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
 119
 120 _u32 = _read_int
 121
 122
 123 def _s32(reader):
 124     v = _read_int(reader)
 125     if v & 0x80000000 != 0:
 126         v = - ((v ^ 0xffffffff) + 1)
 127     return v
 128
 129
 130 def _s24(reader):
 131     bs = reader.read(3)
 132     assert len(bs) == 3
 133     last_byte = b'\xff' if (ord(bs[2:3]) >= 0x80) else b'\x00'
 134     return compat_struct_unpack('<i', bs + last_byte)[0]
 135
 136
 137 def _read_string(reader):
 138     slen = _u30(reader)
 139     resb = reader.read(slen)
 140     assert len(resb) == slen
 141     return resb.decode('utf-8')
 142
 143
 144 def _read_bytes(count, reader):
 145     assert count >= 0
 146     resb = reader.read(count)
 147     assert len(resb) == count
 148     return resb
 149
 150
 151 def _read_byte(reader):
 152     resb = _read_bytes(1, reader=reader)
 153     res = compat_struct_unpack('<B', resb)[0]
 154     return res
 155
 156
 157 StringClass = _AVMClass('(no name idx)', 'String')
 158 ByteArrayClass = _AVMClass('(no name idx)', 'ByteArray')
 159 TimerClass = _AVMClass('(no name idx)', 'Timer')
 160 TimerEventClass = _AVMClass('(no name idx)', 'TimerEvent', {'TIMER': 'timer'})
 161 _builtin_classes = {
 162     StringClass.name: StringClass,
 163     ByteArrayClass.name: ByteArrayClass,
 164     TimerClass.name: TimerClass,
 165     TimerEventClass.name: TimerEventClass,
 166 }
 167
 168
 169 class _Undefined(object):
 170     def __bool__(self):
 171         return False
 172     __nonzero__ = __bool__
 173
 174     def __hash__(self):
 175         return 0
 176
 177     def __str__(self):
 178         return 'undefined'
 179     __repr__ = __str__
 180
 181
 182 undefined = _Undefined()
 183
 184
 185 class SWFInterpreter(object):
 186     def __init__(self, file_contents):
 187         self._patched_functions = {
 188             (TimerClass, 'addEventListener'): lambda params: undefined,
 189         }
 190         code_tag = next(tag
 191                         for tag_code, tag in _extract_tags(file_contents)
 192                         if tag_code == 82)
 193         p = code_tag.index(b'\0', 4) + 1
 194         code_reader = io.BytesIO(code_tag[p:])
 195
 196         # Parse ABC (AVM2 ByteCode)
 197
 198         # Define a couple convenience methods
 199         u30 = lambda *args: _u30(*args, reader=code_reader)
 200         s32 = lambda *args: _s32(*args, reader=code_reader)
 201         u32 = lambda *args: _u32(*args, reader=code_reader)
 202         read_bytes = lambda *args: _read_bytes(*args, reader=code_reader)
 203         read_byte = lambda *args: _read_byte(*args, reader=code_reader)
 204
 205         # minor_version + major_version
 206         read_bytes(2 + 2)
 207
 208         # Constant pool
 209         int_count = u30()
 210         self.constant_ints = [0]
 211         for _c in range(1, int_count):
 212             self.constant_ints.append(s32())
 213         self.constant_uints = [0]
 214         uint_count = u30()
 215         for _c in range(1, uint_count):
 216             self.constant_uints.append(u32())
 217         double_count = u30()
 218         read_bytes(max(0, (double_count - 1)) * 8)
 219         string_count = u30()
 220         self.constant_strings = ['']
 221         for _c in range(1, string_count):
 222             s = _read_string(code_reader)
 223             self.constant_strings.append(s)
 224         namespace_count = u30()
 225         for _c in range(1, namespace_count):
 226             read_bytes(1)  # kind
 227             u30()  # name
 228         ns_set_count = u30()
 229         for _c in range(1, ns_set_count):
 230             count = u30()
 231             for _c2 in range(count):
 232                 u30()
 233         multiname_count = u30()
 234         MULTINAME_SIZES = {
 235             0x07: 2,  # QName
 236             0x0d: 2,  # QNameA
 237             0x0f: 1,  # RTQName
 238             0x10: 1,  # RTQNameA
 239             0x11: 0,  # RTQNameL
 240             0x12: 0,  # RTQNameLA
 241             0x09: 2,  # Multiname
 242             0x0e: 2,  # MultinameA
 243             0x1b: 1,  # MultinameL
 244             0x1c: 1,  # MultinameLA
 245         }
 246         self.multinames = ['']
 247         for _c in range(1, multiname_count):
 248             kind = u30()
 249             assert kind in MULTINAME_SIZES, 'Invalid multiname kind %r' % kind
 250             if kind == 0x07:
 251                 u30()  # namespace_idx
