mirror of
https://github.com/yt-dlp/yt-dlp.git
synced 2024-11-14 15:14:26 +01:00
854 lines
34 KiB
Python
854 lines
34 KiB
Python
import collections
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import contextlib
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import itertools
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import json
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import math
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import operator
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import re
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from .utils import (
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NO_DEFAULT,
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ExtractorError,
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function_with_repr,
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js_to_json,
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remove_quotes,
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truncate_string,
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unified_timestamp,
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write_string,
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)
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def _js_bit_op(op):
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def zeroise(x):
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if x in (None, JS_Undefined):
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return 0
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with contextlib.suppress(TypeError):
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if math.isnan(x): # NB: NaN cannot be checked by membership
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return 0
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return x
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def wrapped(a, b):
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return op(zeroise(a), zeroise(b)) & 0xffffffff
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return wrapped
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def _js_arith_op(op):
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def wrapped(a, b):
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if JS_Undefined in (a, b):
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return float('nan')
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return op(a or 0, b or 0)
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return wrapped
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def _js_div(a, b):
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if JS_Undefined in (a, b) or not (a or b):
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return float('nan')
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return (a or 0) / b if b else float('inf')
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def _js_mod(a, b):
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if JS_Undefined in (a, b) or not b:
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return float('nan')
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return (a or 0) % b
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def _js_exp(a, b):
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if not b:
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return 1 # even 0 ** 0 !!
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elif JS_Undefined in (a, b):
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return float('nan')
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return (a or 0) ** b
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def _js_eq_op(op):
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def wrapped(a, b):
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if {a, b} <= {None, JS_Undefined}:
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return op(a, a)
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return op(a, b)
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return wrapped
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def _js_comp_op(op):
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def wrapped(a, b):
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if JS_Undefined in (a, b):
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return False
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if isinstance(a, str) or isinstance(b, str):
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return op(str(a or 0), str(b or 0))
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return op(a or 0, b or 0)
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return wrapped
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def _js_ternary(cndn, if_true=True, if_false=False):
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"""Simulate JS's ternary operator (cndn?if_true:if_false)"""
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if cndn in (False, None, 0, '', JS_Undefined):
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return if_false
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with contextlib.suppress(TypeError):
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if math.isnan(cndn): # NB: NaN cannot be checked by membership
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return if_false
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return if_true
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# Ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence
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_OPERATORS = { # None => Defined in JSInterpreter._operator
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'?': None,
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'??': None,
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'||': None,
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'&&': None,
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'|': _js_bit_op(operator.or_),
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'^': _js_bit_op(operator.xor),
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'&': _js_bit_op(operator.and_),
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'===': operator.is_,
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'!==': operator.is_not,
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'==': _js_eq_op(operator.eq),
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'!=': _js_eq_op(operator.ne),
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'<=': _js_comp_op(operator.le),
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'>=': _js_comp_op(operator.ge),
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'<': _js_comp_op(operator.lt),
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'>': _js_comp_op(operator.gt),
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'>>': _js_bit_op(operator.rshift),
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'<<': _js_bit_op(operator.lshift),
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'+': _js_arith_op(operator.add),
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'-': _js_arith_op(operator.sub),
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'*': _js_arith_op(operator.mul),
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'%': _js_mod,
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'/': _js_div,
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'**': _js_exp,
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}
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_COMP_OPERATORS = {'===', '!==', '==', '!=', '<=', '>=', '<', '>'}
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_NAME_RE = r'[a-zA-Z_$][\w$]*'
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_MATCHING_PARENS = dict(zip(*zip('()', '{}', '[]')))
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_QUOTES = '\'"/'
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class JS_Undefined:
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pass
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class JS_Break(ExtractorError):
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def __init__(self):
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ExtractorError.__init__(self, 'Invalid break')
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class JS_Continue(ExtractorError):
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def __init__(self):
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ExtractorError.__init__(self, 'Invalid continue')
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class JS_Throw(ExtractorError):
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def __init__(self, e):
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self.error = e
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ExtractorError.__init__(self, f'Uncaught exception {e}')
