youtube_dl/swfinterp.py

   1 from __future__ import unicode_literals
   2
   3 import collections
   4 import io
   5 import zlib
   6
   7 from .compat import (
   8     compat_str,
   9     compat_struct_unpack,
  10 )
  11 from .utils import (
  12     ExtractorError,
  13 )
  14
  15
  16 def _extract_tags(file_contents):
  17     if file_contents[1:3] != b'WS':
  18         raise ExtractorError(
  19             'Not an SWF file; header is %r' % file_contents[:3])
  20     if file_contents[:1] == b'C':
  21         content = zlib.decompress(file_contents[8:])
  22     else:
  23         raise NotImplementedError(
  24             'Unsupported compression format %r' %
  25             file_contents[:1])
  26
  27     # Determine number of bits in framesize rectangle
  28     framesize_nbits = compat_struct_unpack('!B', content[:1])[0] >> 3
  29     framesize_len = (5 + 4 * framesize_nbits + 7) // 8
  30
  31     pos = framesize_len + 2 + 2
  32     while pos < len(content):
  33         header16 = compat_struct_unpack('<H', content[pos:pos + 2])[0]
  34         pos += 2
  35         tag_code = header16 >> 6
  36         tag_len = header16 & 0x3f
  37         if tag_len == 0x3f:
  38             tag_len = compat_struct_unpack('<I', content[pos:pos + 4])[0]
  39             pos += 4
  40         assert pos + tag_len <= len(content), \
  41             ('Tag %d ends at %d+%d - that\'s longer than the file (%d)'
  42                 % (tag_code, pos, tag_len, len(content)))
  43         yield (tag_code, content[pos:pos + tag_len])
  44         pos += tag_len
  45
  46
  47 class _AVMClass_Object(object):
  48     def __init__(self, avm_class):
  49         self.avm_class = avm_class
  50
  51     def __repr__(self):
  52         return '%s#%x' % (self.avm_class.name, id(self))
  53
  54
  55 class _ScopeDict(dict):
  56     def __init__(self, avm_class):
  57         super(_ScopeDict, self).__init__()
  58         self.avm_class = avm_class
  59
  60     def __repr__(self):
  61         return '%s__Scope(%s)' % (
  62             self.avm_class.name,
  63             super(_ScopeDict, self).__repr__())
  64
  65
  66 class _AVMClass(object):
  67     def __init__(self, name_idx, name, static_properties=None):
  68         self.name_idx = name_idx
  69         self.name = name
  70         self.method_names = {}
  71         self.method_idxs = {}
  72         self.methods = {}
  73         self.method_pyfunctions = {}
  74         self.static_properties = static_properties if static_properties else {}
  75
  76         self.variables = _ScopeDict(self)
  77         self.constants = {}
  78
  79     def make_object(self):
  80         return _AVMClass_Object(self)
  81
  82     def __repr__(self):
  83         return '_AVMClass(%s)' % (self.name)
  84
  85     def register_methods(self, methods):
  86         self.method_names.update(methods.items())
  87         self.method_idxs.update(dict(
  88             (idx, name)
  89             for name, idx in methods.items()))
  90
  91
  92 class _Multiname(object):
  93     def __init__(self, kind):
  94         self.kind = kind
  95
  96     def __repr__(self):
  97         return '[MULTINAME kind: 0x%x]' % self.kind
  98
  99
 100 def _read_int(reader):
 101     res = 0
 102     shift = 0
 103     for _ in range(5):
 104         buf = reader.read(1)
 105         assert len(buf) == 1
 106         b = compat_struct_unpack('<B', buf)[0]
 107         res = res | ((b & 0x7f) << shift)
 108         if b & 0x80 == 0:
 109             break
 110         shift += 7
 111     return res
 112
 113
 114 def _u30(reader):
 115     res = _read_int(reader)
 116     assert res & 0xf0000000 == 0
 117     return res
 118 _u32 = _read_int
 119
 120
 121 def _s32(reader):
 122     v = _read_int(reader)
 123     if v & 0x80000000 != 0:
 124         v = - ((v ^ 0xffffffff) + 1)
 125     return v
 126
 127
 128 def _s24(reader):
 129     bs = reader.read(3)
 130     assert len(bs) == 3
 131     last_byte = b'\xff' if (ord(bs[2:3]) >= 0x80) else b'\x00'
 132     return compat_struct_unpack('<i', bs + last_byte)[0]
 133
 134
 135 def _read_string(reader):
 136     slen = _u30(reader)
 137     resb = reader.read(slen)
 138     assert len(resb) == slen
 139     return resb.decode('utf-8')
 140
