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From: Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>
To: Martin Sebor via Libc-alpha <libc-alpha@sourceware.org>
Subject: Re: [RFC patch] avoid warning on accesses to hardwired address
Date: Fri, 09 Jul 2021 08:34:56 +0200	[thread overview]
Message-ID: <87sg0oj8q7.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <59b05c40-d0a8-233a-27c5-104b24bdc9b4@gmail.com> (Martin Sebor via Libc-alpha's message of "Thu, 8 Jul 2021 18:55:26 -0600")

* Martin Sebor via Libc-alpha:

> Thanks to recent code refactoring in GCC 12, -Warray-bounds has
> started to diagnose accesses to constant addresses just like many
> other flow based warnings do (e.g., -Wstringop-overflow).
> The warnings are meant to help detect accesses resulting from
> invalid arithmetic on null pointers.  There may be a better way
> to detect them but GCC doesn't have the detection yet.  This
> warning change has in turn exposed Glibc's uses of this trick
> in the implementation of the THREAD_SELF macro.

The warning needs to be disabled in GCC for named address spaces.  Null
pointers are not special for them.

Thanks,
Florian


  reply	other threads:[~2021-07-09  6:35 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-09  0:55 [RFC patch] avoid warning on accesses to hardwired address Martin Sebor via Libc-alpha
2021-07-09  6:34 ` Florian Weimer via Libc-alpha [this message]
2021-07-21 13:06   ` Florian Weimer via Libc-alpha
2021-07-21 16:17     ` Martin Sebor via Libc-alpha
2021-08-16 11:27 ` Martin Liška
2021-08-16 15:24   ` Martin Sebor via Libc-alpha

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