Re: [Patch, fortran] PR109451 - ICE in gfc_conv_expr_descriptor with ASSOCIATE and substrings

[Harald Anlauf <anlauf@gmx.de>]

Hi Paul,

On 4/14/23 10:18, Paul Richard Thomas via Gcc-patches wrote:
> Hi Harald,
>
> The fix was trivial. An updated patch and testcase are attached.

great, this works, and I couldn't break it again this time ...
Looks good!

Thanks,
Harald

> Thanks
>
> Paul
>
> Fortran: Fix some deferred character problems in associate [PR109451]
>
> 2023-04-14  Paul Thomas  <pault@gcc.gnu.org>
>
> gcc/fortran
> PR fortran/109451
> * trans-array.cc (gfc_conv_expr_descriptor): Guard expression
> character length backend decl before using it. Suppress the
> assignment if lhs equals rhs.
> * trans-io.cc (gfc_trans_transfer): Scalarize transfer of
> associate variables pointing to a variable. Add comment.
> * trans-stmt.cc (trans_associate_var): Remove requirement that
> the character length be deferred before assigning the value
> returned by gfc_conv_expr_descriptor. Also, guard the backend
> decl before testing with VAR_P.
>
> gcc/testsuite/
> PR fortran/109451
> * gfortran.dg/associate_61.f90 : New test
>
>
> On Thu, 13 Apr 2023 at 07:18, Paul Richard Thomas <
> paul.richard.thomas@gmail.com> wrote:
>
>> Hi Harald,
>>
>> That's interesting - the string length '.q' is not set for either of the
>> associate blocks. I'm onto it.
>>
>> Thanks
>>
>> Paul
>>
>>
>> On Wed, 12 Apr 2023 at 20:26, Harald Anlauf <anlauf@gmx.de> wrote:
>>
>>> Hi Paul,
>>>
>>> On 4/12/23 17:25, Paul Richard Thomas via Gcc-patches wrote:
>>>> Hi All,
>>>>
>>>> I think that the changelog says it all. OK for mainline?
>>>
>>> this looks almost fine, but still fails if one directly uses the
>>> dummy argument as the ASSOCIATE target, as in:
>>>
>>> program p
>>>     implicit none
>>>     character(4) :: c(2) = ["abcd","efgh"]
>>>     call dcs0 (c)
>>> ! call dcs0 (["abcd","efgh"])
>>> contains
>>>     subroutine dcs0(a)
>>>       character(len=*), intent(in) :: a(:)
>>>       print *, size(a),len(a)
>>>       associate (q => a(:))
>>>         print *, size(q),len(q)
>>>       end associate
>>>       associate (q => a(:)(:))
>>>         print *, size(q),len(q)
>>>       end associate
>>>       return
>>>     end subroutine dcs0
>>> end
>>>
>>> This prints e.g.
>>>
>>>              2           4
>>>              2           0
>>>              2           0
>>>
>>> (sometimes I also get junk values for the character length).
>>>
>>> Can you please have another look?
>>>
>>> Thanks,
>>> Harald
>>>
>>>
>>>> Paul
>>>>
>>>> Fortran: Fix some deferred character problems in associate [PR109451]
>>>>
>>>> 2023-04-07  Paul Thomas  <pault@gcc.gnu.org>
>>>>
>>>> gcc/fortran
>>>> PR fortran/109451
>>>> * trans-array.cc (gfc_conv_expr_descriptor): Guard expression
>>>> character length backend decl before using it. Suppress the
>>>> assignment if lhs equals rhs.
>>>> * trans-io.cc (gfc_trans_transfer): Scalarize transfer of
>>>> associate variables pointing to a variable. Add comment.
>>>>
>>>>
>>>> gcc/testsuite/
>>>> PR fortran/109451
>>>> * gfortran.dg/associate_61.f90 : New test
>>>
>>>
>>
>> --
>> "If you can't explain it simply, you don't understand it well enough" -
>> Albert Einstein
>>
>
>