kconfig: fix relational operators for bool and tristate symbols

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Since commit 31847b67be ("kconfig: allow use of relations other than
(in)equality") it is possible to use relational operators in Kconfig
statements. However, those operators give unexpected results when
applied to bool/tristate values:

	(n < y) = y (correct)
	(m < y) = y (correct)
	(n < m) = n (wrong)

This happens because relational operators process bool and tristate
symbols as strings and m sorts before n. It makes little sense to do a
lexicographical compare on bool and tristate values though.

Documentation/kbuild/kconfig-language.txt states that expression can have
a value of 'n', 'm' or 'y' (or 0, 1, 2 respectively for calculations).
Let's make it so for relational comparisons with bool/tristate
expressions as well and document them. If at least one symbol is an
actual string then the lexicographical compare works just as before.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

...

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Nicolas Pitre 2017-11-16 20:06:39 -05:00 • committed by Masahiro Yamada

parent cfe17c9bbe

commit 9059a3493e

2 changed files with 19 additions and 9 deletions

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23

Documentation/kbuild/kconfig-language.txt

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5

scripts/kconfig/expr.c

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