分析一下PX4代码CMakeLists.txt文件

#=============================================================================
# CMAKE CODING STANDARD FOR PX4
#
# Structure
# ---------------------------------------------------------------------------
#
# * Common functions should be included in <span style="color:#ff0000;">px_base.cmake.</span>
#
# * OS/ board specific fucntions should be include in
#	px_impl_${OS}.cmake or px4_impl_${OS}_${BOARD}.cmake.
#
# Formatting
# ---------------------------------------------------------------------------
#
# * Use hard indents to match the px4 source code.
#
# * All function and script arguments are upper case.
#
# * All local variables are lower case.
#
# * All cmake functions are lowercase.
#
# * For else, endif, endfunction, etc, never put the name of the statement
#
#	Instead of the very confusing:
#		if (${var} STREQUAL "1") <-- condition now becomes if name
#			# do somthing
#		elseif (${var} STREQUAL "2") <-- another condition
#			# do somthing
#		else (${var} STREQUAL "1") <-- tag is referring to name of if
#			# do somthing
#		endif (${var} STREQUAL "1") <-- tag is referring to name of if
#
#	Do this:
#		if (${var} STREQUAL "1") <-- condition now becomes if name
#			# do somthing
#		elseif (${var} STREQUAL "2") <-- another condition
#			# do somthing
#		else () <-- leave blank
#			# do somthing
#		endif () <-- leave blank
#
# Functions/Macros
# ---------------------------------------------------------------------------
#
# * Use px4_parse_function_args to parse functions and check for required
#   arguments. Unless there is only one argument in the function and it is clear.
#
# * Never use macros. They allow overwriting global variables and this
#	makes variable declarations hard to locate.
#
# * If a target from add_custom_* is set in a function, explicitly pass it
#	as an output argument so that the target name is clear to the user.
#
# * Avoid use of global variables in functions. Functions in a nested
#	scope may use global variables, but this makes it difficult to
#	resuse functions.
#
# Included CMake Files
# ---------------------------------------------------------------------------
#
# * All variables in config files must have the prefix "config_".
#
# * Never set global variables in an included cmake file,
#	you may only define functions. This excludes config and Toolchain files.
#	This makes it clear to the user when variables are being set or targets
#	are being created.
#
# * Setting a global variable in a CMakeLists.txt file is ok, because
#	each CMakeLists.txt file has scope in the current directory and all
#	subdirecties, so it is not truly global.
#
# * All toolchain files should be included in the cmake
#	directory and named Toolchain-"name".cmake.
#
# Misc
# ---------------------------------------------------------------------------
#
# * If referencing a string variable, don't put it in quotes.
#	Don't do "${OS}" STREQUAL "posix",
#	instead type ${OS} STREQUAL "posix". This will throw an
#	error when ${OS} is not defined instead of silently
#	evaluating to false.
#
#=============================================================================

# Warning: Changing this modifies CMake's internal workings
# and leads to wrong toolchain detection
cmake_minimum_required(VERSION 2.8 FATAL_ERROR)

# Use clang
#SET (CMAKE_C_COMPILER /usr/bin/clang-3.6)
#SET (CMAKE_CXX_COMPILER /usr/bin/clang++-3.6)

#=============================================================================
# parameters
#

set(CMAKE_BUILD_TYPE "" CACHE STRING "build type")
set_property(CACHE CMAKE_BUILD_TYPE PROPERTY
	STRINGS ";Debug;Release;RelWithDebInfo;MinSizeRel")
set(CONFIG "nuttx_px4fmu-v2_default" CACHE STRING "desired configuration")
file(GLOB_RECURSE configs RELATIVE cmake/configs "cmake/configs/*.cmake")
set_property(CACHE CONFIG PROPERTY STRINGS ${configs})
set(THREADS "4" CACHE STRING
	"number of threads to use for external build processes")
set(DEBUG_PORT "/dev/ttyACM0" CACHE STRING "debugging port")

