[Bug libfortran/90374] Fortran 2018: Support d0.d, e0.d, es0.d, en0.d, g0.d and ew.d e0 edit descriptors for output

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90374

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
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                 CC|                            |kargl at gcc dot gnu.org

--- Comment #16 from kargl at gcc dot gnu.org ---
(In reply to Thomas Henlich from comment #13)
> Just a minor issue: I think that the sense of the message arguments in calls
> to gfc_notify_std() should be inverted - they should describe the feature as
> supported in the correct standard, and not as an error message.
> 
> For example:
> 
> gfc_notify_std (GFC_STD_F2018, "positive width required at %L",
> &format_locus)
> 
> should read
> gfc_notify_std (GFC_STD_F2018, "zero width at %L", &format_locus)
> 
> It just seems counter-intuitive to read a message like:
> gfortran -std=f2008 -o test-f2018.exe test-f2018.f90
> 
>     2 |     write(*, "(e0.10e2)")  0.00314_4
>       |                1
> Error: Fortran 2018: positive width required at (1)
> 
> because the user is trying to access a feature (zero width) of Fortran 2018,
> but that fails. The current message implies that "Fortran 2018 requires a
> positive width" which is exactly the opposite, this is confusing.

% cd gcc/fortran
% grep gfc_notify_std *c | wc -l
     280

Need to audit at least 280 uses of gfc_notify_std.

<hint>
Looks like a good introductory task for a new gfortran contributor.
</hint>