[Bug fortran/40593] New: Proc-pointer returning function as actual argument

[Bug fortran/40593] New: Proc-pointer returning function as actual argument

[burnus at gcc dot gnu dot org]

Here, the proc-pointer result is passed as actual argument to a procedure which
does not want to have the pointer but the pointer target.

There are two problems: The first program shows wrong code:
  sub (void (*<T3c5>) (integer(kind=4) &) f)
but passed is:
    void (*<T3c5>) (integer(kind=4) &) D.1559;
    D.1559 = getptr ();
    sub (&D.1559);
Result: A segmentation fault.

The second program shows that the argument conformance checking goes wrong:
  call sub(getPtr())
           1
Error: Type mismatch in argument 'f' at (1); passed UNKNOWN to INTEGER(4)


Problem found when writing a test case for PR 40580. Please add also an
-fcheck=pointer test (assuming that PR 40580 gets checked in earlier) - I have
a test there, but it needs to be enabled


!------------ ONE -------------------
module m
contains
  subroutine func(a)
    integer :: a
    a = 42
  end subroutine func
end module m

program test
  use m
  implicit none
  call sub(getPtr())
contains
  subroutine sub(f)
    procedure(func) :: f
    integer :: a
    call f(a)
    if (a /= 42)  call abort()
    print *, a
  end subroutine sub
  function getPtr()
    procedure(func), pointer :: getPtr
    getPtr => func
  end function getPtr
end program test


!------------ TWO -------------------
module m
contains
  function func()
    integer :: func
    func = 42
  end function func
end module m

program test
  use m
  implicit none
  procedure(integer), pointer :: ptr
  call sub(getPtr())
contains
  subroutine sub(f)
    procedure(integer) :: f
    if (f() /= 42)  call abort()
    print *, f()
  end subroutine sub
  function getPtr()
    procedure(func), pointer :: getPtr
    getPtr => func
  end function getPtr
end program test


-- 
           Summary: Proc-pointer returning function as actual argument
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: wrong-code, rejects-valid
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[burnus at gcc dot gnu dot org]

------- Comment #1 from burnus at gcc dot gnu dot org  2009-06-29 17:40 -------
Hmm, something else goes wrong, too, my fix for PR 40580 does not generate a
check (for procpointer results), it does for pointer function results and it
does for normal proc pointers. Thus, it either gets fixed automatically with
this bug, or one needs to spend some time on finding out why it does not work.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2009-06-29 21:00 -------
-fcheck=pointer (remaining issues/features) is now tracked at PR 40593


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[burnus at gcc dot gnu dot org]

------- Comment #3 from burnus at gcc dot gnu dot org  2009-06-30 05:21 -------
> -fcheck=pointer (remaining issues/features) is now tracked at PR 40593
Ignore - that should have gone to PR 40580


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[janus at gcc dot gnu dot org]

------- Comment #4 from janus at gcc dot gnu dot org  2009-07-01 08:35 -------
The second example in comment #0 is fixed by the following patch:

Index: gcc/fortran/resolve.c
===================================================================
--- gcc/fortran/resolve.c       (revision 149129)
+++ gcc/fortran/resolve.c       (working copy)
@@ -1828,7 +1828,10 @@ resolve_specific_f0 (gfc_symbol *sym, gf
 found:
   gfc_procedure_use (sym, &expr->value.function.actual, &expr->where);

-  expr->ts = sym->ts;
+  if (sym->result)
+    expr->ts = sym->result->ts;
+  else
+    expr->ts = sym->ts;
   expr->value.function.name = sym->name;
   expr->value.function.esym = sym;
   if (sym->as != NULL)


-- 

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         |2009-07-01 08:35:59
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[janus at gcc dot gnu dot org]

------- Comment #5 from janus at gcc dot gnu dot org  2009-07-01 08:39 -------
Related problem:

module m
contains
  subroutine func()
    print *,"42"
  end subroutine func
end module m

program test
  use m
  implicit none
  call sub(getPtr())
contains
  subroutine sub(f)
    procedure(func),pointer :: f
    call f()
  end subroutine sub
  function getPtr()
    procedure(func), pointer :: getPtr
    getPtr => func
  end function getPtr
end program test


is rejected with:

  call sub(getPtr())
           1
Error: Expected a procedure pointer for argument 'f' at (1)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[janus at gcc dot gnu dot org]

------- Comment #6 from janus at gcc dot gnu dot org  2009-07-01 08:54 -------
The compile-time error in comment #5 is fixed by:

Index: gcc/fortran/interface.c
===================================================================
--- gcc/fortran/interface.c     (revision 149129)
+++ gcc/fortran/interface.c     (working copy)
@@ -1911,7 +1911,10 @@ compare_actual_formal (gfc_actual_arglis
       /* Satisfy 12.4.1.3 by ensuring that a procedure pointer actual argument
         is provided for a procedure pointer formal argument.  */
       if (f->sym->attr.proc_pointer
-         && !(a->expr->symtree->n.sym->attr.proc_pointer
+         && !((a->expr->expr_type == EXPR_VARIABLE
+               && a->expr->symtree->n.sym->attr.proc_pointer)
+              || (a->expr->expr_type == EXPR_FUNCTION
+                  && a->expr->symtree->n.sym->result->attr.proc_pointer)
               || is_proc_ptr_comp (a->expr, NULL)))
        {
          if (where)


However, it still gives a runtime segfault due to:

    void (*<T63>) (void) D.1556;
    D.1556 = getptr ();
    sub (&&D.1556);


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[janus at gcc dot gnu dot org]

------- Comment #7 from janus at gcc dot gnu dot org  2009-07-04 11:40 -------
Mine. Patch:

http://gcc.gnu.org/ml/fortran/2009-07/msg00016.html


-- 

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|2009-07-01 08:35:59         |2009-07-04 11:40:36
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[janus at gcc dot gnu dot org]

------- Comment #8 from janus at gcc dot gnu dot org  2009-07-04 12:28 -------
Subject: Bug 40593

Author: janus
Date: Sat Jul  4 12:28:43 2009
New Revision: 149227

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=149227
Log:
2009-07-04  Janus Weil  <janus@gcc.gnu.org>

        PR fortran/40593
        * interface.c (compare_actual_formal): Take care of proc-pointer-valued
        functions as actual arguments.
        * trans-expr.c (gfc_conv_procedure_call): Ditto.
        * resolve.c (resolve_specific_f0): Use the correct ts.


2009-07-04  Janus Weil  <janus@gcc.gnu.org>

        PR fortran/40593
        * gfortran.dg/proc_ptr_result_6.f90: New.


Added:
    trunk/gcc/testsuite/gfortran.dg/proc_ptr_result_6.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/interface.c
    trunk/gcc/fortran/resolve.c
    trunk/gcc/fortran/trans-expr.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40593

[Bug fortran/40593] Proc-pointer returning function as actual argument

[janus at gcc dot gnu dot org]

------- Comment #9 from janus at gcc dot gnu dot org  2009-07-04 13:01 -------
Fixed with r149227. 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=40593