exec_program("${CMAKE_C_COMPILER} --version" OUTPUT_VARIABLE "COMPILER_C_VERSION")
exec_program("${CMAKE_CXX_COMPILER} --version" OUTPUT_VARIABLE "COMPILER_CXX_VERSION")
string(REGEX MATCH "[0-9].[0-9].[0-9]" COMPILER_C_VERSION "${COMPILER_C_VERSION}")
exec_program("${CMAKE_C_COMPILER} --version" OUTPUT_VARIABLE "COMPILER_C_VERSION")
exec_program("${CMAKE_CXX_COMPILER} --version" OUTPUT_VARIABLE "COMPILER_CXX_VERSION")
string(REGEX MATCH "[0-9].[0-9].[0-9]" COMPILER_C_VERSION "${COMPILER_C_VERSION}")