cpp-ethereum/cmake/EthPolicy.cmake

# it must be a macro cause policies have scopes
# http://www.cmake.org/cmake/help/v3.0/command/cmake_policy.html
macro (eth_policy)
	# link_directories() treats paths relative to the source dir.
	cmake_policy(SET CMP0015 NEW)

	# let cmake autolink dependencies on windows
	cmake_policy(SET CMP0020 NEW)

	# CMake 2.8.12 and lower allowed the use of targets and files with double
	# colons in target_link_libraries,
#	cmake_policy(SET CMP0028 OLD)

	if (${CMAKE_VERSION} VERSION_GREATER 3.0)

		# fix MACOSX_RPATH
#		cmake_policy(SET CMP0042 OLD)

		# ignore COMPILE_DEFINITIONS_<Config> properties
		cmake_policy(SET CMP0043 OLD)

		# allow VERSION argument in project()
		cmake_policy(SET CMP0048 NEW)

	endif()

	if (${CMAKE_VERSION} VERSION_GREATER 3.1)
		
		# do not interpret if() arguments as variables!
		cmake_policy(SET CMP0054 NEW)

	endif()

endmacro()