[Bug fortran/60255] New: Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[Bug fortran/60255] New: Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[antony at cosmologist dot info]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

            Bug ID: 60255
           Summary: Deferred character length variable at (1) cannot yet
                    be associated with unlimited polymorphic entities
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: antony at cosmologist dot info

Created attachment 32157
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32157&action=edit
OOP module with derived TStringList implementing list of strings

Attached file gives multiple repeated errors

ObjectLists2.f90:818.26:

    end module ObjectLists
                          1
Error: TODO: Deferred character length variable at (1) cannot yet be associated
with unlimited polymorphic entities


It should surely give a line number of the error rather than end of module
(currently very hard to workaround as origin of error is unclear). Better,
actually compile (tested valid in ifort 14).

[Bug fortran/60255] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[kargl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
                 CC|                            |kargl at gcc dot gnu.org
           Severity|major                       |normal

--- Comment #1 from kargl at gcc dot gnu.org ---
Unless a Fortran bug breaks bootstrap, it has an importance of at most normal.

[Bug fortran/60255] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

janus at gcc dot gnu.org changed:

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

--- Comment #2 from janus at gcc dot gnu.org ---
The error message comes from find_intrinsic_vtab, to which we'd have to pass a
locus in order to show a proper line number. Currently we use
gfc_current_locus, which is no good since the error happens during resolution.

Also I think the 'TODO' is not suitable here: It is meant for the developer and
not the user, and as such belongs in the source code and not into an error
message.

What does it actually take to make this feature work? Simply removing the error
and using internally charlen=0 to identify deferred length makes the test
module compile:


Index: class.c
===================================================================
--- class.c    (revision 207836)
+++ class.c    (working copy)
@@ -2404,18 +2404,9 @@ find_intrinsic_vtab (gfc_typespec *ts)
   gfc_symbol *copy = NULL, *src = NULL, *dst = NULL;
   int charlen = 0;

-  if (ts->type == BT_CHARACTER)
-    {
-      if (ts->deferred)
-    {
-      gfc_error ("TODO: Deferred character length variable at %C cannot "
-             "yet be associated with unlimited polymorphic entities");
-      return NULL;
-    }
-      else if (ts->u.cl && ts->u.cl->length
-           && ts->u.cl->length->expr_type == EXPR_CONSTANT)
-    charlen = mpz_get_si (ts->u.cl->length->value.integer);
-    }
+  if (ts->type == BT_CHARACTER && !ts->deferred && ts->u.cl &&
ts->u.cl->length
+      && ts->u.cl->length->expr_type == EXPR_CONSTANT)
+    charlen = mpz_get_si (ts->u.cl->length->value.integer);

   /* Find the top-level namespace.  */
   for (ns = gfc_current_ns; ns; ns = ns->parent)



Apparently we do not handle any non-constant string lengths currently. I guess
all of those should either be rejected (like deferred lengths) or we should
just make them work.

[Bug fortran/60255] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

--- Comment #3 from janus at gcc dot gnu.org ---
Consider the following simple test case:


implicit none
call sub1("test")
call sub2()

contains

  subroutine sub1(dcl)   ! accepted
    character(len=*), target :: dcl
    class(*), pointer :: ucp

    ucp => dcl

    select type (ucp)
    type is (character(len=*))
      print *,"char"
    type is (real)
      print *,"real"
    class default
      print *,"something else"
    end select

  end subroutine


  subroutine sub2   ! rejected
    character(len=:), allocatable, target :: dcl
    class(*), pointer :: ucp

    dcl = "ttt"
    ucp => dcl

    select type (ucp)
    type is (character(len=*))
      print *,"char"
    type is (real)
      print *,"real"
    class default
      print *,"something else"
    end select

  end subroutine

end


While 'sub1' is currently accepted (with unpatched trunk) and shows the right
runtime behavior, 'sub2' is rejected with the error of comment 0.

With the patch in comment 2, both cases are accepted and show the right runtime
behavior.

The only potential problem I can see is that the '_size' component of the vtab
is zero and does not reflect its actual size.

[Bug fortran/60255] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[dominiq at lps dot ens.fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-02-19
     Ever confirmed|0                           |1

[Bug fortran/60255] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

--- Comment #4 from janus at gcc dot gnu.org ---
Antony, is it possible for you to try the patch in comment 2, in order to check
if it produces the expected runtime behavior for your code?

[Bug fortran/60255] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[antony at cosmologist dot info]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

--- Comment #5 from Antony Lewis <antony at cosmologist dot info> ---
The patch generated a SIGSEGV in test code (which works with ifort), but could
be another unrelated issue.


