kconfig: Update IS_ENABLED() internals

The config_enabled() macro currently uses 0 as the default value. Update
it to allow any value, so we can pass it something else, such as a
non-existent function, to produce a build error if it is not defined.

Also tidy up the code style for IS_ENABLED() and drop the unnecessary
brackets (the value is a simple 0 or 1).

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h
index a1d1a2984267ac2c49f91c5bb465c7d0181c9b82..52586a7557b04e8debac514b9daccd9927a5ae76 100644 (file)
--- a/include/linux/kconfig.h
+++ b/include/linux/kconfig.h
@@ -17,18 +17,16 @@
  * the last step cherry picks the 2nd arg, we get a zero.
  */
 #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(cfg, def_val) _config_enabled(cfg, def_val)
+#define _config_enabled(value, def_val) __config_enabled(__ARG_PLACEHOLDER_##value, def_val)
+#define __config_enabled(arg1_or_junk, def_val) ___config_enabled(arg1_or_junk 1, def_val)
 #define ___config_enabled(__ignored, val, ...) val
 
 /*
  * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y',
  * 0 otherwise.
- *
  */
-#define IS_ENABLED(option) \
-       (config_enabled(option))
+#define IS_ENABLED(option)     config_enabled(option, 0)
 
 /*
  * U-Boot add-on: Helper macros to reference to different macros (prefixed by
@@ -76,7 +74,7 @@
 #define __CONFIG_IS_ENABLED_1(option)        __CONFIG_IS_ENABLED_3(option, (1), (0))
 #define __CONFIG_IS_ENABLED_2(option, case1) __CONFIG_IS_ENABLED_3(option, case1, ())
 #define __CONFIG_IS_ENABLED_3(option, case1, case0) \
-       __concat(__unwrap, config_enabled(CONFIG_VAL(option))) (case1, case0)
+       __concat(__unwrap, config_enabled(CONFIG_VAL(option), 0)) (case1, case0)
 
 /*
  * CONFIG_IS_ENABLED(FOO) expands to