Re: select validation (was: Re: [2.6 patch] HID: fix default buildingof all quirky devices)
From: Linus Torvalds
Date: Thu Oct 16 2008 - 14:48:59 EST
On Thu, 16 Oct 2008, Geert Uytterhoeven wrote:
> Would it be possible for kconfig to check for invalid usage of select?
> Like you should not use select to enable something that has
> dependencies. However, that would fail in case both the selector option
> and the selected option depend on the same.
Well, at least in theory you may actually want to select something that
has dependencies, even if you don't want to select the dependencies.
For example, some feature may be enabled by default on some architecture
or with some config. Example:
depends on EXPERIMENTAL
depends on !EMBEDDED
depends on X86
which is just another way of saying
default X86 && !EMBEDDED && EXPERIMENTAL
and it's still possible that some code wants to do a
because the dependency isn't a _code_ dependency, it's a default-value
Now, you could say that then you should use that second version (ie the
"default X86 && !EMBEDDED && EXPERIMENTAL" version), but the thing is,
"depends on" is actually a more powerful and can result in more readable
setup (because you can have multiple "depends on" lines and they are all
logically anded together.
Do we do that? I dunno. But I wouldn't be surprised if we do.
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