At present if an optional Kconfig value needs to be used it must be
bracketed by #ifdef. For example, with this Kconfig setup:
config WIBBLE
bool "Support wibbles, the world needs more wibbles"
config WIBBLE_ADDR
hex "Address of the wibble"
depends on WIBBLE
then the following code must be used:
#ifdef CONFIG_WIBBLE
static void handle_wibble(void)
{
int val = CONFIG_WIBBLE_ADDR;
...
}
#endif
static void init_machine()
{
...
#ifdef CONFIG_WIBBLE
handle_wibble();
#endif
}
Add a new IF_ENABLED_INT() to help with this. So now it is possible to
write, without #ifdefs:
static void handle_wibble(void)
{
int val = IF_ENABLED_INT(CONFIG_WIBBLE, CONFIG_WIBBLE_ADDR);
...
}
static void init_machine()
{
...
if (IS_ENABLED(CONFIG_WIBBLE))
handle_wibble();
}
The value will be CONFIG_WIBBLE_ADDR if CONFIG_WIBBLE is defined and will
produce a build error if not.. This allows us to reduce the use of #ifdef
in the code, ensuring that the compiler still checks the code even if it
is not ultimately used for a particular build.
Add a CONFIG_IF_ENABLED_INT() version as well.
If an attempt is made to use a value that does not exist (i.e. when the
conditional is not enabled), an error about a non-existing function is
generated, e.g.:
common/bloblist.c:447: undefined reference to `invalid_use_of_IF_ENABLED_INT'
Signed-off-by: Simon Glass <sjg@chromium.org>
097ff01fb9