#!/usr/bin/env python3 # pylint: disable=C0114,C0115,C0116,R0902,R0903,R0912,R0915,W0719,W0718 ###################################################################### # # Copyright 2025 by Wilson Snyder. 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-License-Identifier: LGPL-3.0-only OR Artistic-2.0 import argparse import re SUCCESS_CODE = 0 FAILURE_CODE = 1 INSTANCE_TYPE = "INSTANCE" NET_LIST_TYPE = "NET" SIGNAL_TYPE = "SIGNAL" EOF_ERROR = "Unexpected EOF" def saif_assert(expression, message): if not expression: raise Exception(message) def saif_error(message): raise Exception(message) class SAIFSignalBit: name: str high_time: int low_time: int transitions: int def __init__(self, name): self.name = name self.high_time = 0 self.low_time = 0 self.transitions = 0 class SAIFInstance: def __init__(self, scope_name): self.scope_name = scope_name self.parent_instance = None self.nets = {} self.child_instances = {} class SAIFToken: def __init__(self, token): self.token = token self.type = '' self.value = '' class SAIFParser: def __init__(self): self.token_stack = [] # For parsing simplicity self.token_stack.append(SAIFToken('saif_root')) self.current_instance = None self.has_saifile_header = False self.direction = '' self.saif_version = '' self.top_instances = {} self.duration = 0 self.divider = '' self.timescale = '' def parse(self, saif_filename): file_contents = '' with open(saif_filename, 'r', encoding="utf8") as saif_file: content = saif_file.readlines() filtered_lines = [line for line in content if not line.strip().startswith('//')] file_contents = ''.join(filtered_lines) tokens = file_contents.replace('(', ' ( ').replace(')', ' ) ').split() num_of_tokens = len(tokens) index = 0 while index < num_of_tokens: token = tokens[index] index += 1 if token == '(': self.token_stack.append(SAIFToken(token)) self.token_stack[-1].type = self.token_stack[-2].type self.token_stack[-1].value = self.token_stack[-2].value continue if token == ')': if self.token_stack[-1].type == INSTANCE_TYPE: self.current_instance = self.current_instance.parent_instance self.token_stack.pop() continue if re.match(r'SAIFILE', token): self.has_saifile_header = True continue if re.match(r'DIRECTION', token): saif_assert(index < num_of_tokens, EOF_ERROR) self.direction = tokens[index].replace('\"', '') index += 1 continue if re.match(r'SAIFVERSION', token): saif_assert(index < num_of_tokens, EOF_ERROR) self.saif_version = tokens[index].replace('\"', '') index += 1 continue if re.match(r'DESIGN|DATE|VENDOR|PROGRAM_NAME|VERSION', token): # NOP, only skip value saif_assert(index < num_of_tokens, EOF_ERROR) index += 1 continue if re.match(r'DIVIDER', token): saif_assert(index < num_of_tokens, EOF_ERROR) self.divider = tokens[index] index += 1 continue if re.match(r'TIMESCALE', token): saif_assert(index < num_of_tokens, EOF_ERROR) self.timescale = tokens[index] index += 1 continue if re.match(r'DURATION', token): saif_assert(index < num_of_tokens, EOF_ERROR) self.duration = tokens[index] index += 1 continue if re.match(r'INSTANCE', token): saif_assert(index < num_of_tokens, EOF_ERROR) instance_name = tokens[index] index += 1 self.token_stack[-1].type = INSTANCE_TYPE self.token_stack[-1].value = instance_name instance = SAIFInstance(instance_name) if self.current_instance is None: self.top_instances[instance_name] = instance else: self.current_instance.child_instances[instance_name] = instance instance.parent_instance = self.current_instance self.current_instance = instance continue if re.match(r'NET', token): self.token_stack[-1].type = NET_LIST_TYPE continue if re.match(r'T1', token): net_name = self.token_stack[-1].value saif_assert(index < num_of_tokens, EOF_ERROR) self.current_instance.nets[net_name].high_time = tokens[index] index += 1 continue if re.match(r'T0', token): net_name = self.token_stack[-1].value saif_assert(index < num_of_tokens, EOF_ERROR) self.current_instance.nets[net_name].low_time = tokens[index] index += 1 continue if re.match(r'TC', token): net_name = self.token_stack[-1].value saif_assert(index < num_of_tokens, EOF_ERROR) self.current_instance.nets[net_name].transitions = tokens[index] index += 1 continue if re.match(r'TZ|TX|TB|TG|IG|IK', token): # NOP, only skip value index += 1 continue if self.token_stack[-2].type == NET_LIST_TYPE: self.token_stack[-1].type = SIGNAL_TYPE self.token_stack[-1].value = token self.current_instance.nets[token] = SAIFSignalBit(token) saif_assert(self.has_saifile_header, "SAIF file doesn't contain a SAIFILE keyword") saif_assert(self.direction == "backward", f"SAIF file doesn't have a valid/compatible direction: {self.direction}") saif_assert(self.saif_version == "2.0", f"SAIF file doesn't have a valid/compatible version: {self.saif_version}") # Only 'saif_root' token should be left saif_assert(len(self.token_stack) == 1, "Incorrect nesting of scopes") def compare_saif_instances(first: SAIFInstance, second: SAIFInstance): if len(first.nets) != len(second.nets): saif_error(f"Number of nets doesn't match in {first.scope_name}: " f"{len(first.nets)} != {len(second.nets)}") for signal_name, saif_signal in first.nets.items(): if signal_name not in second.nets: saif_error(f"Signal {signal_name} doesn't exist in the second object\n") other_signal = second.nets[signal_name] if (saif_signal.high_time != other_signal.high_time or saif_signal.low_time != other_signal.low_time or saif_signal.transitions != other_signal.transitions): saif_error("Incompatible signal bit parameters in " f"{signal_name}\n") if len(first.child_instances) != len(second.child_instances): saif_error(f"Number of child instances doesn't match in {first.scope_name}: " f"{len(first.child_instances)} != {len(second.child_instances)}") for instance_name, instance in first.child_instances.items(): if instance_name not in second.child_instances: saif_error(f"Instance {instance_name} doesn't exist in the second object\n") compare_saif_instances(instance, second.child_instances[instance_name]) def compare_saif_contents(first_file: str, second_file: str): """Test if second SAIF file has the same values as the first""" first_saif = SAIFParser() first_saif.parse(first_file) second_saif = SAIFParser() second_saif.parse(second_file) if first_saif.duration != second_saif.duration: saif_error("Duration of trace doesn't match: " f"{first_saif.duration} != {second_saif.duration}") if first_saif.divider != second_saif.divider: saif_error(f"Dividers don't match: {first_saif.divider} != {second_saif.divider}") if first_saif.timescale != second_saif.timescale: saif_error(f"Timescale doesn't match: {first_saif.timescale} != {second_saif.timescale}") if len(first_saif.top_instances) != len(second_saif.top_instances): saif_error("Number of top instances doesn't match: " f"{len(first_saif.top_instances)} != {len(second_saif.top_instances)}") for top_instance_name, top_instance in first_saif.top_instances.items(): if top_instance_name not in second_saif.top_instances: saif_error(f"Top instance {top_instance_name} missing in other SAIF") compare_saif_instances(top_instance, second_saif.top_instances[top_instance_name]) return SUCCESS_CODE parser = argparse.ArgumentParser(allow_abbrev=False, formatter_class=argparse.RawDescriptionHelpFormatter, description="""verilator_saif_diff checks if two SAIF files are logically-identical. It returns first encountered difference as output. Run as: cd $VERILATOR_ROOT nodist/code_coverage --first example.saif --second other.saif""") parser.add_argument('--first', action='store', help='First SAIF file') parser.add_argument('--second', action='store', help='Second SAIF file') parser.set_defaults(stop=True) args = parser.parse_args() try: compare_saif_contents(args.first, args.second) except Exception as error: print(error)