From d231b56717c73ee597d2e077d11b69ed48a1b02d Mon Sep 17 00:00:00 2001 From: dirkf Date: Sun, 14 Aug 2022 18:45:45 +0100 Subject: [jsinterp] Overhaul JSInterp to handle new YT players 4c3f79c5, 324f67b9 (#31170) * back-port from yt-dlp 8f53dc44a0cc1c2d98c35740b9293462c080f5d0, thanks pukkandan * also support void, improve <> precedence, improve expressions in comma-list * add more tests --- youtube_dl/jsinterp.py | 589 +++++++++++++++++++++++++++++-------------------- 1 file changed, 354 insertions(+), 235 deletions(-) (limited to 'youtube_dl/jsinterp.py') diff --git a/youtube_dl/jsinterp.py b/youtube_dl/jsinterp.py index 8eaa911cd..c60a9b3c2 100644 --- a/youtube_dl/jsinterp.py +++ b/youtube_dl/jsinterp.py @@ -1,42 +1,87 @@ from __future__ import unicode_literals +import itertools import json +import math import operator import re from .utils import ( + NO_DEFAULT, ExtractorError, + js_to_json, remove_quotes, + unified_timestamp, ) from .compat import ( - compat_collections_abc, + compat_collections_chain_map as ChainMap, + compat_itertools_zip_longest as zip_longest, compat_str, ) -MutableMapping = compat_collections_abc.MutableMapping +_NAME_RE = r'[a-zA-Z_$][\w$]*' -class Nonlocal: - pass - +# (op, definition) in order of binding priority, tightest first +# avoid dict to maintain order +# definition None => Defined in JSInterpreter._operator +_DOT_OPERATORS = ( + ('.', None), + # TODO: ('?.', None), +) -_OPERATORS = [ +_OPERATORS = ( ('|', operator.or_), ('^', operator.xor), ('&', operator.and_), ('>>', operator.rshift), ('<<', operator.lshift), - ('-', operator.sub), ('+', operator.add), - ('%', operator.mod), - ('/', operator.truediv), + ('-', operator.sub), ('*', operator.mul), -] -_ASSIGN_OPERATORS = [(op + '=', opfunc) for op, opfunc in _OPERATORS] -_ASSIGN_OPERATORS.append(('=', (lambda cur, right: right))) + ('/', operator.truediv), + ('%', operator.mod), +) -_NAME_RE = r'[a-zA-Z_$][a-zA-Z_$0-9]*' +_COMP_OPERATORS = ( + ('===', operator.is_), + ('==', operator.eq), + ('!==', operator.is_not), + ('!=', operator.ne), + ('<=', operator.le), + ('>=', operator.ge), + ('<', operator.lt), + ('>', operator.gt), +) + +_LOG_OPERATORS = ( + ('&', operator.and_), + ('|', operator.or_), + ('^', operator.xor), +) + +_SC_OPERATORS = ( + ('?', None), + ('||', None), + ('&&', None), + # TODO: ('??', None), +) + +_OPERATOR_RE = '|'.join(map(lambda x: re.escape(x[0]), _OPERATORS + _LOG_OPERATORS)) _MATCHING_PARENS = dict(zip(*zip('()', '{}', '[]'))) +_QUOTES = '\'"' + + +def _ternary(cndn, if_true=True, if_false=False): + """Simulate JS's ternary operator (cndn?if_true:if_false)""" + if cndn in (False, None, 0, ''): + return if_false + try: + if math.isnan(cndn): # NB: NaN cannot be checked by membership + return if_false + except TypeError: + pass + return if_true class JS_Break(ExtractorError): @@ -49,70 +94,77 @@ class JS_Continue(ExtractorError): ExtractorError.__init__(self, 'Invalid continue') -class LocalNameSpace(MutableMapping): - def __init__(self, *stack): - self.stack = tuple(stack) - - def __getitem__(self, key): - for scope in self.stack: - if key in scope: - return scope[key] - raise KeyError(key) - +class LocalNameSpace(ChainMap): def __setitem__(self, key, value): - for scope in self.stack: + for scope in self.maps: if key in scope: scope[key] = value - break - else: - self.stack[0][key] = value - return value + return + self.maps[0][key] = value def __delitem__(self, key): raise NotImplementedError('Deleting is not supported') - def __iter__(self): - for scope in self.stack: - for scope_item in iter(scope): - yield scope_item - - def __len__(self, key): - return len(iter(self)) - def __repr__(self): - return 'LocalNameSpace%s' % (self.stack, ) + return 'LocalNameSpace%s' % (self.maps, ) class JSInterpreter(object): + __named_object_counter = 0 + def __init__(self, code, objects=None): - if objects is None: - objects = {} - self.code = code - self._functions = {} - self._objects = objects - self.