[Bug fortran/30923] New: Warn by default when respecifiying USE associated NAMELIST

[Bug fortran/30923] New: Warn by default when respecifiying USE associated NAMELIST

[burnus at gcc dot gnu dot org]

Cf. http://gcc.gnu.org/ml/fortran/2007-02/msg00145.html

The following code is invalid Fortran as the USE-associated NAMELIST is
respecified in the main program:
----------------------------
MODULE debug
  LOGICAL debug_area
  NAMELIST/debugging/debug_area
END MODULE debug

PROGRAM ding
  USE debug
  IMPLICIT NONE
  NAMELIST/debugging/debug_area
  INTEGER :: ios
  OPEN(unit=10, status='unknown', file='input.dat')
  READ(unit=10, nml=debugging,  iostat=ios)
  PRINT*, 'nml=debugging',ios
END PROGRAM ding
----------------------------

Gfortran and Portland group Fortran accept it by default, while xlf, ifort, NAG
f95 and g95 reject it by default.

Note that gfortran rejects it with -std=f2003:

Error: Namelist group name 'debugging' at (1) already is USE associated
and cannot be respecified.

Should the GFC_STD_GNU be changed into GFC_STD_LEGACY?
Or should there be a warning only for -std=gnu (= default option)?
Or keep status quo?


-- 
           Summary: Warn by default when respecifiying USE associated
                    NAMELIST
           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=30923

[Bug fortran/30923] Respecifying USE associated NAMELIST should raise warning by default

[fxcoudert at gcc dot gnu dot org]

------- Comment #1 from fxcoudert at gcc dot gnu dot org  2007-03-18 18:01 -------
I'd say the current behaviour is OK. People who want to check their source for
correctness can use either -pedantic or -std=f95/f2003, and they will get the
warning/error. We'd best assume that people who just run "gfortran" want it to
compile their code. This extension is straightforward, so I'd say we do not
change behaviour (this always has a cost).

Put this in WAITING status to clear the bug database a bit. If you feel it
should really be changed, please reopen and confirm. Otherwise, it might be
worth closing as WONTFIX.


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING
            Summary|Warn by default when        |Respecifying USE associated
                   |respecifiying USE associated|NAMELIST should raise
                   |NAMELIST                    |warning by default


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30923

[Bug fortran/30923] Respecifying USE associated NAMELIST should raise warning by default

[burnus at gcc dot gnu dot org]

------- Comment #2 from burnus at gcc dot gnu dot org  2007-03-19 09:07 -------
> > Gfortran and Portland group Fortran accept it by default, while xlf, ifort, 
> > NAG f95 and g95 reject it by default.
> I'd say the current behaviour is OK.

Then close as won't fix.


-- 

burnus at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30923