[Bug fortran/100906] New: Bind(c): failure handling character with len/=1

[Bug fortran/100906] New: Bind(c): failure handling character with len/=1

[jrfsousa at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100906

            Bug ID: 100906
           Summary: Bind(c): failure handling character with len/=1
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jrfsousa at gcc dot gnu.org
  Target Milestone: ---

Created attachment 50929
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50929&action=edit
Fortran code showing problem

Hi All!

Failures (mostly mixing kind with len) on handling character with length
greater than 1.

Seen on:

GNU Fortran (GCC) 10.3.1 20210526 (ICE)
GNU Fortran (GCC) 11.1.1 20210526
GNU Fortran (GCC) 12.0.0 20210529 (experimental)

Thank you very much.

Best regards,
José Rui

[Bug fortran/100906] Bind(c): failure handling character with len/=1

[jrfsousa at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100906

--- Comment #1 from José Rui Faustino de Sousa <jrfsousa at gcc dot gnu.org> ---
Created attachment 50930
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50930&action=edit
C code for bind(c)

[Bug fortran/100906] Bind(c): failure handling character with len/=1

[jrfsousa at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100906

--- Comment #2 from José Rui Faustino de Sousa <jrfsousa at gcc dot gnu.org> ---
Patch posted:

https://gcc.gnu.org/pipermail/fortran/2021-June/056154.html

[Bug fortran/100906] Bind(c): failure handling character with len/=1

[jrfsousa at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100906

--- Comment #3 from José Rui Faustino de Sousa <jrfsousa at gcc dot gnu.org> ---
Created attachment 51001
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51001&action=edit
Patch and changelog

[Bug fortran/100906] Bind(c): failure handling character with len/=1

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100906

Tobias Burnus <burnus at gcc dot gnu.org> changed:

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

--- Comment #4 from Tobias Burnus <burnus at gcc dot gnu.org> ---
I have committed:
  r12-2431-gb3d4011ba10275fbd5d6ec5a16d5aaebbdfb5d3c
  https://gcc.gnu.org/pipermail/gcc-patches/2021-July/575729.html
which should fix most diagnostic issues with character len /= 1 – except for:

* len=0 – in my understanding, that's valid when using a descriptor but not
  when passing the argument as address to the byte stream
  -> with current patch not rejected.

* const-length > 1 module variables with BIND(C). Those should now be valid
  as well, but that was not touched by this patch.

Regarding len=0 and other things, see also thread starting at
https://mailman.j3-fortran.org/pipermail/j3/2021-July/013189.html

  * * *

Other TODO with regards to things diagnostic in my patch:
* See 'sorry' in the patch and in the testsuite. Namely:
  len=* and len=: require an array descriptor, but for
  scalars and (len=*, only) for assumed/explicit-size
  arrays no descriptor is used. (Hence, the code aborts
  with an error)
  -> Requires an update both for the call and for the
  function type and for the function interface declaration.

 * * *

Attached/submitted patch by José:  There is a minor overlap to my committed
patch and some overlap to the issues listed above, but I have not sorted it
out, yet.

[Bug fortran/100906] Bind(c): failure handling character with len/=1

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100906

--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Cross ref:
See also PR 92482 "BIND(C) with array-descriptor mishandled for type character"

[Bug fortran/100906] Bind(c): failure handling character with len/=1

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100906

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Sandra Loosemore <sandra@gcc.gnu.org>:

https://gcc.gnu.org/g:b7cb6d66bd52e884ff33c61e46a9ee9facc2ac60

commit r12-4628-gb7cb6d66bd52e884ff33c61e46a9ee9facc2ac60
Author: Sandra Loosemore <sandra@codesourcery.com>
Date:   Thu Oct 21 19:17:50 2021 -0700

    Add testcase for PR fortran/100906

    2021-10-21  José Rui Faustino de Sousa  <jrfsousa@gmail.com>
                Sandra Loosemore  <sandra@codesourcery.com>

            gcc/testsuite/

            PR fortran/100906
            * gfortran.dg/PR100906.f90: New.
            * gfortran.dg/PR100906.c: New.

[Bug fortran/100906] Bind(c): failure handling character with len/=1

[sandra at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100906

sandra at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |sandra at gcc dot gnu.org
         Resolution|---                         |FIXED

--- Comment #7 from sandra at gcc dot gnu.org ---
This was fixed as part of Tobias's big GFC <-> CFI descriptor re-work, and I've
separately committed the testcase for this issue.  I think we can close this
issue now.