__named_object_counter = 0 + self.code, self._functions = code, {} + self._objects = {} if objects is None else objects + + class Exception(ExtractorError): + def __init__(self, msg, *args, **kwargs): + expr = kwargs.pop('expr', None) + if expr is not None: + msg = '{0} in: {1!r}'.format(msg.rstrip(), expr[:100]) + super(JSInterpreter.Exception, self).__init__(msg, *args, **kwargs) def _named_object(self, namespace, obj): self.__named_object_counter += 1 - name = '__youtube_dl_jsinterp_obj%s' % (self.__named_object_counter, ) + name = '__youtube_dl_jsinterp_obj%d' % (self.__named_object_counter, ) namespace[name] = obj return name @staticmethod - def _separate(expr, delim=',', max_split=None): + def _separate(expr, delim=',', max_split=None, skip_delims=None): if not expr: return counters = {k: 0 for k in _MATCHING_PARENS.values()} - start, splits, pos, delim_len = 0, 0, 0, len(delim) - 1 + start, splits, pos, skipping, delim_len = 0, 0, 0, 0, len(delim) - 1 + in_quote, escaping = None, False for idx, char in enumerate(expr): - if char in _MATCHING_PARENS: - counters[_MATCHING_PARENS[char]] += 1 - elif char in counters: - counters[char] -= 1 - if char != delim[pos] or any(counters.values()): - pos = 0 + if not in_quote: + if char in _MATCHING_PARENS: + counters[_MATCHING_PARENS[char]] += 1 + elif char in counters: + counters[char] -= 1 + if not escaping: + if char in _QUOTES and in_quote in (char, None): + in_quote = None if in_quote else char + else: + escaping = in_quote and char == '\\' + else: + escaping = False + + if char != delim[pos] or any(counters.values()) or in_quote: + pos = skipping = 0 continue - elif pos != delim_len: + elif skipping > 0: + skipping -= 1 + continue + elif pos == 0 and skip_delims: + here = expr[idx:] + for s in skip_delims if isinstance(skip_delims, (list, tuple)) else [skip_delims]: + if here.startswith(s) and s: + skipping = len(s) - 1 + break + if skipping > 0: + continue + if pos < delim_len: pos += 1 continue yield expr[start: idx - delim_len] @@ -122,61 +174,108 @@ class JSInterpreter(object): break yield expr[start:] - @staticmethod - def _separate_at_paren(expr, delim): - separated = list(JSInterpreter._separate(expr, delim, 1)) + @classmethod + def _separate_at_paren(cls, expr, delim): + separated = list(cls._separate(expr, delim, 1)) + if len(separated) < 2: - raise ExtractorError('No terminating paren {0} in {1}'.format(delim, expr)) + raise cls.Exception('No terminating paren {delim} in {expr}'.format(**locals())) return separated[0][1:].strip(), separated[1].strip() + @staticmethod + def _all_operators(): + return itertools.chain( + _SC_OPERATORS, _LOG_OPERATORS, _COMP_OPERATORS, _OPERATORS) + + def _operator(self, op, left_val, right_expr, expr, local_vars, allow_recursion): + if op in ('||', '&&'): + if (op == '&&') ^ _ternary(left_val): + return left_val # short circuiting + elif op == '?': + right_expr = _ternary(left_val, *self._separate(right_expr, ':', 1)) + + right_val = self.interpret_expression(right_expr, local_vars, allow_recursion) + opfunc = op and next((v for k, v in self._all_operators() if k == op), None) + if not opfunc: + return right_val + + try: + return opfunc(left_val, right_val) + except Exception as e: + raise self.Exception('Failed to evaluate {left_val!r} {op} {right_val!r}'.format(**locals()), expr, cause=e) + + def _index(self, obj, idx): + if idx == 'length': + return len(obj) + try: + return obj[int(idx)] if isinstance(obj, list) else obj[idx] + except Exception as e: + raise self.Exception('Cannot get index {idx}'.format(**locals()), expr=repr(obj), cause=e) + + def _dump(self, obj, namespace): + try: + return json.dumps(obj) + except TypeError: + return self._named_object(namespace, obj) + 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 - sub_statements = list(self._separate(stmt, ';')) - stmt = (sub_statements or ['']).pop() + should_return = False + sub_statements = list(self._separate(stmt, ';')) or [''] + expr = stmt = sub_statements.pop().strip() for sub_stmt in sub_statements: - ret, should_abort = self.interpret_statement(sub_stmt, local_vars, allow_recursion - 1) - if should_abort: - return ret + ret, should_return = self.interpret_statement(sub_stmt, local_vars, allow_recursion) + if should_return: + return ret, should_return - 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 - else: - # Try interpreting it as an expression - expr = stmt + m = re.match(r'(?P(?:var|const|let)\s)|return(?:\s+|$)', stmt) + if m: + expr = stmt[len(m.group(0)):].strip() + should_return = not m.group('var') + if not expr: + return None, should_return - v = self.interpret_expression(expr, local_vars, allow_recursion) - return v, should_abort + if expr[0] in _QUOTES: + inner, outer = self._separate(expr, expr[0], 1) + 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 + + if expr.startswith('new '): + obj = expr[4:] + if obj.startswith('Date('): + left, right = self._separate_at_paren(obj[4:], ')') + left = self.interpret_expression(left, local_vars, allow_recursion) + expr = unified_timestamp(left, False) + if not expr: + raise self.Exception('Failed to parse date {left!r}'.format(**locals()), expr=expr) + expr = self._dump(int(expr * 1000), local_vars) + right + else: + raise self.Exception('Unsupported object {obj}'.format(**locals()), expr=expr) - def interpret_expression(self, expr, local_vars, allow_recursion): - expr = expr.strip() - if expr == '': # Empty expression - return None + if expr.startswith('void '): + left = self.interpret_expression(expr[5:], local_vars, allow_recursion) + return None, should_return if expr.startswith('{'): inner, outer = self._separate_at_paren(expr, '}') - inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion - 1) + inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion) if not outer or should_abort: - return inner + return inner, should_abort or should_return else: - expr = json.dumps(inner) + outer + expr = self._dump(inner, local_vars) + outer if expr.startswith('('): inner, outer = self._separate_at_paren(expr, ')') - inner = self.interpret_expression(inner, local_vars, allow_recursion) - if not outer: - return inner + 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 = json.dumps(inner) + outer + expr = self._dump(inner, local_vars) + outer if expr.startswith('['): inner, outer = self._separate_at_paren(expr, ']') @@ -185,57 +284,53 @@ class JSInterpreter(object): for item in self._separate(inner)]) expr = name + outer - m = re.match(r'try\s*', expr) - if m: + m = re.match(r'(?Ptry|finally)\s*|(?:(?Pcatch)|(?Pfor)|(?Pswitch))\s*\(', expr) + md = m.groupdict() if m else {} + if md.get('try'): if expr[m.end()] == '{': try_expr, expr = self._separate_at_paren(expr[m.end():], '}') else: try_expr, expr = expr[m.end() - 1:], '' - ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion - 1) + ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion) if should_abort: - return ret - return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0] + return ret, True + ret, should_abort = self.interpret_statement(expr, local_vars, allow_recursion) + return ret, should_abort or should_return - m = re.match(r'(?:(?Pcatch)|(?Pfor)|(?Pswitch))\s*\(', expr) - md = m.groupdict() if m else {} - if md.get('catch'): + elif md.get('catch'): # We ignore the catch block _, expr = self._separate_at_paren(expr, '}') - return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0] + ret, should_abort = self.interpret_statement(expr, local_vars, allow_recursion) + return ret, should_abort or should_return elif md.get('for'): - def raise_constructor_error(c): - raise ExtractorError( - 'Premature return in the initialization of a for loop in {0!r}'.format(c)) - constructor, remaining = self._separate_at_paren(expr[m.end() - 1:], ')') if remaining.startswith('{'): body, expr = self._separate_at_paren(remaining, '}') else: - m = re.match(r'switch\s*\(', remaining) # FIXME - if m: - switch_val, remaining = self._separate_at_paren(remaining[m.end() - 1:], ')') + switch_m = re.match(r'switch\s*\(', 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, '' start, cndn, increment = self._separate(constructor, ';') - if self.interpret_statement(start, local_vars, allow_recursion - 1)[1]: - raise_constructor_error(constructor) + self.interpret_expression(start, local_vars, allow_recursion) while True: - if not self.interpret_expression(cndn, local_vars, allow_recursion): + if not _ternary(self.interpret_expression(cndn, local_vars, allow_recursion)): break try: - ret, should_abort = self.interpret_statement(body, local_vars, allow_recursion - 1) + ret, should_abort = self.interpret_statement(body, local_vars, allow_recursion) if should_abort: - return ret + return ret, True except JS_Break: break except JS_Continue: pass - if self.interpret_statement(increment, local_vars, allow_recursion - 1)[1]: - raise_constructor_error(constructor) - return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0] + self.interpret_expression(increment, local_vars, allow_recursion) + ret, should_abort = self.interpret_statement(expr, local_vars, allow_recursion) + return ret, should_abort or should_return elif md.get('switch'): switch_val, remaining = self._separate_at_paren(expr[m.end() - 1:], ')') @@ -245,7 +340,7 @@ class JSInterpreter(object): for default in (False, True): matched = False for item in items: - case, stmt = [i.strip() for i in self._separate(item, ':', 1)] + case, stmt = (i.strip() for i in self._separate(item, ':', 1)) if default: matched = matched or case == 'default' elif not matched: @@ -254,24 +349,28 @@ class JSInterpreter(object): if not matched: continue try: - ret, should_abort = self.interpret_statement(stmt, local_vars, allow_recursion - 1) + ret, should_abort = self.interpret_statement(stmt, local_vars, allow_recursion) if should_abort: return ret except JS_Break: break if matched: break - return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0] + ret, should_abort = self.interpret_statement(expr, local_vars, allow_recursion) + return ret, should_abort or should_return # Comma separated statements sub_expressions = list(self._separate(expr)) - expr = sub_expressions.pop().strip() if sub_expressions else '' - for sub_expr in sub_expressions: - self.interpret_expression(sub_expr, local_vars, allow_recursion) + 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 for m in re.finditer(r'''(?x) - (?P\+\+|--)(?P%(_NAME_RE)s)| - (?P%(_NAME_RE)s)(?P\+\+|--)''' % globals(), expr): + (?P\+\+|--)(?P{_NAME_RE})| + (?P{_NAME_RE})(?P\+\+|--)'''.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') @@ -279,85 +378,87 @@ class JSInterpreter(object): local_vars[var] += 1 if sign[0] == '+' else -1 if m.group('pre_sign'): ret = local_vars[var] - expr = expr[:start] + json.dumps(ret) + expr[end:] - - for op, opfunc in _ASSIGN_OPERATORS: - m = re.match(r'''(?x) - (?P%s)(?:\[(?P[^\]]+?)\])? - \s*%s - (?P.*)$''' % (_NAME_RE, re.escape(op)), expr) - if not m: - continue - right_val = self.interpret_expression(m.group('expr'), local_vars, allow_recursion) - - if m.groupdict().get('index'): - lvar = local_vars[m.group('out')] - idx = self.interpret_expression(m.group('index'), local_vars, allow_recursion) - if not isinstance(idx, int): - raise ExtractorError('List indices must be integers: %s' % (idx, )) - cur = lvar[idx] - val = opfunc(cur, right_val) - lvar[idx] = val - return val - else: - cur = local_vars.get(m.group('out')) - val = opfunc(cur, right_val) - local_vars[m.group('out')] = val - return val + expr = expr[:start] + self._dump(ret, local_vars) + expr[end:] - if expr.isdigit(): - return int(expr) - - if expr == 'break': + if not expr: + return None, should_return + + m = re.match(r'''(?x) + (?P + (?P{_NAME_RE})(?:\[(?P[^\]]+?)\])?\s* + (?P{_OPERATOR_RE})? + =(?P.*)$ + )|(?P + (?!if|return|true|false|null|undefined)(?P{_NAME_RE})$ + )|(?P + (?P{_NAME_RE})\[(?P.+)\]$ + )|(?P + (?P{_NAME_RE})(?:\.(?P[^(]+)|\[(?P[^\]]+)\])\s* + )|(?P + (?P{_NAME_RE})\((?P.*)\)$ + )'''.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('index'): + 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 is None: + raise self.Exception('Cannot index undefined variable ' + m.group('out'), expr=expr) + + idx = self.interpret_expression(m.group('index'), local_vars, allow_recursion) + if not isinstance(idx, (int, float)): + raise self.Exception('List index %s must be integer' % (idx, ), expr=expr) + idx = int(idx) + left_val[idx] = self._operator( + m.group('op'), left_val[idx], 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() - var_m = re.match( - r'(?!if|return|true|false|null)(?P%s)$' % _NAME_RE, - expr) - if var_m: - return local_vars[var_m.group('name')] + elif md.get('return'): + return local_vars[m.group('name')], should_return try: - return json.loads(expr) + ret = json.loads(js_to_json(expr)) # strict=True) + if not md.get('attribute'): + return ret, should_return except ValueError: pass - m = re.match( - r'(?P%s)\[(?P.