exec_program("echo `${CMAKE_C_COMPILER} --version | grep -E [0-9].[0-9].[0-9]$`" OUTPUT_VARIABLE "COMPILER_C_VERSION")
exec_program("echo `${CMAKE_CXX_COMPILER} --version | grep -E [0-9].[0-9].[0-9]$`" OUTPUT_VARIABLE "COMPILER_CXX_VERSION")
exec_program("echo `${CMAKE_C_COMPILER} --version | grep -E [0-9].[0-9].[0-9]$`" OUTPUT_VARIABLE "COMPILER_C_VERSION")
exec_program("echo `${CMAKE_CXX_COMPILER} --version | grep -E [0-9].[0-9].[0-9]$`" OUTPUT_VARIABLE "COMPILER_CXX_VERSION")