 141
 142 def _read_bytes(count, reader):
 143     assert count >= 0
 144     resb = reader.read(count)
 145     assert len(resb) == count
 146     return resb
 147
 148
 149 def _read_byte(reader):
 150     resb = _read_bytes(1, reader=reader)
 151     res = compat_struct_unpack('<B', resb)[0]
 152     return res
 153
 154
 155 StringClass = _AVMClass('(no name idx)', 'String')
 156 ByteArrayClass = _AVMClass('(no name idx)', 'ByteArray')
 157 TimerClass = _AVMClass('(no name idx)', 'Timer')
 158 TimerEventClass = _AVMClass('(no name idx)', 'TimerEvent', {'TIMER': 'timer'})
 159 _builtin_classes = {
 160     StringClass.name: StringClass,
 161     ByteArrayClass.name: ByteArrayClass,
 162     TimerClass.name: TimerClass,
 163     TimerEventClass.name: TimerEventClass,
 164 }
 165
 166
 167 class _Undefined(object):
 168     def __bool__(self):
 169         return False
 170     __nonzero__ = __bool__
 171
 172     def __hash__(self):
 173         return 0
 174
 175     def __str__(self):
 176         return 'undefined'
 177     __repr__ = __str__
 178
 179 undefined = _Undefined()
 180
 181
 182 class SWFInterpreter(object):
 183     def __init__(self, file_contents):
 184         self._patched_functions = {
 185             (TimerClass, 'addEventListener'): lambda params: undefined,
 186         }
 187         code_tag = next(tag
 188                         for tag_code, tag in _extract_tags(file_contents)
 189                         if tag_code == 82)
 190         p = code_tag.index(b'\0', 4) + 1
 191         code_reader = io.BytesIO(code_tag[p:])
 192
 193         # Parse ABC (AVM2 ByteCode)
 194
 195         # Define a couple convenience methods
 196         u30 = lambda *args: _u30(*args, reader=code_reader)
 197         s32 = lambda *args: _s32(*args, reader=code_reader)
 198         u32 = lambda *args: _u32(*args, reader=code_reader)
 199         read_bytes = lambda *args: _read_bytes(*args, reader=code_reader)
 200         read_byte = lambda *args: _read_byte(*args, reader=code_reader)
 201
 202         # minor_version + major_version
 203         read_bytes(2 + 2)
 204
 205         # Constant pool
 206         int_count = u30()
 207         self.constant_ints = [0]
 208         for _c in range(1, int_count):
 209             self.constant_ints.append(s32())
 210         self.constant_uints = [0]
 211         uint_count = u30()
 212         for _c in range(1, uint_count):
 213             self.constant_uints.append(u32())
 214         double_count = u30()
 215         read_bytes(max(0, (double_count - 1)) * 8)
 216         string_count = u30()
 217         self.constant_strings = ['']
 218         for _c in range(1, string_count):
 219             s = _read_string(code_reader)
 220             self.constant_strings.append(s)
 221         namespace_count = u30()
 222         for _c in range(1, namespace_count):
 223             read_bytes(1)  # kind
 224             u30()  # name
 225         ns_set_count = u30()
 226         for _c in range(1, ns_set_count):
 227             count = u30()
 228             for _c2 in range(count):
 229                 u30()
 230         multiname_count = u30()
 231         MULTINAME_SIZES = {
 232             0x07: 2,  # QName
 233             0x0d: 2,  # QNameA
 234             0x0f: 1,  # RTQName
 235             0x10: 1,  # RTQNameA
 236             0x11: 0,  # RTQNameL
 237             0x12: 0,  # RTQNameLA
 238             0x09: 2,  # Multiname
 239             0x0e: 2,  # MultinameA
 240             0x1b: 1,  # MultinameL
 241             0x1c: 1,  # MultinameLA
 242         }
 243         self.multinames = ['']
 244         for _c in range(1, multiname_count):
 245             kind = u30()
 246             assert kind in MULTINAME_SIZES, 'Invalid multiname kind %r' % kind
 247             if kind == 0x07:
 248                 u30()  # namespace_idx
 249                 name_idx = u30()
 250                 self.multinames.append(self.constant_strings[name_idx])
 251             elif kind == 0x09:
 252                 name_idx = u30()
 253                 u30()
 254                 self.multinames.append(self.constant_strings[name_idx])
 255             else:
 256                 self.multinames.append(_Multiname(kind))
 257                 for _c2 in range(MULTINAME_SIZES[kind]):
