text: #ifndef __BACKPORT_LINUX_KCONFIG_H
  #define __BACKPORT_LINUX_KCONFIG_H
  #include <linux/version.h>
  #if LINUX_VERSION_IS_GEQ(3,1,0)
  #include_next <linux/kconfig.h>
  #endif
  
  #ifndef __ARG_PLACEHOLDER_1
  #define __ARG_PLACEHOLDER_1 0,
  #define config_enabled(cfg) _config_enabled(cfg)
  #define _config_enabled(value) __config_enabled(__ARG_PLACEHOLDER_##value)
  #define __config_enabled(arg1_or_junk) ___config_enabled(arg1_or_junk 1, 0)
  #define ___config_enabled(__ignored, val, ...) val
  
  /*
   * 3.1 - 3.3 had a broken version of this, so undef
   * (they didn't have __ARG_PLACEHOLDER_1)
   */
  #undef IS_ENABLED
  #define IS_ENABLED(option) \
          (config_enabled(option) || config_enabled(option##_MODULE))
  #endif
  
  /*
   * Since 4.9 config_enabled has been removed in favor of __is_defined.
   */
  #ifndef config_enabled
  #define config_enabled(cfg)	__is_defined(cfg)
  #endif
  
  #undef IS_BUILTIN
  #define IS_BUILTIN(option) config_enabled(option)
  
  #ifndef IS_REACHABLE
  /*
   * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled
   * code can call a function defined in code compiled based on CONFIG_FOO.
   * This is similar to IS_ENABLED(), but returns false when invoked from
   * built-in code when CONFIG_FOO is set to 'm'.
   */
  #define IS_REACHABLE(option) (config_enabled(option) || \
  		 (config_enabled(option##_MODULE) && config_enabled(MODULE)))
  #endif
  
  #endif
  