diff options
Diffstat (limited to 'youtube_dl/jsinterp.py')
| -rw-r--r-- | youtube_dl/jsinterp.py | 1659 |
1 files changed, 1458 insertions, 201 deletions
diff --git a/youtube_dl/jsinterp.py b/youtube_dl/jsinterp.py index 24cdec28c..7630e2099 100644 --- a/youtube_dl/jsinterp.py +++ b/youtube_dl/jsinterp.py @@ -1,258 +1,1515 @@ +# coding: utf-8 from __future__ import unicode_literals +import calendar +import itertools import json import operator import re +import time + +from functools import update_wrapper, wraps from .utils import ( + error_to_compat_str, ExtractorError, + float_or_none, + int_or_none, + js_to_json, + remove_quotes, + str_or_none, + unified_timestamp, + variadic, + write_string, +) +from .compat import ( + compat_basestring, + compat_chr, + compat_collections_chain_map as ChainMap, + compat_contextlib_suppress, + compat_filter as filter, + compat_int, + compat_integer_types, + compat_itertools_zip_longest as zip_longest, + compat_map as map, + compat_numeric_types, + compat_str, ) -_OPERATORS = [ - ('|', operator.or_), - ('^', operator.xor), - ('&', operator.and_), - ('>>', operator.rshift), - ('<<', operator.lshift), - ('-', operator.sub), - ('+', operator.add), - ('%', operator.mod), - ('/', operator.truediv), - ('*', operator.mul), -] -_ASSIGN_OPERATORS = [(op + '=', opfunc) for op, opfunc in _OPERATORS] -_ASSIGN_OPERATORS.append(('=', lambda cur, right: right)) -_NAME_RE = r'[a-zA-Z_$][a-zA-Z_$0-9]*' +# name JS functions +class function_with_repr(object): + # from yt_dlp/utils.py, but in this module + # repr_ is always set + def __init__(self, func, repr_): + update_wrapper(self, func) + self.func, self.__repr = func, repr_ + + def __call__(self, *args, **kwargs): + return self.func(*args, **kwargs) + + def __repr__(self): + return self.__repr + + +# name JS operators +def wraps_op(op): + + def update_and_rename_wrapper(w): + f = update_wrapper(w, op) + # fn names are str in both Py 2/3 + f.__name__ = str('JS_') + f.__name__ + return f + + return update_and_rename_wrapper + + +# NB In principle NaN cannot be checked by membership. +# Here all NaN values are actually this one, so _NaN is _NaN, +# although _NaN != _NaN. Ditto Infinity. + +_NaN = float('nan') +_Infinity = float('inf') + + +class JS_Undefined(object): + pass + + +def _js_bit_op(op, is_shift=False): + + def zeroise(x, is_shift_arg=False): + if isinstance(x, compat_integer_types): + return (x % 32) if is_shift_arg else (x & 0xffffffff) + try: + x = float(x) + if is_shift_arg: + x = int(x % 32) + elif x < 0: + x = -compat_int(-x % 0xffffffff) + else: + x = compat_int(x % 0xffffffff) + except (ValueError, TypeError): + # also here for int(NaN), including float('inf') % 32 + x = 0 + return x + + @wraps_op(op) + def wrapped(a, b): + return op(zeroise(a), zeroise(b, is_shift)) & 0xffffffff + + return wrapped + + +def _js_arith_op(op, div=False): + + @wraps_op(op) + def wrapped(a, b): + if JS_Undefined in (a, b): + return _NaN + # null, "" --> 0 + a, b = (float_or_none( + (x.strip() if isinstance(x, compat_basestring) else x) or 0, + default=_NaN) for x in (a, b)) + if _NaN in (a, b): + return _NaN + try: + return op(a, b) + except ZeroDivisionError: + return _NaN if not (div and (a or b)) else _Infinity + + return wrapped + + +_js_arith_add = _js_arith_op(operator.add) + + +def _js_add(a, b): + if not (isinstance(a, compat_basestring) or isinstance(b, compat_basestring)): + return _js_arith_add(a, b) + if not isinstance(a, compat_basestring): + a = _js_toString(a) + elif not isinstance(b, compat_basestring): + b = _js_toString(b) + return operator.concat(a, b) + + +_js_mod = _js_arith_op(operator.mod) +__js_exp = _js_arith_op(operator.pow) + + +def _js_exp(a, b): + if not b: + return 1 # even 0 ** 0 !! + return __js_exp(a, b) + + +def _js_to_primitive(v): + return ( + ','.join(map(_js_toString, v)) if isinstance(v, list) + else '[object Object]' if isinstance(v, dict) + else compat_str(v) if not isinstance(v, ( + compat_numeric_types, compat_basestring)) + else v + ) + + +# more exact: yt-dlp/yt-dlp#12110 +def _js_toString(v): + return ( + 'undefined' if v is JS_Undefined + else 'Infinity' if v == _Infinity + else 'NaN' if v is _NaN + else 'null' if v is None + # bool <= int: do this first + else ('false', 'true')[v] if isinstance(v, bool) + else re.sub(r'(?<=\d)\.?0*$', '', '{0:.7f}'.format(v)) if isinstance(v, compat_numeric_types) + else _js_to_primitive(v)) + + +_nullish = frozenset((None, JS_Undefined)) + + +def _js_eq(a, b): + # NaN != any + if _NaN in (a, b): + return False + # Object is Object + if isinstance(a, type(b)) and isinstance(b, (dict, list)): + return operator.is_(a, b) + # general case + if a == b: + return True + # null == undefined + a_b = set((a, b)) + if a_b & _nullish: + return a_b <= _nullish + a, b = _js_to_primitive(a), _js_to_primitive(b) + if not isinstance(a, compat_basestring): + a, b = b, a + # Number to String: convert the string to a number + # Conversion failure results in ... false + if isinstance(a, compat_basestring): + return float_or_none(a) == b + return a == b + + +def _js_neq(a, b): + return not _js_eq(a, b) + + +def _js_id_op(op): + + @wraps_op(op) + def wrapped(a, b): + if _NaN in (a, b): + return op(_NaN, None) + if not isinstance(a, (compat_basestring, compat_numeric_types)): + a, b = b, a + # strings are === if == + # why 'a' is not 'a': https://stackoverflow.com/a/1504848 + if isinstance(a, (compat_basestring, compat_numeric_types)): + return a == b if op(0, 0) else a != b + return op(a, b) + + return wrapped + + +def _js_comp_op(op): + + @wraps_op(op) + def wrapped(a, b): + if JS_Undefined in (a, b): + return False + if isinstance(a, compat_basestring): + b = compat_str(b or 0) + elif isinstance(b, compat_basestring): + a = compat_str(a or 0) + return op(a or 0, b or 0) + + return wrapped + + +def _js_ternary(cndn, if_true=True, if_false=False): + """Simulate JS's ternary operator (cndn?if_true:if_false)""" + if cndn in (False, None, 0, '', JS_Undefined, _NaN): + return if_false + return if_true + + +def _js_unary_op(op): + + @wraps_op(op) + def wrapped(a, _): + return op(a) + + return wrapped + + +# https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof +def _js_typeof(expr): + with compat_contextlib_suppress(TypeError, KeyError): + return { + JS_Undefined: 'undefined', + _NaN: 'number', + _Infinity: 'number', + True: 'boolean', + False: 'boolean', + None: 'object', + }[expr] + for t, n in ( + (compat_basestring, 'string'), + (compat_numeric_types, 'number'), + ): + if isinstance(expr, t): + return n + if callable(expr): + return 'function' + # TODO: Symbol, BigInt + return 'object' + + +# (op, definition) in order of binding priority, tightest first +# avoid dict to maintain order +# definition None => Defined in JSInterpreter._operator +_OPERATORS = ( + ('>>', _js_bit_op(operator.rshift, True)), + ('<<', _js_bit_op(operator.lshift, True)), + ('+', _js_add), + ('-', _js_arith_op(operator.sub)), + ('*', _js_arith_op(operator.mul)), + ('%', _js_mod), + ('/', _js_arith_op(operator.truediv, div=True)), + ('**', _js_exp), +) + +_LOG_OPERATORS = ( + ('|', _js_bit_op(operator.or_)), + ('^', _js_bit_op(operator.xor)), + ('&', _js_bit_op(operator.and_)), +) + +_SC_OPERATORS = ( + ('?', None), + ('??', None), + ('||', None), + ('&&', None), +) + +_UNARY_OPERATORS_X = ( + ('void', _js_unary_op(lambda _: JS_Undefined)), + ('typeof', _js_unary_op(_js_typeof)), + # avoid functools.partial here since Py2 update_wrapper(partial) -> no __module__ + ('!', _js_unary_op(lambda x: _js_ternary(x, if_true=False, if_false=True))), +) + +_COMP_OPERATORS = ( + ('===', _js_id_op(operator.is_)), + ('!==', _js_id_op(operator.is_not)), + ('==', _js_eq), + ('!=', _js_neq), + ('<=', _js_comp_op(operator.le)), + ('>=', _js_comp_op(operator.ge)), + ('<', _js_comp_op(operator.lt)), + ('>', _js_comp_op(operator.gt)), +) + +_OPERATOR_RE = '|'.join(map(lambda x: re.escape(x[0]), _OPERATORS + _LOG_OPERATORS + _SC_OPERATORS)) + +_NAME_RE = r'[a-zA-Z_$][\w$]*' +_MATCHING_PARENS = dict(zip(*zip('()', '{}', '[]'))) +_QUOTES = '\'"/' +_NESTED_BRACKETS = r'[^[\]]+(?:\[[^[\]]+(?:\[[^\]]+\])?\])?' + + +class JS_Break(ExtractorError): + def __init__(self): + ExtractorError.__init__(self, 'Invalid break') + + +class JS_Continue(ExtractorError): + def __init__(self): + ExtractorError.__init__(self, 'Invalid continue') + + +class JS_Throw(ExtractorError): + def __init__(self, e): + self.error = e + ExtractorError.__init__(self, 'Uncaught exception ' + error_to_compat_str(e)) + + +class LocalNameSpace(ChainMap): + def __getitem__(self, key): + try: + return super(LocalNameSpace, self).__getitem__(key) + except KeyError: + return JS_Undefined + + def __setitem__(self, key, value): + for scope in self.maps: + if key in scope: + scope[key] = value + return + self.maps[0][key] = value + + def __delitem__(self, key): + raise NotImplementedError('Deleting is not supported') + + def __repr__(self): + return 'LocalNameSpace({0!r})'.format(self.maps) + + +class Debugger(object): + ENABLED = False + + @staticmethod + def write(*args, **kwargs): + level = kwargs.get('level', 100) + + def truncate_string(s, left, right=0): + if s is None or len(s) <= left + right: + return s + return '...'.join((s[:left - 3], s[-right:] if right else '')) + + write_string('[debug] JS: {0}{1}\n'.format( + ' ' * (100 - level), + ' '.join(truncate_string(compat_str(x), 50, 50) for x in args))) + + @classmethod + def wrap_interpreter(cls, f): + if not cls.ENABLED: + return f + + @wraps(f) + def interpret_statement(self, stmt, local_vars, allow_recursion, *args, **kwargs): + if cls.ENABLED and stmt.strip(): + cls.write(stmt, level=allow_recursion) + try: + ret, should_ret = f(self, stmt, local_vars, allow_recursion, *args, **kwargs) + except Exception as e: + if cls.ENABLED: + if isinstance(e, ExtractorError): + e = e.orig_msg + cls.write('=> Raises:', e, '<-|', stmt, level=allow_recursion) + raise + if cls.ENABLED and stmt.strip(): + if should_ret or repr(ret) != stmt: + cls.write(['->', '=>'][bool(should_ret)], repr(ret), '<-|', stmt, level=allow_recursion) + return ret, should_ret + return interpret_statement class JSInterpreter(object): + __named_object_counter = 0 + + _OBJ_NAME = '__youtube_dl_jsinterp_obj' + + OP_CHARS = None + def __init__(self, code, objects=None): - if objects is None: - objects = {} - self.code = code - self._functions = {} - self._objects = objects + self.code, self._functions = code, {} + self._objects = {} if objects is None else objects + if type(self).OP_CHARS is None: + type(self).OP_CHARS = self.OP_CHARS = self.__op_chars() + + class Exception(ExtractorError): + def __init__(self, msg, *args, **kwargs): + expr = kwargs.pop('expr', None) + msg = str_or_none(msg, default='"None"') + if expr is not None: + msg = '{0} in: {1!r:.100}'.format(msg.rstrip(), expr) + super(JSInterpreter.Exception, self).__init__(msg, *args, **kwargs) + + class JS_Object(object): + def __getitem__(self, key): + if hasattr(self, key): + return getattr(self, key) + raise KeyError(key) + + def dump(self): + """Serialise the instance""" + raise NotImplementedError + + class JS_RegExp(JS_Object): + RE_FLAGS = { + # special knowledge: Python's re flags are bitmask values, current max 128 + # invent new bitmask values well above that for literal parsing + # JS 'u' flag is effectively always set (surrogate pairs aren't seen), + # but \u{...} and \p{...} escapes aren't handled); no additional JS 'v' + # features are supported + # TODO: execute matches with these flags (remaining: d, y) + 'd': 1024, # Generate indices for substring matches + 'g': 2048, # Global search + 'i': re.I, # Case-insensitive search + 'm': re.M, # Multi-line search + 's': re.S, # Allows . to match newline characters + 'u': re.U, # Treat a pattern as a sequence of unicode code points + 'v': re.U, # Like 'u' with extended character class and \p{} syntax + 'y': 4096, # Perform a "sticky" search that matches starting at the current position in the target string + } + + def __init__(self, pattern_txt, flags=0): + if isinstance(flags, compat_str): + flags, _ = self.regex_flags(flags) + self.__self = None + pattern_txt = str_or_none(pattern_txt) or '(?:)' + # escape unintended embedded flags + pattern_txt = re.sub( + r'(\(\?)([aiLmsux]*)(-[imsx]+:|(?<!\?)\))', + lambda m: ''.join( + (re.escape(m.group(1)), m.group(2), re.escape(m.group(3))) + if m.group(3) == ')' + else ('(?:', m.group(2), m.group(3))), + pattern_txt) + # Avoid https://github.com/python/cpython/issues/74534 + self.source = pattern_txt.replace('[[', r'[\[') + self.__flags = flags + + def __instantiate(self): + if self.__self: + return + self.__self = re.compile(self.source, self.__flags) + # Thx: https://stackoverflow.com/questions/44773522/setattr-on-python2-sre-sre-pattern + for name in dir(self.__self): + # Only these? Obviously __class__, __init__. + # PyPy creates a __weakref__ attribute with value None + # that can't be setattr'd but also can't need to be copied. + if name in ('__class__', '__init__', '__weakref__'): + continue + if name == 'flags': + setattr(self, name, getattr(self.__self, name, self.__flags)) + else: + setattr(self, name, getattr(self.__self, name)) + + def __getattr__(self, name): + self.