#6. A host of issues around
sample
arguments. One thing that occurred to us -- without, I'll note,
Gordon's
blessing! -- is that we could possibly allow this:
int a;
covergroup ct function sample(ref int x = a);
coverpoint a;
This would allow event-based
sampling to occur as well
as procedural sampling, let's say with this syntax (which I know would
be a
change from the proposal):
covergroup ct function
sample(ref int x = a) @(e);
With event-based sampling, the
default arguments would
be used, which as you see cause "a" from the enclosing scope to be
sampled. It wasn't clear from Mike's original e-mail whether the
override
was expected to be optional (used occasionally) or required (used
always).
I am
very uncomfortable with this change. The current proposal makes it
clear that
there are two mutually exclusive ways to trigger a covergroup: via an
events (or
block event) or procedurally through the sample method. Otherwise,
there are
other issues like “strobe” sampling that rear their ugly head.