[Bug fortran/41556] New: Errors in applying operator/assignment to an abstract type

[Bug fortran/41556] New: Errors in applying operator/assignment to an abstract type

[damian at rouson dot net]

When defining an abstract type with generic operators that map to deferred
bindings and using these operators in an expression, the development branch of
gfortran 4.5.0 (20090925) gives the errors shown below the program below.  In
case it helps to know, IBM XL Fortran 12.1 compiles the program without errors
or warnings. 

Damian


$ cat abstract_algebra.f03
module abstract_algebra
  implicit none 
  private      
  public :: rescale
  public :: object

  type ,abstract :: object
  contains
    procedure(assign_interface) ,deferred :: assign   
    procedure(product_interface) ,deferred :: product
    generic  :: assignment(=) => assign
    generic  :: operator(*) => product
  end type 

  abstract interface
    function product_interface(lhs,rhs) result(product)
      import :: object
      class(object) ,intent(in)  :: lhs
      class(object) ,allocatable :: product
      real          ,intent(in)  :: rhs
    end function 
    subroutine assign_interface(lhs,rhs) 
      import :: object 
      class(object) ,intent(inout) :: lhs
      class(object) ,intent(in)    :: rhs
    end subroutine 
  end interface

contains

  subroutine rescale(operand,scale)    
    class(object)    :: operand
    real ,intent(in) :: scale
    operand = operand*scale           ! preferred implementation 
    operand = operand%product(scale)  ! alternate implementation
  end subroutine 
end module

$ /usr/local/gfortran/bin/gfortran-4.5 -c abstract_algebra.f03 
abstract_algebra.f03:9.54:

    procedure(assign_interface) ,deferred :: assign   
                                                      1
Error: Assignment operator interface at (1) must not redefine an INTRINSIC type
assignment
abstract_algebra.f03:34.14:

    operand = operand*scale           ! preferred implementation 
              1
Error: Operands of binary numeric operator '*' at (1) are CLASS(object)/REAL(4)
abstract_algebra.f03:35.14:

    operand = operand%product(scale)  
              1
Error: ABSTRACT INTERFACE 'product_interface' must not be referenced at (1)

$ /usr/local/gfortran/bin/gfortran-4.5 --version
GNU Fortran (GCC) 4.5.0 20090925 (experimental)


-- 
           Summary: Errors in applying operator/assignment to an abstract
                    type
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: damian at rouson dot net
 GCC build triplet: Mac OS X 10.5.8
  GCC host triplet: Mac OS X 10.5.8
GCC target triplet: Mac OS X 10.5.8


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #1 from janus at gcc dot gnu dot org  2009-10-06 13:22 -------
The first error message can be trivially fixed by:

Index: interface.c
===================================================================
--- interface.c (Revision 152488)
+++ interface.c (Arbeitskopie)
@@ -626,6 +626,7 @@ gfc_check_operator_interface (gfc_symbol *sym, gfc
         - Types and kinds do not conform, and
         - First argument is of derived type.  */
       if (sym->formal->sym->ts.type != BT_DERIVED
+         && sym->formal->sym->ts.type != BT_CLASS
          && (r1 == 0 || r1 == r2)
          && (sym->formal->sym->ts.type == sym->formal->next->sym->ts.type
              || (gfc_numeric_ts (&sym->formal->sym->ts)

The other two may be a bit harder.


-- 

janus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-10-06 13:22:14
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #2 from janus at gcc dot gnu dot org  2009-11-04 19:41 -------
Subject: Bug 41556

Author: janus
Date: Wed Nov  4 19:41:07 2009
New Revision: 153911

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=153911
Log:
2009-11-04  Tobias Burnus <burnus@gcc.gnu.org>
            Janus Weil  <janus@gcc.gnu.org>

        PR fortran/41556
        PR fortran/41937
        * interface.c (gfc_check_operator_interface): Handle CLASS arguments.
        * resolve.c (resolve_allocate_expr): Handle allocatable components of
        CLASS variables.


2009-11-04  Janus Weil  <janus@gcc.gnu.org>

        PR fortran/41556
        PR fortran/41937
        * gfortran.dg/class_11.f03: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/class_11.f03
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/interface.c
    trunk/gcc/fortran/resolve.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #3 from janus at gcc dot gnu dot org  2009-11-04 19:55 -------
The commit in comment #2 contains the patchlet from comment #1 and fixes the
first of the error messages in comment #0.