 258                     u30()
 259
 260         # Methods
 261         method_count = u30()
 262         MethodInfo = collections.namedtuple(
 263             'MethodInfo',
 264             ['NEED_ARGUMENTS', 'NEED_REST'])
 265         method_infos = []
 266         for method_id in range(method_count):
 267             param_count = u30()
 268             u30()  # return type
 269             for _ in range(param_count):
 270                 u30()  # param type
 271             u30()  # name index (always 0 for youtube)
 272             flags = read_byte()
 273             if flags & 0x08 != 0:
 274                 # Options present
 275                 option_count = u30()
 276                 for c in range(option_count):
 277                     u30()  # val
 278                     read_bytes(1)  # kind
 279             if flags & 0x80 != 0:
 280                 # Param names present
 281                 for _ in range(param_count):
 282                     u30()  # param name
 283             mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
 284             method_infos.append(mi)
 285
 286         # Metadata
 287         metadata_count = u30()
 288         for _c in range(metadata_count):
 289             u30()  # name
 290             item_count = u30()
 291             for _c2 in range(item_count):
 292                 u30()  # key
 293                 u30()  # value
 294
 295         def parse_traits_info():
 296             trait_name_idx = u30()
 297             kind_full = read_byte()
 298             kind = kind_full & 0x0f
 299             attrs = kind_full >> 4
 300             methods = {}
 301             constants = None
 302             if kind == 0x00:  # Slot
 303                 u30()  # Slot id
 304                 u30()  # type_name_idx
 305                 vindex = u30()
 306                 if vindex != 0:
 307                     read_byte()  # vkind
 308             elif kind == 0x06:  # Const
 309                 u30()  # Slot id
 310                 u30()  # type_name_idx
 311                 vindex = u30()
 312                 vkind = 'any'
 313                 if vindex != 0:
 314                     vkind = read_byte()
 315                 if vkind == 0x03:  # Constant_Int
 316                     value = self.constant_ints[vindex]
 317                 elif vkind == 0x04:  # Constant_UInt
 318                     value = self.constant_uints[vindex]
 319                 else:
 320                     return {}, None  # Ignore silently for now
 321                 constants = {self.multinames[trait_name_idx]: value}
 322             elif kind in (0x01, 0x02, 0x03):  # Method / Getter / Setter
 323                 u30()  # disp_id
 324                 method_idx = u30()
 325                 methods[self.multinames[trait_name_idx]] = method_idx
 326             elif kind == 0x04:  # Class
 327                 u30()  # slot_id
 328                 u30()  # classi
 329             elif kind == 0x05:  # Function
 330                 u30()  # slot_id
 331                 function_idx = u30()
 332                 methods[function_idx] = self.multinames[trait_name_idx]
 333             else:
 334                 raise ExtractorError('Unsupported trait kind %d' % kind)
 335
 336             if attrs & 0x4 != 0:  # Metadata present
 337                 metadata_count = u30()
 338                 for _c3 in range(metadata_count):
 339                     u30()  # metadata index
 340
 341             return methods, constants
 342
 343         # Classes
 344         class_count = u30()
 345         classes = []
 346         for class_id in range(class_count):
 347             name_idx = u30()
 348
 349             cname = self.multinames[name_idx]
 350             avm_class = _AVMClass(name_idx, cname)
 351             classes.append(avm_class)
 352
 353             u30()  # super_name idx
 354             flags = read_byte()
 355             if flags & 0x08 != 0:  # Protected namespace is present
 356                 u30()  # protected_ns_idx
 357             intrf_count = u30()
 358             for _c2 in range(intrf_count):
 359                 u30()
 360             u30()  # iinit
 361             trait_count = u30()
 362             for _c2 in range(trait_count):
