[Bug fortran/55825] New: [OOP] Bogus rank error with CLASS pointer assignment using structure constructors

[Bug fortran/55825] New: [OOP] Bogus rank error with CLASS pointer assignment using structure constructors

[burnus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55825

             Bug #: 55825
           Summary: [OOP] Bogus rank error with CLASS pointer assignment
                    using structure constructors
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: burnus@gcc.gnu.org
                CC: janus@gcc.gnu.org, pault@gcc.gnu.org


Created attachment 29058
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29058
Failing test case

Another test case by Reinhold Bader.

  type :: t_ptr
     class(interior), pointer :: r(:) => null()
  end type t_ptr
...
  type(interior), target :: r(3)
  type(t_ptr) :: o1
...
  o1 = t_ptr(r)

Gives:

  o1 = t_ptr(r)      ! fine, r has TARGET attribute and can't go away
             1
Error: The rank of the element in the structure constructor at (1) does not
match that of the component (1/0)

[Bug fortran/55825] [OOP] Bogus rank error with CLASS pointer assignment using structure constructors

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55825

--- Comment #1 from janus at gcc dot gnu.org 2012-12-28 17:36:39 UTC ---
Reduced test case:


program construct_poly

  implicit none

  type :: interior
     real :: x
  end type interior

  type :: t_ptr
     class(interior), pointer :: r(:) => null()
  end type t_ptr

  type(t_ptr) :: o1
  type(interior), target :: r(3)

  o1 = t_ptr(r)

end program 


This gives me:

test.f90:16.13:

  o1 = t_ptr(r)
             1
Error: The rank of the element in the structure constructor at (1) does not
match that of the component (1/0)
test.f90:16.13:

  o1 = t_ptr(r)
             1
Error: Can't convert TYPE(interior) to CLASS(interior) at (1)


For the original test case, I get some more of these errors (on line 38, 52 and
63).

[Bug fortran/55825] [OOP] Bogus rank error with CLASS pointer assignment using structure constructors

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55825

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-12-28
     Ever Confirmed|0                           |1

--- Comment #2 from janus at gcc dot gnu.org 2012-12-28 17:49:41 UTC ---
Draft patch:

Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c    (revision 194743)
+++ gcc/fortran/resolve.c    (working copy)
@@ -1089,7 +1089,10 @@ resolve_structure_cons (gfc_expr *expr, int init)
       continue;
     }

-      rank = comp->as ? comp->as->rank : 0;
+      if (comp->ts.type == BT_CLASS)
+    rank = CLASS_DATA (comp)->as ? CLASS_DATA (comp)->as->rank : 0;
+      else
+    rank = comp->as ? comp->as->rank : 0;
       if (cons->expr->expr_type != EXPR_NULL && rank != cons->expr->rank
       && (comp->attr.allocatable || cons->expr->rank))
     {


This gets me past the first error in comment 1, but does not fix the second
one.

[Bug fortran/55825] [OOP] Bogus rank error with CLASS pointer assignment using structure constructors

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55825

--- Comment #3 from janus at gcc dot gnu.org 2012-12-28 19:23:38 UTC ---
The second error is fixed by the following:

Index: gcc/fortran/intrinsic.c
===================================================================
--- gcc/fortran/intrinsic.c    (revision 194743)
+++ gcc/fortran/intrinsic.c    (working copy)
@@ -4287,8 +4287,9 @@ gfc_convert_type_warn (gfc_expr *expr, gfc_typespe
   if (expr->ts.type == BT_UNKNOWN)
     goto bad;

-  if (expr->ts.type == BT_DERIVED && ts->type == BT_DERIVED
-      && gfc_compare_types (&expr->ts, ts))
+  if (expr->ts.type == BT_DERIVED
+      && (ts->type == BT_DERIVED || ts->type == BT_CLASS) 
+      && gfc_compare_types (ts, &expr->ts))
     return SUCCESS;

   sym = find_conv (&expr->ts, ts);

[Bug fortran/55825] [OOP] Bogus rank error with CLASS pointer assignment using structure constructors

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55825

--- Comment #4 from janus at gcc dot gnu.org 2012-12-28 20:19:06 UTC ---
After getting past the error messages with the patches in comment 2 and 3, the
test case segfaults with the following backtrace:

internal compiler error: Segmentation fault
   o1 = t_ptr(r)
 ^
0xb0a58d crash_signal
        /home/jweil/gcc48/trunk/gcc/toplev.c:334
0x63466e gfc_conv_scalarized_array_ref
        /home/jweil/gcc48/trunk/gcc/fortran/trans-array.c:3042
0x634cd6 gfc_conv_array_ref(gfc_se*, gfc_array_ref*, gfc_symbol*, locus*)
        /home/jweil/gcc48/trunk/gcc/fortran/trans-array.c:3168
0x661b9b gfc_conv_variable
        /home/jweil/gcc48/trunk/gcc/fortran/trans-expr.c:1795

[Bug fortran/55825] [OOP] Bogus rank error with CLASS pointer assignment using structure constructors

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55825

--- Comment #5 from janus at gcc dot gnu.org 2012-12-28 21:53:38 UTC ---
There are problems with handling CLASS components in
gfc_trans_subcomponent_assign:


Index: gcc/fortran/trans-expr.c
===================================================================
--- gcc/fortran/trans-expr.c    (revision 194743)
+++ gcc/fortran/trans-expr.c    (working copy)
@@ -5934,11 +5934,14 @@ gfc_trans_subcomponent_assign (tree dest, gfc_comp

   gfc_start_block (&block);

-  if (cm->attr.pointer || cm->attr.proc_pointer)
+  if (cm->attr.pointer || cm->attr.proc_pointer
+      || (cm->ts.type == BT_CLASS && CLASS_DATA (cm)->attr.pointer))
     {
       gfc_init_se (&se, NULL);
       /* Pointer component.  */
-      if (cm->attr.dimension && !cm->attr.proc_pointer)
+      if ((cm->attr.dimension
+       || (cm->ts.type == BT_CLASS && CLASS_DATA (cm)->attr.dimension))
+      && !cm->attr.proc_pointer)
     {
       /* Array pointer.  */
       if (expr->expr_type == EXPR_NULL)



However, this is not enough. The test case still gives an ICE.