RE: [sv-bc] Mantis 1602: task/function default inout arguments

From: Bresticker, Shalom <shalom.bresticker_at_.....>
Date: Tue Jul 17 2007 - 23:10:10 PDT
The LRM is quite clear that default arguments resolve in the declarative
scope.

The current spec about default inout arguments is ambiguous, it has to
be resolved.

There are several possible resolutions. Once a resolution is chosen, it
is straight-forward to write it up. No real complexity here. It simply
requires choosing a direction.

Shalom
 

> -----Original Message-----
> From: owner-sv-bc@server.eda.org 
> [mailto:owner-sv-bc@server.eda.org] On Behalf Of Greg Jaxon
> Sent: Wednesday, July 18, 2007 2:29 AM
> To: sv-bc@server.eda.org
> Subject: Re: [sv-bc] Mantis 1602: task/function default inout 
> arguments
> 
> The big issue with default arguments is the binding environment to use
> when interpreting the expressions.   For functions and tasks, this
> ought to be quite tame: the names clearly resolve in the 
> declarative scope that defines the function or task.  For 
> modules and other instantiatable things, I know the committee 
> has debated several alternatives.
> I don't know off-hand how that debate was resolved, but it 
> may impact user expectations for function argument defaults.
> 
> I also can't judge ROI for this feature.  Are we talking 
> committee investment? - There it may be worth the exercise to 
> make the edit and specify one clean definition; the cost of 
> not doing so is divergence of our ever-fractious vendors. If 
> we're speculating about vendors'
> ROI for their higher cost of developing and testing a default 
> output feature, the outcome turns on what customers are 
> willing to pay for structured programming features like this. 
>  I'd leave that to the marketplace to sort out.
> 
> Greg
> 
> disclaimer: my humble opinions only...
> 
> Brad Pierce wrote:
> > And the questions are -- should it be legal in 
> SystemVerilog 2008 to 
> > declare default argument values for inout and output arguments of 
> > subroutines, and, if so, what should the semantics be?
> > 
> > I think it wouldn't be good ROI to support such default argument 
> > values in SystemVerilog 2008, and, if SystemVerilog 2005 did not 
> > explicitly forbid such default arguments, then we should update the 
> > LRM to forbid them.
> > 
> > This feature could always be added in future revs of the standard.
> > 
> > -- Brad
> > 
> > -----Original Message-----
> > From: owner-sv-bc@eda.org [mailto:owner-sv-bc@eda.org] On Behalf Of 
> > Bresticker, Shalom
> > Sent: Tuesday, July 17, 2007 11:42 AM
> > To: Greg Jaxon
> > Cc: sv-bc@eda.org
> > Subject: RE: [sv-bc] Mantis 1602: task/function default inout 
> > arguments
> > 
> > Greg,
> > 
> > But what do you (and Brad and everyone else) think about 
> the questions 
> > on Mantis 1602?
> > 
> > Thanks,
> > Shalom
> > 
> > --
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> > 
> 
> 
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Received on Tue Jul 17 23:10:47 2007

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