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From: "matheus.a.m.moreira at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/112840] feature request: warn on incorrect tagged union value
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Date: Tue, 30 Jan 2024 00:40:43 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D112840

--- Comment #3 from Matheus Afonso Martins Moreira <matheus.a.m.moreira at =
gmail dot com> ---
(In reply to uecker from comment #2)
> I would go for a more generic feature where one can specify some invarian=
t /
> condition that needs be true when a member of a struct / union is accesse=
d.

So the proposed solution is a guard(expr) attribute that causes the compile=
r to
warn the developer if it can't statically determine that expr is true in the
appropriate context.

This would be great!! Much more flexible than the tag attribute I proposed.=
 How
can we make it happen? I've never hacked on GCC before.=