Re: [sv-ac] Re: [sv-ec]e-mail ballot Closes Wednesday February 20 2008, 11:59pm PST

Steven Sharp wrote:
>> From: Gordon Vreugdenhil <gordonv@model.com>
> 
>> But that is immaterial to my question.  If you have an auto declaration
>> in the enclosing scope, can a checker instance refer to that?  No
>> one has (yet) made any restrictions regarding the resolution rules,
>> so I am assuming that the answer is yes.
> 
> In defense of this part of the proposal, I think the same issue arises
> for static variable initializers.  An initializer on a local static
> variable could be within the scope of an automatic variable, and I don't
> see anything in the LRM restricting it from referencing one.  However,
> clearly it cannot be allowed to do so.  Automatic variables are created
> by procedural execution entering their scope, and static variable
> initializers are not executed in the context of a procedural entry into
> the scope.


I agree on both fronts.  My concerns are mostly that while I can
reason about why something like:
     initial begin:b
         automatic int x = 1;
         static int y = x;
       ...
should be illegal, it is harder for me to reason about things
in the AC space since in various contexts more "synthesis"
like behaviors seem to be expected and I haven't quite gotten to
a point where I can predict what AC expects the behavior to be.

> If concurrent assertions and checkers in procedural code were similarly
> static objects, independent of any procedural execution of the code, then
> things would be simplified.  However, Mantis 1995 and 2110 break that
> conceptual model.

This is also what I'm struggling with.  Some of the aspects
of checkers appear to in fact be static (the text requires
that for checker variables, etc), but it isn't quite clear
to me yet exactly what the boundaries are and whether those
boundaries are well formed.

Part of my difficulty lies in lack of time to get everything in
my head; part of it is also that various relevant pieces of
the semantics and rules appear to be distributed in a half-dozen
Mantis items and I don't know what is all relevant.

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


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