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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug middle-end/104069] -Werror=use-after-free false positive on
 elfutils-0.186
Date: Tue, 18 Jan 2022 22:56:13 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104069

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
It is not, because it emits a false positive on a fairly common code.
Anyway, if bb3 jumps to bb4, then bb3 should have in the ranger assertion t=
hat
in bb3 ret_17 is 0 (it is on the true branch of the ret_17 =3D=3D 0 && some=
thing
test),
so for the PHI, while it is or, it is either 2->4 is the executable edge and
then ret_7 =3D=3D 0 implies ret_17 =3D=3D 0, or 3->4 is the executable edge=
 and then
ret_17 =3D=3D 0 too because that was what was the assertion in bb 3.  But a=
rguably
it isn't a very common case for PHIs.  So, either the ranger can have speci=
al
case for something like that, or the warning code can.=