+)\]$' % _NAME_RE, expr) - if m: + if md.get('indexing'): val = local_vars[m.group('in')] idx = self.interpret_expression(m.group('idx'), local_vars, allow_recursion) - return val[idx] - - def raise_expr_error(where, op, exp): - raise ExtractorError('Premature {0} return of {1} in {2!r}'.format(where, op, exp)) + return self._index(val, idx), should_return - for op, opfunc in _OPERATORS: - separated = list(self._separate(expr, op)) + 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 + separated = list(self._separate(expr, op, skip_delims=skip_delim)) if len(separated) < 2: continue - right_val = separated.pop() - left_val = op.join(separated) - left_val, should_abort = self.interpret_statement( - left_val, local_vars, allow_recursion - 1) - if should_abort: - raise_expr_error('left-side', op, expr) - right_val, should_abort = self.interpret_statement( - right_val, local_vars, allow_recursion - 1) - if should_abort: - raise_expr_error('right-side', op, expr) - return opfunc(left_val or 0, right_val) - m = re.match( - r'(?P%s)(?:\.(?P[^(]+)|\[(?P[^]]+)\])\s*' % _NAME_RE, - expr) - if m: - variable = m.group('var') - nl = Nonlocal() + right_expr = separated.pop() + while op == '-' and len(separated) > 1 and not separated[-1].strip(): + right_expr = '-' + right_expr + separated.pop() + left_val = self.interpret_expression(op.join(separated), local_vars, allow_recursion) + return self._operator(op, 0 if left_val is None else left_val, + right_expr, expr, local_vars, allow_recursion), should_return - nl.member = remove_quotes(m.group('member') or m.group('member2')) + if md.get('attribute'): + variable = m.group('var') + member = m.group('member') + 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, ')') @@ -367,25 +468,24 @@ class JSInterpreter(object): def assertion(cndn, msg): """ assert, but without risk of getting optimized out """ if not cndn: - raise ExtractorError('{0} {1}: {2}'.format(nl.member, msg, expr)) + raise ExtractorError('{member} {msg}'.format(**locals()), expr=expr) def eval_method(): - # nonlocal member - member = nl.member - if variable == 'String': - obj = compat_str - elif variable in local_vars: - obj = local_vars[variable] - else: + if (variable, member) == ('console', 'debug'): + return + types = { + 'String': compat_str, + 'Math': float, + } + obj = local_vars.get(variable, types.get(variable, NO_DEFAULT)) + if obj is NO_DEFAULT: if variable not in self._objects: self._objects[variable] = self.extract_object(variable) obj = self._objects[variable] + # Member access if arg_str is None: - # Member access - if member == 'length': - return len(obj) - return obj[member] + return self._index(obj, member) # Function call argvals = [ @@ -396,12 +496,17 @@ class JSInterpreter(object): if member == 'fromCharCode': assertion(argvals, 'takes one or more arguments') return ''.join(map(chr, argvals)) - raise ExtractorError('Unsupported string method %s' % (member, )) + raise self.Exception('Unsupported string method ' + member, expr=expr) + elif obj == 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) if member == 'split': assertion(argvals, 'takes one or more arguments') - assertion(argvals == [''], 'with arguments is not implemented') - return list(obj) + assertion(len(argvals) == 1, 'with limit argument is not implemented') + return obj.split(argvals[0]) if argvals[0] else list(obj) elif member == 'join': assertion(isinstance(obj, list), 'must be applied on a list') assertion(len(argvals) == 1, 'takes exactly one argument') @@ -447,7 +552,7 @@ class JSInterpreter(object): 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) for idx, item in enumerate(obj)] + 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') @@ -457,32 +562,35 @@ class JSInterpreter(object): except