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From: "marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug sanitizer/108085] gcc trunk's ASAN at -O3 missed a
 stack-use-after-scope
Date: Fri, 23 Dec 2022 15:25:17 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108085

--- Comment #3 from Martin Li=C5=A1ka <marxin at gcc dot gnu.org> ---
Created attachment 54153
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D54153&action=3Dedit
pr108085.c.216t.uncprop1.dot.svg

So no, it's a real issue where we optimize out .ASAN_CHECK (6, &f, 4, 8); in
the exit block. As seen in the dump file, we have the very ASAN_CHECK in bb=
_3:
.ASAN_CHECK (7, &f, 4, 8), however, there are 2 ASAN_MARK (POISON, &f, 4) c=
alls
that are on the path from bb_3 to the exit block.

@Jakub: Can you please take a look at the optimization algorithm why the ch=
eck
is not preserved?=