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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug c++/99677] [[gnu::const]] attribute does not prevent dead
 global variable gets emitted.
Date: Mon, 22 Mar 2021 09:10:38 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99677

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

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

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
As the functions aren't constexpr, they aren't even considered during C++ FE
constexpr processing.  gnu::const means something completely different.
I bet we optimize away static const variables only written (even with
non-constant initializers) and never address taken or otherwise used, this =
PR
seems to ask to handle inline const (with the C++ FE specific behavior for
them) in such cases too.
I'm not sure it is valid if the vars are odr-used somewhere and the odr-uses
are later optimized away, I think emitting the inline vars in that case is =
part
of the ABI.  And the not odr-used cases which are only used by their
initialization is yet another question.=