From: Andreas Schwab <schwab@linux-m68k.org>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: Po Lu <luangruo@yahoo.com>, Eli Zaretskii <eliz@gnu.org>,
emacs-devel@gnu.org
Subject: Re: Compiler warnings in dispnew.c
Date: Mon, 29 Nov 2021 18:53:17 +0100 [thread overview]
Message-ID: <8735neq25u.fsf@igel.home> (raw)
In-Reply-To: <jwvmtlm6ej5.fsf-monnier+emacs@gnu.org> (Stefan Monnier's message of "Mon, 29 Nov 2021 12:49:56 -0500")
On Nov 29 2021, Stefan Monnier wrote:
> Andreas Schwab [2021-11-28 12:07:01] wrote:
>> - memcpy (&to->x, &from->x, sizeof *to - off);
>> + memcpy ((char *) to + off, (char *) from + off, sizeof *to - off);
>
> I wonder: is the (char*) cast sufficient or is it necessary to
> "obfuscate" the code by writing `to + off` instead of `&to->x`?
I think the point is that the address expression is not based on the
subobject.
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
next prev parent reply other threads:[~2021-11-29 17:53 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87fsrg7gdt.fsf.ref@yahoo.com>
2021-11-28 9:56 ` Compiler warnings in dispnew.c Po Lu
2021-11-28 10:48 ` Eli Zaretskii
2021-11-28 10:57 ` Andreas Schwab
2021-11-28 11:02 ` Po Lu
2021-11-28 11:07 ` Andreas Schwab
2021-11-28 15:29 ` Eli Zaretskii
2021-11-29 0:35 ` Po Lu
2021-11-29 17:49 ` Stefan Monnier
2021-11-29 17:53 ` Andreas Schwab [this message]
2021-11-28 11:03 ` Eli Zaretskii
2021-11-28 11:10 ` Andreas Schwab
2021-11-28 11:18 ` Eli Zaretskii
2021-11-28 11:44 ` Andreas Schwab
2021-11-28 11:11 ` Po Lu
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