Date: Wed Aug 10 2011 - 02:37:09 PDT
Hi Doug,
The proposal to separate between the regular syntax and the additional pragmas originates from the desire to add an extra declarative syntax (not needed for a SystemVerilog compiler) that can be used for automated generation of the foreign language definitions.
In other words, everything in the pragmas is optional - we can drop that syntax completely. I just thought that it would be beneficial for the users to have the standard pragmas in case the vendors decide to implement generation of the foreign language definitions (classes etc.), based on the SystemVerilog DPI-OO declarations.
Regards,
Vitaly
From: Warmke, Doug [mailto:doug_warmke@mentor.com]
Sent: Wednesday, August 10, 2011 12:32 AM
To: Vitaly Yankelevich; Maidment, Matthew R; Jim Vellenga; brad_pierce@acm.org; Rich, Dave
Cc: SystemVerilog CC DWG (sv-cc@eda.org); sv-bc@eda.org
Subject: RE: [sv-cc] Re: [sv-bc] Mantis 3087 Uses of comment pragmas instead of attributes
Hi All,
I don't understand why there is so much debate on pragmas vs. attributes.
To me, it seems clear that if DPI-OO is to be a first-class language feature,
it should follow in the path of DPI-C and use regular SV syntax and keywords.
This has advantages both on the usage side as well as the implementation side.
Earlier someone pointed out the advantages of using `include.
But one can liberally use `include in SystemVerilog source code,
whether it be for attributes, pragmas, or other kinds of SV syntax.
Thanks,
Doug
From: owner-sv-bc@eda.org [mailto:owner-sv-bc@eda.org] On Behalf Of Vitaly Yankelevich
Sent: Tuesday, August 09, 2011 5:06 PM
To: Maidment, Matthew R; Jim Vellenga; brad_pierce@acm.org; Rich, Dave
Cc: SystemVerilog CC DWG (sv-cc@eda.org); sv-bc@eda.org
Subject: RE: [sv-cc] Re: [sv-bc] Mantis 3087 Uses of comment pragmas instead of attributes
The common opinion is to replace the comment-based pragmas with `pragmas or attributes.
The advantage of using `pragma syntax rather than an attribute is that the pragma can be added separately of the declaration, while the attribute must be provided together with a declaration.
Using configuration pragmas separate from the declarations provides for higher flexibility. For example, one can use different include files with different DPI-OO configuration options without changing the core source code.
So my preference is to support the following syntax (with an example how it can be layered with help of include files):
packet.svh:
class packet;
extern function int f1();
extern function void f2();
endclass
packet_dpi.svh:
`include "packet.svh"
export "DPI-OO" "ref" class packet;
packet_configuration.svh:
`include "packet_dpi.svh"
`pragma DPI-OO class="packet" exclude="f2" language="SystemC" foreign="P::Packet"
Vitaly
From: Maidment, Matthew R [mailto:matthew.r.maidment@intel.com]
Sent: Monday, August 08, 2011 9:52 AM
To: Vitaly Yankelevich; Jim Vellenga; brad_pierce@acm.org; Rich, Dave
Cc: SystemVerilog CC DWG (sv-cc@eda.org); sv-bc@eda.org
Subject: RE: [sv-cc] Re: [sv-bc] Mantis 3087 Uses of comment pragmas instead of attributes
I was demonstrating how attributes can be used in lieu of comment-based pragmas for clause 36 of the proposal.
