def build(self, pre=None, shortest=False):
"""Build this rule definition
:param list pre: The prerequisites list
:param bool shortest: Whether or not the shortest reference-chain (most minimal) version of the field should be generated.
"""
if pre is None:
pre = []
res = deque()
for value in self.values:
try:
res.append(utils.val(value, pre, shortest=shortest))
except errors.FlushGrams as e:
prev = "".join(res)
res.clear()
# this is assuming a scope was pushed!
if len(self.fuzzer._scope_stack) == 1:
pre.append(prev)
else:
stmts = self.fuzzer._curr_scope.setdefault(
"prev_append", deque())
stmts.extend(pre)
stmts.append(prev)
pre.clear()
continue
except errors.OptGram as e:
continue
except errors.GramFuzzError as e:
print("{} : {}".format(self.name, str(e)))
raise
return self.sep.join(res)
def build(self, pre=None, shortest=False):
"""Build the ``Or`` instance
:param list pre: The prerequisites list
:param bool shortest: Whether or not the shortest reference-chain (most minimal) version of the field should be generated.
"""
if pre is None:
pre = []
# self.shortest_vals will be set by the GramFuzzer and will
# contain a list of value options that have a minimal reference
# chain
if shortest and self.shortest_vals is not None:
return utils.val(rand.choice(self.shortest_vals), pre, shortest=shortest)
else:
return utils.val(rand.choice(self.values), pre, shortest=shortest)
def build(self, pre=None, shortest=False):
"""
:param list pre: The prerequisites list
:param bool shortest: Whether or not the shortest reference-chain (most minimal)
version of the field should be generated.
"""
if pre is None:
pre = []
# self.shortest_vals will be set by the GramFuzzer and will
# contain a list of value options that have a minimal reference chain
#
# see https://narly.me/posts/controlling-recursion-depth-in-grammars/
# for an in-depth discussion
if shortest and self.shortest_vals is not None:
chosen_weights = [self.weights[idx] for idx in self.shortest_indices]
chosen_vals = self.shortest_vals
total_percent = sum(chosen_weights)
# scale the percent weights up if the new chosen weights don't sum
# to 1.0
if total_percent != 1.0:
scale = 1.0 / total_percent
chosen_weights = [x * scale for x in chosen_weights]
else:
chosen_weights = self.weights
chosen_vals = self.values
val = rand.weighted_choice(chosen_vals, chosen_weights)
return utils.val(val, pre, shortest=shortest)
def test_or_probabilities(self):
"""Make sure that Or does its probabilities correctly
"""
# for two items, their probability of being generated should
# be 50%
hello_count = 0
int_count = 0
data = Or(UInt, "hello")
for x in six.moves.range(LOOP_NUM):
res = data.build()
val = gutils.val(res)
if val == b"hello":
hello_count += 1
elif re.match(gutils.binstr(r'^\d+$'), val) is not None:
int_count += 1
else:
self.assertTrue(False, "was neither an int or hello")
for v in [hello_count, int_count]:
percent = v / float(LOOP_NUM)
diff = abs(percent - 0.50)
self.assertLess(
diff, PERCENT_ERROR,
"{}/{} == {}% error, bad".format(v, LOOP_NUM, diff))
def build(self, pre=None, shortest=False):
"""Build the ``Ref`` instance by fetching the rule from
the GramFuzzer instance and building it
:param list pre: The prerequisites list
:param bool shortest: Whether or not the shortest reference-chain (most minimal) version of the field should be generated.
"""
global REF_LEVEL
REF_LEVEL += 1
try:
if pre is None:
pre = []
#print("{:04d} - {} - {}:{}".format(REF_LEVEL, shortest, self.cat, self.refname))
definition = self.fuzzer.get_ref(self.cat, self.refname)
res = utils.val(definition,
pre,
shortest=(shortest
or REF_LEVEL >= self.max_recursion))
return res
# this needs to happen no matter what
finally:
REF_LEVEL -= 1
def build(self, pre=None, shortest=False):
"""Build the ``Join`` field instance.
:param list pre: The prerequisites list
:param bool shortest: Whether or not the shortest reference-chain (most minimal) version of the field should be generated.
