from .utils import ExtractorError, remove_quotes
-_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_$0-9]*'
+_NAME_RE = r'[a-zA-Z_$][\w$]*'
+_OPERATORS = {
+ '|': operator.or_,
+ '^': operator.xor,
+ '&': operator.and_,
+ '>>': operator.rshift,
+ '<<': operator.lshift,
+ '-': operator.sub,
+ '+': operator.add,
+ '%': operator.mod,
+ '/': operator.truediv,
+ '*': operator.mul,
+}
_MATCHING_PARENS = dict(zip('({[', ')}]'))
_QUOTES = '\'"'
class JSInterpreter:
+ __named_object_counter = 0
+
def __init__(self, code, objects=None):
- if objects is None:
- objects = {}
- self.code = code
- self._functions = {}
- self._objects = objects
- self.__named_object_counter = 0
+ self.code, self._functions = code, {}
+ self._objects = {} if objects is None else objects
def _named_object(self, namespace, obj):
self.__named_object_counter += 1
break
yield expr[start:]
- @staticmethod
- def _separate_at_paren(expr, delim):
- separated = list(JSInterpreter._separate(expr, delim, 1))
+ @classmethod
+ def _separate_at_paren(cls, expr, delim):
+ separated = list(cls._separate(expr, delim, 1))
if len(separated) < 2:
raise ExtractorError(f'No terminating paren {delim} in {expr}')
return separated[0][1:].strip(), separated[1].strip()
if allow_recursion < 0:
raise ExtractorError('Recursion limit reached')
- sub_statements = list(self._separate(stmt, ';'))
- stmt = (sub_statements or ['']).pop()
+ should_abort = False
+ sub_statements = list(self._separate(stmt, ';')) or ['']
+ stmt = sub_statements.pop().lstrip()
+
for sub_stmt in sub_statements:
ret, should_abort = self.interpret_statement(sub_stmt, local_vars, allow_recursion - 1)
if should_abort:
- return ret
+ return ret, should_abort
- should_abort = False
- stmt = stmt.lstrip()
- stmt_m = re.match(r'var\s', stmt)
- if stmt_m:
- expr = stmt[len(stmt_m.group(0)):]
+ m = re.match(r'(?P<var>var\s)|return(?:\s+|$)', stmt)
+ if not m: # Try interpreting it as an expression
+ expr = stmt
+ elif m.group('var'):
+ expr = stmt[len(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
+ expr = stmt[len(m.group(0)):]
+ should_abort = True
- v = self.interpret_expression(expr, local_vars, allow_recursion)
- return v, should_abort
+ return self.interpret_expression(expr, local_vars, allow_recursion), should_abort
def interpret_expression(self, expr, local_vars, allow_recursion):
expr = expr.strip()
- if expr == '': # Empty expression
+ if not expr:
return None
if expr.startswith('{'):
for item in self._separate(inner)])
expr = name + outer
- m = re.match(r'try\s*', expr)
- if m:
+ m = re.match(r'(?P<try>try)\s*|(?:(?P<catch>catch)|(?P<for>for)|(?P<switch>switch))\s*\(', expr)
+ if m and m.group('try'):
if expr[m.end()] == '{':
try_expr, expr = self._separate_at_paren(expr[m.end():], '}')
else:
return ret
return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
- m = re.match(r'catch\s*\(', expr)
- if m:
+ elif m and m.group('catch'):
# We ignore the catch block
_, expr = self._separate_at_paren(expr, '}')
return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
- m = re.match(r'for\s*\(', expr)
- if m:
+ elif m and m.group('for'):
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:
f'Premature return in the initialization of a for loop in {constructor!r}')
return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
- m = re.match(r'switch\s*\(', expr)
- if m:
+ elif m and m.group('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, '}')
ret = local_vars[var]
expr = expr[:start] + json.dumps(ret) + expr[end:]
- for op, opfunc in _ASSIGN_OPERATORS:
- m = re.match(rf'''(?x)
- (?P<out>{_NAME_RE})(?:\[(?P<index>[^\]]+?)\])?
- \s*{re.escape(op)}
- (?P<expr>.*)$''', expr)
- if not m:
- continue
- right_val = self.interpret_expression(m.group('expr'), local_vars, allow_recursion)
+ if not expr:
+ return None
- 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(f'List indices must be integers: {idx}')
- cur = lvar[idx]
- val = opfunc(cur, right_val)
- lvar[idx] = val
- return val
+ m = re.match(fr'''(?x)
+ (?P<assign>
+ (?P<out>{_NAME_RE})(?:\[(?P<index>[^\]]+?)\])?\s*
+ (?P<op>{"|".join(map(re.escape, _OPERATORS))})?