 363                 trait_methods, trait_constants = parse_traits_info()
 364                 avm_class.register_methods(trait_methods)
 365                 if trait_constants:
 366                     avm_class.constants.update(trait_constants)
 367
 368         assert len(classes) == class_count
 369         self._classes_by_name = dict((c.name, c) for c in classes)
 370
 371         for avm_class in classes:
 372             avm_class.cinit_idx = u30()
 373             trait_count = u30()
 374             for _c2 in range(trait_count):
 375                 trait_methods, trait_constants = parse_traits_info()
 376                 avm_class.register_methods(trait_methods)
 377                 if trait_constants:
 378                     avm_class.constants.update(trait_constants)
 379
 380         # Scripts
 381         script_count = u30()
 382         for _c in range(script_count):
 383             u30()  # init
 384             trait_count = u30()
 385             for _c2 in range(trait_count):
 386                 parse_traits_info()
 387
 388         # Method bodies
 389         method_body_count = u30()
 390         Method = collections.namedtuple('Method', ['code', 'local_count'])
 391         self._all_methods = []
 392         for _c in range(method_body_count):
 393             method_idx = u30()
 394             u30()  # max_stack
 395             local_count = u30()
 396             u30()  # init_scope_depth
 397             u30()  # max_scope_depth
 398             code_length = u30()
 399             code = read_bytes(code_length)
 400             m = Method(code, local_count)
 401             self._all_methods.append(m)
 402             for avm_class in classes:
 403                 if method_idx in avm_class.method_idxs:
 404                     avm_class.methods[avm_class.method_idxs[method_idx]] = m
 405             exception_count = u30()
 406             for _c2 in range(exception_count):
 407                 u30()  # from
 408                 u30()  # to
 409                 u30()  # target
 410                 u30()  # exc_type
 411                 u30()  # var_name
 412             trait_count = u30()
 413             for _c2 in range(trait_count):
 414                 parse_traits_info()
 415
 416         assert p + code_reader.tell() == len(code_tag)
 417
 418     def patch_function(self, avm_class, func_name, f):
 419         self._patched_functions[(avm_class, func_name)] = f
 420
 421     def extract_class(self, class_name, call_cinit=True):
 422         try:
 423             res = self._classes_by_name[class_name]
 424         except KeyError:
 425             raise ExtractorError('Class %r not found' % class_name)
 426
 427         if call_cinit and hasattr(res, 'cinit_idx'):
 428             res.register_methods({'$cinit': res.cinit_idx})
 429             res.methods['$cinit'] = self._all_methods[res.cinit_idx]
 430             cinit = self.extract_function(res, '$cinit')
 431             cinit([])
 432
 433         return res
 434
 435     def extract_function(self, avm_class, func_name):
 436         p = self._patched_functions.get((avm_class, func_name))
 437         if p:
 438             return p
 439         if func_name in avm_class.method_pyfunctions:
 440             return avm_class.method_pyfunctions[func_name]
 441         if func_name in self._classes_by_name:
 442             return self._classes_by_name[func_name].make_object()
 443         if func_name not in avm_class.methods:
 444             raise ExtractorError('Cannot find function %s.%s' % (
 445                 avm_class.name, func_name))
 446         m = avm_class.methods[func_name]
 447
 448         def resfunc(args):
 449             # Helper functions
 450             coder = io.BytesIO(m.code)
 451             s24 = lambda: _s24(coder)
 452             u30 = lambda: _u30(coder)
 453
 454             registers = [avm_class.variables] + list(args) + [None] * m.local_count
 455             stack = []
 456             scopes = collections.deque([
 457                 self._classes_by_name, avm_class.constants, avm_class.variables])
 458             while True:
 459                 opcode = _read_byte(coder)
 460                 if opcode == 9:  # label
 461                     pass  # Spec says: "Do nothing."
