[jsinterp] Minimally handle arithmetic operator precedence

Resolves #32066
This commit is contained in:
dirkf 2023-04-21 14:04:30 +01:00
parent 26035bde46
commit 211cbfd5d4
2 changed files with 48 additions and 3 deletions

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@ -505,6 +505,17 @@ class TestJSInterpreter(unittest.TestCase):
jsi = JSInterpreter('function x(){return 1236566549 << 5}') jsi = JSInterpreter('function x(){return 1236566549 << 5}')
self.assertEqual(jsi.call_function('x'), 915423904) self.assertEqual(jsi.call_function('x'), 915423904)
def test_32066(self):
jsi = JSInterpreter("function x(){return Math.pow(3, 5) + new Date('1970-01-01T08:01:42.000+08:00') / 1000 * -239 - -24205;}")
self.assertEqual(jsi.call_function('x'), 70)
def test_unary_operators(self):
jsi = JSInterpreter('function f(){return 2 - - - 2;}')
self.assertEqual(jsi.call_function('f'), 0)
# fails
# jsi = JSInterpreter('function f(){return 2 + - + - - 2;}')
# self.assertEqual(jsi.call_function('f'), 0)
""" # fails so far """ # fails so far
def test_packed(self): def test_packed(self):
jsi = JSInterpreter('''function x(p,a,c,k,e,d){while(c--)if(k[c])p=p.replace(new RegExp('\\b'+c.toString(a)+'\\b','g'),k[c]);return p}''') jsi = JSInterpreter('''function x(p,a,c,k,e,d){while(c--)if(k[c])p=p.replace(new RegExp('\\b'+c.toString(a)+'\\b','g'),k[c]);return p}''')

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@ -1,5 +1,6 @@
from __future__ import unicode_literals from __future__ import unicode_literals
from functools import update_wrapper
import itertools import itertools
import json import json
import math import math
@ -23,11 +24,23 @@ from .compat import (
) )
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
def _js_bit_op(op): def _js_bit_op(op):
def zeroise(x): def zeroise(x):
return 0 if x in (None, JS_Undefined) else x return 0 if x in (None, JS_Undefined) else x
@wraps_op(op)
def wrapped(a, b): def wrapped(a, b):
return op(zeroise(a), zeroise(b)) & 0xffffffff return op(zeroise(a), zeroise(b)) & 0xffffffff
@ -36,6 +49,7 @@ def _js_bit_op(op):
def _js_arith_op(op): def _js_arith_op(op):
@wraps_op(op)
def wrapped(a, b): def wrapped(a, b):
if JS_Undefined in (a, b): if JS_Undefined in (a, b):
return float('nan') return float('nan')
@ -66,6 +80,7 @@ def _js_exp(a, b):
def _js_eq_op(op): def _js_eq_op(op):
@wraps_op(op)
def wrapped(a, b): def wrapped(a, b):
if set((a, b)) <= set((None, JS_Undefined)): if set((a, b)) <= set((None, JS_Undefined)):
return op(a, a) return op(a, a)
@ -76,6 +91,7 @@ def _js_eq_op(op):
def _js_comp_op(op): def _js_comp_op(op):
@wraps_op(op)
def wrapped(a, b): def wrapped(a, b):
if JS_Undefined in (a, b): if JS_Undefined in (a, b):
return False return False
@ -356,6 +372,7 @@ class JSInterpreter(object):
return right_val return right_val
try: try:
# print('Eval:', opfunc.__name__, left_val, right_val)
return opfunc(left_val, right_val) return opfunc(left_val, right_val)
except Exception as e: except Exception as e:
raise self.Exception('Failed to evaluate {left_val!r:.50} {op} {right_val!r:.50}'.format(**locals()), expr, cause=e) raise self.Exception('Failed to evaluate {left_val!r:.50} {op} {right_val!r:.50}'.format(**locals()), expr, cause=e)
@ -395,6 +412,7 @@ class JSInterpreter(object):
raise self.Exception('Recursion limit reached') raise self.Exception('Recursion limit reached')
allow_recursion -= 1 allow_recursion -= 1
# print('At: ' + stmt[:60])
should_return = False should_return = False
# fails on (eg) if (...) stmt1; else stmt2; # fails on (eg) if (...) stmt1; else stmt2;
sub_statements = list(self._separate(stmt, ';')) or [''] sub_statements = list(self._separate(stmt, ';')) or ['']
@ -702,9 +720,24 @@ class JSInterpreter(object):
continue continue
right_expr = separated.pop() right_expr = separated.pop()
while op == '-' and len(separated) > 1 and not separated[-1].strip(): # handle operators that are both unary and binary, minimal BODMAS
right_expr = '-' + right_expr if op in ('+', '-'):
separated.pop() undone = 0
while len(separated) > 1 and not separated[-1].strip():
undone += 1
separated.pop()
if op == '-' and undone % 2 != 0:
right_expr = op + right_expr
left_val = separated[-1]
for dm_op in ('*', '%', '/', '**'):
bodmas = tuple(self._separate(left_val, dm_op, skip_delims=skip_delim))
if len(bodmas) > 1 and not bodmas[-1].strip():
expr = op.join(separated) + op + right_expr
right_expr = None
break
if right_expr is None:
continue
left_val = self.interpret_expression(op.join(separated), local_vars, allow_recursion) 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 return self._operator(op, left_val, right_expr, expr, local_vars, allow_recursion), should_return
@ -955,6 +988,7 @@ class JSInterpreter(object):
def build_function(self, argnames, code, *global_stack): def build_function(self, argnames, code, *global_stack):
global_stack = list(global_stack) or [{}] global_stack = list(global_stack) or [{}]
argnames = tuple(argnames) argnames = tuple(argnames)
# import pdb; pdb.set_trace()
def resf(args, kwargs={}, allow_recursion=100): def resf(args, kwargs={}, allow_recursion=100):
global_stack[0].update( global_stack[0].update(