Commit Graph

2 Commits

Author SHA1 Message Date
Paul Gortmaker
69349c2dc0 kconfig: fix IS_ENABLED to not require all options to be defined
Using IS_ENABLED() within C (vs.  within CPP #if statements) in its
current form requires us to actually define every possible bool/tristate
Kconfig option twice (__enabled_* and __enabled_*_MODULE variants).

This results in a huge autoconf.h file, on the order of 16k lines for a
x86_64 defconfig.

Fixing IS_ENABLED to be able to work on the smaller subset of just
things that we really have defined is step one to fixing this.  Which
means it has to not choke when fed non-enabled options, such as:

  include/linux/netdevice.h:964:1: warning: "__enabled_CONFIG_FCOE_MODULE" is not defined [-Wundef]

The original prototype of how to implement a C and preprocessor
compatible way of doing this came from the Google+ user "comex ." in
response to Linus' crowdsourcing challenge for a possible improvement on
his earlier C specific solution:

	#define config_enabled(x)       (__stringify(x)[0] == '1')

In this implementation, I've chosen variable names that hopefully make
how it works more understandable.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-12 18:35:58 -07:00
Michal Marek
2a11c8ea20 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>
2011-07-29 21:53:30 +02:00