[Bug fortran/33541] New: gfortran wrongly imports renamed-use-associated symbol unrenamed

[burnus at gcc dot gnu dot org]

Reported by John Harper,
http://gcc.gnu.org/ml/fortran/2007-09/msg00397.html

The following
  use module
  use module, only: xrenamed => x
surely makes xrenamed available; however, -- see clause (3) below -- it does
not make 'x' available. In gfortran the symbol 'x' is also imported into the
namespace.

The Fortran 2003 standard contains (11.2.1):

    More than one USE statement for a given module may appear in
    a scoping unit.  If one of the USE statements is without an
    ONLY qualifier, all public entities in the module are accessible.
    If all the USE statements have ONLY qualifiers, only those
    entities named in one or more of the only-lists are accessible.

however, this is followed by the following restrictions:

    An accessible entity in the referenced module has one or more
    local identifiers. These identifiers are
    (1) The identifier of the entity in the referenced module if
        that identifier appears as an only use-name or as the
        defined-operator of a generic-spec in any only for that module,
    (2) Each of the local-names or local-defined-operators that the
        entity is given in any rename for that module, and
    (3) The identifier of the entity in the referenced module if
        that identifier does not appear as a use-name or
        use-defined-operator in any rename for that module.

For 'x' case 3 applies (or better it does not apply) and thus 'x' shall not be
imported.

Example by John Harper (ifort, sunf95, NAG f95 and openf95 properly print
.FALSE., gfortran prints .TRUE.):

MODULE xmod
  REAL(kind(1d0)) :: x = -666
END MODULE xmod

PROGRAM test2uses
  USE xmod
  USE xmod, ONLY: xrenamed => x ! kind(1d0)
  x = 666                       ! kind(1.0): see below
  PRINT *,'kind(xrenamed)==kind(x)?',kind(xrenamed)==kind(x)
  PRINT *,'That should have printed',.FALSE.
END PROGRAM test2uses


-- 
           Summary: gfortran wrongly imports renamed-use-associated symbol
                    unrenamed
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          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=33541