 462                 elif opcode == 16:  # jump
 463                     offset = s24()
 464                     coder.seek(coder.tell() + offset)
 465                 elif opcode == 17:  # iftrue
 466                     offset = s24()
 467                     value = stack.pop()
 468                     if value:
 469                         coder.seek(coder.tell() + offset)
 470                 elif opcode == 18:  # iffalse
 471                     offset = s24()
 472                     value = stack.pop()
 473                     if not value:
 474                         coder.seek(coder.tell() + offset)
 475                 elif opcode == 19:  # ifeq
 476                     offset = s24()
 477                     value2 = stack.pop()
 478                     value1 = stack.pop()
 479                     if value2 == value1:
 480                         coder.seek(coder.tell() + offset)
 481                 elif opcode == 20:  # ifne
 482                     offset = s24()
 483                     value2 = stack.pop()
 484                     value1 = stack.pop()
 485                     if value2 != value1:
 486                         coder.seek(coder.tell() + offset)
 487                 elif opcode == 21:  # iflt
 488                     offset = s24()
 489                     value2 = stack.pop()
 490                     value1 = stack.pop()
 491                     if value1 < value2:
 492                         coder.seek(coder.tell() + offset)
 493                 elif opcode == 32:  # pushnull
 494                     stack.append(None)
 495                 elif opcode == 33:  # pushundefined
 496                     stack.append(undefined)
 497                 elif opcode == 36:  # pushbyte
 498                     v = _read_byte(coder)
 499                     stack.append(v)
 500                 elif opcode == 37:  # pushshort
 501                     v = u30()
 502                     stack.append(v)
 503                 elif opcode == 38:  # pushtrue
 504                     stack.append(True)
 505                 elif opcode == 39:  # pushfalse
 506                     stack.append(False)
 507                 elif opcode == 40:  # pushnan
 508                     stack.append(float('NaN'))
 509                 elif opcode == 42:  # dup
 510                     value = stack[-1]
 511                     stack.append(value)
 512                 elif opcode == 44:  # pushstring
 513                     idx = u30()
 514                     stack.append(self.constant_strings[idx])
 515                 elif opcode == 48:  # pushscope
 516                     new_scope = stack.pop()
 517                     scopes.append(new_scope)
 518                 elif opcode == 66:  # construct
 519                     arg_count = u30()
 520                     args = list(reversed(
 521                         [stack.pop() for _ in range(arg_count)]))
 522                     obj = stack.pop()
 523                     res = obj.avm_class.make_object()
 524                     stack.append(res)
 525                 elif opcode == 70:  # callproperty
 526                     index = u30()
 527                     mname = self.multinames[index]
 528                     arg_count = u30()
 529                     args = list(reversed(
 530                         [stack.pop() for _ in range(arg_count)]))
 531                     obj = stack.pop()
 532
 533                     if obj == StringClass:
 534                         if mname == 'String':
 535                             assert len(args) == 1
 536                             assert isinstance(args[0], (
 537                                 int, compat_str, _Undefined))
 538                             if args[0] == undefined:
 539                                 res = 'undefined'
 540                             else:
 541                                 res = compat_str(args[0])
 542                             stack.append(res)
 543                             continue
 544                         else:
 545                             raise NotImplementedError(
 546                                 'Function String.%s is not yet implemented'
 547                                 % mname)
 548                     elif isinstance(obj, _AVMClass_Object):
 549                         func = self.extract_function(obj.avm_class, mname)
 550                         res = func(args)
 551                         stack.append(res)
 552                         continue
 553                     elif isinstance(obj, _AVMClass):
 554                         func = self.extract_function(obj, mname)
 555                         res = func(args)
 556                         stack.append(res)
 557                         continue
 558                     elif isinstance(obj, _ScopeDict):
 559                         if mname in obj.avm_class.method_names:
 560                             func = self.extract_function(obj.avm_class, mname)
 561                             res = func(args)
 562                         else:
 563                             res = obj[mname]
 564                         stack.append(res)
 565                         continue
 566                     elif isinstance(obj, compat_str):
 567                         if mname == 'split':
 568                             assert len(args) == 1
 569                             assert isinstance(args[0], compat_str)
 570                             if args[0] == '':
 571                                 res = list(obj)
 572                             else:
 573                                 res = obj.split(args[0])
 574                             stack.append(res)
 575                             continue
 576                         elif mname == 'charCodeAt':
 577                             assert len(args) <= 1
 578                             idx = 0 if len(args) == 0 else args[0]
 579                             assert isinstance(idx, int)
 580                             res = ord(obj[idx])
 581                             stack.append(res)
 582                             continue
