Support for Elaboration System Tasks

[abradd]

I wasn't sure if this was better posted as a discussion or issue.

Are elaboration system tasks supported in master or v12?

According to this comment, there was initial support for Elaboration System Tasks on the development branch as of late 2021.

Is the development branch master? I'm not sure if this change would have appeared in the v12 release, but my initial testing suggests they are ignored. As a further test, I compiled 2898727 and it seems like the elaboration system task is being ignored. I took the following example from the 1800-2017 Standard (Sec 20.11) and modified it to attempt to force the task to be picked up, but as far as I can tell it is being ignored.

module test #(N = 1) (input [N-1:0] in, output [N-1:0] out);
  if (1) begin 
    $fatal(0, "This should be a problem.");
  end
  assign out = in;
endmodule

[caryr]

I just checked and both V12 and development (master) support the four elaboration tasks as described in my comment on Ubuntu 22.04. I didn't check if $fatal() correctly aborted the elaboration, but it does display a message like the other three tasks.

They should not be ignored, though if they are not coded correctly they could be interpreted as runtime calls. What you wrote looks like it should be an elaboration time call and this does require a SystemVerilog flag, but if you forget that the compiler should tell you that as well.

Try something simple like:

module top;
  $error("This is an elaboration error");
endmodule

[larsclausen]

It looks like it works when it is in the module scope, but not when in a conditional generate, where it is the most useful.

[caryr]

Yes, that is where it is most useful and I thought I had tested it previously there as well, but I know I skipped that yesterday because of time constraints. Seems like a real bug then in both V12 and development.

[abradd]

Thanks for troubleshooting. Seems reasonable to close this as it has moved into Issue #1029.