"""
if pre is None:
pre = []
if self.max is not None:
if shortest:
vals = [self.values[0]]
else:
# +1 to make it inclusive
vals = [self.values[0]] * rand.randint(1, self.max + 1)
else:
vals = self.values
joins = []
for val in vals:
try:
v = utils.val(val, pre, shortest=shortest)
joins.append(v)
except errors.OptGram as e:
continue
return self.sep.join(joins)
def build(self, pre=None, shortest=False):
"""Build the String instance
:param list pre: The prerequisites list (optional, default=None)
:param bool shortest: Whether or not the shortest reference-chain (most minimal) version of the field should be generated.
"""
if pre is None:
pre = []
if self.value is not None and rand.maybe():
return utils.val(self.value, pre, shortest=shortest)
length = super(String, self).build(pre, shortest=shortest)
res = rand.data(length, self.charset)
return res
def test_weighted_or_probabilities(self):
"""Make sure that WeightedOr does its probabilities correctly
"""
counts = {
"int": {
"prob": 0.1,
"val": UInt,
"count": 0,
"match": lambda x: re.match(gutils.binstr(r'^\d+$'), x) is not None
},
"hello": {
"prob": 0.6,
"val": b"hello",
"count": 0,
"match": lambda x: x == b"hello"
},
"a": {
"prob": 0.3,
"val": b"a",
"count": 0,
"match": lambda x: x == b"a"
},
}
values = [(v["val"], v["prob"]) for k, v in counts.items()]
data = WeightedOr(*values)
for x in six.moves.range(LOOP_NUM):
res = data.build()
val = gutils.val(res)
matched = False
for val_name, val_info in counts.items():
if val_info["match"](val):
val_info["count"] += 1
matched = True
if matched is False:
raise Exception("Something went wrong, could not match to a value")
for val_name, val_info in counts.items():
percent = val_info["count"] / float(LOOP_NUM)
diff = abs(percent - val_info["prob"])
self.assertLess(diff, PERCENT_ERROR, "{}: {}/{} == {}% error, bad".format(
val_name,
val_info["count"],
LOOP_NUM,
diff
))
def build(self, pre=None, shortest=False):
"""Build the integer, optionally providing a ``pre`` list
that *may* be used to define prerequisites for a Field being built.
:param list pre: A list of prerequisites to be collected during the building of a Field.
:param bool shortest: Whether or not the shortest reference-chain (most minimal) version of the field should be generated.
"""
if pre is None:
pre = []
if self.value is not None and rand.maybe():
return utils.val(self.value, pre, shortest=shortest)
if self.min == self.max:
return self.min
return self._odds_val()
def build(self, pre=None, shortest=False):
"""Build the ``Or`` instance
:param list pre: The prerequisites list
:param bool shortest: Whether or not the shortest reference-chain (most minimal)
version of the field should be generated.
"""
if pre is None:
pre = []
# self.shortest_vals will be set by the GramFuzzer and will
# contain a list of value options that have a minimal reference
# chain
#
# see https://narly.me/posts/controlling-recursion-depth-in-grammars/
# for an in-depth discussion
if shortest and self.shortest_vals is not None:
chosen_val = rand.choice(self.shortest_vals)
else:
chosen_val = rand.choice(self.values)
return utils.val(chosen_val, pre, shortest=shortest)
def test_uint(self):
i = UInt
res = i().build()
val = gutils.val(res)
self.assertRegexpMatches(val, gutils.binstr(r'^\d+$'))
def test_or_explicit(self):
data = Or(UInt, "hello")
res = data.build()
val = gutils.val(res)
self.assertRegexpMatches(val, gutils.binstr(r'^(\d+|hello)'))
def test_or_operator(self):
data = UInt | "hello"
res = data.build()
val = gutils.val(res)
self.assertRegexpMatches(val, gutils.binstr(r'^(\d+|hello)'))
def test_and_explicit(self):
data = And(UInt, ",", UInt)
res = data.build()
val = gutils.val(res)
self.assertRegexpMatches(val, gutils.binstr(r'^\d+,\d+$'))
def test_and_operator(self):
data = UInt & "," & UInt
res = data.build()
val = gutils.val(res)
self.assertRegexpMatches(val, gutils.binstr(r'^\d+,\d+$'))
def test_ufloat(self):
f = UFloat
res = f().build()
val = gutils.val(res)
self.assertRegexpMatches(val, gutils.binstr(r'^\d+(\.\d+)?$'))
def test_float(self):
f = Float
res = f().build()
val = gutils.val(res)
self.assertRegexpMatches(val, r'^(-)?\d+(\.\d+)?$')
def test_int(self):
i = Int
res = i().build()
val = gutils.val(res)
self.assertRegexpMatches(val, r'^(-)?\d+$')