Re: [Patch, fortran] PR78737 - [OOP] linking error with deferred, undefined user-defined derived-type I/O

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

Dear Janus,

To make amends for what I can only describe as a brainstorm :-) ,
please find attached a version of your patch that runs all the dtio
testcases successfully.

I have even written a code that made extensive use of dynamic dispatch
of generic typebound procedures... I can't imagine what I have been
thinking.

Cheers

Paul


On 13 December 2016 at 06:33, Paul Richard Thomas
<paul.richard.thomas@gmail.com> wrote:
> Dear Janus,
>
> I woke up in the middle of the night realising that not only are you
> right about the need for dynamic dispatch but that my dtio_20.f90 must
> already work.
>
> Thanks for putting me right!
>
> Paul
>
> On 13 December 2016 at 00:30, Janus Weil <janus@gcc.gnu.org> wrote:
>> Hi Paul, hi all,
>>
>> 2016-12-12 21:04 GMT+01:00 Janus Weil <janus@gcc.gnu.org>:
>>> As commented several times in bugzilla, my feeling is that the
>>> solution for this PR would be to utilize the vtable machinery, in
>>> order to generate a truly polymorphic call to the DTIO procedure.
>>
>> in order to elaborate what I have in mind, I'm attaching a draft patch
>> which implements polymorphic DTIO in the most straightforward manner I
>> could come up with. I have not regtested it yet, but at least it
>> removes the link failure on comment 0 and 6 in the PR and most
>> importantly it generates the correct output for comment 18, which none
>> of the previous attempts have accomplished.
>>
>> I'd be grateful for any comments, in particular whether I'm on the
>> right track here or whether I'm misinterpreting the F03 standard in
>> any way ...
>>
>> (Btw, it seems that Paul's dtio_20.f90 works already on current trunk,
>> so it's not very well suited to test for the problem at hand.)
>>
>> Cheers,
>> Janus
>>
>> PS: A quick check of the dtio_* tests shows ICEs on dtio_7.f90 and
>> dtio_13.f90. I'll look into those tomorrow.
>
>
>
> --
> If you're walking down the right path and you're willing to keep
> walking, eventually you'll make progress.
>
> Barack Obama



-- 
If you're walking down the right path and you're willing to keep
walking, eventually you'll make progress.

Barack Obama

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