kconfig: Introduce IS_ENABLED(), IS_BUILTIN() and IS_MODULE()

Replace the config_is_*() macros with a variant that allows for grepping
for usage of CONFIG_* options in the code. Usage:

  if (IS_ENABLED(CONFIG_NUMA))

or

  #if IS_ENABLED(CONFIG_NUMA)

The IS_ENABLED() macro evaluates to 1 if the argument is set (to either 'y'
or 'm'), IS_BUILTIN() tests if the option is 'y' and IS_MODULE() test if
the option is 'm'. Only boolean and tristate options are supported.

Reviewed-by: Arnaud Lacombe <lacombar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 32 insertions, 0 deletions

diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h
new file mode 100644
index 00000000000..067eda0e4b3
--- /dev/null
+++ b/include/linux/kconfig.h
@@ -0,0 +1,32 @@
+#ifndef __LINUX_KCONFIG_H
+#define __LINUX_KCONFIG_H
+
+#include <generated/autoconf.h>
+
+/*
+ * Helper macros to use CONFIG_ options in C expressions. Note that
+ * these only work with boolean and tristate options.
+ */
+
+/*
+ * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm',
+ * 0 otherwise.
+ *
+ */
+#define IS_ENABLED(option) \
+	(__enabled_ ## option || __enabled_ ## option ## _MODULE)
+
+/*
+ * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0
+ * otherwise. For boolean options, this is equivalent to
+ * IS_ENABLED(CONFIG_FOO).
+ */
+#define IS_BUILTIN(option) __enabled_ ## option
+
+/*
+ * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0
+ * otherwise.
+ */
+#define IS_MODULE(option) __enabled_ ## option ## _MODULE
+
+#endif /* __LINUX_KCONFIG_H */