+ =(?P<expr>.*)$
+ )|(?P<return>
+ (?!if|return|true|false|null)(?P<name>{_NAME_RE})$
+ )|(?P<indexing>
+ (?P<in>{_NAME_RE})\[(?P<idx>.+)\]$
+ )|(?P<attribute>
+ (?P<var>{_NAME_RE})(?:\.(?P<member>[^(]+)|\[(?P<member2>[^\]]+)\])\s*
+ )|(?P<function>
+ (?P<fname>{_NAME_RE})\((?P<args>[\w$,]*)\)$
+ )''', expr)
+ if m and m.group('assign'):
+ if not m.group('op'):
+ opfunc = lambda curr, right: right
else:
- cur = local_vars.get(m.group('out'))
- val = opfunc(cur, right_val)
- local_vars[m.group('out')] = val
- return val
+ opfunc = _OPERATORS[m.group('op')]
+ right_val = self.interpret_expression(m.group('expr'), local_vars, allow_recursion)
+ left_val = local_vars.get(m.group('out'))
+
+ if not m.group('index'):
+ local_vars[m.group('out')] = opfunc(left_val, right_val)
+ return local_vars[m.group('out')]
+ elif left_val is None:
+ raise ExtractorError(f'Cannot index undefined variable: {m.group("out")}')
+
+ idx = self.interpret_expression(m.group('index'), local_vars, allow_recursion)
+ if not isinstance(idx, int):
+ raise ExtractorError(f'List indices must be integers: {idx}')
+ left_val[idx] = opfunc(left_val[idx], right_val)
+ return left_val[idx]
- if expr.isdigit():
+ elif expr.isdigit():
return int(expr)
- if expr == 'break':
+ elif expr == 'break':
raise JS_Break()
elif expr == 'continue':
raise JS_Continue()
- var_m = re.match(
- r'(?!if|return|true|false|null)(?P<name>%s)$' % _NAME_RE,
- expr)
- if var_m:
- return local_vars[var_m.group('name')]
+ elif m and m.group('return'):
+ return local_vars[m.group('name')]
with contextlib.suppress(ValueError):
return json.loads(expr)
- m = re.match(
- r'(?P<in>%s)\[(?P<idx>.+)\]$' % _NAME_RE, expr)
- if m:
+ if m and m.group('indexing'):
val = local_vars[m.group('in')]
idx = self.interpret_expression(m.group('idx'), local_vars, allow_recursion)
return val[idx]
- for op, opfunc in _OPERATORS:
+ for op, opfunc in _OPERATORS.items():
separated = list(self._separate(expr, op))
if len(separated) < 2:
continue
raise ExtractorError(f'Premature right-side return of {op} in {expr!r}')
return opfunc(left_val or 0, right_val)
- m = re.match(
- r'(?P<var>%s)(?:\.(?P<member>[^(]+)|\[(?P<member2>[^]]+)\])\s*' % _NAME_RE,
- expr)
- if m:
+ if m and m.group('attribute'):
variable = m.group('var')
member = remove_quotes(m.group('member') or m.group('member2'))
arg_str = expr[m.end():]
raise ExtractorError(f'{member} {msg}: {expr}')
def eval_method():
- nonlocal member
if variable == 'String':
obj = str
elif variable in local_vars:
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]
except ValueError:
return -1
- if isinstance(obj, list):
- member = int(member)
- return obj[member](argvals)
+ return obj[int(member) if isinstance(obj, list) else member](argvals)
if remaining:
return self.interpret_expression(
else:
return eval_method()
- m = re.match(r'^(?P<func>%s)\((?P<args>[a-zA-Z0-9_$,]*)\)$' % _NAME_RE, expr)
- if m:
- fname = m.group('func')
+ elif m and m.group('function'):
+ fname = m.group('fname')
argvals = tuple(
int(v) if v.isdigit() else local_vars[v]
for v in self._separate(m.group('args')))
self._functions[fname] = self.extract_function(fname)
return self._functions[fname](argvals)
- if expr:
- raise ExtractorError('Unsupported JS expression %r' % expr)
+ raise ExtractorError(f'Unsupported JS expression {expr!r}')
def extract_object(self, objname):
_FUNC_NAME_RE = r'''(?:[a-zA-Z$0-9]+|"[a-zA-Z$0-9]+"|'[a-zA-Z$0-9]+')'''
""" @returns argnames, code """
func_m = re.search(
r'''(?x)
- (?:function\s+%s|[{;,]\s*%s\s*=\s*function|var\s+%s\s*=\s*function)\s*
+ (?:
+ function\s+%(name)s|
+ [{;,]\s*%(name)s\s*=\s*function|
+ var\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)
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)
+ raise ExtractorError(f'Could not find JS function "{funcname}"')
return func_m.group('args').split(','), code
def extract_function(self, funcname):
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(
- [str.strip(x) for x in mobj.group('args').split(',')],
- body, local_vars, *global_stack))
+ 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)
projects / yt-dlp.git / commitdiff
