gen_from_tables.py

#! /usr/bin/env python2
# -*- coding: utf-8 -*-

"""
gen_from_tables.py

Generate a Python instruction table from the one provided in DSPTables.cpp
(part of the Dolphin project).

Copyright (C) 2011 Pierre Bourdon <delroth@dolphin-emu.org>

Licensed under the GPLv2 license, see the LICENSE file at the root of this
repository.
"""

import ast
import sys

class Modes:  # enumeration
    SKIP = 0
    OPCODES = 1
    OPCODES_EXT = 2

def full_strip(line):
    """Strips comments and trailing whitespaces from a line."""
    comment_start = line.find('//')
    if comment_start != -1:
        line = line[:comment_start]
    return line.strip()

def gen_from_text(text):
    """Generates the Python code from the file text."""
    lines = [full_strip(l) for l in text.split('\n')]
    mode = Modes.SKIP

    opcodes = []
    opcodes_ext = []

    for line in lines:
        if mode == Modes.SKIP:
            if line == 'const DSPOPCTemplate opcodes[] =':
                mode = Modes.OPCODES
            elif line == 'const DSPOPCTemplate opcodes_ext[] =':
                mode = Modes.OPCODES_EXT
        else:
            if line == '};':
                mode = Modes.SKIP
            elif line == '{' or not line:
                continue
            else:
                fields = line.replace('{', '[').replace('}', ']').split(',')
                fields = fields[0:3] + fields[5:-5] + [fields[-4]]
                fields = map(str.strip, fields)
                fields = ','.join(fields) + ']'
                fields = fields.replace('true', 'True')
                fields = fields.replace('false', 'False')
                fields = fields.replace('P_', 'OpType.')
                if mode == Modes.OPCODES:
                    opcodes.append(fields)
                else:
                    opcodes_ext.append(fields)

    print 'opcodes = ['
    print '    ' + ',\n    '.join(opcodes)
    print ']'
    print
    print 'opcodes_ext = ['
    print '    ' + ',\n    '.join(opcodes_ext)
    print ']'

if __name__ == '__main__':
    if len(sys.argv) != 2:
        print 'usage: %s /path/to/DSPTables.cpp' % sys.argv[0]
        sys.exit(1)

    text = open(sys.argv[1]).read()

    print "#### THIS CODE WAS AUTO-GENERATED BY gen_from_tables.py ####"
    gen_from_text(text)
    print "#### END AUTO-GENERATED CODE ####"