[Bug fortran/31817] New: Give at least a warning for specification function without explicit interface

[Bug fortran/31817] New: Give at least a warning for specification function without explicit interface

[burnus at gcc dot gnu dot org]

"A function is a specification function if it is a pure function, is not a
standard intrinsic function, is not an internal function, is not a statement
function, and does not have a dummy procedure argument."

This is true for "fn" in:

  function f2 (fn, i)
    integer :: i, fn
    character (len = fn (i)) :: f2

Other compilers give an error as "fn" has no explicit interface (with "PURE").
gfortran simply accepts this statement function. It should at least spit out a
warning.

$ ifort gfortran.dg/char_result_7.f90
fortcom: Error: gfortran.dg/char_result_7.f90, line 36: An explicit interface
is required for a specification function.   [FN]

$ NAG f95  gfortran.dg/char_result_7.f90
Error: gfortran.dg/char_result_7.f90, line 36: Reference to non-specification
function FN in specification expression

$ g95  gfortran.dg/char_result_7.f90 [...]
Error: Specification function 'fn' at (1) must be PURE


-- 
           Summary: Give at least a warning for specification function
                    without explicit interface
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          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=31817

[Bug fortran/31817] Give at least a warning for specification function without explicit interface

[fxcoudert at gcc dot gnu dot org]

-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fxcoudert at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |accepts-invalid
   Last reconfirmed|0000-00-00 00:00:00         |2007-08-08 16:43:25
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31817

[Bug fortran/31817] Give at least a warning for specification function without explicit interface

[fxcoudert at gcc dot gnu dot org]

------- Comment #1 from fxcoudert at gcc dot gnu dot org  2007-11-08 19:16 -------
I think we already emit the error you'd like (and probably have done so for
quite some time):

$ cat k.f90
  function f2 (fn, i)
    integer :: i, fn
    character (len = fn (i)) :: f2
  end function f2
$ gfortran -c k.f90
k.f90:3.20:

    character (len = fn (i)) :: f2
                   1
Error: Function 'fn' at (1) must be PURE


Is there anything more than that?


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31817

[Bug fortran/31817] Give at least a warning for specification function without explicit interface

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2007-11-08 20:46 -------
> I think we already emit the error you'd like (and probably have done so for
> quite some time):
>
> Error: Function 'fn' at (1) must be PURE

Ok. Seemingly it has been fixed by collateral damage of a pure patch during
4.3.0. (It does not show this message in 4.2.2.)

> Is there anything more than that?
No.


-- 

burnus at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31817