At this point, the test case still triggers three error messages:

c0.f90:34.14:

    operand = operand*scale           ! preferred implementation
              1
Error: Operands of binary numeric operator '*' at (1) are CLASS(object)/REAL(4)
c0.f90:35.14:

    operand = operand%product(scale)  ! alternate implementation
              1
Error: ABSTRACT INTERFACE 'product_interface' must not be referenced at (1)
c0.f90:35.14:

    operand = operand%product(scale)  ! alternate implementation
              1
Error: ABSTRACT INTERFACE 'product_interface' must not be referenced at (1)

The last two also appear in PR 41873.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #4 from janus at gcc dot gnu dot org  2009-11-05 10:43 -------
Subject: Bug 41556

Author: janus
Date: Thu Nov  5 10:42:48 2009
New Revision: 153934

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=153934
Log:
2009-11-05  Janus Weil  <janus@gcc.gnu.org>

        PR fortran/41556
        PR fortran/41873
        * resolve.c (resolve_function,resolve_call): Prevent abstract
interfaces
        from being called, but allow deferred type-bound procedures with
        abstract interface.


2009-11-05  Janus Weil  <janus@gcc.gnu.org>

        PR fortran/41556
        PR fortran/41873
        * gfortran.dg/interface_abstract_4.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/interface_abstract_4.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/resolve.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #5 from janus at gcc dot gnu dot org  2009-11-05 11:52 -------
r153934 fixes the third error message in comment #0. The output for the test
case is now:

c0.f90:34.14:

    operand = operand*scale           ! preferred implementation
              1
Error: Operands of binary numeric operator '*' at (1) are CLASS(object)/REAL(4)
c0.f90:35.4:

    operand = operand%product(scale)  ! alternate implementation
    1
Error: Variable must not be polymorphic in assignment at (1)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #6 from janus at gcc dot gnu dot org  2009-11-05 13:43 -------
(In reply to comment #5)
>     operand = operand%product(scale)  ! alternate implementation
>     1
> Error: Variable must not be polymorphic in assignment at (1)

This error message has been added in r152919, as a fix for PR41719. In
principle it should only apply to intrinsic assignments (cf. F03 standard,
section 7.4.1.2), but it falsely rejects the defined assignment in the test
case.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #7 from janus at gcc dot gnu dot org  2009-11-05 14:27 -------
Here is a patch which fixes both errors in comment #5, and thereby makes the
test case in comment #0 compile cleanly:

Index: gcc/fortran/interface.c
===================================================================
--- gcc/fortran/interface.c     (revision 153933)
+++ gcc/fortran/interface.c     (working copy)
@@ -2574,13 +2574,16 @@ matching_typebound_op (gfc_expr** tb_base,
   gfc_actual_arglist* base;

   for (base = args; base; base = base->next)
-    if (base->expr->ts.type == BT_DERIVED)
+    if (base->expr->ts.type == BT_DERIVED || base->expr->ts.type == BT_CLASS)
       {
        gfc_typebound_proc* tb;
        gfc_symbol* derived;
        gfc_try result;

-       derived = base->expr->ts.u.derived;
+       if (base->expr->ts.type == BT_CLASS)
+         derived = base->expr->ts.u.derived->components->ts.u.derived;
+       else
+         derived = base->expr->ts.u.derived;

        if (op == INTRINSIC_USER)
          {
@@ -2837,7 +2840,7 @@ gfc_extend_assign (gfc_code *c, gfc_namespace *ns)
   rhs = c->expr2;

   /* Don't allow an intrinsic assignment to be replaced.  */
-  if (lhs->ts.type != BT_DERIVED
+  if (lhs->ts.type != BT_DERIVED && lhs->ts.type != BT_CLASS
       && (rhs->rank == 0 || rhs->rank == lhs->rank)
       && (lhs->ts.type == rhs->ts.type
          || (gfc_numeric_ts (&lhs->ts) && gfc_numeric_ts (&rhs->ts))))


I will regtest this now and (if successful) commit as obvious.


-- 

janus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |janus at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2009-10-06 13:22:14         |2009-11-05 14:27:59
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] [OOP] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #8 from janus at gcc dot gnu dot org  2009-11-05 15:31 -------
Subject: Bug 41556

Author: janus
Date: Thu Nov  5 15:31:07 2009
New Revision: 153946

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=153946
Log:
2009-11-05  Janus Weil  <janus@gcc.gnu.org>

        PR fortran/41556
        * interface.c (matching_typebound_op,gfc_extend_assign): Handle CLASS
        variables.

2009-11-05  Janus Weil  <janus@gcc.gnu.org>

        PR fortran/41556
        * gfortran.dg/class_12.f03: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/class_12.f03
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/interface.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556

[Bug fortran/41556] [OOP] Errors in applying operator/assignment to an abstract type

[janus at gcc dot gnu dot org]

------- Comment #9 from janus at gcc dot gnu dot org  2009-11-05 15:33 -------
Fixed with r153946. Closing.


-- 

janus at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41556