Messages in this thread | | | Date | Fri, 3 Jul 2015 12:16:23 +0200 | Subject | Re: Kconfig: '+config' valid syntax? | From | Ulf Magnusson <> |
| |
On Thu, Jul 2, 2015 at 10:08 AM, Valentin Rothberg <valentinrothberg@gmail.com> wrote: > 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
For another take on this, you could look at the Config._tokenize() function in Kconfiglib (https://github.com/ulfalizer/Kconfiglib/blob/master/kconfiglib.py). Here's a relevant comment from that function:
# The initial word on a line is parsed specially. Let # command_chars = [A-Za-z0-9_]. Then # - leading non-command_chars characters are ignored, and # - the first token consists the following one or more # command_chars characters. # This is why things like "----help--" are accepted.
The root cause is sloppy lexing in zconf.l, IIRC. I didn't check whether it's been improved, but Kconfiglib needs to be backwards compatible either way.
/Ulf
| |