verilator/test_regress/t/trace_struct_alias_common.py

86 lines
2.9 KiB
Python

# DESCRIPTION: Verilator: Verilog Test driver/expect definition
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of either the GNU Lesser General Public License Version 3
# or the Perl Artistic License Version 2.0.
# SPDX-FileCopyrightText: 2026 Wilson Snyder
# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
def _vcd_extract_codes(filename):
"""Parse VCD header and return dict mapping 'scope.signal' -> code."""
codes = {}
scope_stack = []
with open(filename, 'r', encoding='latin-1') as fh:
for line in fh:
line = line.strip()
if line.startswith("$scope"):
parts = line.split()
# $scope <type> <name> $end
scope_stack.append(parts[2])
elif line.startswith("$var"):
parts = line.split()
# $var <type> <width> <code> <name> ... $end
code = parts[3]
name = parts[4]
full = '.'.join(scope_stack) + '.' + name
codes[full] = code
elif line.startswith("$upscope"):
scope_stack.pop()
elif line.startswith("$enddefinitions"):
break
return codes
def _check_aliased(test, codes, sig_a, sig_b):
code_a = codes.get(sig_a)
code_b = codes.get(sig_b)
if code_a is None:
test.error(f"Signal '{sig_a}' not found in VCD")
if code_b is None:
test.error(f"Signal '{sig_b}' not found in VCD")
if code_a != code_b:
test.error(f"Expected '{sig_a}' (code {code_a}) to alias "
f"'{sig_b}' (code {code_b})")
def _check_not_aliased(test, codes, sig_a, sig_b):
code_a = codes.get(sig_a)
code_b = codes.get(sig_b)
if code_a is None:
test.error(f"Signal '{sig_a}' not found in VCD")
if code_b is None:
test.error(f"Signal '{sig_b}' not found in VCD")
if code_a == code_b:
test.error(f"Expected '{sig_a}' and '{sig_b}' to have different codes, "
f"both have code {code_a}")
def run(test):
(fmt, ) = test.parse_name(r"t_trace_struct_alias_([a-z]+)")
test.top_filename = "t/t_trace_struct_alias.v"
test.golden_filename = test.py_filename.rpartition(fmt)[0] + fmt + ".out"
flags = ["--cc", f"--trace-{fmt}", "--trace-structs"]
test.compile(verilator_flags2=flags)
test.execute()
if fmt == "vcd":
codes = _vcd_extract_codes(test.trace_filename)
_check_not_aliased(test, codes, "top.t.s1.a", "top.t.s2.a")
_check_aliased(test, codes, "top.t.s3.a", "top.t.alias_of_s3a")
_check_aliased(test, codes, "top.t.s4.a", "top.t.s5.a")
_check_aliased(test, codes, "top.t.s4.b", "top.t.s5.b")
_check_aliased(test, codes, "top.t.s6.a", "top.t.source_val")
test.trace_identical(test.trace_filename, test.golden_filename)
test.passes()