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class LocalNameSpace(collections.ChainMap):
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def __setitem__(self, key, value):
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for scope in self.maps:
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if key in scope:
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scope[key] = value
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return
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self.maps[0][key] = value
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def __delitem__(self, key):
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raise NotImplementedError('Deleting is not supported')
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class Debugger:
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import sys
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ENABLED = False and 'pytest' in sys.modules
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@staticmethod
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def write(*args, level=100):
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write_string(f'[debug] JS: {" " * (100 - level)}'
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f'{" ".join(truncate_string(str(x), 50, 50) for x in args)}\n')
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@classmethod
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def wrap_interpreter(cls, f):
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def interpret_statement(self, stmt, local_vars, allow_recursion, *args, **kwargs):
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if cls.ENABLED and stmt.strip():
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cls.write(stmt, level=allow_recursion)
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try:
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ret, should_ret = f(self, stmt, local_vars, allow_recursion, *args, **kwargs)
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except Exception as e:
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if cls.ENABLED:
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if isinstance(e, ExtractorError):
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e = e.orig_msg
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cls.write('=> Raises:', e, '<-|', stmt, level=allow_recursion)
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raise
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if cls.ENABLED and stmt.strip():
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if should_ret or not repr(ret) == stmt:
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cls.write(['->', '=>'][should_ret], repr(ret), '<-|', stmt, level=allow_recursion)
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return ret, should_ret
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return interpret_statement
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class JSInterpreter:
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__named_object_counter = 0
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_RE_FLAGS = {
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# special knowledge: Python's re flags are bitmask values, current max 128
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# invent new bitmask values well above that for literal parsing
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# TODO: new pattern class to execute matches with these flags
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'd': 1024, # Generate indices for substring matches
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'g': 2048, # Global search
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'i': re.I, # Case-insensitive search
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'm': re.M, # Multi-line search
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's': re.S, # Allows . to match newline characters
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'u': re.U, # Treat a pattern as a sequence of unicode code points
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'y': 4096, # Perform a "sticky" search that matches starting at the current position in the target string
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}
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def __init__(self, code, objects=None):
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self.code, self._functions = code, {}
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self._objects = {} if objects is None else objects
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class Exception(ExtractorError):
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def __init__(self, msg, expr=None, *args, **kwargs):
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if expr is not None:
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msg = f'{msg.rstrip()} in: {truncate_string(expr, 50, 50)}'
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super().__init__(msg, *args, **kwargs)
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def _named_object(self, namespace, obj):
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self.__named_object_counter += 1
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name = f'__yt_dlp_jsinterp_obj{self.__named_object_counter}'
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if callable(obj) and not isinstance(obj, function_with_repr):
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obj = function_with_repr(obj, f'F<{self.__named_object_counter}>')
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namespace[name] = obj
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return name
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@classmethod
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def _regex_flags(cls, expr):
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flags = 0
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if not expr:
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return flags, expr
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for idx, ch in enumerate(expr):
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if ch not in cls._RE_FLAGS:
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break
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flags |= cls._RE_FLAGS[ch]
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return flags, expr[idx + 1:]
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@staticmethod
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def _separate(expr, delim=',', max_split=None):
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OP_CHARS = '+-*/%&|^=<>!,;{}:['
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if not expr:
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return
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counters = {k: 0 for k in _MATCHING_PARENS.values()}
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start, splits, pos, delim_len = 0, 0, 0, len(delim) - 1
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in_quote, escaping, after_op, in_regex_char_group = None, False, True, False
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for idx, char in enumerate(expr):
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if not in_quote and char in _MATCHING_PARENS:
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counters[_MATCHING_PARENS[char]] += 1
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elif not in_quote and char in counters:
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# Something's wrong if we get negative, but ignore it anyway
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if counters[char]:
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counters[char] -= 1
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elif not escaping:
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if char in _QUOTES and in_quote in (char, None):
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if in_quote or after_op or char != '/':
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in_quote = None if in_quote and not in_regex_char_group else char
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elif in_quote == '/' and char in '[]':
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in_regex_char_group = char == '['
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escaping = not escaping and in_quote and char == '\\'
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in_unary_op = (not in_quote and not in_regex_char_group
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and after_op not in (True, False) and char in '-+')
