http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49112
--- Comment #4 from John <jwmwalrus at gmail dot com> 2011-05-22 17:58:39 UTC
---
(In reply to comment #3)
> (In reply to comment #0)
> > ...:~$ gfortran -c test_gfortran_ice.f90
> > test_gfortran_ice.f90:20.41:
> >
> > class(DateTime), intent(IN) :: dt
> > 1
> > Warning: Duplicate SAVE attribute specified at (1)
> > test_gfortran_ice.f90:20.41:
> >
> > class(DateTime), intent(IN) :: dt
> > 1
> > Warning: Duplicate SAVE attribute specified at (1)
>
>
> Here is a reduced test case for the duplicate SAVE attribute:
>
>
> module datetime_mod
>
> implicit none
> save
>
> type :: DateTime
> end type
>
> contains
>
> character function getString (dt)
> class(DateTime) :: dt
> end function
>
> end module
>
>
> At first glance I would save this is invalid, and should be rejected with an
> error. In particular, is it allowed to give a lonely SAVE statement? If yes,
> what effect should this have? Usually SAVE is specified as an attribute for a
> specific variable, right?
SAVE can be either a statement or an attribute. When it's statement, it
affects all the variables within the containing unit (e.g., in the case of a
module, it affects all the variables declared before the "contains"). When
it's the attribute for a particular variable declaration, it affects the
variable only.
Since in Fortran initialization implies SAVE, and the ISO_REFERENCE_DATE is
being (sort of) initialized, the compiler is assuming a duplicate SAVE.
The standard also allows the confirmation, as an attribute, of the SAVE at the
module level, so, for a "triple save" example:
module t1_mod
save
type :: t1
integer :: dummy = 0
end type
type(t1), save :: a = t1(2), b = t1(3)
end type
Which also triggers a duplicate save warning.
