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From: "gniibe at fsij dot org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/102151] Spurious warning by -Warray-bounds
 when allocating with flexible array member
Date: Thu, 02 Sep 2021 02:34:38 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102151

--- Comment #4 from Niibe Yutaka <gniibe at fsij dot org> ---
Thank you for the explanation.  I understand how (current version of) GCC
warns.

>>From the viewpoint of use of structure with flexible array member, still, t=
his
could be considered as a bug of GCC, because the warning itself is irreleva=
nt.

My point is that:

(1) In the test case, use of offsetof(struct arg_and_data_s, arg) is valid =
(I
mean, no violation of language/feature).  In other words,

(2) Allocated space for an object of the structure may be smaller than
sizeof().  There are such cases, for structure with flexible array member,
because of structure alignment.

(3) It seems for me that by (current version of) GCC, the fact (2) is ignor=
ed.=