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after_op = char if (not in_quote and char in OP_CHARS) else (char.isspace() and after_op)
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if char != delim[pos] or any(counters.values()) or in_quote or in_unary_op:
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pos = 0
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continue
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elif pos != delim_len:
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pos += 1
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continue
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yield expr[start: idx - delim_len]
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start, pos = idx + 1, 0
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splits += 1
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if max_split and splits >= max_split:
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break
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yield expr[start:]
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@classmethod
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def _separate_at_paren(cls, expr, delim=None):
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if delim is None:
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delim = expr and _MATCHING_PARENS[expr[0]]
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separated = list(cls._separate(expr, delim, 1))
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if len(separated) < 2:
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raise cls.Exception(f'No terminating paren {delim}', expr)
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return separated[0][1:].strip(), separated[1].strip()
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def _operator(self, op, left_val, right_expr, expr, local_vars, allow_recursion):
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if op in ('||', '&&'):
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if (op == '&&') ^ _js_ternary(left_val):
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return left_val # short circuiting
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elif op == '??':
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if left_val not in (None, JS_Undefined):
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return left_val
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elif op == '?':
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right_expr = _js_ternary(left_val, *self._separate(right_expr, ':', 1))
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right_val = self.interpret_expression(right_expr, local_vars, allow_recursion)
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if not _OPERATORS.get(op):
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return right_val
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try:
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return _OPERATORS[op](left_val, right_val)
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except Exception as e:
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raise self.Exception(f'Failed to evaluate {left_val!r} {op} {right_val!r}', expr, cause=e)
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def _index(self, obj, idx, allow_undefined=False):
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if idx == 'length':
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return len(obj)
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try:
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return obj[int(idx)] if isinstance(obj, list) else obj[idx]
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except Exception as e:
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if allow_undefined:
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return JS_Undefined
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raise self.Exception(f'Cannot get index {idx}', repr(obj), cause=e)
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def _dump(self, obj, namespace):
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try:
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return json.dumps(obj)
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except TypeError:
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return self._named_object(namespace, obj)
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@Debugger.wrap_interpreter
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def interpret_statement(self, stmt, local_vars, allow_recursion=100):
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if allow_recursion < 0:
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raise self.Exception('Recursion limit reached')
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allow_recursion -= 1
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should_return = False
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sub_statements = list(self._separate(stmt, ';')) or ['']
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expr = stmt = sub_statements.pop().strip()
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for sub_stmt in sub_statements:
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ret, should_return = self.interpret_statement(sub_stmt, local_vars, allow_recursion)
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if should_return:
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return ret, should_return
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m = re.match(r'(?P<var>(?:var|const|let)\s)|return(?:\s+|(?=["\'])|$)|(?P<throw>throw\s+)', stmt)
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if m:
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expr = stmt[len(m.group(0)):].strip()
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if m.group('throw'):
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raise JS_Throw(self.interpret_expression(expr, local_vars, allow_recursion))
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should_return = not m.group('var')
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if not expr:
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return None, should_return
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if expr[0] in _QUOTES:
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inner, outer = self._separate(expr, expr[0], 1)
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if expr[0] == '/':
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flags, outer = self._regex_flags(outer)
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# We don't support regex methods yet, so no point compiling it
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inner = f'{inner}/{flags}'
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# Avoid https://github.com/python/cpython/issues/74534
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# inner = re.compile(inner[1:].replace('[[', r'[\['), flags=flags)
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else:
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inner = json.loads(js_to_json(f'{inner}{expr[0]}', strict=True))
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if not outer:
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return inner, should_return
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expr = self._named_object(local_vars, inner) + outer
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if expr.startswith('new '):
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obj = expr[4:]
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if obj.startswith('Date('):
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left, right = self._separate_at_paren(obj[4:])
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date = unified_timestamp(
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self.interpret_expression(left, local_vars, allow_recursion), False)
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if date is None:
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raise self.Exception(f'Failed to parse date {left!r}', expr)
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expr = self._dump(int(date * 1000), local_vars) + right
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else:
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raise self.Exception(f'Unsupported object {obj}', expr)
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if expr.startswith('void '):
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left = self.interpret_expression(expr[5:], local_vars, allow_recursion)
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return None, should_return
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if expr.startswith('{'):
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inner, outer = self._separate_at_paren(expr)
