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From: "qinzhao at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/108896] provide "element_count" attribute to give more
 context to __builtin_dynamic_object_size() and -fsanitize=bounds
Date: Wed, 08 Mar 2023 17:36:39 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108896

--- Comment #25 from qinzhao at gcc dot gnu.org ---
(In reply to Martin Uecker from comment #17)
> The syntax with the dot would make it not conflict.  But I need
> this for this use case
>=20
> struct foo {
>   int count;
>   int (*buf)[.count];
> };
>=20
> so that ARRAY_SIZE(*foo->buf) works correctly and also accesses
> to foo->buf are bounds checkked.  So it would make sense to=C2=A0
> solve to treat flexible array members in the same way.
Yes, I agree.=20

then the size of the array type (even though it's not a constant) will be
embedded in the TYPE consistently. therefore simplify compiler's implementa=
tion
and make it consistently.=20

>=20
> But I agree that we should simply add the attribute now also
> because it makes it possible to use it for existing code bases.
Yes.=