Issue with build_coverpoint() method for enum/list type

[hodjat91]

Hi Matthew,

I need to define some coverpoints with enum/list type, but I guess build_coverpoint() method doesn't work properly if cp_t=enum type or cp_t=list type. It throws a ZeroDivisionError due to not properly detecting the coverItems.

Thanks,
Hodjat

[mballance]

Hi Hodjat,
Interesting... I thought I had a test for coverpoints on enum types, but perhaps not. Can you add a testcase for both cases (enum, list) to the issue?

Thanks,
Matthew

[hodjat91]

Hi Matthew,

There is actually separate tests for the covergroup and coverage report, but not a combination for a coverpoint with cp_t=enum type and the coverage report. Here is a small test:

import vsc
from enum import IntEnum, auto
from vsc import *


class my_e(IntEnum):
    A = auto()
    B = auto()


my_l = ["one", "two"]


@covergroup
class my_covergroup(object):
    def __init__(self, a, b, c):  # Need to use lambda for non-reference values
        super().__init__()
        self.cp1 = coverpoint(a,
                              options=dict(
                                  auto_bin_max=64
                              ),
                              bins=dict(
                                  a=bin_array([], [1, 15])
                              ))

        self.cp2 = coverpoint(b, cp_t=my_e)

        self.cp3 = coverpoint(c, cp_t=my_l)


a = 1
b = my_e.A
c = "one"
cg = my_covergroup(lambda: a, lambda: b, lambda: c)

cg.sample()

cg.dump()

vsc.report_coverage(details=True)

-Hodjat

[mballance]

Hi Hodjat,
Okay, there might be a couple of issues here. I uncovered a few issues with coverpoints on enumerated types. These are resolved now, and the only change needed to the enumerated-type portion of your test is that you need to wrap the parameter value for cp_t with enum_t:

pyvsc/ve/unit/test_coverpoint_bins.py

Lines 46 to 49 in 67735fc

	def __init__(self):
	self.with_sample(dict(
	a=vsc.enum_t(my_e)))
	self.a_cp = vsc.coverpoint(self.a)

The coverpoint on a string is a different story. PyVSC doesn't currently support coverpoints on string values -- not to say that it shouldn't ;-). Is there a reason you need to use a string instead of an enum? If so, please open a separate enhancement request for that.
By the way, I've released version 0.0.8 with the fixes needed for coverpoints on enum types.

Thanks and Best Regards,
Matthew