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# try for object expression (Map)
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sub_expressions = [list(self._separate(sub_expr.strip(), ':', 1)) for sub_expr in self._separate(inner)]
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if all(len(sub_expr) == 2 for sub_expr in sub_expressions):
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def dict_item(key, val):
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val = self.interpret_expression(val, local_vars, allow_recursion)
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if re.match(_NAME_RE, key):
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return key, val
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return self.interpret_expression(key, local_vars, allow_recursion), val
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return dict(dict_item(k, v) for k, v in sub_expressions), should_return
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inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion)
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if not outer or should_abort:
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return inner, should_abort or should_return
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else:
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expr = self._dump(inner, local_vars) + outer
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if expr.startswith('('):
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inner, outer = self._separate_at_paren(expr)
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inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion)
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if not outer or should_abort:
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return inner, should_abort or should_return
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else:
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expr = self._dump(inner, local_vars) + outer
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if expr.startswith('['):
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inner, outer = self._separate_at_paren(expr)
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name = self._named_object(local_vars, [
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self.interpret_expression(item, local_vars, allow_recursion)
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for item in self._separate(inner)])
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expr = name + outer
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m = re.match(r'''(?x)
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(?P<try>try)\s*\{|
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(?P<if>if)\s*\(|
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(?P<switch>switch)\s*\(|
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(?P<for>for)\s*\(
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''', expr)
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md = m.groupdict() if m else {}
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if md.get('if'):
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cndn, expr = self._separate_at_paren(expr[m.end() - 1:])
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if_expr, expr = self._separate_at_paren(expr.lstrip())
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# TODO: "else if" is not handled
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else_expr = None
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m = re.match(r'else\s*{', expr)
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if m:
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else_expr, expr = self._separate_at_paren(expr[m.end() - 1:])
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cndn = _js_ternary(self.interpret_expression(cndn, local_vars, allow_recursion))
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ret, should_abort = self.interpret_statement(
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if_expr if cndn else else_expr, local_vars, allow_recursion)
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if should_abort:
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return ret, True
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if md.get('try'):
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try_expr, expr = self._separate_at_paren(expr[m.end() - 1:])
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err = None
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try:
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ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion)
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if should_abort:
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return ret, True
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except Exception as e:
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# XXX: This works for now, but makes debugging future issues very hard
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err = e
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pending = (None, False)
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m = re.match(fr'catch\s*(?P<err>\(\s*{_NAME_RE}\s*\))?\{{', expr)
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if m:
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sub_expr, expr = self._separate_at_paren(expr[m.end() - 1:])
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if err:
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catch_vars = {}
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if m.group('err'):
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catch_vars[m.group('err')] = err.error if isinstance(err, JS_Throw) else err
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catch_vars = local_vars.new_child(catch_vars)
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err, pending = None, self.interpret_statement(sub_expr, catch_vars, allow_recursion)
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m = re.match(r'finally\s*\{', expr)
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if m:
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sub_expr, expr = self._separate_at_paren(expr[m.end() - 1:])
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ret, should_abort = self.interpret_statement(sub_expr, local_vars, allow_recursion)
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if should_abort:
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return ret, True
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ret, should_abort = pending
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if should_abort:
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return ret, True
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if err:
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raise err
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elif md.get('for'):
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constructor, remaining = self._separate_at_paren(expr[m.end() - 1:])
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if remaining.startswith('{'):
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body, expr = self._separate_at_paren(remaining)
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else:
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switch_m = re.match(r'switch\s*\(', remaining) # FIXME
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if switch_m:
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switch_val, remaining = self._separate_at_paren(remaining[switch_m.end() - 1:])
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body, expr = self._separate_at_paren(remaining, '}')
|
|
body = 'switch(%s){%s}' % (switch_val, body)
|
|
else:
|
|
body, expr = remaining, ''
|
|
start, cndn, increment = self._separate(constructor, ';')
|
|
self.interpret_expression(start, local_vars, allow_recursion)
|
|
while True:
|
|
if not _js_ternary(self.interpret_expression(cndn, local_vars, allow_recursion)):
|
|
break
|
|
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
|
|
self.interpret_expression(increment, local_vars, allow_recursion)
|
|
|
|
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
|
|
|
|
if md:
|
|
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))
|
|
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(rf'''(?x)
|
|
(?P<pre_sign>\+\+|--)(?P<var1>{_NAME_RE})|
|
|
(?P<var2>{_NAME_RE})(?P<post_sign>\+\+|--)''', 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] += 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(fr'''(?x)
|
|
(?P<assign>
|
|
(?P<out>{_NAME_RE})(?:\[(?P<index>[^\]]+?)\])?\s*
|
|
(?P<op>{"|".join(map(re.escape, set(_OPERATORS) - _COMP_OPERATORS))})?
