From: "Gerd Möllmann" <gerd.moellmann@gmail.com>
To: Andrea Corallo <acorallo@gnu.org>
Cc: emacs-devel@gnu.org
Subject: Re: scratch/igc warning
Date: Wed, 26 Jun 2024 16:39:24 +0200 [thread overview]
Message-ID: <m2sewzwyxv.fsf@pro2.fritz.box> (raw)
In-Reply-To: <yp1zfr7n6dm.fsf@fencepost.gnu.org> (Andrea Corallo's message of "Wed, 26 Jun 2024 10:08:53 -0400")
Andrea Corallo <acorallo@gnu.org> writes:
> Hi,
>
> GCC 12.3 is giving me this warning building scratch/igc:
>
> ========
> CC xfaces.o
> In file included from /usr/include/string.h:535,
> from ../lib/string.h:41,
> from lisp.h:29,
> from xfaces.c:226:
> In function ‘memset’,
> inlined from ‘make_realized_face’ at xfaces.c:4581:3,
> inlined from ‘realize_gui_face’ at xfaces.c:6214:10,
> inlined from ‘realize_face’ at xfaces.c:6124:12:
> /usr/include/x86_64-linux-gnu/bits/string_fortified.h:59:10: warning: ‘__builtin_memset’ offset [164, 303] from the object at ‘face’ is out of the bounds of referenced subobject ‘id’ with type ‘int’ at offset 160 [-Warray-bounds]
> 59 | return __builtin___memset_chk (__dest, __ch, __len,
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 60 | __glibc_objsize0 (__dest));
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~
> In file included from termhooks.h:27,
> from frame.h:22,
> from xfaces.c:229:
> dispextern.h: In function ‘realize_face’:
> dispextern.h:1730:7: note: subobject ‘id’ declared here
> 1730 | int id;
> | ^~
> In function ‘memset’,
> inlined from ‘make_realized_face’ at xfaces.c:4581:3,
> inlined from ‘realize_tty_face’ at xfaces.c:6641:10,
> inlined from ‘realize_face’ at xfaces.c:6126:12:
> /usr/include/x86_64-linux-gnu/bits/string_fortified.h:59:10: warning: ‘__builtin_memset’ offset [164, 303] from the object at ‘face’ is out of the bounds of referenced subobject ‘id’ with type ‘int’ at offset 160 [-Warray-bounds]
> 59 | return __builtin___memset_chk (__dest, __ch, __len,
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 60 | __glibc_objsize0 (__dest));
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~
> dispextern.h: In function ‘realize_face’:
> dispextern.h:1730:7: note: subobject ‘id’ declared here
> 1730 | int id;
> | ^~
> In function ‘memset’,
> inlined from ‘make_realized_face’ at xfaces.c:4581:3,
> inlined from ‘realize_face’ at xfaces.c:6130:14:
> /usr/include/x86_64-linux-gnu/bits/string_fortified.h:59:10: warning: ‘__builtin_memset’ offset [164, 303] from the object at ‘face’ is out of the bounds of referenced subobject ‘id’ with type ‘int’ at offset 160 [-Warray-bounds]
> 59 | return __builtin___memset_chk (__dest, __ch, __len,
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 60 | __glibc_objsize0 (__dest));
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~
> dispextern.h: In function ‘realize_face’:
> dispextern.h:1730:7: note: subobject ‘id’ declared here
> 1730 | int id;
> | ^~
> ========
>
> ATM don't know if it's a real issue or a false positive so I thought was
> worth mentioning.
Hm, that's this one, right?
static struct face *
make_realized_face (Lisp_Object *attr)
{
enum { off = offsetof (struct face, id) };
#ifdef HAVE_MPS
struct face *face = igc_make_face ();
#else
struct face *face = xmalloc (sizeof *face);
#endif
memcpy (face->lface, attr, sizeof face->lface);
memset (&face->id, 0, sizeof *face - off);
face->ascii_face = face;
return face;
}
which we can rewrite, for MPS
static struct face *
make_realized_face (Lisp_Object *attr)
{
#ifdef HAVE_MPS
struct face *face = igc_make_face ();
memcpy (face->lface, attr, sizeof face->lface);
#else
enum { off = offsetof (struct face, id) };
struct face *face = xmalloc (sizeof *face);
memcpy (face->lface, attr, sizeof face->lface);
memset (&face->id, 0, sizeof *face - off);
#endif
face->ascii_face = face;
return face;
}
because igc returns something zero-initialized anyway. (I'll do that.).
But I wonder - does GCC 12 also complain for the non-MPS case?
next prev parent reply other threads:[~2024-06-26 14:39 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-26 14:08 scratch/igc warning Andrea Corallo
2024-06-26 14:31 ` Pip Cet
2024-06-26 14:43 ` Andrea Corallo
2024-06-26 15:45 ` Pip Cet
2024-06-26 14:39 ` Gerd Möllmann [this message]
2024-06-26 14:48 ` Andrea Corallo
2024-06-26 14:57 ` Gerd Möllmann
2024-06-26 16:25 ` scratch/igc lread testsuite error [was Re: scratch/igc warning] Andrea Corallo
2024-06-26 16:35 ` Gerd Möllmann
2024-06-27 7:01 ` Helmut Eller
2024-06-27 7:09 ` Gerd Möllmann
2024-06-27 12:09 ` Andrea Corallo
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