 252                 name_idx = u30()
 253                 self.multinames.append(self.constant_strings[name_idx])
 254             elif kind == 0x09:
 255                 name_idx = u30()
 256                 u30()
 257                 self.multinames.append(self.constant_strings[name_idx])
 258             else:
 259                 self.multinames.append(_Multiname(kind))
 260                 for _c2 in range(MULTINAME_SIZES[kind]):
 261                     u30()
 262
 263         # Methods
 264         method_count = u30()
 265         MethodInfo = collections.namedtuple(
 266             'MethodInfo',
 267             ['NEED_ARGUMENTS', 'NEED_REST'])
 268         method_infos = []
 269         for method_id in range(method_count):
 270             param_count = u30()
 271             u30()  # return type
 272             for _ in range(param_count):
 273                 u30()  # param type
 274             u30()  # name index (always 0 for youtube)
 275             flags = read_byte()
 276             if flags & 0x08 != 0:
 277                 # Options present
 278                 option_count = u30()
 279                 for c in range(option_count):
 280                     u30()  # val
 281                     read_bytes(1)  # kind
 282             if flags & 0x80 != 0:
 283                 # Param names present
 284                 for _ in range(param_count):
 285                     u30()  # param name
 286             mi = MethodInfo(flags & 0x01 != 0, flags & 0x04 != 0)
 287             method_infos.append(mi)
 288
 289         # Metadata
 290         metadata_count = u30()
 291         for _c in range(metadata_count):
 292             u30()  # name
 293             item_count = u30()
 294             for _c2 in range(item_count):
 295                 u30()  # key
 296                 u30()  # value
 297
 298         def parse_traits_info():
 299             trait_name_idx = u30()
 300             kind_full = read_byte()
 301             kind = kind_full & 0x0f
 302             attrs = kind_full >> 4
 303             methods = {}
 304             constants = None
 305             if kind == 0x00:  # Slot
 306                 u30()  # Slot id
 307                 u30()  # type_name_idx
 308                 vindex = u30()
 309                 if vindex != 0:
 310                     read_byte()  # vkind
 311             elif kind == 0x06:  # Const
 312                 u30()  # Slot id
 313                 u30()  # type_name_idx
 314                 vindex = u30()
 315                 vkind = 'any'
 316                 if vindex != 0:
 317                     vkind = read_byte()
 318                 if vkind == 0x03:  # Constant_Int
 319                     value = self.constant_ints[vindex]
 320                 elif vkind == 0x04:  # Constant_UInt
 321                     value = self.constant_uints[vindex]
 322                 else:
 323                     return {}, None  # Ignore silently for now
 324                 constants = {self.multinames[trait_name_idx]: value}
 325             elif kind in (0x01, 0x02, 0x03):  # Method / Getter / Setter
 326                 u30()  # disp_id
 327                 method_idx = u30()
 328                 methods[self.multinames[trait_name_idx]] = method_idx
 329             elif kind == 0x04:  # Class
 330                 u30()  # slot_id
 331                 u30()  # classi
 332             elif kind == 0x05:  # Function
 333                 u30()  # slot_id
 334                 function_idx = u30()
 335                 methods[function_idx] = self.multinames[trait_name_idx]
 336             else:
 337                 raise ExtractorError('Unsupported trait kind %d' % kind)
 338
 339             if attrs & 0x4 != 0:  # Metadata present
 340                 metadata_count = u30()
 341                 for _c3 in range(metadata_count):
 342                     u30()  # metadata index
 343
 344             return methods, constants
 345
 346         # Classes
 347         class_count = u30()
 348         classes = []
 349         for class_id in range(class_count):
 350             name_idx = u30()
 351
 352             cname = self.multinames[name_idx]
 353             avm_class = _AVMClass(name_idx, cname)
 354             classes.append(avm_class)
 355
 356             u30()  # super_name idx
 357             flags = read_byte()
 358             if flags & 0x08 != 0:  # Protected namespace is present
 359                 u30()  # protected_ns_idx