|
|
=(?!=)(?P<expr>.*)$
|
|
)|(?P<return>
|
|
(?!if|return|true|false|null|undefined|NaN)(?P<name>{_NAME_RE})$
|
|
)|(?P<indexing>
|
|
(?P<in>{_NAME_RE})\[(?P<idx>.+)\]$
|
|
)|(?P<attribute>
|
|
(?P<var>{_NAME_RE})(?:(?P<nullish>\?)?\.(?P<member>[^(]+)|\[(?P<member2>[^\]]+)\])\s*
|
|
)|(?P<function>
|
|
(?P<fname>{_NAME_RE})\((?P<args>.*)\)$
|
|
)''', expr)
|
|
if m and m.group('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 in (None, JS_Undefined):
|
|
raise self.Exception(f'Cannot index undefined variable {m.group("out")}', expr)
|
|
|
|
idx = self.interpret_expression(m.group('index'), local_vars, allow_recursion)
|
|
if not isinstance(idx, (int, float)):
|
|
raise self.Exception(f'List index {idx} must be integer', expr)
|
|
idx = int(idx)
|
|
left_val[idx] = self._operator(
|
|
m.group('op'), self._index(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()
|
|
elif expr == 'undefined':
|
|
return JS_Undefined, should_return
|
|
elif expr == 'NaN':
|
|
return float('NaN'), should_return
|
|
|
|
elif m and m.group('return'):
|
|
return local_vars.get(m.group('name'), JS_Undefined), should_return
|
|
|
|
with contextlib.suppress(ValueError):
|
|
return json.loads(js_to_json(expr, strict=True)), should_return
|
|
|
|
if m and m.group('indexing'):
|
|
val = local_vars[m.group('in')]
|
|
idx = self.interpret_expression(m.group('idx'), local_vars, allow_recursion)
|
|
return self._index(val, idx), should_return
|
|
|
|
for op in _OPERATORS:
|
|
separated = list(self._separate(expr, op))
|
|
right_expr = separated.pop()
|
|
while True:
|
|
if op in '?<>*-' and len(separated) > 1 and not separated[-1].strip():
|
|
separated.pop()
|
|
elif not (separated and op == '?' and right_expr.startswith('.')):
|
|
break
|
|
right_expr = f'{op}{right_expr}'
|
|
if op != '-':
|
|
right_expr = f'{separated.pop()}{op}{right_expr}'
|
|
if not separated:
|
|
continue
|
|
left_val = self.interpret_expression(op.join(separated), local_vars, allow_recursion)
|
|
return self._operator(op, left_val, right_expr, expr, local_vars, allow_recursion), should_return
|
|
|
|
if m and m.group('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:
|
|
arg_str, remaining = None, arg_str
|
|
|
|
def assertion(cndn, msg):
|
|
""" assert, but without risk of getting optimized out """
|
|
if not cndn:
|
|
raise self.Exception(f'{member} {msg}', expr)
|
|
|
|
def eval_method():
|
|
if (variable, member) == ('console', 'debug'):
|
|
if Debugger.ENABLED:
|
|
Debugger.write(self.interpret_expression(f'[{arg_str}]', local_vars, allow_recursion))
|
|
return
|
|
|
|
types = {
|
|
'String': str,
|
|
'Math': float,
|
|
}
|
|
obj = local_vars.get(variable, types.get(variable, NO_DEFAULT))
|
|
if obj is NO_DEFAULT:
|
|
if variable not in self._objects:
|
|
try:
|
|
self._objects[variable] = self.extract_object(variable)
|
|
except self.Exception:
|
|
if not nullish:
|
|
raise
|
|
obj = self._objects.get(variable, JS_Undefined)
|
|
|
|
if nullish and obj is JS_Undefined:
|
|
return JS_Undefined
|
|
|
|
# Member access
|
|
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)]
|
|
|
|
if obj == str:
|
|
if member == 'fromCharCode':
|
|
assertion(argvals, 'takes one or more arguments')
|
|
return ''.join(map(chr, argvals))
|
|
raise self.Exception(f'Unsupported String method {member}', expr)
|
|
elif obj == float:
|
|
if member == 'pow':
|
|
assertion(len(argvals) == 2, 'takes two arguments')
|
|
return argvals[0] ** argvals[1]
|
|
raise self.Exception(f'Unsupported Math method {member}', expr)
|
|
|
|
if member == 'split':
|
|
assertion(argvals, 'takes one or more arguments')
|
|
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')
|
|
return argvals[0].join(obj)
|
|
elif member == 'reverse':
|
|
assertion(not argvals, 'does not take any arguments')
|
|
obj.reverse()
|
|
return obj
|
|
