[J3] Question involving explicit initialization

[Robert Corbett]

Bill has it right.  Subroutines are scoping units.  The name "i" identifies  one variable in one subroutine, and a different variable in the other subroutine.

If the variable "i" was declared in the scope of the module and the name "i" was not redeclared in the subroutines, the name "i" would still refer to different entities in the subroutines, but they would both be host associated with the variable "i" in the scope of the module.

Bob Corbett

> On May 4, 2019, at 9:13 AM, Vipul Parekh via J3 <j3 at mailman.j3-fortran.org> wrote:
> 
> On Sat, May 4, 2019 at 11:00 AM Bill Long via J3
> <j3 at mailman.j3-fortran.org> wrote:
>> 
>> 
>>> On May 4, 2019, at 9:46 AM, Vipul Parekh via J3 <j3 at mailman.j3-fortran.org> wrote:
>>> 
>>> Does the following code conform to the Fortran standard?
>> 
>> Yes.  I don’t see any cause for doubt.
>> 
>> In each subroutine the variable i is local. Initialization causes it to have the SAVE attribute.  Since there is no method for the value of i to be exposed outside the subroutine, I don’t see any value to incrementing it. But there are lots of examples of pointless codes that are standard conforming.   If i did not have the SAVE attribute, almost certainly the compiler would not generate code for the increment or allocate storage for i.
>> ..
> 
> Thanks, Bill.
> 
> And yes, my concern is with the standard-conforming aspect and not the
> pointless instructions.
> 
> Consider this from the standard (reformatting and emphasis is be me):
> 
> --- begin text ---
>  8.4 Initialization
> 
> 1 The appearance of initialization in an entity-decl for an entity without
>  the PARAMETER attribute specifies that the entity is a variable with
>  explicit initialization.  Explicit initialization alternatively may be
>  specified in a DATA statement unless the variable is of a derived type
>  for which default initialization is specified. If initialization is =
>  constant-expr, the variable is initially defined with the value specified
>  by the constant-expr; if necessary, the value is converted according to
>  the rules of intrinsic assignment (10.2.1.3) to a value that agrees in
>  type, type parameters, and shape with the variable. *A variable, or part
>  of a variable, shall not be explicitly initialized more than once in a
>  program.* ..
> --- begin text ---
> 
> Does the statement, "A variable, or part of a variable, shall not be
> explicitly initialized more than once in a program" apply to the code
> I showed in the initial note?  If not, can readers here provide input
> on the what is meant by "A variable, or part of a variable" and
> "program" in this sentence in the standard?  At first glance, the
> sentence looks rather confusing.
> 
> Thanks,
> Vipul