__instantiate() + if name == 'pattern': + self.pattern = self.source + return self.pattern + elif hasattr(self.__self, name): + v = getattr(self.__self, name) + setattr(self, name, v) + return v + elif name in ('groupindex', 'groups'): + return 0 if name == 'groupindex' else {} + else: + flag_attrs = ( # order by 2nd elt + ('hasIndices', 'd'), + ('global', 'g'), + ('ignoreCase', 'i'), + ('multiline', 'm'), + ('dotAll', 's'), + ('unicode', 'u'), + ('unicodeSets', 'v'), + ('sticky', 'y'), + ) + for k, c in flag_attrs: + if name == k: + return bool(self.RE_FLAGS[c] & self.__flags) + else: + if name == 'flags': + return ''.join( + (c if self.RE_FLAGS[c] & self.__flags else '') + for _, c in flag_attrs) + + raise AttributeError('{0} has no attribute named {1}'.format(self, name)) + + @classmethod + def regex_flags(cls, expr): + flags = 0 + if not expr: + return flags, expr + for idx, ch in enumerate(expr): + if ch not in cls.RE_FLAGS: + break + flags |= cls.RE_FLAGS[ch] + return flags, expr[idx + 1:] + + def dump(self): + return '(/{0}/{1})'.format( + re.sub(r'(?<!\\)/', r'\/', self.source), + self.flags) + + @staticmethod + def escape(string_): + return re.escape(string_) + + class JS_Date(JS_Object): + _t = None + + @staticmethod + def __ymd_etc(*args, **kw_is_utc): + # args: year, monthIndex, day, hours, minutes, seconds, milliseconds + is_utc = kw_is_utc.get('is_utc', False) + + args = list(args[:7]) + args += [0] * (9 - len(args)) + args[1] += 1 # month 0..11 -> 1..12 + ms = args[6] + for i in range(6, 9): + args[i] = -1 # don't know + if is_utc: + args[-1] = 1 + # TODO: [MDN] When a segment overflows or underflows its expected + # range, it usually "carries over to" or "borrows from" the higher segment. + try: + mktime = calendar.timegm if is_utc else time.mktime + return mktime(time.struct_time(args)) * 1000 + ms + except (OverflowError, ValueError): + return None + + @classmethod + def UTC(cls, *args): + t = cls.__ymd_etc(*args, is_utc=True) + return _NaN if t is None else t + + @staticmethod + def parse(date_str, **kw_is_raw): + is_raw = kw_is_raw.get('is_raw', False) + + t = unified_timestamp(str_or_none(date_str), False) + return int(t * 1000) if t is not None else t if is_raw else _NaN + @staticmethod + def now(**kw_is_raw): + is_raw = kw_is_raw.get('is_raw', False) + + t = time.time() + return int(t * 1000) if t is not None else t if is_raw else _NaN + + def __init__(self, *args): + if not args: + args = [self.now(is_raw=True)] + if len(args) == 1: + if isinstance(args[0], JSInterpreter.JS_Date): + self._t = int_or_none(args[0].valueOf(), default=None) + else: + arg_type = _js_typeof(args[0]) + if arg_type == 'string': + self._t = self.parse(args[0], is_raw=True) + elif arg_type == 'number': + self._t = int(args[0]) + else: + self._t = self.__ymd_etc(*args) + + def toString(self): + try: + return time.strftime('%a %b %0d %Y %H:%M:%S %Z%z', self._t).rstrip() + except TypeError: + return "Invalid Date" + + def valueOf(self): + return _NaN if self._t is None else self._t + + def dump(self): + return '(new Date({0}))'.format(self.toString()) + + @classmethod + def __op_chars(cls): + op_chars = set(';,[') + for op in cls._all_operators(): + if op[0].isalpha(): + continue + op_chars.update(op[0]) + return op_chars + + def _named_object(self, namespace, obj): + self.__named_object_counter += 1 + name = '%s%d' % (self._OBJ_NAME, self.__named_object_counter) + if callable(obj) and not isinstance(obj, function_with_repr): + obj = function_with_repr(obj, 'F<%s>' % (self.__named_object_counter, )) + namespace[name] = obj + return name + + @classmethod + def _separate(cls, expr, delim=',', max_split=None, skip_delims=None): + if not expr: + return + # collections.Counter() is ~10% slower in both 2.7 and 3.9 + counters = dict((k, 0) for k in _MATCHING_PARENS.values()) + start, splits, pos, delim_len = 0, 0, 0, len(delim) - 1 + in_quote, escaping, after_op, in_regex_char_group = None, False, True, False + skipping = 0 + if skip_delims: + skip_delims = variadic(skip_delims) + skip_txt = None + for idx, char in enumerate(expr): + if skip_txt and idx <= skip_txt[1]: + continue + paren_delta = 0 + if not in_quote: + if char == '/' and expr[idx:idx + 2] == '/*': + # skip a comment + skip_txt = expr[idx:].find('*/', 2) + skip_txt = [idx, idx + skip_txt + 1] if skip_txt >= 2 else None + if skip_txt: + continue + if char in _MATCHING_PARENS: + counters[_MATCHING_PARENS[char]] += 1 + paren_delta = 1 + elif char in counters: + counters[char] -= 1 + paren_delta = -1 + if not escaping: + if char in _QUOTES and in_quote in (char, None): + if in_quote or after_op or char != '/': + in_quote = None if in_quote and not in_regex_char_group else char + elif in_quote == '/' and char in '[]': + in_regex_char_group = char == '[' + escaping = not escaping and in_quote and char == '\\' + after_op = not in_quote and (char in cls.OP_CHARS or paren_delta > 0 or (after_op and char.isspace())) + + if char != delim[pos] or any(counters.values()) or in_quote: + pos = skipping = 0 + continue + elif skipping > 0: + skipping -= 1 + continue + elif pos == 0 and skip_delims: + here = expr[idx:] + for s in skip_delims: + if here.startswith(s) and s: + skipping = len(s) - 1 + break + if skipping > 0: + continue + if pos < delim_len: + pos += 1 + continue + if skip_txt and skip_txt[0] >= start and skip_txt[1] <= idx - delim_len: + yield expr[start:skip_txt[0]] + expr[skip_txt[1] + 1: idx - delim_len] + else: + yield expr[start: idx - delim_len] + skip_txt = None + start, pos = idx + 1, 0 + splits += 1 + if max_split and splits >= max_split: + break + if skip_txt and skip_txt[0] >= start: + yield expr[start:skip_txt[0]] + expr[skip_txt[1] + 1:] + else: + yield expr[start:] + + @classmethod + def _separate_at_paren(cls, expr, delim=None): + if delim is None: + delim = expr and _MATCHING_PARENS[expr[0]] + separated = list(cls._separate(expr, delim, 1)) + if len(separated) < 2: + raise cls.Exception('No terminating paren {delim} in {expr!r:.5500}'.format(**locals())) + return separated[0][1:].strip(), separated[1].strip() + + @staticmethod + def _all_operators(_cached=[]): + if not _cached: + _cached.extend(itertools.chain( + # Ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence + _SC_OPERATORS, _LOG_OPERATORS, _COMP_OPERATORS, _OPERATORS, _UNARY_OPERATORS_X)) + return _cached + + def _separate_at_op(self, expr, max_split=None): + + for op, _ in self._all_operators(): + # hackety: </> have higher priority than <</>>, but don't confuse them + skip_delim = (op + op) if op in '<>*?' else None + if op == '?': + skip_delim = (skip_delim, '?.') + separated = list(self._separate(expr, op, skip_delims=skip_delim)) + if len(separated) < 2: + continue + + right_expr = separated.pop() + # handle operators that are both unary and binary, minimal BODMAS + if op in ('+', '-'): + # simplify/adjust consecutive instances of these operators + undone = 0 + separated = [s.strip() for s in separated] + while len(separated) > 1 and not separated[-1]: + undone += 1 + separated.pop() + if op == '-' and undone % 2 != 0: + right_expr = op + right_expr + elif op == '+': + while len(separated) > 1 and set(separated[-1]) <= self.OP_CHARS: + right_expr = separated.pop() + right_expr + if separated[-1][-1:] in self.OP_CHARS: + right_expr = separated.pop() + right_expr + # hanging op at end of left => unary + (strip) or - (push right) + separated.append(right_expr) + dm_ops = ('*', '%', '/', '**') + dm_chars = set(''.join(dm_ops)) + + def yield_terms(s): + skip = False + for i, term in enumerate(s[:-1]): + if skip: + skip = False + continue + if not (dm_chars & set(term)): + yield term + continue + for dm_op in dm_ops: + bodmas = list(self._separate(term, dm_op, skip_delims=skip_delim)) + if len(bodmas) > 1 and not bodmas[-1].strip(): + bodmas[-1] = (op if op == '-' else '') + s[i + 1] + yield dm_op.join(bodmas) + skip = True + break + else: + if term: + yield term + + if not skip and s[-1]: + yield s[-1] + + separated = list(yield_terms(separated)) + right_expr = separated.pop() if len(separated) > 1 else None + expr = op.join(separated) + if right_expr is None: + continue + return op, separated, right_expr + + def _operator(self, op, left_val, right_expr, expr, local_vars, allow_recursion): + if op in ('||', '&&'): + if (op == '&&') ^ _js_ternary(left_val): + return left_val # short circuiting + elif op == '??': + if left_val not in (None, JS_Undefined): + return left_val + elif op == '?': + right_expr = _js_ternary(left_val, *self._separate(right_expr, ':', 1)) + + right_val = self.interpret_expression(right_expr, local_vars, allow_recursion) if right_expr else left_val + opfunc = op and next((v for k, v in self._all_operators() if k == op), None) + if not opfunc: + return right_val + + try: + # print('Eval:', opfunc.__name__, left_val, right_val) + return opfunc(left_val, right_val) + except Exception as e: + raise self.Exception('Failed to evaluate {left_val!r:.50} {op} {right_val!r:.50}'.format(**locals()), expr, cause=e) + + def _index(self, obj, idx, allow_undefined=None): + if idx == 'length' and isinstance(obj, list): + return len(obj) + try: + return obj[int(idx)] if isinstance(obj, list) else obj[compat_str(idx)] + except (TypeError, KeyError, IndexError, ValueError) as e: + # allow_undefined is None gives correct behaviour + if allow_undefined or ( + allow_undefined is None and not isinstance(e, TypeError)): + return JS_Undefined + raise self.Exception('Cannot get index {idx!r:.100}'.format(**locals()), expr=repr(obj), cause=e) + + def _dump(self, obj, namespace): + if obj is JS_Undefined: + return 'undefined' + try: + return json.dumps(obj) + except TypeError: + return self._named_object(namespace, obj) + + # used below + _VAR_RET_THROW_RE = re.compile(r'''(?x) + (?:(?P<var>var|const|let)\s+|(?P<ret>return)(?:\s+|(?=["'])|$)|(?P<throw>throw)\s+) + ''') + _COMPOUND_RE = re.compile(r'''(?x) + (?P<try>try)\s*\{| + (?P<if>if)\s*\(| + (?P<switch>switch)\s*\(| + (?P<for>for)\s*\(| + (?P<while>while)\s*\( + ''') + _FINALLY_RE = re.compile(r'finally\s*\{') + _SWITCH_RE = re.compile(r'switch\s*\(') + + def _eval_operator(self, op, left_expr, right_expr, expr, local_vars, allow_recursion): + left_val = self.interpret_expression(left_expr, local_vars, allow_recursion) + return self._operator(op, left_val, right_expr, expr, local_vars, allow_recursion) + + @Debugger.wrap_interpreter def interpret_statement(self, stmt, local_vars, allow_recursion=100): if allow_recursion < 0: - raise ExtractorError('Recursion limit reached') + raise self.Exception('Recursion limit reached') + allow_recursion -= 1 - should_abort = False - stmt = stmt.lstrip() - stmt_m = re.match(r'var\s', stmt) - if stmt_m: - expr = stmt[len(stmt_m.group(0)):] - else: - return_m = re.match(r'return(?:\s+|$)', stmt) - if return_m: - expr = stmt[len(return_m.group(0)):] - should_abort = True + # print('At: ' + stmt[:60]) + should_return = False + # fails on (eg) if (...) stmt1; else stmt2; + sub_statements = list(self._separate(stmt, ';')) or [''] + expr = stmt = sub_statements.pop().strip() + + for sub_stmt in sub_statements: + ret, should_return = self.interpret_statement(sub_stmt, local_vars, allow_recursion) + if should_return: + return ret, should_return + + m = self._VAR_RET_THROW_RE.match(stmt) + if m: + expr = stmt[len(m.group(0)):].strip() + if m.group('throw'): + raise JS_Throw(self.interpret_expression(expr, local_vars, allow_recursion)) + should_return = 'return' if m.group('ret') else False + if not expr: + return None, should_return + + if expr[0] in _QUOTES: + inner, outer = self._separate(expr, expr[0], 1) + if expr[0] == '/': + flags, outer = self.JS_RegExp.regex_flags(outer) + inner = self.JS_RegExp(inner[1:], flags=flags) else: - # Try interpreting it as an expression - expr = stmt + inner = json.loads(js_to_json(inner + expr[0])) # , strict=True)) + if not outer: + return inner, should_return + expr = self._named_object(local_vars, inner) + outer - v = self.interpret_expression(expr, local_vars, allow_recursion) - return v, should_abort + new_kw, _, obj = expr.partition('new ') + if not new_kw: + for klass, konstr in (('Date', lambda *x: self.JS_Date(*x).valueOf()), + ('RegExp', self.JS_RegExp), + ('Error', self.Exception)): + if not obj.startswith(klass + '('): + continue + left, right = self._separate_at_paren(obj[len(klass):]) + argvals = self.interpret_iter(left, local_vars, allow_recursion) + expr = konstr(*argvals) + if expr is None: + raise self.Exception('Failed to parse {klass} {left!r:.100}'.format(**locals()), expr=expr) + expr = self._dump(expr, local_vars) + right + break + else: + raise self.Exception('Unsupported object {obj:.100}'.format(**locals()), expr=expr) - def interpret_expression(self, expr, local_vars, allow_recursion): - expr = expr.strip() + # apply unary operators (see new above) + for op, _ in _UNARY_OPERATORS_X: + if not expr.startswith(op): + continue + operand = expr[len(op):] + if not operand or (op.isalpha() and operand[0] != ' '): + continue + separated = self._separate_at_op(operand, max_split=1) + if separated: + next_op, separated, right_expr = separated + separated.append(right_expr) + operand = next_op.join(separated) + return