path: root/Documentation/kbuild/kconfig-language.txt
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authorJarek Poplawski <jarkao2@o2.pl>2007-08-10 13:01:04 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-08-11 15:47:41 -0700
commitf8a745942b1b7f052cb76bb8a893d12cb6329c84 (patch)
tree11ae43b36bd76b64fb55e7c4d2a3255c635d3128 /Documentation/kbuild/kconfig-language.txt
parent09736bd36a19aa8c0630e626563e447213c372b5 (diff)
docs: note about select in kconfig-language.txt
A warning note from Sam Ravnborg about kconfig's select evilness, dependencies and the future (slightly corrected). Signed-off-by: Jarek Poplawski <jarkao2@o2.pl> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/kbuild/kconfig-language.txt')
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt
index 536d5bfbdb8d..fe8b0c4892cf 100644
--- a/Documentation/kbuild/kconfig-language.txt
+++ b/Documentation/kbuild/kconfig-language.txt
@@ -98,6 +98,15 @@ applicable everywhere (see syntax).
times, the limit is set to the largest selection.
Reverse dependencies can only be used with boolean or tristate
+ 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 promts 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

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