[PATCH] fortran/45495 -- optional dummy args cannot not be in restricted expressions

[Tobias Burnus]

  Steve Kargl wrote:
> C710  (R729) The scalar-int-expr shall be a restricted expression.
>    (2)  An object designator with a base object that is a dummy
>         argument that has neither the OPTIONAL nor the INTENT(OUT)
>         attribute,
>
> The attach patch enforces the above restriction.  It has been
> built and regression tested on x86_64-*-freebsd.  OK for trunk?

+	if (not_restricted == 0
+	&&  ap->expr->expr_type == EXPR_VARIABLE
+	&&  ap->expr->symtree->n.sym->attr.optional
+	&&  ap->expr->symtree->n.sym->attr.dummy)


The "sym.dummy" part is not needed (but can stay). However, can you add 
you add a check whether the dummy is INTENT(OUT)? The following is 
invalid and not detected:

subroutine f(a, str)
   integer, intent(out) :: a
   character(*) :: str
   character(len=len(str(1:a))+1) :: b
end subroutine

With that change and test case, the patch is OK.

Thanks for the patch and digging for the constraint!

Tobias

> 2010-09-02  Steven G. Kargl<kargl@gcc.gnu.org>
>
> 	PR fortran/45495
> 	* gfortran.dg/dummy_optional_arg.f90: New test.
>
> 2010-09-02  Steven G. Kargl<kargl@gcc.gnu.org>
>
> 	PR fortran/45495
> 	* fortran/expr.c (check_inquiry): Optional dummy argument are not
> 	permitted in a restricted expression.
>