[Bug fortran/41733] Proc-pointer conformance checks: Elemental-proc-ptr => non-elemental-proc

[Bug fortran/41733] Proc-pointer conformance checks: Elemental-proc-ptr => non-elemental-proc

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41733

janus at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011-09-15
         AssignedTo|unassigned at gcc dot       |janus at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #3 from janus at gcc dot gnu.org 2011-09-15 19:32:59 UTC ---
(In reply to comment #2)
> C728 (R742) The proc-target shall not be a nonintrinsic elemental procedure.

Here is a simple patch for this constraint:


Index: gcc/fortran/expr.c
===================================================================
--- gcc/fortran/expr.c    (revision 178888)
+++ gcc/fortran/expr.c    (working copy)
@@ -3448,6 +3448,14 @@ gfc_check_pointer_assign (gfc_expr *lvalue, gfc_ex
                   rvalue->symtree->name, &rvalue->where) == FAILURE)
         return FAILURE;
     }
+      /* Check for F08:C730.  */
+      if (attr.elemental && !attr.intrinsic)
+    {
+      gfc_error ("Nonintrinsic elemental procedure '%s' is invalid "
+             "in procedure pointer assigment at %L",
+             rvalue->symtree->name, &rvalue->where);
+      return FAILURE;
+    }

       /* Ensure that the calling convention is the same. As other attributes
      such as DLLEXPORT may differ, one explicitly only tests for the


and a minimal test case:


  implicit none
  procedure(my_dcos), pointer :: f
  f => my_dcos
contains
  real elemental function my_dcos(x)
    real, intent(in) :: x
    my_dcos = cos(x)
  end function
end

[Bug fortran/41733] Proc-pointer conformance checks: Elemental-proc-ptr => non-elemental-proc

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41733

--- Comment #4 from janus at gcc dot gnu.org 2011-09-15 19:47:21 UTC ---
Also we need to check for the following F08 constraints:


"12.5.2.9 Actual arguments associated with dummy procedure entities
If the interface of a dummy procedure is explicit, its characteristics as a
procedure (12.3.1) shall be the same as those of its effective argument, except
that a pure effective argument may be associated with a dummy argument that is
not pure and an elemental intrinsic actual procedure may be associated with a
dummy procedure (which cannot be elemental)."


and


"7.2.2.4 Procedure pointer assignment
3 If the pointer object has an explicit interface, its characteristics shall be
the same as the pointer target except that the pointer target may be pure even
if the pointer object is not pure and the pointer target may be an elemental
intrinsic procedure even if the pointer object is not elemental."

[Bug fortran/41733] Proc-pointer conformance checks: Elemental-proc-ptr => non-elemental-proc

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41733

--- Comment #5 from janus at gcc dot gnu.org 2011-09-22 09:32:14 UTC ---
Author: janus
Date: Thu Sep 22 09:32:11 2011
New Revision: 179080

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=179080
Log:
2011-09-22  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/41733
    * expr.c (gfc_check_pointer_assign): Check for nonintrinsic elemental
    procedures.
    * interface.c (gfc_compare_interfaces): Rename 'intent_flag'. Check
    for PURE and ELEMENTAL attributes.
    (compare_actual_formal): Remove pureness check here.


2011-09-22  Janus Weil  <janus@gcc.gnu.org>

    PR fortran/41733
    * gfortran.dg/impure_actual_1.f90: Modified error message.
    * gfortran.dg/proc_ptr_32.f90: New.
    * gfortran.dg/proc_ptr_33.f90: New.

Added:
    trunk/gcc/testsuite/gfortran.dg/proc_ptr_32.f90
    trunk/gcc/testsuite/gfortran.dg/proc_ptr_33.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/expr.c
    trunk/gcc/fortran/interface.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/impure_actual_1.f90

[Bug fortran/41733] Proc-pointer conformance checks: Elemental-proc-ptr => non-elemental-proc

[janus at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41733

janus at gcc dot gnu.org changed:

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

--- Comment #6 from janus at gcc dot gnu.org 2011-09-22 09:40:07 UTC ---
r179080 should fix all issues in the c.l.f. thread. Closing as fixed.

[Bug fortran/41733] Proc-pointer conformance checks: Elemental-proc-ptr => non-elemental-proc

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2009-10-17 19:07 -------
There is the following additional restriction, which I could not find (Thanks
James!):

C728 (R742) The proc-target shall not be a nonintrinsic elemental procedure.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41733

[Bug fortran/41733] Proc-pointer conformance checks: Elemental-proc-ptr => non-elemental-proc

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2009-10-16 20:35 -------
The first example,
   procedure(fun), pointer :: f
   f => my_dcos
   write(*,*) f(x)
looks fine to me. "fun" is elemental - and my_dcos is also elemental.

The second example is wrong: "fun" is elemental, but "my_dcos" is not thus
   f => my_dcos
is invalid per F2003, 7.4.2.2 Procedure pointer assignment:
 "If proc-pointer-object has an explicit interface, its characteristics shall
be
  the same as proc-target except that proc-target may be pure even if 
  proc-pointer-object is not pure and proc-target may be an elemental intrinsic
  procedure even if proc-pointer-object is not elemental."

The third example looks OK again - actually, it is the same as the first,
except that one uses an intrinsic elemental procedure (dcos).

Test case for the second example:

 module funcs
   implicit none
   integer, parameter :: dp = kind(1.0d0)
   abstract interface
      elemental function fun(x)
         import
         implicit none
         real(dp), intent(in) :: x
         real(dp) fun
      end function fun
   end interface
   contains
  function my_dcos(x)
    integer, parameter :: dp = kind(1.0d0)
    real(dp), intent(in) :: x
    real(dp) :: my_dcos
    my_dcos = cos(x)
  end function
end module funcs

program start
   use funcs
   implicit none
   procedure(fun), pointer :: f
   real(dp) x(3)
   x = [1,2,3]
   f => my_dcos
   write(*,*) f(x)
end program start


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|Proc-pointer conformance    |Proc-pointer conformance
                   |checks                      |checks: Elemental-proc-ptr
                   |                            |=> non-elemental-proc


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41733