 583                     elif isinstance(obj, list):
 584                         if mname == 'slice':
 585                             assert len(args) == 1
 586                             assert isinstance(args[0], int)
 587                             res = obj[args[0]:]
 588                             stack.append(res)
 589                             continue
 590                         elif mname == 'join':
 591                             assert len(args) == 1
 592                             assert isinstance(args[0], compat_str)
 593                             res = args[0].join(obj)
 594                             stack.append(res)
 595                             continue
 596                     raise NotImplementedError(
 597                         'Unsupported property %r on %r'
 598                         % (mname, obj))
 599                 elif opcode == 71:  # returnvoid
 600                     res = undefined
 601                     return res
 602                 elif opcode == 72:  # returnvalue
 603                     res = stack.pop()
 604                     return res
 605                 elif opcode == 73:  # constructsuper
 606                     # Not yet implemented, just hope it works without it
 607                     arg_count = u30()
 608                     args = list(reversed(
 609                         [stack.pop() for _ in range(arg_count)]))
 610                     obj = stack.pop()
 611                 elif opcode == 74:  # constructproperty
 612                     index = u30()
 613                     arg_count = u30()
 614                     args = list(reversed(
 615                         [stack.pop() for _ in range(arg_count)]))
 616                     obj = stack.pop()
 617
 618                     mname = self.multinames[index]
 619                     assert isinstance(obj, _AVMClass)
 620
 621                     # We do not actually call the constructor for now;
 622                     # we just pretend it does nothing
 623                     stack.append(obj.make_object())
 624                 elif opcode == 79:  # callpropvoid
 625                     index = u30()
 626                     mname = self.multinames[index]
 627                     arg_count = u30()
 628                     args = list(reversed(
 629                         [stack.pop() for _ in range(arg_count)]))
 630                     obj = stack.pop()
 631                     if isinstance(obj, _AVMClass_Object):
 632                         func = self.extract_function(obj.avm_class, mname)
 633                         res = func(args)
 634                         assert res is undefined
 635                         continue
 636                     if isinstance(obj, _ScopeDict):
 637                         assert mname in obj.avm_class.method_names
 638                         func = self.extract_function(obj.avm_class, mname)
 639                         res = func(args)
 640                         assert res is undefined
 641                         continue
 642                     if mname == 'reverse':
 643                         assert isinstance(obj, list)
 644                         obj.reverse()
 645                     else:
 646                         raise NotImplementedError(
 647                             'Unsupported (void) property %r on %r'
 648                             % (mname, obj))
 649                 elif opcode == 86:  # newarray
 650                     arg_count = u30()
 651                     arr = []
 652                     for i in range(arg_count):
 653                         arr.append(stack.pop())
 654                     arr = arr[::-1]
 655                     stack.append(arr)
 656                 elif opcode == 93:  # findpropstrict
 657                     index = u30()
 658                     mname = self.multinames[index]
 659                     for s in reversed(scopes):
 660                         if mname in s:
 661                             res = s
 662                             break
 663                     else:
 664                         res = scopes[0]
 665                     if mname not in res and mname in _builtin_classes:
 666                         stack.append(_builtin_classes[mname])
 667                     else:
 668                         stack.append(res[mname])
 669                 elif opcode == 94:  # findproperty
 670                     index = u30()
 671                     mname = self.multinames[index]
 672                     for s in reversed(scopes):
 673                         if mname in s:
 674                             res = s
 675                             break
 676                     else:
 677                         res = avm_class.variables
 678                     stack.append(res)
 679                 elif opcode == 96:  # getlex
 680                     index = u30()
 681                     mname = self.multinames[index]
 682                     for s in reversed(scopes):
 683                         if mname in s:
 684                             scope = s
 685                             break
 686                     else:
 687                         scope = avm_class.variables
 688
 689                     if mname in scope:
 690                         res = scope[mname]
 691                     elif mname in _builtin_classes:
 692                         res = _builtin_classes[mname]
 693                     else:
 694                         # Assume uninitialized
 695                         # TODO warn here
 696                         res = undefined
 697                     stack.append(res)
 698                 elif opcode == 97:  # setproperty
 699                     index = u30()
 700                     value = stack.pop()
 701                     idx = self.multinames[index]
 702                     if isinstance(idx, _Multiname):
 703                         idx = stack.pop()
 704                     obj = stack.pop()
 705                     obj[idx] = value
 706                 elif opcode == 98:  # getlocal
 707                     index = u30()