 360             intrf_count = u30()
 361             for _c2 in range(intrf_count):
 362                 u30()
 363             u30()  # iinit
 364             trait_count = u30()
 365             for _c2 in range(trait_count):
 366                 trait_methods, trait_constants = parse_traits_info()
 367                 avm_class.register_methods(trait_methods)
 368                 if trait_constants:
 369                     avm_class.constants.update(trait_constants)
 370
 371         assert len(classes) == class_count
 372         self._classes_by_name = dict((c.name, c) for c in classes)
 373
 374         for avm_class in classes:
 375             avm_class.cinit_idx = u30()
 376             trait_count = u30()
 377             for _c2 in range(trait_count):
 378                 trait_methods, trait_constants = parse_traits_info()
 379                 avm_class.register_methods(trait_methods)
 380                 if trait_constants:
 381                     avm_class.constants.update(trait_constants)
 382
 383         # Scripts
 384         script_count = u30()
 385         for _c in range(script_count):
 386             u30()  # init
 387             trait_count = u30()
 388             for _c2 in range(trait_count):
 389                 parse_traits_info()
 390
 391         # Method bodies
 392         method_body_count = u30()
 393         Method = collections.namedtuple('Method', ['code', 'local_count'])
 394         self._all_methods = []
 395         for _c in range(method_body_count):
 396             method_idx = u30()
 397             u30()  # max_stack
 398             local_count = u30()
 399             u30()  # init_scope_depth
 400             u30()  # max_scope_depth
 401             code_length = u30()
 402             code = read_bytes(code_length)
 403             m = Method(code, local_count)
 404             self._all_methods.append(m)
 405             for avm_class in classes:
 406                 if method_idx in avm_class.method_idxs:
 407                     avm_class.methods[avm_class.method_idxs[method_idx]] = m
 408             exception_count = u30()
 409             for _c2 in range(exception_count):
 410                 u30()  # from
 411                 u30()  # to
 412                 u30()  # target
 413                 u30()  # exc_type
 414                 u30()  # var_name
 415             trait_count = u30()
 416             for _c2 in range(trait_count):
 417                 parse_traits_info()
 418
 419         assert p + code_reader.tell() == len(code_tag)
 420
 421     def patch_function(self, avm_class, func_name, f):
 422         self._patched_functions[(avm_class, func_name)] = f
 423
 424     def extract_class(self, class_name, call_cinit=True):
 425         try:
 426             res = self._classes_by_name[class_name]
 427         except KeyError:
 428             raise ExtractorError('Class %r not found' % class_name)
 429
 430         if call_cinit and hasattr(res, 'cinit_idx'):
 431             res.register_methods({'$cinit': res.cinit_idx})
 432             res.methods['$cinit'] = self._all_methods[res.cinit_idx]
 433             cinit = self.extract_function(res, '$cinit')
 434             cinit([])
 435
 436         return res
 437
 438     def extract_function(self, avm_class, func_name):
 439         p = self._patched_functions.get((avm_class, func_name))
 440         if p:
 441             return p
 442         if func_name in avm_class.method_pyfunctions:
 443             return avm_class.method_pyfunctions[func_name]
 444         if func_name in self._classes_by_name:
 445             return self._classes_by_name[func_name].make_object()
 446         if func_name not in avm_class.methods:
 447             raise ExtractorError('Cannot find function %s.%s' % (
 448                 avm_class.name, func_name))
 449         m = avm_class.methods[func_name]
 450
 451         def resfunc(args):
 452             # Helper functions
 453             coder = io.BytesIO(m.code)
 454             s24 = lambda: _s24(coder)
 455             u30 = lambda: _u30(coder)
 456
 457             registers = [avm_class.variables] + list(args) + [None] * m.local_count
 458             stack = []
 459             scopes = collections.deque([
 460                 self._classes_by_name, avm_class.constants, avm_class.variables])
 461             while True:
 462                 opcode = _read_byte(coder)
 463                 if opcode == 9:  # label
 464                     pass  # Spec says: "Do nothing."
