Re: [sv-bc] Functions in nested modules (19.6)

Brad, this is only one of a long list of name binding issues
that I am worried about.  The current rules aren't terribly
clear on all of this and are very unclear when it comes to
interactions with classes, etc.  I am planning on writing up
the issues and a proposed resolution algorithm in a couple
of weeks when I have a bit more time than right now.

For this particular example, I believe that "f" should bind
to up_m.f.  If the user wants to get $unit::f, the user
should explicitly state that via the $unit form of reference.

Note that this is *really* interesting when you start talking
about a function made (potentially) visible via a pkg::*
import.  For example:

    package pkg;
       function f; ... endfunction
    endpackage

     ...
    module down_m;
    import pkg::*;
         .... f(...);
    endmodule


Even if down_m is separately compiled, you *cannot* bind "f"
to pkg::f at compile since the instantiation hierarchy trumps
the pkg reference.

Situations like this also make me *extremely* wary about adopting
a strategy of only elaborating packages that have items references
that are used (see the other discussion thread).  In cases like
this there is no way to know until elab time whether "f" is actually
used from pkg or not.

This is, well, "not exactly intuitive".

Gord.

Brad Pierce wrote:

> Which version of "f" does "down_inst" call in the skeleton below?
> 
> module container;
> 
>   function f; ... endfunction
> 
>   module up_m; ...
>        function f; ... endfunction
>        down_m down_inst(...);
>   endmodule
> 
>   module down_m; ...
>        ... f(...) ...
>   endmodule
> 
> endmodule
> 
> As I understand it, the function/task names are not resolved until after 
> the design has been elaborated, at which time they are resolved by 
> looking first in the calling instance, then in its parent and so on.
> So when I resolve the name "f" in "down_inst", should I find the version 
> that "down_m" sees in its lexical scope or the version that the parent 
> of "down_inst" sees in its lexical scope?
> 
> -- Brad
>  
>  

-- 
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Gordon Vreugdenhil                                503-685-0808
Model Technology (Mentor Graphics)                gordonv@model.com