[greybus-dev] [PATCH] Kbuild: remove -std=gnu89 from compiler arguments

Alex Elder elder at linaro.org
Sun Feb 27 15:57:52 PST 2022


On 2/27/22 5:11 PM, Linus Torvalds wrote:
> On Sun, Feb 27, 2022 at 3:04 PM Alex Elder <elder at linaro.org> wrote:
>>
>> Glancing at the Greybus code, I don't believe there's any
>> reason it needs to shift a negative value.  Such warnings
>> could be fixed by making certain variables unsigned, for
>> example.
> 
> As mentioned in the original thread, making things unsigned actually
> is likely to introduce bugs and make things worse.

Understood.  What I meant is that the shifts were producing
single-bit masks from plain int values that range from 0 to 10
or something (in a for loop).  Looking again though, that it's
not so simple.  Regardless, your point about the warning is
good and I won't plan to "fix" this.

Thanks.

					-Alex
> 
> The warning is simply bogus, and the fact that it was enabled by
> -Wextra in gcc for std=gnu99 and up was a mistake that looks likely to
> be fixed in gcc.
> 
> So don't try to "fix" the code to make any possible warnings go away.
> You may just make things worse.
> 
> (That is often true in general for the more esoteric warnings, but in
> this case it's just painfully more obvious).
> 
>                Linus




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