self._eval_operator(op, operand, '', expr, local_vars, allow_recursion), should_return - if expr == '': # Empty expression - return None + if expr.startswith('{'): + inner, outer = self._separate_at_paren(expr) + # try for object expression (Map) + sub_expressions = [list(self._separate(sub_expr.strip(), ':', 1)) for sub_expr in self._separate(inner)] + if all(len(sub_expr) == 2 for sub_expr in sub_expressions): + return dict( + (key_expr if re.match(_NAME_RE, key_expr) else key_expr, + self.interpret_expression(val_expr, local_vars, allow_recursion)) + for key_expr, val_expr in sub_expressions), should_return + # or statement list + inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion) + if not outer or should_abort: + return inner, should_abort or should_return + else: + expr = self._dump(inner, local_vars) + outer if expr.startswith('('): - parens_count = 0 - for m in re.finditer(r'[()]', expr): - if m.group(0) == '(': - parens_count += 1 + m = re.match(r'\((?P<d>[a-z])%(?P<e>[a-z])\.length\+(?P=e)\.length\)%(?P=e)\.length', expr) + if m: + # short-cut eval of frequently used `(d%e.length+e.length)%e.length`, worth ~6% on `pytest -k test_nsig` + outer = None + inner, should_abort = self._offset_e_by_d(m.group('d'), m.group('e'), local_vars) + else: + inner, outer = self._separate_at_paren(expr) + inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion) + if not outer or should_abort: + return inner, should_abort or should_return + else: + expr = self._dump(inner, local_vars) + outer + + if expr.startswith('['): + inner, outer = self._separate_at_paren(expr) + name = self._named_object(local_vars, [ + self.interpret_expression(item, local_vars, allow_recursion) + for item in self._separate(inner)]) + expr = name + outer + + m = self._COMPOUND_RE.match(expr) + md = m.groupdict() if m else {} + if md.get('if'): + cndn, expr = self._separate_at_paren(expr[m.end() - 1:]) + if expr.startswith('{'): + if_expr, expr = self._separate_at_paren(expr) + else: + # may lose ... else ... because of ll.368-374 + if_expr, expr = self._separate_at_paren(' %s;' % (expr,), delim=';') + else_expr = None + m = re.match(r'else\s*(?P<block>\{)?', expr) + if m: + if m.group('block'): + else_expr, expr = self._separate_at_paren(expr[m.end() - 1:]) else: - parens_count -= 1 - if parens_count == 0: - sub_expr = expr[1:m.start()] - sub_result = self.interpret_expression( - sub_expr, local_vars, allow_recursion) - remaining_expr = expr[m.end():].strip() - if not remaining_expr: - return sub_result + # handle subset ... else if (...) {...} else ... + # TODO: make interpret_statement do this properly, if possible + exprs = list(self._separate(expr[m.end():], delim='}', max_split=2)) + if len(exprs) > 1: + if re.match(r'\s*if\s*\(', exprs[0]) and re.match(r'\s*else\b', exprs[1]): + else_expr = exprs[0] + '}' + exprs[1] + expr = (exprs[2] + '}') if len(exprs) == 3 else None else: - expr = json.dumps(sub_result) + remaining_expr - break + else_expr = exprs[0] + exprs.append('') + expr = '}'.join(exprs[1:]) + else: + else_expr = exprs[0] + expr = None + else_expr = else_expr.lstrip() + '}' + cndn = _js_ternary(self.interpret_expression(cndn, local_vars, allow_recursion)) + ret, should_abort = self.interpret_statement( + if_expr if cndn else else_expr, local_vars, allow_recursion) + if should_abort: + return ret, True + + elif md.get('try'): + try_expr, expr = self._separate_at_paren(expr[m.end() - 1:]) + err = None + try: + ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion) + if should_abort: + return ret, True + except Exception as e: + # XXX: This works for now, but makes debugging future issues very hard + err = e + + pending = (None, False) + m = re.match(r'catch\s*(?P<err>\(\s*{_NAME_RE}\s*\))?\{{'.format(**globals()), expr) + if m: + sub_expr, expr = self._separate_at_paren(expr[m.end() - 1:]) + if err: + catch_vars = {} + if m.group('err'): + catch_vars[m.group('err')] = err.error if isinstance(err, JS_Throw) else err + catch_vars = local_vars.new_child(m=catch_vars) + err, pending = None, self.interpret_statement(sub_expr, catch_vars, allow_recursion) + + m = self._FINALLY_RE.match(expr) + if m: + sub_expr, expr = self._separate_at_paren(expr[m.end() - 1:]) + ret, should_abort = self.interpret_statement(sub_expr, local_vars, allow_recursion) + if should_abort: + return ret, True + + ret, should_abort = pending + if should_abort: + return ret, True + + if err: + raise err + + elif md.get('for') or md.get('while'): + init_or_cond, remaining = self._separate_at_paren(expr[m.end() - 1:]) + if remaining.startswith('{'): + body, expr = self._separate_at_paren(remaining) else: - raise ExtractorError('Premature end of parens in %r' % expr) - - for op, opfunc in _ASSIGN_OPERATORS: - m = re.match(r'''(?x) - (?P<out>%s)(?:\[(?P<index>[^\]]+?)\])? - \s*%s - (?P<expr>.*)$''' % (_NAME_RE, re.escape(op)), expr) - if not m: - continue - right_val = self.interpret_expression( - m.group('expr'), local_vars, allow_recursion - 1) - - if m.groupdict().get('index'): - lvar = local_vars[m.group('out')] - idx = self.interpret_expression( - m.group('index'), local_vars, allow_recursion) - assert isinstance(idx, int) - cur = lvar[idx] - val = opfunc(cur, right_val) - lvar[idx] = val - return val + switch_m = self._SWITCH_RE.match(remaining) # FIXME + if switch_m: + switch_val, remaining = self._separate_at_paren(remaining[switch_m.end() - 1:]) + body, expr = self._separate_at_paren(remaining, '}') + body = 'switch(%s){%s}' % (switch_val, body) + else: + body, expr = remaining, '' + if md.get('for'): + start, cndn, increment = self._separate(init_or_cond, ';') + self.interpret_expression(start, local_vars, allow_recursion) else: - cur = local_vars.get(m.group('out')) - val = opfunc(cur, right_val) - local_vars[m.group('out')] = val - return val + cndn, increment = init_or_cond, None + while _js_ternary(self.interpret_expression(cndn, local_vars, allow_recursion)): + try: + ret, should_abort = self.interpret_statement(body, local_vars, allow_recursion) + if should_abort: + return ret, True + except JS_Break: + break + except JS_Continue: + pass + if increment: + self.interpret_expression(increment, local_vars, allow_recursion) - if expr.isdigit(): - return int(expr) + elif md.get('switch'): + switch_val, remaining = self._separate_at_paren(expr[m.end() - 1:]) + switch_val = self.interpret_expression(switch_val, local_vars, allow_recursion) + body, expr = self._separate_at_paren(remaining, '}') + items = body.replace('default:', 'case default:').split('case ')[1:] + for default in (False, True): + matched = False + for item in items: + case, stmt = (i.strip() for