，现介绍CMakeLists.txt里面的基本指令。
指令介绍
cmake_minimum_required(VERSION 2.8.3)
版本声明，需要2.8.3版本或者更高
project(chapter8_tutorials)
cmake时创建包的名字，如chapter8_tutorials
往往我们需要利用find_package()函数找到一些依赖包来建立我们的新包，至少需要给一个依赖给catkin。
在建立包的过程中给了包环境变量的信息，环境变量提供了：头文件是什么、源文件在哪、库文件的依赖是什么以及库文件的路径是什么。
find_package(catkin REQUIRED COMPONENTS
roscpp
rospy
tf
)
给建立新包所需所处不同文件夹的依赖，如roscpp,rospy,tf
加COMPONENTS限定是可以将环境变量的信息直接添加到catkin_variables里面，如果直接
find_package(nodelet)
将不能如此。
在同一个文件夹用下面这句
find_package(catkin REQUIRED)
catkin_package(
# INCLUDE_DIRS include
# LIBRARIES chapter8_tutorials
# CATKIN_DEPENDS roscpp rospy
# DEPENDS system_lib
)
设定catkin的信息，必须声明在add_excutable()和add_librariey()前面
include_directories(
${catkin_INCLUDE_DIRS}
)
包含的目录，由find_package整合使用，含有目录的路径信息。
进一步的，如果使用boost，你的include_directories看起来是这样的：
include_directories(include ${Boost_INCLUDE_DIRS} ${catkin_INCLUDE_DIRS})
第一个参数指明了include/ 的目录同样是一个建包所需路径的一部分。
add_executable(tf_broadcast src/tf_broadcaster.cpp)
add_executable(tf_listener src/tf_listener.cpp)
add_executable(laser src/laser.cpp)
add_executable(odometry src/odometry.cpp)
add_executable(base_controller src/base_controller.cpp)
添加可执行文件的路径，以tf_broadcaster.cpp文件为例：
第一个参数表示编译后该cpp对应的编译文件名称，一般与.cpp前的文件名同；
第二个参数是指，tf_broadcaster.cpp在CMakeLists.txt所在文件夹同级目录的src文件夹里面（即这个cpp所在的文件夹src与CMakeLists.txt在同一个文件夹），所以可用src/tf_broadcaster.cpp表示。
图层如下图：
这是我们编写代文件后编译前需要的步骤，需要特别注意，python语言后缀是.py，c++的是.cpp。
target_link_libraries(tf_broadcast ${catkin_LIBRARIES})
target_link_libraries(tf_listener ${catkin_LIBRARIES})
target_link_libraries(laser ${catkin_LIBRARIES})
target_link_libraries(odometry ${catkin_LIBRARIES})
target_link_libraries(base_controller ${catkin_LIBRARIES})
第一个参数：是指你前面编译后文件名，如tf_broadcast。
第二个参数：添加可执行文件所依赖的库。如tf_broadcast.cpp用到了
#include <ros/ros.h>
#include <tf/transform_broadcaster.h>
这两个头文件ros/ros.h和tf/transform_broadcaster.h已经自动由find_package添加了，一般不需要特别指定，所以用了${catkin_LIBRARIES}。
如果需要特别指定，参照下面这句：
add_executable(foo src/foo.cpp) add_library(moo src/moo.cpp) target_link_libraries(foo moo) -- This links foo against libmoo.so
这也是我们编写代文件后编译前需要的步骤，需要特别注意.
参考资料
http://wiki.ros.org/catkin/CMakeLists.txt
注释的部分一般都是从模板上没有使用但遗留下来的。
由于实例代码没用用到所有指令和时间原因，所以本次的介绍
未完待续
以后学习过程有机会再补上。
实例代码如下：
cmake_minimum_required(VERSION 2.8.3)
project(chapter8_tutorials)
## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
roscpp
rospy
tf
)
