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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/95725] Confusing error diagnostic in an invalid template
Date: Thu, 18 Jun 2020 11:26:15 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95725

--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Haoxin Tu from comment #6)
> Hi, there.
>=20
> I hold the view that the compiler should have good fault tolerance, which
> means giving an input(even invalid), the compiler might emit appropriate
> error message diagnostics so that we can fix them into valid code accordi=
ng
> to the diagnostics.=20

In an ideal world, yes. But this testcase is complete garbage. Nobody is go=
ing
to accidentally write that and be unable to see what's wrong with the code =
when
they get an error.

We could spend time giving perfect diagnostics for unrealistic garbage, or =
do
more useful things.

> I have tested in both GCC and Clang, the results show that GCC has lots of
> unrelated diagnostic messages than Clang.=20

They're not unrelated, they're all directly related to the error in the cod=
e.

> In this report, GCC-trunk seems ok, but GCC-9 emits too many duplicated
> error messages. So I guess there might something not correct in FE.

So it's already fixed then.

> Finally, I am wondering if those cases are useful for the GCC community?

This particular case is not useful.=