[Bug fortran/114475] New: [14.0 Regression] Regression with iso_c_binding and submodules

[Bug fortran/114475] New: [14.0 Regression] Regression with iso_c_binding and submodules

[juergen.reuter at desy dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

            Bug ID: 114475
           Summary: [14.0 Regression] Regression with iso_c_binding and
                    submodules
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: juergen.reuter at desy dot de
  Target Milestone: ---

Between ca. March 18 and March 25, a regression has been introduced into the
gfortran 14.0.1 code, which makes the following valid code fail to compile, cf.
below:
gfortran  -c t1.f90
t1.f90:28:13:

   28 | submodule (t1) t1_s
      |             1
Error: Variable ‘n_external’ cannot appear in the expression at (1)

It would be cool if that could be fixed before the release of gcc 14.1 which I
believe is very soon. 



module t1
  use, intrinsic :: iso_c_binding !NODEP!                                       
  implicit none
  private
  public :: t1_t
  integer :: N_EXTERNAL = 0

  type :: t1_t
  contains
    procedure :: set_n_external => t1_set_n_external
  end type t1_t

  abstract interface
     subroutine ol_eval (id, pp, emitter) bind(C)
       import
       real(kind = c_double), intent(in) :: pp(5 * N_EXTERNAL)
     end subroutine ol_eval
  end interface
  interface
    module subroutine t1_set_n_external (object, n)
      class(t1_t), intent(inout) :: object
      integer, intent(in) :: n
    end subroutine t1_set_n_external
  end interface

end module t1

submodule (t1) t1_s
  implicit none
contains
  module subroutine t1_set_n_external (object, n)
    class(t1_t), intent(inout) :: object
    integer, intent(in) :: n
    N_EXTERNAL = n
  end subroutine t1_set_n_external

end submodule t1_s

[Bug fortran/114475] [14.0 Regression] Regression with iso_c_binding and submodules

[juergen.reuter at desy dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

--- Comment #1 from Jürgen Reuter <juergen.reuter at desy dot de> ---
I suspect this commit here,
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=44c0398e65347def316700911a51ca8b4ec0a411
but not totally certain.

[Bug fortran/114475] [14 Regression] Regression with iso_c_binding and submodules

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
            Summary|[14.0 Regression]           |[14 Regression] Regression
                   |Regression with             |with iso_c_binding and
                   |iso_c_binding and           |submodules
                   |submodules                  |
   Target Milestone|---                         |14.0

[Bug fortran/114475] [14 Regression] Regression with iso_c_binding and submodules

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|anlauf at gmx dot de               |anlauf at gcc dot gnu.org
   Last reconfirmed|                            |2024-03-26

[Bug fortran/114475] [14 Regression] Regression with iso_c_binding and submodules

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

--- Comment #2 from anlauf at gcc dot gnu.org ---
(In reply to Jürgen Reuter from comment #1)
> I suspect this commit here,
> https://gcc.gnu.org/git/?p=gcc.git;a=commit;
> h=44c0398e65347def316700911a51ca8b4ec0a411
> but not totally certain.

The following patch fixes the apparent regression:

diff --git a/gcc/fortran/expr.cc b/gcc/fortran/expr.cc
index 9a042cd7040..68d16a9a378 100644
--- a/gcc/fortran/expr.cc
+++ b/gcc/fortran/expr.cc
@@ -3517,6 +3563,7 @@ check_restricted (gfc_expr *e)
       if (e->error
            || sym->attr.in_common
            || sym->attr.use_assoc
+           || sym->attr.used_in_submodule
            || sym->attr.dummy
            || sym->attr.implied_index
            || sym->attr.flavor == FL_PARAMETER


Looks like the commit actually uncovered a latent issue.

Mikael, do you want to follow up?

[Bug fortran/114475] [14 Regression] Regression with iso_c_binding and submodules

[mikael at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

Mikael Morin <mikael at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |mikael at gcc dot gnu.org

--- Comment #3 from Mikael Morin <mikael at gcc dot gnu.org> ---
(In reply to anlauf from comment #2)
> (In reply to Jürgen Reuter from comment #1)
> > I suspect this commit here,
> > https://gcc.gnu.org/git/?p=gcc.git;a=commit;
> > h=44c0398e65347def316700911a51ca8b4ec0a411
> > but not totally certain.
> 
> The following patch fixes the apparent regression:
> 
> diff --git a/gcc/fortran/expr.cc b/gcc/fortran/expr.cc
> index 9a042cd7040..68d16a9a378 100644
> --- a/gcc/fortran/expr.cc
> +++ b/gcc/fortran/expr.cc
> @@ -3517,6 +3563,7 @@ check_restricted (gfc_expr *e)
>        if (e->error
>  	    || sym->attr.in_common
>  	    || sym->attr.use_assoc
> +	    || sym->attr.used_in_submodule
>  	    || sym->attr.dummy
>  	    || sym->attr.implied_index
>  	    || sym->attr.flavor == FL_PARAMETER
> 
Yes, I was coming to the same fix.
I'm not too sure about it though.

> 
> Looks like the commit actually uncovered a latent issue.
> 
> Mikael, do you want to follow up?

Yes, this is mine in any case.

[Bug fortran/114475] [14 Regression] Regression with iso_c_binding and submodules

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Mikael Morin <mikael@gcc.gnu.org>:

https://gcc.gnu.org/g:7f233feafd657250340be3b3500d2697948ae3ed

commit r14-9703-g7f233feafd657250340be3b3500d2697948ae3ed
Author: Mikael Morin <mikael@gcc.gnu.org>
Date:   Wed Mar 27 16:30:42 2024 +0100

    fortran: Fix specification expression check in submodules [PR114475]

    The patch fixing PR111781 made the check of specification expressions more
    restrictive, disallowing local variables in specification expressions of
    dummy arguments.  PR114475 showed an example where that change regressed,
    disallowing in submodules expressions that had been allowed in the parent
    module.  In submodules indeed, the hierarchy of namespaces inherited from
    the parent module is not reproduced so the host-association of symbols
    can't be recognized by checking the nesting of namespaces.

    This change fixes the problem by allowing in specification expressions
    all the symbols in a submodule that are inherited from the parent module.

            PR fortran/111781
            PR fortran/114475

    gcc/fortran/ChangeLog:

            * expr.cc (check_restricted): In submodules, allow variables host-
            associated from the parent module.

    gcc/testsuite/ChangeLog:

            * gfortran.dg/spec_expr_10.f90: New test.

    Co-authored-by: Harald Anlauf <anlauf@gmx.de>

[Bug fortran/114475] [14 Regression] Regression with iso_c_binding and submodules

[mikael at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114475

Mikael Morin <mikael at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #5 from Mikael Morin <mikael at gcc dot gnu.org> ---
Fixed.