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From: "avi at scylladb dot com" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/63164] unnecessary calls to __dynamic_cast
Date: Thu, 28 Apr 2022 14:57:29 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D63164

--- Comment #3 from Avi Kivity <avi at scylladb dot com> ---
I have something like this:

=E2=94=82     2680  future<> system_keyspace_make(distributed<replica::data=
base>&
dist_db, distributed<service::storage_service>& dist_ss,
sharded<gms::gossiper>& dist_gossiper, db::config& cfg) {               =E2=
=94=82
=E2=94=82     2681      register_virtual_tables(dist_db, dist_ss, dist_goss=
iper, cfg);=20=20
...
=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=
=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=
=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=20=
=20=20=20=20
                                        =E2=94=82
=E2=94=82     2687      for (auto&& table : system_keyspace::all_tables(db_=
config)) {=20=20=20

...

=E2=94=82     2695              co_await db.create_keyspace(ksm,
dist_ss.local().get_erm_factory(), true,
replica::database::system_keyspace::yes);=20=20=20


And I see a crash as if the std::vector returned by all_tables() is not
persisted. This worked in previous gcc versions and works in clang.

I don't now what the standard says, but it really should persist temporarie=
s in
range for that contains a suspension point, or a lot of buggy code will be
written.=