i in self._separate(item, ':', 1)) + if default: + matched = matched or case == 'default' + elif not matched: + matched = (case != 'default' + and switch_val == self.interpret_expression(case, local_vars, allow_recursion)) + if not matched: + continue + try: + ret, should_abort = self.interpret_statement(stmt, local_vars, allow_recursion) + if should_abort: + return ret + except JS_Break: + break + if matched: + break - var_m = re.match( - r'(?!if|return|true|false)(?P<name>%s)$' % _NAME_RE, - expr) - if var_m: - return local_vars[var_m.group('name')] + if md: + ret, should_abort = self.interpret_statement(expr, local_vars, allow_recursion) + return ret, should_abort or should_return - try: - return json.loads(expr) - except ValueError: - pass + # Comma separated statements + sub_expressions = list(self._separate(expr)) + if len(sub_expressions) > 1: + for sub_expr in sub_expressions: + ret, should_abort = self.interpret_statement(sub_expr, local_vars, allow_recursion) + if should_abort: + return ret, True + return ret, False - m = re.match( - r'(?P<var>%s)\.(?P<member>[^(]+)(?:\(+(?P<args>[^()]*)\))?$' % _NAME_RE, - expr) - if m: - variable = m.group('var') - member = m.group('member') - arg_str = m.group('args') + for m in re.finditer(r'''(?x) + (?P<pre_sign>\+\+|--)(?P<var1>{_NAME_RE})| + (?P<var2>{_NAME_RE})(?P<post_sign>\+\+|--)'''.format(**globals()), expr): + var = m.group('var1') or m.group('var2') + start, end = m.span() + sign = m.group('pre_sign') or m.group('post_sign') + ret = local_vars[var] + local_vars[var] = _js_add(ret, 1 if sign[0] == '+' else -1) + if m.group('pre_sign'): + ret = local_vars[var] + expr = expr[:start] + self._dump(ret, local_vars) + expr[end:] + + if not expr: + return None, should_return + + m = re.match(r'''(?x) + (?P<assign> + (?P<out>{_NAME_RE})(?P<out_idx>(?:\[{_NESTED_BRACKETS}\])+)?\s* + (?P<op>{_OPERATOR_RE})? + =(?!=)(?P<expr>.*)$ + )|(?P<return> + (?!if|return|true|false|null|undefined|NaN|Infinity)(?P<name>{_NAME_RE})$ + )|(?P<attribute> + (?P<var>{_NAME_RE})(?: + (?P<nullish>\?)?\.(?P<member>[^(]+)| + \[(?P<member2>{_NESTED_BRACKETS})\] + )\s* + )|(?P<indexing> + (?P<in>{_NAME_RE})(?P<in_idx>\[.+\])$ + )|(?P<function> + (?P<fname>{_NAME_RE})\((?P<args>.*)\)$ + )'''.format(**globals()), expr) + md = m.groupdict() if m else {} + if md.get('assign'): + left_val = local_vars.get(m.group('out')) + + if not m.group('out_idx'): + local_vars[m.group('out')] = self._operator( + m.group('op'), left_val, m.group('expr'), expr, local_vars, allow_recursion) + return local_vars[m.group('out')], should_return + elif left_val in (None, JS_Undefined): + raise self.Exception('Cannot index undefined variable ' + m.group('out'), expr=expr) - if variable in local_vars: - obj = local_vars[variable] + indexes = md['out_idx'] + while indexes: + idx, indexes = self._separate_at_paren(indexes) + idx = self.interpret_expression(idx, local_vars, allow_recursion) + if indexes: + left_val = self._index(left_val, idx) + if isinstance(idx, float): + idx = int(idx) + if isinstance(left_val, list) and len(left_val) <= int_or_none(idx, default=-1): + # JS Array is a sparsely assignable list + # TODO: handle extreme sparsity without memory bloat, eg using auxiliary dict + left_val.extend((idx - len(left_val) + 1) * [JS_Undefined]) + left_val[idx] = self._operator( + m.group('op'), self._index(left_val, idx) if m.group('op') else None, + m.group('expr'), expr, local_vars, allow_recursion) + return left_val[idx], should_return + + elif expr.isdigit(): + return int(expr), should_return + + elif expr == 'break': + raise JS_Break() + elif expr == 'continue': + raise JS_Continue() + elif expr == 'undefined': + return JS_Undefined, should_return + elif expr == 'NaN': + return _NaN, should_return + elif expr == 'Infinity': + return _Infinity, should_return + + elif md.get('return'): + ret = local_vars[m.group('name')] + # challenge may try to force returning the original value + # use an optional internal var to block this + if should_return == 'return': + if '_ytdl_do_not_return' not in local_vars: + return ret, True + return (ret, True) if ret != local_vars['_ytdl_do_not_return'] else (ret, False) + else: + return ret, should_return + + with compat_contextlib_suppress(ValueError): + ret = json.loads(js_to_json(expr)) # strict=True) + if not md.get('attribute'): + return ret, should_return + + if md.get('indexing'): + val = local_vars[m.group('in')] + indexes = m.group('in_idx') + while indexes: + idx, indexes = self._separate_at_paren(indexes) + idx = self.interpret_expression(idx, local_vars, allow_recursion) + val = self._index(val, idx) + return val, should_return + + separated = self._separate_at_op(expr) + if separated: + op, separated, right_expr = separated + return self._eval_operator(op, op.join(separated), right_expr, expr, local_vars, allow_recursion), should_return + + if md.get('attribute'): + variable, member, nullish = m.group('var', 'member', 'nullish') + if not member: + member = self.interpret_expression(m.group('member2'), local_vars, allow_recursion) + arg_str = expr[m.end():] + if arg_str.startswith('('): + arg_str, remaining = self._separate_at_paren(arg_str) else: - if variable not in self._objects: - self._objects[variable] = self.extract_object(variable) - obj = self._objects[variable] + arg_str, remaining = None, arg_str + + def assertion(cndn, msg): + """ assert, but without risk of getting optimized out """ + if not cndn: + memb = member + raise self.Exception('{memb} {msg}'.format(**locals()), expr=expr) + + def eval_method(variable, member): + if (variable, member) == ('console', 'debug'): + if Debugger.ENABLED: + Debugger.write(self.interpret_expression('[{0}]'.format(arg_str), local_vars, allow_recursion)) + return + types = { + 'String': compat_str, + 'Math': float, + 'Array': list, + 'Date': self.JS_Date, + 'RegExp': self.JS_RegExp, + # 'Error': self.Exception, # has no std static methods + } + obj = local_vars.get(variable) + if obj in (JS_Undefined, None): + obj = types.get(variable, JS_Undefined) + if obj is JS_Undefined: + try: + if variable not in self._objects: + self._objects[variable] = self.extract_object(variable, local_vars) + obj = self._objects[variable] + except self.Exception: + if not nullish: + raise + + if nullish and obj is JS_Undefined: + return JS_Undefined - if arg_str is None: # Member access - if member == 'length': + if arg_str is None: + return self._index(obj, member, nullish) + + # Function call + argvals = [ + self.interpret_expression(v, local_vars, allow_recursion) + for v in self._separate(arg_str)] + + # Fixup prototype call + if isinstance(obj, type): + new_member, rest = member.partition('.')