elif member == 'slice':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(len(argvals) == 1, 'takes exactly one argument')
|
|
return obj[argvals[0]:]
|
|
elif member == 'splice':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(argvals, 'takes one or more arguments')
|
|
index, howMany = map(int, (argvals + [len(obj)])[:2])
|
|
if index < 0:
|
|
index += len(obj)
|
|
add_items = argvals[2:]
|
|
res = []
|
|
for i in range(index, min(index + howMany, len(obj))):
|
|
res.append(obj.pop(index))
|
|
for i, item in enumerate(add_items):
|
|
obj.insert(index + i, item)
|
|
return res
|
|
elif member == 'unshift':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(argvals, 'takes one or more arguments')
|
|
for item in reversed(argvals):
|
|
obj.insert(0, item)
|
|
return obj
|
|
elif member == 'pop':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(not argvals, 'does not take any arguments')
|
|
if not obj:
|
|
return
|
|
return obj.pop()
|
|
elif member == 'push':
|
|
assertion(argvals, 'takes one or more arguments')
|
|
obj.extend(argvals)
|
|
return 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, str), 'must be applied on a string')
|
|
assertion(len(argvals) == 1, 'takes exactly one argument')
|
|
idx = argvals[0] if isinstance(argvals[0], int) else 0
|
|
if idx >= len(obj):
|
|
return None
|
|
return ord(obj[idx])
|
|
|
|
idx = int(member) if isinstance(obj, list) else member
|
|
return obj[idx](argvals, allow_recursion=allow_recursion)
|
|
|
|
if remaining:
|
|
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(), should_return
|
|
|
|
elif m and m.group('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, allow_recursion=allow_recursion), should_return
|
|
|
|
raise self.Exception(
|
|
f'Unsupported JS expression {truncate_string(expr, 20, 20) if expr != stmt else ""}', 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]+')'''
|
|
obj = {}
|
|
obj_m = re.search(
|
|
r'''(?x)
|
|
(?<!\.)%s\s*=\s*{\s*
|
|
(?P<fields>(%s\s*:\s*function\s*\(.*?\)\s*{.*?}(?:,\s*)?)*)
|
|
}\s*;
|
|
''' % (re.escape(objname), _FUNC_NAME_RE),
|
|
self.code)
|
|
if not obj_m:
|
|
raise self.Exception(f'Could not find object {objname}')
|
|
fields = obj_m.group('fields')
|
|
# Currently, it only supports function definitions
|
|
fields_m = re.finditer(
|
|
r'''(?x)
|
|
(?P<key>%s)\s*:\s*function\s*\((?P<args>(?:%s|,)*)\){(?P<code>[^}]+)}
|
|
''' % (_FUNC_NAME_RE, _NAME_RE),
|
|
fields)
|
|
for f in fields_m:
|
|
argnames = f.group('args').split(',')
|
|
name = remove_quotes(f.group('key'))
|
|
obj[name] = function_with_repr(self.build_function(argnames, f.group('code')), f'F<{name}>')
|
|
|
|
return obj
|
|
|
|
def extract_function_code(self, funcname):
|
|
""" @returns argnames, code """
|
|
func_m = re.search(
|
|
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>{.+})''' % {'name': re.escape(funcname)},
|
|
self.code)
|
|
code, _ = self._separate_at_paren(func_m.group('code'))
|
|
if func_m is None:
|
|
raise self.Exception(f'Could not find JS function "{funcname}"')
|
|
return [x.strip() for x in func_m.group('args').split(',')], code
|
|
|
|
def extract_function(self, funcname):
|
|
return function_with_repr(
|
|
self.extract_function_from_code(*self.extract_function_code(funcname)),
|
|
f'F<{funcname}>')
|
|
|
|
def extract_function_from_code(self, argnames, code, *global_stack):
|
|
local_vars = {}
|
|
while True:
|
|
mobj = re.search(r'function\((?P<args>[^)]*)\)\s*{', code)
|
|
if mobj is None:
|
|
break
|
|
start, body_start = 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):
|
|
return self.extract_function(funcname)(args)
|
|
|
|
def build_function(self, argnames, code, *global_stack):
|
|
global_stack = list(global_stack) or [{}]
|
|
argnames = tuple(argnames)
|
|
|
|
def resf(args, kwargs={}, allow_recursion=100):
|
|
global_stack[0].update(itertools.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
|