Kconfig: '+config' valid syntax?

[Valentin Rothberg]

Hi,

commit ed013214afa7 ("ACPI / init: Make it possible to override _REV")
is in today's linux-next tree (i.e., next-20150702) adding the
following hunk to drivers/acpi/Kconfig:

--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -428,6 +428,26 @@ config XPOWER_PMIC_OPREGION
        help
          This config adds ACPI operation region support for XPower AXP288 PMIC.

++config ACPI_REV_OVERRIDE_POSSIBLE
+       bool "Allow supported ACPI revision to be overriden"
+       depends on X86
+       default y
[...]

By having a close look at the first added line, we can see that
'+config ACPI_...' is added.  To my great surprise, it's valid Kconfig
syntax.  How is that possible?  IMHO it's an invalid token, such that
Kconfig should complain about it.  Or do I miss something?

Kind regards,
 Valentin
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/