def test_length_reference(self):
a1 = Field('a1', 8)
a = Sequence('a', [a1])
b1 = Field('b1', LengthResult('a'))
b = Sequence('b', [b1])
spec = Sequence('blah', [a,b])
vars = ExpressionParameters([spec])
self.assertEqual([Local('a length', _Integer())], vars.get_locals(spec))
self.assertFalse(vars.is_length_referenced(a1))
self.assertTrue(vars.is_length_referenced(a))
self.assertEqual([Param('a length', Param.OUT, EntryLengthType(a))], vars.get_params(a))
self.assertEqual([Param('a length', Param.IN, EntryLengthType(a))], vars.get_params(b))
def test_length_and_value_reference(self):
# Test a length reference and a value reference to the same entry.
a = Field('a', length=8)
c = Field('c', length=parse('len{a}'))
d = Field('d', length=parse('${a}'))
b = Sequence('b', [a, c, d])
# Lets just try a quick decode to make sure we've specified it ok...
#list(b.decode(Data('\x08cd')))
# Now test the parameters being passed around.
lookup = ExpressionParameters([b])
self.assertEqual([Param('a', Param.OUT, _Integer()),
Param('a length', Param.OUT, _Integer())],
lookup.get_params(a))
self.assertEqual([Param('a', Param.OUT, _Integer()),
Param('a length', Param.OUT, _Integer())],
list(lookup.get_passed_variables(b, b.children[0])))
self.assertEqual([Param('a length', Param.IN, _Integer())],
list(lookup.get_passed_variables(b, b.children[1])))
self.assertEqual([Param('a length', Param.IN, _Integer())],
lookup.get_params(c))
self.assertEqual([Local('a', _Integer()), Local('a length', _Integer())],
lookup.get_locals(b))
self.assertTrue(lookup.is_length_referenced(a))
def test_name_ends_in_length(self):
a = Field('data length', 8, Field.INTEGER)
b = Field('data', parse('${data length} * 8'))
c = Sequence('c', [a, b])
params = ExpressionParameters([c])
self.assertEqual([Local('data length', _Integer())], params.get_locals(c))
self.assertEqual([], params.get_params(c))
self.assertEqual([Param('data length', Param.OUT, _Integer())], params.get_params(a))
self.assertEqual([Param('data length', Param.IN, _Integer())], params.get_params(b))
self.assertEqual(True, params.is_value_referenced(a))
self.assertEqual(False, params.is_length_referenced(a))
