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Re: Use "[warning enabled by default]" for default warnings
- From: Richard Sandiford <rdsandiford at googlemail dot com>
- To: Robert Dewar <dewar at adacore dot com>
- Cc: Richard Biener <richard dot guenther at gmail dot com>, Arnaud Charlet <charlet at adacore dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 11 Feb 2014 12:48:59 +0000
- Subject: Re: Use "[warning enabled by default]" for default warnings
- Authentication-results: sourceware.org; auth=none
- References: <87eh3c3vl1 dot fsf at talisman dot default> <20140209200926 dot GA4940 at adacore dot com> <52F7E0D2 dot 3070307 at adacore dot com> <87zjm02fy5 dot fsf at talisman dot default> <52F7E578 dot 8010805 at adacore dot com> <CAFiYyc1a6sQxvEkQ55gFwLM8qt81wKsGgLZX-VzHs9anH4WLUg at mail dot gmail dot com> <87zjlydltr dot fsf at talisman dot default> <52FA11E2 dot 4050708 at adacore dot com>
Robert Dewar <dewar@adacore.com> writes:
> On 2/11/2014 4:45 AM, Richard Sandiford wrote:
>> OK, this version drops the "[enabled by default]" altogether.
>> Tested as before. OK to install?
>
> Still a huge earthquake in terms of affecting test suites and
> baselines of many users. is it really worth it? In the case of
> GNAT we have only recently started tagging messages in this
> way, so changes would not be so disruptive, and we can debate
> following whatever gcc does, but I think it is important to
> understand that any change in this area is a big one in terms
> of impact on users.
The patch deliberately didn't affect Ada's diagnostic routines given
your comments from the first round. Calling this a "huge earthquake"
for other languages seems like a gross overstatement.
I don't think gcc, g++, gfortran, etc, have ever made a commitment
to producing textually identical warnings and errors for given inputs
across different releases. It seems ridiculous to require that,
especially if it stands in the way of improving the diagnostics
or introducing finer-grained -W control.
E.g. Florian's complaint was that we shouldn't have warnings that
are not under the control of any -W options. But by your logic
we couldn't change that either, because all those "[enabled by default]"s
would become "[-Wnew-option]"s.
Thanks,
Richard