Re: [Patch, fortran] PR86328 - [8/9 Regression] Runtime segfault reading an allocatable class(*) object in allocate statements

[Paul Richard Thomas <paul.richard.thomas@gmail.com>]

Hi Janus,

Thanks for the review. I decided to commit just the parts that address
the regression to both branches. Assignment to polymorphic variables
is in such a mess that I did not consider it sensible to apply part of
a fragment of Band Aid. I will raise a PR for the bugs that I know of.

Committed to 8-branch as r264027 and trunk as r264008

Cheers

Paul


On 29 August 2018 at 20:18, Janus Weil <janus@gcc.gnu.org> wrote:
> Hi Paul,
>
>> The attached patch fixes PR86328 and PR86760. The regression was
>> caused by my commit r252949.
>>
>> The parts of the patch that fix the PRs are in trans.c and
>> trans-array.c. The problem was caused by fixing the expressions that
>> would provide the 'span' in gfc_build_array_ref, since the latter
>> expected a variable expression. A number of evaluations of component
>> array elements were producing pre blocks that were not added and so
>> the temporaries were not being evaluated.
>>
>> The fix is to pass the COMPONENT_REF and extract the 'span' directly from it.
>>
>> The rest of the patch arises from PR86328 comment #12. In fact, this
>> took most of the time that I have spent on these PRs :-(  Having done
>> this, I felt that I had to include this part of the patch in the
>> submission. However, I have found a host of related bugs, which I will
>> put together in one PR.
>>
>> My inclination is to commit the patch without the parts in resolve.c,
>> trans-expr.c and pr86328_12.f90, especially for 8-branch. I am open to
>> suggestions for 9-branch.
>>
>> Bootstraps and regtests on FC28/x68_64 - OK for 8- and 9-branches?
>
> the patch is ok for trunk from my side. I also agree that it makes
> sense to backport those parts that address the regression to 8-branch.
> Thanks for the fix!
>
> Cheers,
> Janus



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