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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/104213] [12 Regression] bogus use-after-free in virtual
 dtor with -ffat-lto-objects on ARM
Date: Mon, 24 Jan 2022 21:22:00 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D104213

--- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Try:

       val =3D build2 (MODIFY_EXPR, TREE_TYPE (val),
                     DECL_RESULT (delete_dtor), val);
       tree stmt =3D build_stmt (0, RETURN_EXPR, val);
       suppress_warning (stmt, OPT_Wuse_after_free);
       add_stmt (stmt);


That is do it for the RETURN_EXPR instead of the MODIFY_EXPR. It might be
saved. Otherwise the gimplification of RETURN_EXPR to GIMPLE_RETURN needs to
save it around.=