[Patch, fortran] PR29642 - Fortran 2003: VALUE Attribute (pass by value)

[Paul Thomas]

I wrote:
> On checking through this submission, as it arrived on the list, I 
> realised that there is another testcase that I will have to write, 
> that checks that an external C-procedure gets passed a value, if the 
> dummy in the interface has the value attribute.  Please do not hold up 
> reviewing the patch for this, I will submit an additional patch 
> tonight or tomorrow.
Please find the testcase below.

Regards

Paul

_______________value_4.f90________________

! { dg-do run }
! { dg-additional-sources value_4.c }
! { dg-options "-ff2c -w -O0" }
!
! Tests the functionality of the patch for PR29642, which requested the
! implementation of the F2003 VALUE attribute for gfortran, by calling
! external C functions by value and by reference.  This is effectively
! identical to c_by_val_1.f, which does the same for %VAL.
!
! Contributed by Paul Thomas  <pault@gcc.gnu.org>
!
program value_4

  interface
    real function f_to_f (x, y)
      real :: x, y
      value :: x
    end function f_to_f
  end interface

  interface
    integer function i_to_i (x, y)
      integer :: x, y
      value :: x
    end function i_to_i
  end interface

  interface
    complex function c_to_c (x, y)
      complex :: x, y
      value :: x
    end function c_to_c
  end interface

  real       a, b, c
  integer    i, j, k
  complex    u, v, w

  a = 42.0
  b = 0.0
  c = a
  b = f_to_f (a, c)
  if ((2.0 * a).ne.b) call abort ()

  i = 99
  j = 0
  k = i
  j = i_to_i (i, k)
  if ((3 * i).ne.j) call abort ()

  u = (-1.0, 2.0)
  v = (1.0, -2.0)
  w = u
  v = c_to_c (u, w)
  if ((4.0 * u).ne.v) call abort ()
end program value_4


_______________value_4.c________________


/*  Passing from fortran to C by value, using VALUE.  This is identical
    to c_by_val_1.c, which performs the same function for %VAL.  */

typedef struct { float r, i; } complex;
extern float f_to_f__ (float, float*);
extern long i_to_i__ (long, long*);
extern void c_to_c__ (complex*, complex, complex*);
extern void abort (void);

float
f_to_f__(float a1, float *a2)
{
  if ( a1 != *a2 ) abort();
  a1 = 0.0;
  return *a2 * 2.0;
}

long
i_to_i__(long i1, long *i2)
{
  if ( i1 != *i2 ) abort();
  i1 = 0;
  return *i2 * 3.0;
}

void
c_to_c__(complex *retval, complex c1, complex *c2)
{
  if ( c1.r != c2->r ) abort();
  if ( c1.i != c2->i ) abort();
  c1.r = 0.0;
  c1.i = 0.0;
  retval->r = c2->r * 4.0;
  retval->i = c2->i * 4.0;
  return;
}