linux-kernel - Re: Calculating array sizes in C - was: Re: Build regressions/improvements in v6.2-rc1

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Message-ID: <0d238f02-4d78-6f14-1b1b-f53f0317a910@physik.fu-berlin.de>
Date:   Tue, 17 Jan 2023 21:37:35 +0100
From:   John Paul Adrian Glaubitz <glaubitz@...sik.fu-berlin.de>
To:     Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     linux-kernel@...r.kernel.org, amd-gfx@...ts.freedesktop.org,
        linux-arm-kernel@...ts.infradead.org, linux-media@...r.kernel.org,
        linux-wireless@...r.kernel.org, linux-mips@...r.kernel.org,
        linux-sh@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net,
        linuxppc-dev@...ts.ozlabs.org, kasan-dev@...glegroups.com,
        linux-xtensa@...ux-xtensa.org,
        Michael Karcher <kernel@...rcher.dialup.fu-berlin.de>,
        Arnd Bergmann <arnd@...db.de>
Subject: Re: Calculating array sizes in C - was: Re: Build
 regressions/improvements in v6.2-rc1

Hi!

On 1/17/23 21:05, Geert Uytterhoeven wrote:
>> Isn't this supposed to be caught by this check:
>>
>>          a, __same_type(a, NULL)
>>
>> ?
> 
> Yeah, but gcc thinks it is smarter than us...
> Probably it drops the test, assuming UB cannot happen.

Hmm, sounds like a GGC bug to me then. Not sure how to fix this then.

Adrian

-- 
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