verilator/src/flexfix

#!/usr/bin/env python3
# mypy: disallow-untyped-defs
# pylint: disable=C0114,C0301
######################################################################
#
# Copyright 2002-2025 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
#
######################################################################
# DESCRIPTION: Edits flex output to get around various broken flex issues.

import re
import sys

for line in sys.stdin:
    # Fix flex 2.6.1 warning
    line = re.sub(r'for \( i = 0; i < _yybytes_len; \+\+i \)',
                  r'for ( i = 0; (yy_size_t)(i) < (yy_size_t)(_yybytes_len); ++i )', line)
    # Fix flex 2.6.0+ sign comparison warnings
    line = re.sub(
        r'\(\(int\) \(\(yy_n_chars\) \+ number_to_move\) > YY_CURRENT_BUFFER_LVALUE->yy_buf_size\)',
        r'((int) ((yy_n_chars) + number_to_move) > (int) YY_CURRENT_BUFFER_LVALUE->yy_buf_size)',
        line)
    line = re.sub(r' number_to_move == YY_MORE_ADJ ', r' (int)number_to_move == (int)YY_MORE_ADJ ',
                  line)
    line = re.sub(
        r'\(\(\(yy_n_chars\) \+ number_to_move\) > YY_CURRENT_BUFFER_LVALUE->yy_buf_size\)',
        r'(((int)(yy_n_chars) + (int)number_to_move) > (int)YY_CURRENT_BUFFER_LVALUE->yy_buf_size)',
        line)
    # Fix flex 2.5.4 namespace omission
    line = re.sub(r'^class istream;', '#include <iostream>\nusing namespace std;\n', line)
    # Fix flex 2.5.31 redefinition
    line = re.sub(r'(\#define\s+yyFlexLexer\s+yyFlexLexer)', r'//flexfix: \1', line)
    # Fix flex 2.5.1 yytext_ptr undef
    line = re.sub(r'(\#undef\s+yytext_ptr)', r'//flexfix: \1', line)
    # Fix flex 2.5.4 and GCC 4.1.0 warn_unused_result
    line = re.sub(r'\(void\) *fwrite\((.*)\)', r'if (fwrite(\1)) {}', line)
    # Fix flex 2.5.33 and GCC 4.1.2 "warning: comparison between signed and unsigned integer expressions" in YY_INPUT
    line = re.sub(r'for \( n = 0; n < max_size && ',
                  r'for ( n = 0; ((size_t)n < (size_t)max_size) && ', line)
    # Fix flex 2.5.4 and GCC 4.0.2 under FLEX_DEBUG
    line = re.sub(r'--accepting rule at line %d ', r'--accepting rule at line %ld ', line)
    # Fix compiler warning filenames
    line = re.sub(r'(#line \d+ ".*)_pretmp', r'\1', line)
    # Fix 'register' storage class specifier is deprecated and incompatible with C++17
    line = re.sub(r'register ', '', line)

    print(line, end='')