 465                 elif opcode == 16:  # jump
 466                     offset = s24()
 467                     coder.seek(coder.tell() + offset)
 468                 elif opcode == 17:  # iftrue
 469                     offset = s24()
 470                     value = stack.pop()
 471                     if value:
 472                         coder.seek(coder.tell() + offset)
 473                 elif opcode == 18:  # iffalse
 474                     offset = s24()
 475                     value = stack.pop()
 476                     if not value:
 477                         coder.seek(coder.tell() + offset)
 478                 elif opcode == 19:  # ifeq
 479                     offset = s24()
 480                     value2 = stack.pop()
 481                     value1 = stack.pop()
 482                     if value2 == value1:
 483                         coder.seek(coder.tell() + offset)
 484                 elif opcode == 20:  # ifne
 485                     offset = s24()
 486                     value2 = stack.pop()
 487                     value1 = stack.pop()
 488                     if value2 != value1:
 489                         coder.seek(coder.tell() + offset)
 490                 elif opcode == 21:  # iflt
 491                     offset = s24()
 492                     value2 = stack.pop()
 493                     value1 = stack.pop()
 494                     if value1 < value2:
 495                         coder.seek(coder.tell() + offset)
 496                 elif opcode == 32:  # pushnull
 497                     stack.append(None)
 498                 elif opcode == 33:  # pushundefined
 499                     stack.append(undefined)
 500                 elif opcode == 36:  # pushbyte
 501                     v = _read_byte(coder)
 502                     stack.append(v)
 503                 elif opcode == 37:  # pushshort
 504                     v = u30()
 505                     stack.append(v)
 506                 elif opcode == 38:  # pushtrue
 507                     stack.append(True)
 508                 elif opcode == 39:  # pushfalse
 509                     stack.append(False)
 510                 elif opcode == 40:  # pushnan
 511                     stack.append(float('NaN'))
 512                 elif opcode == 42:  # dup
 513                     value = stack[-1]
 514                     stack.append(value)
 515                 elif opcode == 44:  # pushstring
 516                     idx = u30()
 517                     stack.append(self.constant_strings[idx])
 518                 elif opcode == 48:  # pushscope
 519                     new_scope = stack.pop()
 520                     scopes.append(new_scope)
 521                 elif opcode == 66:  # construct
 522                     arg_count = u30()
 523                     args = list(reversed(
 524                         [stack.pop() for _ in range(arg_count)]))
 525                     obj = stack.pop()
 526                     res = obj.avm_class.make_object()
 527                     stack.append(res)
 528                 elif opcode == 70:  # callproperty
 529                     index = u30()
 530                     mname = self.multinames[index]
 531                     arg_count = u30()
 532                     args = list(reversed(
 533                         [stack.pop() for _ in range(arg_count)]))
 534                     obj = stack.pop()
 535
 536                     if obj == StringClass:
 537                         if mname == 'String':
 538                             assert len(args) == 1
 539                             assert isinstance(args[0], (
 540                                 int, compat_str, _Undefined))
 541                             if args[0] == undefined:
 542                                 res = 'undefined'
 543                             else:
 544                                 res = compat_str(args[0])
 545                             stack.append(res)
 546                             continue
 547                         else:
 548                             raise NotImplementedError(
 549                                 'Function String.%s is not yet implemented'
 550                                 % mname)
 551                     elif isinstance(obj, _AVMClass_Object):
 552                         func = self.extract_function(obj.avm_class, mname)
 553                         res = func(args)
 554                         stack.append(res)
 555                         continue
 556                     elif isinstance(obj, _AVMClass):
 557                         func = self.extract_function(obj, mname)
 558                         res = func(args)
 559                         stack.append(res)
 560                         continue
 561                     elif isinstance(obj, _ScopeDict):
 562                         if mname in obj.avm_class.method_names:
 563                             func = self.extract_function(obj.avm_class, mname)
 564                             res = func(args)
 565                         else:
 566                             res = obj[mname]
 567                         stack.append(res)
 568                         continue
 569                     elif isinstance(obj, compat_str):
 570                         if mname == 'split':
 571                             assert len(args) == 1
 572                             assert isinstance(args[0], compat_str)
 573                             if args[0] == '':
 574                                 res = list(obj)
 575                             else:
 576                                 res = obj.split(args[0])
 577                             stack.append(res)
 578                             continue
 579                         elif mname == 'charCodeAt':
 580                             assert len(args) <= 1
 581                             idx = 0 if len(args) == 0 else args[0]
 582                             assert isinstance(idx, int)
 583                             res = ord(obj[idx])
 584                             stack.append(res)
 585                             continue
