From: Po Lu <luangruo@yahoo.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: emacs-devel@gnu.org
Subject: Re: Compiler warnings in dispnew.c
Date: Sun, 28 Nov 2021 19:02:36 +0800 [thread overview]
Message-ID: <87bl247dbn.fsf@yahoo.com> (raw)
In-Reply-To: <83tufwwo7z.fsf@gnu.org> (Eli Zaretskii's message of "Sun, 28 Nov 2021 12:48:00 +0200")
Eli Zaretskii <eliz@gnu.org> writes:
>> From: Po Lu <luangruo@yahoo.com>
>> Date: Sun, 28 Nov 2021 17:56:30 +0800
>>
>> Building with checking, I get:
>>
>> CC dispnew.o
>> In function ‘copy_row_except_pointers’,
>> inlined from ‘assign_row’ at dispnew.c:1050:3,
>> inlined from ‘mirror_make_current’ at dispnew.c:2761:3:
>> dispnew.c:1037:3: warning: ‘memcpy’ offset [48, 255] from the object at ‘current_row’ is out of the bounds of referenced subobject ‘x’ with type ‘int’ at offset 44 [-Warray-bounds]
>> 1037 | memcpy (&to->x, &from->x, sizeof *to - off);
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> In file included from termchar.h:23,
>> from dispnew.c:28:
>> dispnew.c: In function ‘mirror_make_current’:
>> dispextern.h:885:7: note: subobject ‘x’ declared here
>> 885 | int x, y;
>> | ^
>>
>> I think it would be prudent to fix this, thanks.
> Do you understand the problem? It looks like a compiler bug to me.
> We copy into the address of glyph_row->x and the size of the copy is
> the size of glyph_row structure minus the offset of x from the
> beginning. So what is wrong with that? what am I missing?
I don't see anything wrong with it, but I think someone has to find a
way to silence the warning.
I could not find some reasonable way to do so that did not involve
#pragma GCC, which I think is not allowed in Emacs code (is that
correct?)
Thanks.
> When you say "building with checking", what do you mean, exactly? Did
> you use some non-default warning switches, and if so, which ones?
I meant to say with '--enable-checking="yes,glyphs"'.
> And what version of GCC is that?
It's GCC 11.2.1.
Thanks.
next prev parent reply other threads:[~2021-11-28 11:02 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 [this message]
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
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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