 708                     stack.append(registers[index])
 709                 elif opcode == 99:  # setlocal
 710                     index = u30()
 711                     value = stack.pop()
 712                     registers[index] = value
 713                 elif opcode == 102:  # getproperty
 714                     index = u30()
 715                     pname = self.multinames[index]
 716                     if pname == 'length':
 717                         obj = stack.pop()
 718                         assert isinstance(obj, (compat_str, list))
 719                         stack.append(len(obj))
 720                     elif isinstance(pname, compat_str):  # Member access
 721                         obj = stack.pop()
 722                         if isinstance(obj, _AVMClass):
 723                             res = obj.static_properties[pname]
 724                             stack.append(res)
 725                             continue
 726
 727                         assert isinstance(obj, (dict, _ScopeDict)),\
 728                             'Accessing member %r on %r' % (pname, obj)
 729                         res = obj.get(pname, undefined)
 730                         stack.append(res)
 731                     else:  # Assume attribute access
 732                         idx = stack.pop()
 733                         assert isinstance(idx, int)
 734                         obj = stack.pop()
 735                         assert isinstance(obj, list)
 736                         stack.append(obj[idx])
 737                 elif opcode == 104:  # initproperty
 738                     index = u30()
 739                     value = stack.pop()
 740                     idx = self.multinames[index]
 741                     if isinstance(idx, _Multiname):
 742                         idx = stack.pop()
 743                     obj = stack.pop()
 744                     obj[idx] = value
 745                 elif opcode == 115:  # convert_
 746                     value = stack.pop()
 747                     intvalue = int(value)
 748                     stack.append(intvalue)
 749                 elif opcode == 128:  # coerce
 750                     u30()
 751                 elif opcode == 130:  # coerce_a
 752                     value = stack.pop()
 753                     # um, yes, it's any value
 754                     stack.append(value)
 755                 elif opcode == 133:  # coerce_s
 756                     assert isinstance(stack[-1], (type(None), compat_str))
 757                 elif opcode == 147:  # decrement
 758                     value = stack.pop()
 759                     assert isinstance(value, int)
 760                     stack.append(value - 1)
 761                 elif opcode == 149:  # typeof
 762                     value = stack.pop()
 763                     return {
 764                         _Undefined: 'undefined',
 765                         compat_str: 'String',
 766                         int: 'Number',
 767                         float: 'Number',
 768                     }[type(value)]
 769                 elif opcode == 160:  # add
 770                     value2 = stack.pop()
 771                     value1 = stack.pop()
 772                     res = value1 + value2
 773                     stack.append(res)
 774                 elif opcode == 161:  # subtract
 775                     value2 = stack.pop()
 776                     value1 = stack.pop()
 777                     res = value1 - value2
 778                     stack.append(res)
 779                 elif opcode == 162:  # multiply
 780                     value2 = stack.pop()
 781                     value1 = stack.pop()
 782                     res = value1 * value2
 783                     stack.append(res)
 784                 elif opcode == 164:  # modulo
 785                     value2 = stack.pop()
 786                     value1 = stack.pop()
 787                     res = value1 % value2
 788                     stack.append(res)
 789                 elif opcode == 168:  # bitand
 790                     value2 = stack.pop()
 791                     value1 = stack.pop()
 792                     assert isinstance(value1, int)
 793                     assert isinstance(value2, int)
 794                     res = value1 & value2
 795                     stack.append(res)
 796                 elif opcode == 171:  # equals
 797                     value2 = stack.pop()
 798                     value1 = stack.pop()
 799                     result = value1 == value2
 800                     stack.append(result)
 801                 elif opcode == 175:  # greaterequals
 802                     value2 = stack.pop()
 803                     value1 = stack.pop()
 804                     result = value1 >= value2
 805                     stack.append(result)
 806                 elif opcode == 192:  # increment_i
 807                     value = stack.pop()
 808                     assert isinstance(value, int)
 809                     stack.append(value + 1)
 810                 elif opcode == 208:  # getlocal_0
 811                     stack.append(registers[0])
 812                 elif opcode == 209:  # getlocal_1
 813                     stack.append(registers[1])
 814                 elif opcode == 210:  # getlocal_2
 815                     stack.append(registers[2])
 816                 elif opcode == 211:  # getlocal_3
 817                     stack.append(registers[3])
 818                 elif opcode == 212:  # setlocal_0
 819                     registers[0] = stack.pop()
 820                 elif opcode == 213:  # setlocal_1
 821                     registers[1] = stack.pop()
 822                 elif opcode == 214:  # setlocal_2
 823                     registers[2] = stack.pop()
 824                 elif opcode == 215:  # setlocal_3
 825                     registers[3] = stack.pop()
 826                 else:
 827                     raise NotImplementedError(
 828                         'Unsupported opcode %d' % opcode)
 829
 830         avm_class.method_pyfunctions[func_name] = resfunc
 831         return resfunc