#=============================================================================
# configuration
#
# must come before project to set toolchain

string(REPLACE "_" ";" config_args ${CONFIG})
list(GET config_args 0 OS)
list(GET config_args 1 BOARD)
list(GET config_args 2 LABEL)
set(target_name "${OS}-${BOARD}-${LABEL}")

message(STATUS "${target_name}")

# switch to ros CMake file if building ros
if (${OS} STREQUAL "ros")
	include("cmake/ros-CMakeLists.txt")
else()  # otherwise use the rest of this file

list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake)
set(config_module "configs/${CONFIG}")
include(${config_module})

# cmake modules
include(ExternalProject)

# require px4 module interface
set(px4_required_interface
	px4_os_prebuild_targets
	px4_os_add_flags
	)
foreach(cmd ${px4_required_interface})
	if(NOT COMMAND ${cmd})
		message(FATAL_ERROR "${config_module} must implement ${cmd}")
	endif()
endforeach()
set(px4_required_config
	config_module_list
	)
foreach(conf ${px4_required_config})
	if(NOT DEFINED ${conf})
		message(FATAL_ERROR "cmake/${config_module} must define ${conf}")
	endif()
endforeach()

# List the DriverFramework drivers
if(DEFINED config_df_driver_list)
	message("DF Drivers: ${config_df_driver_list}")
endif()

#=============================================================================
# project definition
#
project(px4 CXX C ASM)
if (NOT ${CMAKE_VERSION} VERSION_LESS 3.0.0)
	cmake_policy(SET CMP0045 NEW) # error on non-existent target in get prop
	cmake_policy(SET CMP0046 NEW) # no non-existent targets as dependencies
	cmake_policy(SET CMP0025 OLD) # still report AppleClang as Clang
endif()
if (NOT ${CMAKE_VERSION} VERSION_LESS 3.1.0)
	cmake_policy(SET CMP0054 NEW) # don't dereference quoted variables
endif()

set(version_major 1)
set(version_minor 0)
set(version_patch 1)
set(version "${version_major}.${version_minor}.${version_patch}")
set(package-contact "[email protected]")

#=============================================================================
# programs
#
find_package(PythonInterp REQUIRED)

#=============================================================================
# cmake modules
#
enable_testing()

#=============================================================================
# check required toolchain variables
#
set(required_variables
	CMAKE_C_COMPILER_ID
	)
foreach(var ${required_variables})
	if (NOT ${var})
		message(FATAL_ERROR "Toolchain/config must define ${var}")
	endif()
endforeach()

#=============================================================================
# git
#
px4_add_git_submodule(TARGET git_genmsg PATH "Tools/genmsg")
px4_add_git_submodule(TARGET git_gencpp PATH "Tools/gencpp")
px4_add_git_submodule(TARGET git_mavlink PATH "mavlink/include/mavlink/v1.0")
px4_add_git_submodule(TARGET git_gtest PATH "unittets/gtest")
px4_add_git_submodule(TARGET git_uavcan PATH "src/modules/uavcan/libuavcan")
px4_add_git_submodule(TARGET git_nuttx PATH "NuttX")
px4_add_git_submodule(TARGET git_driverframework PATH "src/lib/DriverFramework")
px4_add_git_submodule(TARGET git_ecl PATH "src/lib/ecl")
px4_add_git_submodule(TARGET git_jmavsim PATH "Tools/jMAVSim")
px4_add_git_submodule(TARGET git_gazebo PATH "Tools/sitl_gazebo")
px4_add_git_submodule(TARGET git_matrix PATH "src/lib/matrix")
px4_add_git_submodule(TARGET git_cmake_hexagon PATH "cmake/cmake_hexagon")

add_custom_target(submodule_clean
	WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
	COMMAND git submodule deinit -f .
	COMMAND rm -rf .git/modules/*
	)

#=============================================================================
# misc targets
#
add_custom_target(check_format
	COMMAND Tools/check_code_style.sh
	WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
	)

add_custom_target(config
	COMMAND cmake-gui .
	WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
	)

#=============================================================================
# external libraries
#
px4_os_prebuild_targets(OUT prebuild_targets
	BOARD ${BOARD}
	THREADS ${THREADS})