-- Matt Maidment mmaidmen@ichips.intel.com From: Vitaly Yankelevich [mailto:vitaly@cadence.com] Sent: Sunday, August 07, 2011 2:09 AM To: Maidment, Matthew R; Jim Vellenga; brad_pierce@acm.org; Rich, Dave Cc: SystemVerilog CC DWG (sv-cc@eda.org); sv-bc@eda.org Subject: RE: [sv-cc] Re: [sv-bc] Mantis 3087 Uses of comment pragmas instead of attributes Just in case if the proposal below is to replace the export/import DPI-OO declarations with attributes completely: I think that the basic declarations' syntax should be stronger than attributes because the class properties of being export/import class directly influence compilation of the classes and objects. In particular: - an allocation of an import class object should be implemented differently than a native class - garbage collection of an export/import classes should be implemented differently - arguments of DPI-OO subroutines need to be checked by the compiler to be export/import DPI-OO classes - DPI-OO copy classes are required to support deep copying. Given the above, I think that the attributes can replace the comment-based pragmas but they cannot substitute the explicit export/import class declarations completely. Vitaly From: owner-sv-cc@eda.org [mailto:owner-sv-cc@eda.org] On Behalf Of Maidment, Matthew R Sent: Thursday, August 04, 2011 8:02 PM To: Jim Vellenga; brad_pierce@acm.org; Rich, Dave Cc: SystemVerilog CC DWG (sv-cc@eda.org); sv-bc@eda.org Subject: RE: [sv-cc] Re: [sv-bc] Mantis 3087 Uses of comment pragmas instead of attributes Here's some idea of what attributes might look like (*DPIOO, export, exclude="f2", language="SystemC" foreign="P::Packet"*) class packet; extern function int f1(); extern function void f2(); endclass class packet; (*DPIOO, export, foreign="GetByte" *) function byte get_byte(int j); ... endfunction // pragma DPI-OO export function get_byte foreign=GetByte endclass The benefits of attributes include clearer semantics as to which syntax elements they apply as to where they apply and that they can be interrogated by VPI. I'd like to see attributes given more consideration given that strings can store most everything and there is no ambiguity regarding placement. Matt -- Matt Maidment mmaidmen@ichips.intel.com<mailto:mmaidmen@ichips.intel.com> From: owner-sv-cc@eda.org [mailto:owner-sv-cc@eda.org] On Behalf Of Jim Vellenga Sent: Wednesday, August 03, 2011 8:55 AM To: brad_pierce@acm.org; Rich, Dave Cc: SystemVerilog CC DWG (sv-cc@eda.org); sv-bc@eda.org Subject: RE: [sv-cc] Re: [sv-bc] Mantis 3087 Uses of comment pragmas instead of attributes Syntax 22-8 comes a lot closer to what's in the proposal. Using Syntax 22-8, the complex values supported by the proposal could be represented as strings. So that would work out OK. From: owner-sv-cc@eda.org [mailto:owner-sv-cc@eda.org] On Behalf Of Brad Pierce Sent: Tuesday, 2 Aug 2011 3:22 PM To: Rich, Dave Cc: SystemVerilog CC DWG (sv-cc@eda.org); sv-bc@eda.org Subject: [sv-cc] Re: [sv-bc] Mantis 3087 Uses of comment pragmas instead of attributes Can the impoverished attribute syntax of Syntax 5-3 really carry the weight? Why not use/extend the `pragma directive of Syntax 22-8? On Tue, Aug 2, 2011 at 8:02 AM, Rich, Dave <Dave_Rich@mentor.com<mailto:Dave_Rich@mentor.com>> wrote: Why does this proposal continue to promote the use comment pragmas instead of attributes? I thought the use of attributes is to be encouraged because you can't construct macros to deal with comments. Or are we giving up on attributes? Dave Rich Verification Technologist Mentor Graphics Corporation [cid:image001.png@01CC575A.38CDB420]<http://www.twitter.com/dave_59>[cid:image002.png@01CC575A.38CDB420]<http://go.mentor.com/drich> -- This message has been scanned for viruses and dangerous content by MailScanner<http://www.mailscanner.info/>, and is believed to be clean. -- This message has been scanned for viruses and dangerous content by MailScanner<http://www.mailscanner.info/>, and is believed to be clean. -- This message has been scanned for viruses and dangerous content by MailScanner<http://www.mailscanner.info/>, and is believed to be clean. -- This message has been scanned for viruses and dangerous content by MailScanner<http://www.mailscanner.info/>, and is believed to be clean. -- This message has been scanned for viruses and dangerous content by MailScanner<http://www.mailscanner.info/>, and is believed to be clean. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.