 586                     elif isinstance(obj, list):
 587                         if mname == 'slice':
 588                             assert len(args) == 1
 589                             assert isinstance(args[0], int)
 590                             res = obj[args[0]:]
 591                             stack.append(res)
 592                             continue
 593                         elif mname == 'join':
 594                             assert len(args) == 1
 595                             assert isinstance(args[0], compat_str)
 596                             res = args[0].join(obj)
 597                             stack.append(res)
 598                             continue
 599                     raise NotImplementedError(
 600                         'Unsupported property %r on %r'
 601                         % (mname, obj))
 602                 elif opcode == 71:  # returnvoid
 603                     res = undefined
 604                     return res
 605                 elif opcode == 72:  # returnvalue
 606                     res = stack.pop()
 607                     return res
 608                 elif opcode == 73:  # constructsuper
 609                     # Not yet implemented, just hope it works without it
 610                     arg_count = u30()
 611                     args = list(reversed(
 612                         [stack.pop() for _ in range(arg_count)]))
 613                     obj = stack.pop()
 614                 elif opcode == 74:  # constructproperty
 615                     index = u30()
 616                     arg_count = u30()
 617                     args = list(reversed(
 618                         [stack.pop() for _ in range(arg_count)]))
 619                     obj = stack.pop()
 620
 621                     mname = self.multinames[index]
 622                     assert isinstance(obj, _AVMClass)
 623
 624                     # We do not actually call the constructor for now;
 625                     # we just pretend it does nothing
 626                     stack.append(obj.make_object())
 627                 elif opcode == 79:  # callpropvoid
 628                     index = u30()
 629                     mname = self.multinames[index]
 630                     arg_count = u30()
 631                     args = list(reversed(
 632                         [stack.pop() for _ in range(arg_count)]))
 633                     obj = stack.pop()
 634                     if isinstance(obj, _AVMClass_Object):
 635                         func = self.extract_function(obj.avm_class, mname)
 636                         res = func(args)
 637                         assert res is undefined
 638                         continue
 639                     if isinstance(obj, _ScopeDict):
 640                         assert mname in obj.avm_class.method_names
 641                         func = self.extract_function(obj.avm_class, mname)
 642                         res = func(args)
 643                         assert res is undefined
 644                         continue
 645                     if mname == 'reverse':
 646                         assert isinstance(obj, list)
 647                         obj.reverse()
 648                     else:
 649                         raise NotImplementedError(
 650                             'Unsupported (void) property %r on %r'
 651                             % (mname, obj))
 652                 elif opcode == 86:  # newarray
 653                     arg_count = u30()
 654                     arr = []
 655                     for i in range(arg_count):
 656                         arr.append(stack.pop())
 657                     arr = arr[::-1]
 658                     stack.append(arr)
 659                 elif opcode == 93:  # findpropstrict
 660                     index = u30()
 661                     mname = self.multinames[index]
 662                     for s in reversed(scopes):
 663                         if mname in s:
 664                             res = s
 665                             break
 666                     else:
 667                         res = scopes[0]
 668                     if mname not in res and mname in _builtin_classes:
 669                         stack.append(_builtin_classes[mname])
 670                     else:
 671                         stack.append(res[mname])
 672                 elif opcode == 94:  # findproperty
 673                     index = u30()
 674                     mname = self.multinames[index]
 675                     for s in reversed(scopes):
 676                         if mname in s:
 677                             res = s
 678                             break
 679                     else:
 680                         res = avm_class.variables
 681                     stack.append(res)
 682                 elif opcode == 96:  # getlex
 683                     index = u30()
 684                     mname = self.multinames[index]
 685                     for s in reversed(scopes):
 686                         if mname in s:
 687                             scope = s
 688                             break
 689                     else:
 690                         scope = avm_class.variables
 691
 692                     if mname in scope:
 693                         res = scope[mname]
 694                     elif mname in _builtin_classes:
 695                         res = _builtin_classes[mname]
 696                     else:
 697                         # Assume uninitialized
 698                         # TODO warn here
 699                         res = undefined
 700                     stack.append(res)
 701                 elif opcode == 97:  # setproperty
 702                     index = u30()
 703                     value = stack.pop()
 704                     idx = self.multinames[index]
 705                     if isinstance(idx, _Multiname):
 706                         idx = stack.pop()
 707                     obj = stack.pop()
 708                     obj[idx] = value
 709                 elif opcode == 98:  # getlocal
 710                     index = u30()
