docs: note about select in kconfig-language.txt

[pandora-kernel.git] / Documentation / kbuild / kconfig-language.txt

diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt
index 536d5bf..fe8b0c4 100644 (file)
--- 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
   symbols.
   times, the limit is set to the largest selection.
   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 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
 
 - numerical ranges: "range" <symbol> <symbol> ["if" <expr>]
   This allows to limit the range of possible input values for int