[0::2] + if new_member == 'prototype': + new_member, func_prototype = rest.partition('.')[0::2] + assertion(argvals, 'takes one or more arguments') + assertion(isinstance(argvals[0], obj), 'must bind to type {0}'.format(obj)) + if func_prototype == 'call': + obj = argvals.pop(0) + elif func_prototype == 'apply': + assertion(len(argvals) == 2, 'takes two arguments') + obj, argvals = argvals + assertion(isinstance(argvals, list), 'second argument must be a list') + else: + raise self.Exception('Unsupported Function method ' + func_prototype, expr) + member = new_member + + if obj is compat_str: + if member == 'fromCharCode': + assertion(argvals, 'takes one or more arguments') + return ''.join(compat_chr(int(n)) for n in argvals) + raise self.Exception('Unsupported string method ' + member, expr=expr) + elif obj is float: + if member == 'pow': + assertion(len(argvals) == 2, 'takes two arguments') + return argvals[0] ** argvals[1] + raise self.Exception('Unsupported Math method ' + member, expr=expr) + elif obj is self.JS_Date: + return getattr(obj, member)(*argvals) + + if member == 'split': + assertion(len(argvals) <= 2, 'takes at most two arguments') + if len(argvals) > 1: + limit = argvals[1] + assertion(isinstance(limit, int) and limit >= 0, 'integer limit >= 0') + if limit == 0: + return [] + else: + limit = 0 + if len(argvals) == 0: + argvals = [JS_Undefined] + elif isinstance(argvals[0], self.JS_RegExp): + # avoid re.split(), similar but not enough + + def where(): + for m in argvals[0].finditer(obj): + yield m.span(0) + yield (None, None) + + def splits(limit=limit): + i = 0 + for j, jj in where(): + if j == jj == 0: + continue + if j is None and i >= len(obj): + break + yield obj[i:j] + if jj is None or limit == 1: + break + limit -= 1 + i = jj + + return list(splits()) + return ( + obj.split(argvals[0], limit - 1) if argvals[0] and argvals[0] != JS_Undefined + else list(obj)[:limit or None]) + elif member == 'join': + assertion(isinstance(obj, list), 'must be applied on a list') + assertion(len(argvals) <= 1, 'takes at most one argument') + return (',' if len(argvals) == 0 or argvals[0] in (None, JS_Undefined) + else argvals[0]).join( + ('' if x in (None, JS_Undefined) else _js_toString(x)) + for x in obj) + elif member == 'reverse': + assertion(not argvals, 'does not take any arguments') + obj.reverse() + return obj + elif member == 'slice': + assertion(isinstance(obj, (list, compat_str)), 'must be applied on a list or string') + # From [1]: + # .slice() - like [:] + # .slice(n) - like [n:] (not [slice(n)] + # .slice(m, n) - like [m:n] or [slice(m, n)] + # [1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice + assertion(len(argvals) <= 2, 'takes between 0 and 2 arguments') + if len(argvals) < 2: + argvals += (None,) + return obj[slice(*argvals)] + elif member == 'splice': + assertion(isinstance(obj, list), 'must be applied on a list') + assertion(argvals, 'takes one or more arguments') + index, how_many = map(int, (argvals + [len(obj)])[:2]) + if index < 0: + index += len(obj) + res = [obj.pop(index) + for _ in range(index, min(index + how_many, len(obj)))] + obj[index:index] = argvals[2:] + return res + elif member in ('shift', 'pop'): + assertion(isinstance(obj, list), 'must be applied on a list') + assertion(not argvals, 'does not take any arguments') + return obj.pop(0 if member == 'shift' else -1) if len(obj) > 0 else JS_Undefined + elif member == 'unshift': + assertion(isinstance(obj, list), 'must be applied on a list') + # not enforced: assertion(argvals, 'takes one or more arguments') + obj[0:0] = argvals return len(obj) - return obj[member] + elif member == 'push': + # not enforced: assertion(argvals, 'takes one or more arguments') + obj.extend(argvals) + return len(obj) + elif member == 'forEach': + assertion(argvals, 'takes one or more arguments') + assertion(len(argvals) <= 2, 'takes at most 2 arguments') + f, this = (argvals + [''])[:2] + return [f((item, idx, obj), {'this': this}, allow_recursion) for idx, item in enumerate(obj)] + elif member == 'indexOf': + assertion(argvals, 'takes one or more arguments') + assertion(len(argvals) <= 2, 'takes at most 2 arguments') + idx, start = (argvals + [0])[:2] + try: + return obj.index(idx, start) + except ValueError: + return -1 + elif member == 'charCodeAt': + assertion(isinstance(obj, compat_str), 'must be applied on a string') + # assertion(len(argvals) == 1, 'takes exactly one argument') # but not enforced + idx = argvals[0] if len(argvals) > 0 and isinstance(argvals[0], int) else 0 + if idx >= len(obj): + return None + return ord(obj[idx]) + elif member in ('replace', 'replaceAll'): + assertion(isinstance(obj, compat_str), 'must be applied on a string') + assertion(len(argvals) == 2, 'takes exactly two arguments') + # TODO: argvals[1] callable, other Py vs JS edge cases + if isinstance(argvals[0], self.JS_RegExp): + # access JS member with Py reserved name + count = 0 if self._index(argvals[0], 'global') else 1 + assertion(member != 'replaceAll' or count == 0, + 'replaceAll must be called with a global RegExp') + return argvals[0].sub(argvals[1], obj, count=count) + count = ('replaceAll', 'replace').index(member) + return re.sub(re.escape(argvals[0]), argvals[1], obj, count=count) + + idx = int(member) if isinstance(obj, list) else member + return obj[idx](argvals, allow_recursion=allow_recursion) - assert expr.endswith(')') - # Function call - if arg_str == '': - argvals = tuple() + if remaining: + ret, should_abort = self.interpret_statement( + self._named_object(local_vars, eval_method(variable, member)) + remaining, + local_vars, allow_recursion) + return ret, should_return or should_abort else: - argvals = tuple([ - self.interpret_expression(v, local_vars, allow_recursion) - for v in arg_str.split(',')]) - - if member == 'split': - assert argvals == ('',) - return list(obj) - if member == 'join': - assert len(argvals) == 1 - return argvals[0].join(obj) - if member == 'reverse': - assert len(argvals) == 0 - obj.reverse() - return obj - if member == 'slice': - assert len(argvals) == 1 - return obj[argvals[0]:] - if member == 'splice': - assert isinstance(obj, list) - index, howMany = argvals - res = [] - for i in range(index, min(index + howMany, len(obj))): - res.append(obj.pop(index)) - return res - - return obj[member](argvals) - - m = re.match( - r'(?P<in>%s)\[(?P<idx>.+)\]$' % _NAME_RE, expr) - if m: - val = local_vars[m.group('in')] - idx = self.interpret_expression( - m.group('idx'), local_vars, allow_recursion - 1) - return val[idx] + return eval_method(variable, member), should_return - for op, opfunc in _OPERATORS: - m = re.match(r'(?P<x>.