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kconifg: 'select' considered less evil 

While select should be used with care, it is not actually evil.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
This commit is contained in:
Matthew Wilcox 2008-04-19 14:45:11 -06:00 committed by Sam Ravnborg
parent beda8ae716
commit dfecbec8b5
1 changed files with 9 additions and 8 deletions
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17
Documentation/kbuild/kconfig-language.txt
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@ -104,14 +104,15 @@ applicable everywhere (see syntax).
Reverse dependencies can only be used with boolean or tristate
symbols.
Note:
select is evil.... select will by brute force set a symbol
equal to 'y' without visiting the dependencies. So abusing
select you are able to select a symbol FOO even if FOO depends
on BAR that is not set. In general use select only for
non-visible symbols (no prompts anywhere) and for symbols with
no dependencies. That will limit the usefulness but on the
other hand avoid the illegal configurations all over. kconfig
should one day warn about such things.
select should be used with care. select will force
a symbol to a value without visiting the dependencies.
By abusing select you are able to select a symbol FOO even
if FOO depends on BAR that is not set.
In general use select only for non-visible symbols
(no prompts anywhere) and for symbols with no dependencies.
That will limit the usefulness but on the other hand avoid
the illegal configurations all over.
kconfig should one day warn about such things.
- numerical ranges: "range" <symbol> <symbol> ["if" <expr>]
This allows to limit the range of possible input values for int