#=============================================================================
# build flags
#
px4_os_add_flags(
	BOARD ${BOARD}
	C_FLAGS c_flags
	CXX_FLAGS cxx_flags
	EXE_LINKER_FLAGS exe_linker_flags
	INCLUDE_DIRS include_dirs
	LINK_DIRS link_dirs
	DEFINITIONS definitions)

px4_join(OUT CMAKE_EXE_LINKER_FLAGS LIST "${exe_linker_flags}" GLUE " ")
px4_join(OUT CMAKE_C_FLAGS LIST "${c_flags}" GLUE " ")
px4_join(OUT CMAKE_CXX_FLAGS LIST "${cxx_flags}" GLUE " ")

include_directories(${include_dirs})
#message("INCLUDE_DIRS=${include_dirs}")
link_directories(${link_dirs})
add_definitions(${definitions})

#=============================================================================
# source code generation
#
add_subdirectory(msg)
px4_generate_messages(TARGET msg_gen
	MSG_FILES ${msg_files}
	OS ${OS}
	DEPENDS git_genmsg git_gencpp prebuild_targets
	)
px4_generate_parameters_xml(OUT parameters.xml BOARD ${BOARD})
px4_generate_airframes_xml(OUT airframes.xml BOARD ${BOARD})
add_custom_target(xml_gen
	DEPENDS parameters.xml airframes.xml)

#=============================================================================
# external projects
#

set(ep_base ${CMAKE_BINARY_DIR}/external)
set_property(DIRECTORY PROPERTY EP_BASE ${ep_base})

# add external project install folders to build
link_directories(${ep_base}/Install/lib)
include_directories(${ep_base}/Install/include)
# add the directories so cmake won't warn
execute_process(COMMAND cmake -E make_directory ${ep_base}/Install/lib)
execute_process(COMMAND cmake -E make_directory ${ep_base}/Install/include)

#=============================================================================
# DriverFramework Drivers
#
set(df_driver_libs)
foreach(driver ${config_df_driver_list})
	add_subdirectory(src/lib/DriverFramework/drivers/${driver})
	list(APPEND df_driver_libs df_${driver})
	message("Adding DF driver: ${driver}")
endforeach()

#=============================================================================
# subdirectories
#
set(module_libraries)
foreach(module ${config_module_list})
	string(REGEX MATCH "^[./]" external_module ${module})
	if(external_module)
		STRING(REGEX REPLACE "//" "/" EXT_MODULE ${module})
		STRING(REGEX REPLACE "/" "__" EXT_MODULE_PREFIX ${EXT_MODULE})
		add_subdirectory(${module} ${CMAKE_BINARY_DIR}/${EXT_MODULE_PREFIX})
	else()
		add_subdirectory(src/${module})
	endif()
	px4_mangle_name(${module} mangled_name)
	list(APPEND module_libraries ${mangled_name})
	#message(STATUS "adding module: ${module}")
endforeach()

# Keep track of external shared libs required for modules
set(module_external_libraries "${module_external_libraries}" CACHE INTERNAL "module_external_libraries")

add_subdirectory(src/firmware/${OS})

#add_dependencies(df_driver_framework nuttx_export_${CONFIG}.stamp)
if (NOT "${OS}" STREQUAL "nuttx")
endif()

if (config_io_board)
	add_subdirectory(src/modules/px4iofirmware)
endif()

#=============================================================================
# generate git version
#
px4_create_git_hash_header(HEADER ${CMAKE_BINARY_DIR}/build_git_version.h)

#=============================================================================
# packaging
#
# Important to having packaging at end of cmake file.
#
set(CPACK_PACKAGE_VERSION ${version})
set(CPACK_PACKAGE_CONTACT ${package_contact})
set(CPACK_GENERATOR "ZIP")
set(CPACK_SOURCE_GENERATOR "ZIP")
include(CPack)

endif() # ros alternative endif

# vim: set noet fenc=utf-8 ff=unix ft=cmake :