Here's another simple test case for the original issue:


program test
    character(LEN=:), allocatable :: S
    call subP(S)
contains

subroutine subP(P)
    class(*) :: P
end subroutine

end program

[Bug fortran/60255] [OOP] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[pault at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

--- Comment #7 from Paul Thomas <pault at gcc dot gnu.org> ---
Author: pault
Date: Sun Jan 18 22:01:29 2015
New Revision: 219827

URL: https://gcc.gnu.org/viewcvs?rev=219827&root=gcc&view=rev
Log:
2015-01-18  Andre Vehreschild  <vehre@gmx.de>
        Janus Weil <janus@gcc.gnu.org>

    PR fortran/60255
    * class.c (gfc_get_len_component): New.
    (gfc_build_class_symbol): Add _len component to unlimited
    polymorphic entities.
    (find_intrinsic_vtab): Removed emitting of error message.
    * gfortran.h: Added prototype for gfc_get_len_component.
    * simplify.c (gfc_simplify_len): Use _len component where
    available.
    * trans-expr.c (gfc_class_len_get): New.
    (gfc_conv_intrinsic_to_class): Add handling for deferred
    character arrays.
    (gfc_conv_structure): Treat _len component correctly.
    (gfc_conv_expr): Prevent bind_c handling when not required.
    (gfc_trans_pointer_assignment): Propagate _len component.
    * trans-stmt.c (class_has_len_component): New.
    (trans_associate_var): _len component treatment for associate
    context.
    (gfc_trans_allocate): Same as for trans_associate_var()
    * trans.h: Added prototype for gfc_class_len_get.

2015-01-18  Andre Vehreschild  <vehre@gmx.de>

    PR fortran/60255
    * gfortran.dg/unlimited_polymorphic_2.f03: Removed error.
    * gfortran.dg/unlimited_polymorphic_20.f03: New test.

2015-01-18  Paul Thomas  <pault@gcc.gnu.org>

    PR fortran/64578
    * gfortran.dg/unlimited_polymorphic_21.f90: New test

Added:
    trunk/gcc/testsuite/gfortran.dg/unlimited_polymorphic_20.f90
    trunk/gcc/testsuite/gfortran.dg/unlimited_polymorphic_21.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/class.c
    trunk/gcc/fortran/gfortran.h
    trunk/gcc/fortran/simplify.c
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/fortran/trans-stmt.c
    trunk/gcc/fortran/trans.h
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/unlimited_polymorphic_2.f03

[Bug fortran/60255] [OOP] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[vehre at gmx dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

Andre Vehreschild <vehre at gmx dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
            Version|4.9.0                       |5.0
         Resolution|---                         |FIXED

--- Comment #8 from Andre Vehreschild <vehre at gmx dot de> ---
Fixed with r219827.

[Bug fortran/60255] [OOP] Deferred character length variable at (1) cannot yet be associated with unlimited polymorphic entities

[vehre at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60255

--- Comment #9 from vehre at gcc dot gnu.org ---
Author: vehre
Date: Mon Mar 23 11:58:49 2015
New Revision: 221591

URL: https://gcc.gnu.org/viewcvs?rev=221591&root=gcc&view=rev
Log:
gcc/fortran/ChangeLog

2015-03-23  Andre Vehreschild  <vehre@gmx.de>
        Janus Weil  <janus@gcc.gnu.org>

    Backported from mainline
    PR fortran/60255
    Initial patch version: Janus Weil
    * class.c (gfc_get_len_component): New.
    (gfc_build_class_symbol): Add _len component to unlimited
    polymorphic entities.
    (find_intrinsic_vtab): Removed emitting of error message.
    * gfortran.h: Added prototype for gfc_get_len_component.
    * simplify.c (gfc_simplify_len): Use _len component where
    available.
    * trans-expr.c (gfc_class_len_get): New.
    (gfc_conv_intrinsic_to_class): Add handling for deferred
    character arrays.
    (gfc_conv_structure): Treat _len component correctly.
    (gfc_conv_expr): Prevent bind_c handling when not required.
    (gfc_trans_pointer_assignment): Propagate _len component.
    * trans-stmt.c (class_has_len_component): New.
    (trans_associate_var): _len component treatement for associate
    context.
    (gfc_trans_allocate): Same as for trans_associate_var()
    * trans.h: Add prototype for gfc_class_len_get.

gcc/testsuite/ChangeLog

2015-03-20  Andre Vehreschild  <vehre@gmx.de>

    Backport from mainline
    PR fortran/60255
    * gfortran.dg/unlimited_polymorphic_2.f03: Removed error.
    Converted from dos to unix line endings.
    * gfortran.dg/unlimited_polymorphic_20.f03: New test.


Added:
   
branches/gcc-4_9-branch/gcc/testsuite/gfortran.dg/unlimited_polymorphic_20.f03
Modified:
    branches/gcc-4_9-branch/gcc/fortran/ChangeLog
    branches/gcc-4_9-branch/gcc/fortran/class.c
    branches/gcc-4_9-branch/gcc/fortran/gfortran.h
    branches/gcc-4_9-branch/gcc/fortran/simplify.c
    branches/gcc-4_9-branch/gcc/fortran/trans-expr.c
    branches/gcc-4_9-branch/gcc/fortran/trans-stmt.c
    branches/gcc-4_9-branch/gcc/fortran/trans.h
    branches/gcc-4_9-branch/gcc/testsuite/ChangeLog
   
branches/gcc-4_9-branch/gcc/testsuite/gfortran.dg/unlimited_polymorphic_2.f03