bgiop.py

"""
Defines BGI script bytecode operations.

Besides functions, exports
  bgiop.ops and bgiop.rops dictionaries
  bgiop.offsets
"""

import re

import buriko_common
import buriko_setup

import asdis

re_fcn = re.compile(r'([A-Za-z_][A-Za-z0-9_:]*)\(.*\)')

offsets = set()


def clear_offsets():
    offsets.clear()


def get_string(code, addr, defines, *args):
    pos0 = args[0]
    pos1 = code.find(b'\x00', pos0)
    string = buriko_common.get_escaped_text(code[pos0:pos1]).decode(buriko_setup.senc)
    string = asdis.escape(string)
    return (string,)


def get_file(code, addr, defines, *args):
    pos0 = args[0]
    pos1 = code.find(b'\x00', pos0)
    string = code[pos0:pos1].decode(buriko_setup.senc)
    string = asdis.escape(string)
    lno = args[1]
    return (string, lno)


def get_offset(code, addr, defines, *args):
    offset = args[0]
    offsets.add(offset)
    if offset in defines:
        offset_s = defines[offset]
    else:
        offset_s = 'L%05x' % offset
    return (offset_s,)


ops = {
    0x000: ('<i', 'push_dword({:d})', None),
    0x001: ('<I', 'push_offset({})', get_offset),
    0x002: ('<i', 'push_base_offset({:d})', None),
    0x003: ('<I', 'push_string(MSGID::{1:04d}, "{0}")', get_string),
    0x008: ('<i', 'load({:d})', None),
    0x009: ('<i', 'move({:d})', None),
    0x00A: ('<i', 'move_arg({:d})', None),
    0x010: ('', 'load_base()', None),
    0x011: ('', 'store_base()', None),
    0x018: ('', 'jmp()', None),
    0x019: ('<I', 'jc({:#x})', None),
    0x01A: ('', 'call()', None),
    0x01B: ('', 'ret()', None),
    0x01E: ('', 'reg_exception_handler()', None),
    0x01F: ('', 'unreg_exception_handler()', None),
    0x020: ('', 'add()', None),
    0x021: ('', 'sub()', None),
    0x022: ('', 'mul()', None),
    0x023: ('', 'div()', None),
    0x024: ('', 'mod()', None),
    0x025: ('', 'and()', None),
    0x026: ('', 'or()', None),
    0x027: ('', 'xor()', None),
    0x028: ('', 'not()', None),
    0x029: ('', 'shl()', None),
    0x02A: ('', 'shr()', None),
    0x02B: ('', 'sar()', None),
    0x030: ('', 'eq()', None),
    0x031: ('', 'neq()', None),
    0x032: ('', 'leq()', None),
    0x033: ('', 'geq()', None),
    0x034: ('', 'lt()', None),
    0x035: ('', 'gt()', None),
    0x038: ('', 'bool_and()', None),
    0x039: ('', 'bool_or()', None),
    0x03A: ('', 'bool_zero()', None),
    0x03F: ('<i', 'nargs({:d})', None),
    0x07F: ('<Ii', 'line("{}", {:d})', get_file),
}

rops = {}


def _make_ops():
    """
    (Internal) Creates generic names for `ops` not explicitly defined above
    """
    for op in range(0x400):
        if op not in ops:
            if op < 0x100:
                ops[op] = ('', 'f_%03x()' % op, None)
            elif 0x100 <= op < 0x140:
                ops[op] = ('', 'sys_::f_%03x()' % op, None)
            elif 0x140 <= op < 0x160:
                ops[op] = ('', 'msg_::f_%03x()' % op, None)
            elif 0x160 <= op < 0x180:
                ops[op] = ('', 'slct::f_%03x()' % op, None)
            elif 0x180 <= op < 0x200:
                ops[op] = ('', 'snd_::f_%03x()' % op, None)
            elif 0x200 <= op < 0x400:
                ops[op] = ('', 'grp_::f_%03x()' % op, None)


def _make_rops():
    """
    (Internal) Defines the reverse-lookup dictionary `rops`
    """
    for op in ops:
        fcn, = re_fcn.match(ops[op][1]).groups()
        rops[fcn] = op


_make_ops()
_make_rops()