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From: "avi at scylladb dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/105373] miscompile involving lambda coroutines and an
 object bitwise copied instead of via the copy constructor
Date: Tue, 26 Apr 2022 10:07:08 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105373

--- Comment #7 from Avi Kivity <avi at scylladb dot com> ---
To give more context:

    struct ._anon_973 D.2159793 [value-expr: frame_ptr->D.2159793_4_7];
    struct lw_shared_ptr D.2159792 [value-expr: frame_ptr->D.2159792_4_7];

(I determined that _anon_973 is the non-coroutine-lambda that is giving me
grief)

                            frame_ptr->D.2159793_4_7.__this =3D _51;
                            frame_ptr->D.2159793_4_7.__old4 =3D
frame_ptr->D.2159792_4_7;
                            _52 =3D frame_ptr->__closure;
                            _53 =3D _52->__newtabs;
                            frame_ptr->D.2159793_4_7.__newtabs =3D _53;


Here I suspect copying __old4 is bypassing the copy constructor. The source=
 of
the copy (D.2159792) has lw_shared_ptr type.

I'm not fluent in gimple so maybe I'm misinterpreting it.=