ValueError: return -1 - if isinstance(obj, list): - member = int(member) - nl.member = member - return obj[member](argvals) + idx = int(member) if isinstance(obj, list) else member + return obj[idx](argvals, allow_recursion=allow_recursion) if remaining: - return self.interpret_expression( + ret, should_abort = self.interpret_statement( self._named_object(local_vars, eval_method()) + remaining, local_vars, allow_recursion) + return ret, should_return or should_abort else: - return eval_method() + return eval_method(), should_return - m = re.match(r'^(?P%s)\((?P[a-zA-Z0-9_$,]*)\)$' % _NAME_RE, expr) - if m: - fname = m.group('func') - argvals = tuple([ - int(v) if v.isdigit() else local_vars[v] - for v in self._separate(m.group('args'))]) + 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) + 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 - if expr: - raise ExtractorError('Unsupported JS expression %r' % expr) + raise self.Exception( + 'Unsupported JS expression ' + (expr[:40] if expr != stmt else ''), expr=stmt) + + 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 extract_object(self, objname): _FUNC_NAME_RE = r'''(?:[a-zA-Z$0-9]+|"[a-zA-Z$0-9]+"|'[a-zA-Z$0-9]+')''' @@ -494,15 +602,17 @@ class JSInterpreter(object): }\s*; ''' % (re.escape(objname), _FUNC_NAME_RE), self.code) + if not obj_m: + raise self.Exception('Could not find object ' + objname) fields = obj_m.group('fields') # Currently, it only supports function definitions fields_m = re.finditer( r'''(?x) - (?P%s)\s*:\s*function\s*\((?P[a-z,]+)\){(?P[^}]+)} - ''' % _FUNC_NAME_RE, + (?P%s)\s*:\s*function\s*\((?P(?:%s|,)*)\){(?P[^}]+)} + ''' % (_FUNC_NAME_RE, _NAME_RE), fields) for f in fields_m: - argnames = f.group('args').split(',') + argnames = self.build_arglist(f.group('args')) obj[remove_quotes(f.group('key'))] = self.build_function(argnames, f.group('code')) return obj @@ -510,15 +620,19 @@ class JSInterpreter(object): def extract_function_code(self, funcname): """ @returns argnames, code """ func_m = re.search( - r'''(?x) - (?:function\s+%(f_n)s|[{;,]\s*%(f_n)s\s*=\s*function|var\s+%(f_n)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* \((?P[^)]*)\)\s* - (?P\{(?:(?!};)[^"]|"([^"]|\\")*")+\})''' % {'f_n': re.escape(funcname), }, + (?P{.+})''' % {'name': re.escape(funcname)}, self.code) code, _ = self._separate_at_paren(func_m.group('code'), '}') # refine the match if func_m is None: - raise ExtractorError('Could not find JS function %r' % funcname) - return func_m.group('args').split(','), code + raise self.Exception('Could not find JS function "{funcname}"'.format(**locals())) + return self.build_arglist(func_m.group('args')), code def extract_function(self, funcname): return self.extract_function_from_code(*self.extract_function_code(funcname)) @@ -534,7 +648,7 @@ class JSInterpreter(object): name = self._named_object( local_vars, self.extract_function_from_code( - [x.strip() for x in mobj.group('args').split(',')], + self.build_arglist(mobj.group('args')), body, local_vars, *global_stack)) code = code[:start] + name + remaining return self.build_function(argnames, code, local_vars, *global_stack) @@ -542,17 +656,22 @@ class JSInterpreter(object): def call_function(self, funcname, *args): return self.extract_function(funcname)(args) + @classmethod + def build_arglist(cls, arg_text): + if not arg_text: + return [] + return list(filter(None, (x.strip() or None for x in cls._separate(arg_text)))) + def build_function(self, argnames, code, *global_stack): global_stack = list(global_stack) or [{}] - local_vars = global_stack.pop(0) - - def resf(args, **kwargs): - local_vars.update(dict(zip(argnames, args))) - local_vars.update(kwargs) - var_stack = LocalNameSpace(local_vars, *global_stack) - for stmt in self._separate(code.replace('\n', ''), ';'): - ret, should_abort = self.interpret_statement(stmt, var_stack) - if should_abort: - break - return ret + argnames = tuple(argnames) + + def resf(args, kwargs={}, allow_recursion=100): + global_stack[0].update( + zip_longest(argnames, args, fillvalue=None)) + 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 -- cgit 1.4.1