def self.builtin_functions
@builtin_functions ||= %w(
add_global_arguments add_project_arguments
add_global_link_arguments add_project_link_arguments add_test_setup add_languages
alias_target assert benchmark both_libraries build_target configuration_data configure_file
custom_target declare_dependency dependency disabler environment error executable
generator gettext get_option get_variable files find_library find_program
include_directories import install_data install_headers install_man install_subdir
is_disabler is_variable jar join_paths library message option project
run_target run_command set_variable subdir subdir_done
subproject summary shared_library shared_module static_library test vcs_tag warning
)
end