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From: "kees at outflux dot net" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug middle-end/101836] __builtin_object_size(P->M, 1) where M is an
 array and the last member of a struct fails
Date: Sat, 11 Jun 2022 08:21:58 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101836

--- Comment #17 from Kees Cook <kees at outflux dot net> ---
(In reply to qinzhao from comment #16)
> additional work are needed in order to make this task complete:
>=20
> 1. add one more new gcc option:
>=20
> -fstrict-flex-arrays
>=20
> when it's on, only treat the following cases as flexing array:
>=20
> trailing array with size 0;
> trailing array with size 1;
> trailing flexible array;
>=20
> all other trailing arrays with size > 1 will be treated as normal arrays.=
=20

Under -fstrict-flex-arrays, arrays of size 0 and 1 should *not* be treated =
as
flex arrays. Only "[]" should be a flexible array. Everything else should be
treated as having the literal size given.=