+?)%s(?P<y>.+)' % re.escape(op), expr) - if not m: - continue - x, abort = self.interpret_statement( - m.group('x'), local_vars, allow_recursion - 1) - if abort: - raise ExtractorError( - 'Premature left-side return of %s in %r' % (op, expr)) - y, abort = self.interpret_statement( - m.group('y'), local_vars, allow_recursion - 1) - if abort: - raise ExtractorError( - 'Premature right-side return of %s in %r' % (op, expr)) - return opfunc(x, y) - - m = re.match( - r'^(?P<func>%s)\((?P<args>[a-zA-Z0-9_$,]*)\)$' % _NAME_RE, expr) - if m: - fname = m.group('func') - argvals = tuple([ - int(v) if v.isdigit() else local_vars[v] - for v in m.group('args').split(',')]) if len(m.group('args')) > 0 else tuple() - if fname not in self._functions: + elif md.get('function'): + fname = m.group('fname') + argvals = [self.interpret_expression(v, local_vars, allow_recursion) + for v in self._separate(m.group('args'))] + if fname in local_vars: + return local_vars[fname](argvals, allow_recursion=allow_recursion), should_return + elif fname not in self._functions: self._functions[fname] = self.extract_function(fname) - return self._functions[fname](argvals) + return self._functions[fname](argvals, allow_recursion=allow_recursion), should_return - raise ExtractorError('Unsupported JS expression %r' % expr) + raise self.Exception( + 'Unsupported JS expression ' + (expr[:40] if expr != stmt else ''), expr=stmt) - def extract_object(self, objname): + def interpret_expression(self, expr, local_vars, allow_recursion): + ret, should_return = self.interpret_statement(expr, local_vars, allow_recursion) + if should_return: + raise self.Exception('Cannot return from an expression', expr) + return ret + + def interpret_iter(self, list_txt, local_vars, allow_recursion): + for v in self._separate(list_txt): + yield self.interpret_expression(v, local_vars, allow_recursion) + + def extract_object(self, objname, *global_stack): + _FUNC_NAME_RE = r'''(?:{n}|"{n}"|'{n}')'''.format(n=_NAME_RE) obj = {} - obj_m = re.search( - (r'(?<!this\.)%s\s*=\s*\{' % re.escape(objname)) + - r'\s*(?P<fields>([a-zA-Z$0-9]+\s*:\s*function\(.*?\)\s*\{.*?\}(?:,\s*)?)*)' + - r'\}\s*;', - self.code) - fields = obj_m.group('fields') + fields = next(filter(None, ( + obj_m.group('fields') for obj_m in re.finditer( + r'''(?xs) + {0}\s*\.\s*{1}|{1}\s*=\s*\{{\s* + (?P<fields>({2}\s*:\s*function\s*\(.*?\)\s*\{{.*?}}(?:,\s*)?)*) + }}\s*; + '''.format(_NAME_RE, re.escape(objname), _FUNC_NAME_RE), + self.code))), None) + if not fields: + raise self.Exception('Could not find object ' + objname) # Currently, it only supports function definitions - fields_m = re.finditer( - r'(?P<key>[a-zA-Z$0-9]+)\s*:\s*function' - r'\((?P<args>[a-z,]+)\){(?P<code>[^}]+)}', - fields) - for f in fields_m: - argnames = f.group('args').split(',') - obj[f.group('key')] = self.build_function(argnames, f.group('code')) + for f in re.finditer( + r'''(?x) + (?P<key>%s)\s*:\s*function\s*\((?P<args>(?:%s|,)*)\){(?P<code>[^}]+)} + ''' % (_FUNC_NAME_RE, _NAME_RE), + fields): + argnames = self.build_arglist(f.group('args')) + name = remove_quotes(f.group('key')) + obj[name] = function_with_repr( + self.build_function(argnames, f.group('code'), *global_stack), 'F<{0}>'.format(name)) return obj - def extract_function(self, funcname): + @staticmethod + def _offset_e_by_d(d, e, local_vars): + """ Short-cut eval: (d%e.length+e.length)%e.length """ + try: + d = local_vars[d] + e = local_vars[e] + e = len(e) + return _js_mod(_js_mod(d, e) + e, e), False + except Exception: + return None, True + + def extract_function_code(self, funcname): + """ @returns argnames, code """ func_m = re.search( - r'''(?x) - (?:function\s+%s|[{;,]\s*%s\s*=\s*function|var\s+%s\s*=\s*function)\s* + r'''(?xs) + (?: + function\s+%(name)s| + [{;,]\s*%(name)s\s*=\s*function| + (?:var|const|let)\s+%(name)s\s*=\s*function + )\s* \((?P<args>[^)]*)\)\s* - \{(?P<code>[^}]+)\}''' % ( - re.escape(funcname), re.escape(funcname), re.escape(funcname)), + (?P<code>{.+})''' % {'name': re.escape(funcname)}, self.code) if func_m is None: - raise ExtractorError('Could not find JS function %r' % funcname) - argnames = func_m.group('args').split(',') + raise self.Exception('Could not find JS function "{funcname}"'.format(**locals())) + code, _ = self._separate_at_paren(func_m.group('code')) # refine the match + return self.build_arglist(func_m.group('args')), code - return self.build_function(argnames, func_m.group('code')) + def extract_function(self, funcname, *global_stack): + return function_with_repr( + self.extract_function_from_code(*itertools.chain( + self.extract_function_code(funcname), global_stack)), + 'F<%s>' % (funcname,)) - def call_function(self, funcname, *args): - f = self.extract_function(funcname) - return f(args) + def extract_function_from_code(self, argnames, code, *global_stack): + local_vars = {} - def build_function(self, argnames, code): - def resf(args): - local_vars = dict(zip(argnames, args)) - for stmt in code.split(';'): - res, abort = self.interpret_statement(stmt, local_vars) - if abort: - break - return res + start = None + while True: + mobj = re.search(r'function\((?P<args>[^)]*)\)\s*{', code[start:]) + if mobj is None: + break + start, body_start = ((start or 0) + x for x in mobj.span()) + body, remaining = self._separate_at_paren(code[body_start - 1:]) + name = self._named_object(local_vars, self.extract_function_from_code( + [x.strip() for x in mobj.group('args').split(',')], + body, local_vars, *global_stack)) + code = code[:start] + name + remaining + + return self.build_function(argnames, code, local_vars, *global_stack) + + def call_function(self, funcname, *args, **kw_global_vars): + return self.extract_function(funcname)(args, kw_global_vars) + + @classmethod + def build_arglist(cls, arg_text): + if not arg_text: + return [] + + def valid_arg(y): + y = y.strip() + if not y: + raise cls.Exception('Missing arg in "%s"' % (arg_text, )) + return y + + return [valid_arg(x) for x in cls._separate(arg_text)] + + def build_function(self, argnames, code, *global_stack): + global_stack = list(global_stack) or [{}] + argnames = tuple(argnames) + + def resf(args, kwargs=None, allow_recursion=100): + kwargs = kwargs or {} + global_stack[0].update(zip_longest(argnames, args, fillvalue=JS_Undefined)) + global_stack[0].update(kwargs) + var_stack = LocalNameSpace(*global_stack) + ret, should_abort = self.interpret_statement(code.replace('\n', ' '), var_stack, allow_recursion - 1) + if should_abort: + return ret return resf |