linux-kernel - Re: [PATCH] kconfig: Warn if help text is blank

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Date:   Tue, 30 Jan 2018 20:33:51 +0100
From:   Ulf Magnusson <ulfalizer@...il.com>
To:     Paul Bolle <pebolle@...cali.nl>
Cc:     Masahiro Yamada <yamada.masahiro@...ionext.com>,
        "Luis R . Rodriguez" <mcgrof@...nel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Linux Kbuild mailing list <linux-kbuild@...r.kernel.org>
Subject: Re: [PATCH] kconfig: Warn if help text is blank

On Tue, Jan 30, 2018 at 7:34 PM, Paul Bolle <pebolle@...cali.nl> wrote:
> On Tue, 2018-01-30 at 19:18 +0100, Ulf Magnusson wrote:
>> Print a warning if a 'help' token is given but the help text is blank.
>> Personal pet peeve.
>>
>> Example warnings:
>>
>>       net/sched/Kconfig:860: warning: 'NET_IFE_SKBMARK' defined with blank help text
>>       net/sched/Kconfig:865: warning: 'NET_IFE_SKBPRIO' defined with blank help text
>>       net/sched/Kconfig:870: warning: 'NET_IFE_SKBTCINDEX' defined with blank help text
>>       drivers/video/fbdev/Kconfig:1159: warning: 'FB_I810_I2C' defined with blank help text
>>       drivers/mmc/host/Kconfig:877: warning: 'MMC_TOSHIBA_PCI' defined with blank help text
>>       drivers/staging/rtl8192u/Kconfig:8: warning: 'RTL8192U' defined with blank help text
>>       drivers/staging/rtl8192e/rtl8192e/Kconfig:9: warning: 'RTL8192E' defined with blank help text
>>       lib/Kconfig.debug:354: warning: 'ARCH_WANT_FRAME_POINTERS' defined with blank help text
>>
>> A separate patchset will be sent to fix all current instances of blank
>> help texts for all arches. I added the same warning to Kconfiglib.
>
> If you do this it would be better to first fix or remove those help texts

I agree that this shouldn't go in until/unless a significant portion
of those empty help texts get removed first.

> and only then add this warning. Ie, add the warning in the last patch of a cleanup
> series.

Might have been better to arrange it like that, yeah. The patchset
that removes the empty help texts is at
https://lkml.org/lkml/2018/1/30/574. I could make another one if you'd
prefer that.

>
>> --- a/scripts/kconfig/zconf.y
>> +++ b/scripts/kconfig/zconf.y
>> @@ -436,6 +436,12 @@ help: help_start T_HELPTEXT
>>               zconfprint("warning: '%s' defined with more than one help text -- only the last one will be used",
>>                          current_entry->sym->name ?: "<choice>");
>>       }
>> +
>> +     /* Is the help text empty or all whitespace? */
>> +     if ($2[strspn($2, " \f\n\r\t\v")] == '\0')
>> +             zconfprint("warning: '%s' defined with blank help text",
>> +                        current_entry->sym->name ?: "<choice>");
>> +
>
> Does this go to stderr?

Yep - goes to stderr. zconfprint() is the standard error reporting
function during parsing, and also prints the parsing location.

>
> Another fix would be to ignore empty help texts and not render them at all. Is
> that possible?

I haven't even checked how they are rendered to be honest. I was more
concerned with the Kconfig mess.

> Thanks,
>
>
> Paul Bolle

Cheers,
Ulf