RE: [sv-ec] mantis item 2848

 

Actually should we make it an error only if someone tries to create a
virtual interface access through the 
class? or should it just be an error to connect an virtual interface to
such an interface.
i.e:

vi.ch expression should be an error or vi = ifc1 is an error?

The problem really arises when you write an expression which is of the
class datatype and
that expression prefix is the virtual interface.

Francoise
    '
-----Original Message-----
From: Francoise Martinolle 
Sent: Thursday, August 13, 2009 9:13 PM
To: 'Gordon Vreugdenhil'
Cc: sv-ec@server.eda.org
Subject: RE: [sv-ec] mantis item 2848


Good. If the vendors agree that it should be an error, I think we will
be ok.
It is not very useful anyways to declare a class inside an interface. 

Francoise
    '

-----Original Message-----
From: Gordon Vreugdenhil [mailto:gordonv@model.com]
Sent: Thursday, August 13, 2009 6:31 PM
To: Francoise Martinolle
Cc: sv-ec@server.eda.org
Subject: Re: [sv-ec] mantis item 2848

Francoise,

This is where the "type" nature of interfaces really breaks down.  I
agree with the issue -- there is no definite type for "vi.ch" since the
referenced type is dependent on the instance of the target.  Most such
issues were resolved by the introduction of parameterized virtual
interface typing, but strong types (classes, unions, enums, structs) are
not addressed by the current LRM.  The "best" argument that I can make
is that since the types are not statically determinable, it should
probably be an error.  It is certainly going to be ill-defined across
vendors at this point.

Gord.


Francoise Martinolle wrote:
> I filed a mantis item today regarding virtual interfaces which can get

> assigned interfaces containing class declarations.
> I think it should be illegal to traverse through such virtual 
> interface to a class handle declared in the interface if its class 
> datatype is also in the interface declaration.
> The datatype of the virtual interface select expression cannot be 
> statically determined by the elaborator.
> ex:
> interface ifc;
>    class C;
>    int i;
>    endclass
>      C ch;
>    
> endinterface // ifc
> 
> module top;
> 
>    ifc ifc1();
> 
>    ifc ifc2();
>    
>    virtual interface ifc vi = ifc1;
>    
>    initial begin
>       vi.ch = new(); // is this legal
>       $display(vi.ch.i); // is this legal?
>       vi = ifc2;
>       $display (vi.ch.i);
>    end
> 
> endmodule // top
>  
> Comments?
>  
> Francoise
>        '
> 
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Gordon Vreugdenhil                                503-685-0808
Model Technology (Mentor Graphics)                gordonv@model.com


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