## System dependencies are found with CMake's conventions
# find_package(Boost REQUIRED COMPONENTS system)
## Uncomment this if the package has a setup.py. This macro ensures
## modules and global scripts declared therein get installed
## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
# catkin_python_setup()
################################################
## Declare ROS messages, services and actions ##
################################################
## To declare and build messages, services or actions from within this
## package, follow these steps:
## * Let MSG_DEP_SET be the set of packages whose message types you use in
## your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
## * In the file package.xml:
## * add a build_depend and a run_depend tag for each package in MSG_DEP_SET
## * If MSG_DEP_SET isn't empty the following dependencies might have been
## pulled in transitively but can be declared for certainty nonetheless:
## * add a build_depend tag for "message_generation"
## * add a run_depend tag for "message_runtime"
## * In this file (CMakeLists.txt):
## * add "message_generation" and every package in MSG_DEP_SET to
## find_package(catkin REQUIRED COMPONENTS ...)
## * add "message_runtime" and every package in MSG_DEP_SET to
## catkin_package(CATKIN_DEPENDS ...)
## * uncomment the add_*_files sections below as needed
## and list every .msg/.srv/.action file to be processed
## * uncomment the generate_messages entry below
## * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)
## Generate messages in the 'msg' folder
# add_message_files(
# FILES
# Message1.msg
# Message2.msg
# )
## Generate services in the 'srv' folder
# add_service_files(
# FILES
# Service1.srv
# Service2.srv
# )
## Generate actions in the 'action' folder
# add_action_files(
# FILES
# Action1.action
# Action2.action
# )
## Generate added messages and services with any dependencies listed here
# generate_messages(
# DEPENDENCIES
# std_msgs # Or other packages containing msgs
# )
###################################
## catkin specific configuration ##
###################################
## The catkin_package macro generates cmake config files for your package
## Declare things to be passed to dependent projects
## INCLUDE_DIRS: uncomment this if you package contains header files
## LIBRARIES: libraries you create in this project that dependent projects also need
## CATKIN_DEPENDS: catkin_packages dependent projects also need
## DEPENDS: system dependencies of this project that dependent projects also need
catkin_package(
# INCLUDE_DIRS include
# LIBRARIES chapter8_tutorials
# CATKIN_DEPENDS roscpp rospy
# DEPENDS system_lib
)
###########
## Build ##
###########
## Specify additional locations of header files
## Your package locations should be listed before other locations
# include_directories(include)
include_directories(
${catkin_INCLUDE_DIRS}
)
## Declare a cpp library
# add_library(chapter8_tutorials
# src/${PROJECT_NAME}/chapter8_tutorials.cpp
# )
## Declare a cpp executable
# add_executable(chapter8_tutorials_node src/chapter8_tutorials_node.cpp)
## Add cmake target dependencies of the executable/library
## as an example, message headers may need to be generated before nodes
# add_dependencies(chapter8_tutorials_node chapter8_tutorials_generate_messages_cpp)
add_executable(tf_broadcast src/tf_broadcaster.cpp)
add_executable(tf_listener src/tf_listener.cpp)
add_executable(laser src/laser.cpp)
add_executable(odometry src/odometry.cpp)
add_executable(base_controller src/base_controller.cpp)
## Specify libraries to link a library or executable target against
# target_link_libraries(chapter8_tutorials_node
# ${catkin_LIBRARIES}
# )
target_link_libraries(tf_broadcast ${catkin_LIBRARIES})
target_link_libraries(tf_listener ${catkin_LIBRARIES})
target_link_libraries(laser ${catkin_LIBRARIES})
target_link_libraries(odometry ${catkin_LIBRARIES})
target_link_libraries(base_controller ${catkin_LIBRARIES})
#############
## Install ##
#############
# all install targets should use catkin DESTINATION variables
# See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html
## Mark executable scripts (Python etc.) for installation
## in contrast to setup.py, you can choose the destination
# install(PROGRAMS
# scripts/my_python_script
# DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )
## Mark executables and/or libraries for installation
# install(TARGETS chapter8_tutorials chapter8_tutorials_node
# ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
# LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
# RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )
## Mark cpp header files for installation
# install(DIRECTORY include/${PROJECT_NAME}/
# DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
# FILES_MATCHING PATTERN "*.h"
# PATTERN ".svn" EXCLUDE
# )
## Mark other files for installation (e.g. launch and bag files, etc.)
# install(FILES
# # myfile1
# # myfile2
# DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
# )
#############
## Testing ##
#############
## Add gtest based cpp test target and link libraries
# catkin_add_gtest(${PROJECT_NAME}-test test/test_chapter8_tutorials.cpp)
# if(TARGET ${PROJECT_NAME}-test)
# target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
# endif()
## Add folders to be run by python nosetests
# catkin_add_nosetests(test)
