add_cflag_if_supported("-Wimplicit-function-declaration")
add_cflag_if_supported("-Wredundant-decls")
add_cflag_if_supported("-Wundef")
add_cflag_if_supported("-Wimplicit-function-declaration")
add_cflag_if_supported("-Wredundant-decls")
add_cflag_if_supported("-Wundef")