Re: [Patch, Fortran] PR fortran/83522 – reject array-valued substrings

[Paul Richard Thomas <paul dot richard dot thomas at gmail dot com>]

The section from the standard in comment #2 is being misinterpreted.
R609 and R610 concern substrings in the context of section 6.4, which
concerns SCALARS!

Section 6.5 concerns arrays and you will find there:

R618 array-section is data-ref [ ( substring-range ) ] or
complex-part-designator

C624 (R618) Exactly one part-ref shall have nonzero rank, and either
the final part-ref shall have a section-
subscript-list with nonzero rank, another part-ref shall have nonzero
rank, or the complex-part-designator
shall be an array.

Further lines appear later in which in which substrings of array
sections are explicitly mentioned: eg.
If a substring-range appears in an array-section, each element is the
designated substring of the corresponding element of the array
section. The value of a subscript in an array element shall be within
the bounds for its dimension.

Thus the patch is contrary to the standard and must be removed as soon
as possible.

Paul


On Thu, 11 Oct 2018 at 15:20, David Edelsohn <dje.gcc@gmail.com> wrote:
>
> Another data point: I tried some of the testcases with IBM XL Fortran
> compiler and it didn't complain or fail.  I have no idea if this
> behavior is an IBM extension or how other Fortran compilers behave.
>
> GNU Fortran probably should be compatible with other Fortran
> compilers, even if the behavior is not pedantically conformant with
> the standard.
>
> Thanks, David
>
> On Wed, Oct 10, 2018 at 7:12 PM Paul Richard Thomas
> <paul.richard.thomas@gmail.com> wrote:
> >
> > This seems to have caused errors in the testsuite. I guess that the
> > problem is that the testcases are invalid :-(
> >
> > From David Edelsohn:
> > Error: Substring reference of nonscalar not permitted at (1)
> >
> > arrayio_11.f90
> > arrayio_12.f90
> > associate_23.f90
> > data_char_1.f90
> > deferred_character_2.f90
> > deferred_character_22.f90
> > deferred_character_23.f90
> > deferred_character_8.f90
> > deferred_type_component_3.f90
> >
> > Cheers
> >
> > Paul
> >
> > On Mon, 8 Oct 2018 at 23:16, Thomas Koenig <tkoenig@netcologne.de> wrote:
> > >
> > > Hi Tobias,
> > >
> > > nice to hear from you again!
> > >
> > > > Build and regtested on x86_64-linux.
> > > > OK for the trunk?
> > >
> > > OK. Thanks for the patch!
> > >
> > > Regards
> > >
> > >         Thomas
> >
> >
> >
> > --
> > "If you can't explain it simply, you don't understand it well enough"
> > - Albert Einstein



-- 
"If you can't explain it simply, you don't understand it well enough"
- Albert Einstein