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From: Masahiro Yamada <masahiroy@kernel.org>
Date: Tue, 4 Jun 2024 11:08:37 +0900
Message-ID: <CAK7LNATNMcUR9j+tLRynJH5tFPcET0kzDeRuSBhC7uoTbEB_wQ@mail.gmail.com>
Subject: Re: [PATCH 3/3] kconfig: remove wrong expr_trans_bool()
To: linux-kbuild@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
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On Tue, Jun 4, 2024 at 1:19=E2=80=AFAM Masahiro Yamada <masahiroy@kernel.or=
g> wrote:
>
> expr_trans_bool() performs an incorrect transformation.
>
> [Test Code]
>
>     config MODULES
>             def_bool y
>             modules
>
>     config A
>             def_bool y
>             select C if B !=3D n
>
>     config B
>             def_tristate m
>
>     config C
>             tristate
>
> [Result]
>
>     CONFIG_MODULES=3Dy
>     CONFIG_A=3Dy
>     CONFIG_B=3Dm
>     CONFIG_C=3Dm
>
> This result is incorrect because CONFIG_C=3Dy is expected.
>
> Documentation/kbuild/kconfig-language.rst clearly explains the function
> of the '!=3D' operator:
>
>   (3) If the values of both symbols are equal, it returns 'n',
>       otherwise 'y'.
>
> Therefore, the statement:
>
>     select C if A !=3D n

This is wrong.

I meant this:


      select C if B !=3D n


--=20
Best Regards
Masahiro Yamada