 711                     stack.append(registers[index])
 712                 elif opcode == 99:  # setlocal
 713                     index = u30()
 714                     value = stack.pop()
 715                     registers[index] = value
 716                 elif opcode == 102:  # getproperty
 717                     index = u30()
 718                     pname = self.multinames[index]
 719                     if pname == 'length':
 720                         obj = stack.pop()
 721                         assert isinstance(obj, (compat_str, list))
 722                         stack.append(len(obj))
 723                     elif isinstance(pname, compat_str):  # Member access
 724                         obj = stack.pop()
 725                         if isinstance(obj, _AVMClass):
 726                             res = obj.static_properties[pname]
 727                             stack.append(res)
 728                             continue
 729
 730                         assert isinstance(obj, (dict, _ScopeDict)),\
 731                             'Accessing member %r on %r' % (pname, obj)
 732                         res = obj.get(pname, undefined)
 733                         stack.append(res)
 734                     else:  # Assume attribute access
 735                         idx = stack.pop()
 736                         assert isinstance(idx, int)
 737                         obj = stack.pop()
 738                         assert isinstance(obj, list)
 739                         stack.append(obj[idx])
 740                 elif opcode == 104:  # initproperty
 741                     index = u30()
 742                     value = stack.pop()
 743                     idx = self.multinames[index]
 744                     if isinstance(idx, _Multiname):
 745                         idx = stack.pop()
 746                     obj = stack.pop()
 747                     obj[idx] = value
 748                 elif opcode == 115:  # convert_
 749                     value = stack.pop()
 750                     intvalue = int(value)
 751                     stack.append(intvalue)
 752                 elif opcode == 128:  # coerce
 753                     u30()
 754                 elif opcode == 130:  # coerce_a
 755                     value = stack.pop()
 756                     # um, yes, it's any value
 757                     stack.append(value)
 758                 elif opcode == 133:  # coerce_s
 759                     assert isinstance(stack[-1], (type(None), compat_str))
 760                 elif opcode == 147:  # decrement
 761                     value = stack.pop()
 762                     assert isinstance(value, int)
 763                     stack.append(value - 1)
 764                 elif opcode == 149:  # typeof
 765                     value = stack.pop()
 766                     return {
 767                         _Undefined: 'undefined',
 768                         compat_str: 'String',
 769                         int: 'Number',
 770                         float: 'Number',
 771                     }[type(value)]
 772                 elif opcode == 160:  # add
 773                     value2 = stack.pop()
 774                     value1 = stack.pop()
 775                     res = value1 + value2
 776                     stack.append(res)
 777                 elif opcode == 161:  # subtract
 778                     value2 = stack.pop()
 779                     value1 = stack.pop()
 780                     res = value1 - value2
 781                     stack.append(res)
 782                 elif opcode == 162:  # multiply
 783                     value2 = stack.pop()
 784                     value1 = stack.pop()
 785                     res = value1 * value2
 786                     stack.append(res)
 787                 elif opcode == 164:  # modulo
 788                     value2 = stack.pop()
 789                     value1 = stack.pop()
 790                     res = value1 % value2
 791                     stack.append(res)
 792                 elif opcode == 168:  # bitand
 793                     value2 = stack.pop()
 794                     value1 = stack.pop()
 795                     assert isinstance(value1, int)
 796                     assert isinstance(value2, int)
 797                     res = value1 & value2
 798                     stack.append(res)
 799                 elif opcode == 171:  # equals
 800                     value2 = stack.pop()
 801                     value1 = stack.pop()
 802                     result = value1 == value2
 803                     stack.append(result)
 804                 elif opcode == 175:  # greaterequals
 805                     value2 = stack.pop()
 806                     value1 = stack.pop()
 807                     result = value1 >= value2
 808                     stack.append(result)
 809                 elif opcode == 192:  # increment_i
 810                     value = stack.pop()
 811                     assert isinstance(value, int)
 812                     stack.append(value + 1)
 813                 elif opcode == 208:  # getlocal_0
 814                     stack.append(registers[0])
 815                 elif opcode == 209:  # getlocal_1
 816                     stack.append(registers[1])
 817                 elif opcode == 210:  # getlocal_2
 818                     stack.append(registers[2])
 819                 elif opcode == 211:  # getlocal_3
 820                     stack.append(registers[3])
 821                 elif opcode == 212:  # setlocal_0
 822                     registers[0] = stack.pop()
 823                 elif opcode == 213:  # setlocal_1
 824                     registers[1] = stack.pop()
 825                 elif opcode == 214:  # setlocal_2
 826                     registers[2] = stack.pop()
 827                 elif opcode == 215:  # setlocal_3
 828                     registers[3] = stack.pop()
 829                 else:
 830                     raise NotImplementedError(
 831                         'Unsupported opcode %d' % opcode)
 832
 833         avm_class.method_pyfunctions[func_name] = resfunc
 834         return resfunc