[Bug fortran/100094] New: Undefined pointers have incorrect rank when using optimization

[Bug fortran/100094] New: Undefined pointers have incorrect rank when using optimization

[jrfsousa at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100094

            Bug ID: 100094
           Summary: Undefined pointers have incorrect rank when using
                    optimization
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jrfsousa at gmail dot com
  Target Milestone: ---

Created attachment 50599
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50599&action=edit
Fortran code showing problem

Hi All!

Rank information is not correctly written into the pointer descriptor when
using optimization or -ffpe-trap.

Seen on:

GNU Fortran (GCC) 11.0.1 20210415 (experimental)
GNU Fortran (GCC) 10.3.1 20210415

Thank you very much.

Best regards,
José Rui

[Bug fortran/100094] Undefined pointers have incorrect rank when using optimization

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100094

kargl at gcc dot gnu.org changed:

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

--- Comment #1 from kargl at gcc dot gnu.org ---
Isn't the code invalid Fortran because it references an undefined pointer?
If yes, the compiler is allows to do whatever it wants with the code.

[Bug fortran/100094] Undefined pointers have incorrect rank when using optimization

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100094

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-04-16
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Confirmed.

[Bug fortran/100094] Undefined pointers have incorrect rank when using optimization

[jrfsousa at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100094

--- Comment #3 from José Rui Faustino de Sousa <jrfsousa at gmail dot com> ---
(In reply to kargl from comment #1)
> Isn't the code invalid Fortran because it references an undefined pointer?
> If yes, the compiler is allows to do whatever it wants with the code.

AFAIK that is correct off all the "associate-like" constructs, the only
exception is select rank.

11.1.10.3 Attributes of a SELECT RANK associate name, paragraph 3:

"The associating entity has the ALLOCATABLE, POINTER, or TARGET attribute if
the selector has that attribute. The other attributes of the associating entity
are described in 11.1.3.3."

Best regards,
José Rui

[Bug fortran/100094] Undefined pointers have incorrect rank when using optimization

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100094

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING
             Blocks|87477                       |

--- Comment #4 from Paul Thomas <pault at gcc dot gnu.org> ---
Hi Jose,

This seems to me to have fixed itself.

I'll put the PR to "waiting" until you confirm (or not!).

I have also stopped it from blocking the associate meta-bug 87477.

Thanks

Paul


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87477
[Bug 87477] [meta-bug] [F03] issues concerning the ASSOCIATE statement