def test_get_exit_surface_metrics(self):
# Arrange
expected = {
Call('', './src/greetings.c', Env.C, Gran.FILE):
{
'points': None, 'proximity': None, 'surface_coupling': None
},
Call('', './src/helloworld.c', Env.C, Gran.FILE):
{
'points': None, 'proximity': None, 'surface_coupling': None
}
}
for i in expected:
# Act
actual = self.target.get_exit_surface_metrics(i)
# Assert
self.assertIsInstance(actual, dict)
self.assertTrue('points' in actual)
self.assertTrue('proximity' in actual)
self.assertTrue('surface_coupling' in actual)
if expected[i]['points'] is None:
self.assertEqual(expected[i]['points'], actual['points'])
else:
self.assertCountEqual(expected[i]['points'], actual['points'])
self.assertEqual(expected[i]['proximity'], actual['proximity'])
self.assertEqual(
expected[i]['surface_coupling'], actual['surface_coupling']
)
def test_load_call_graph_nodes(self):
# Arrange
expected = [
Call('GreeterSayHiTo', './src/helloworld.c', Env.C),
Call('greet_a', './src/helloworld.c', Env.C),
Call('greet', './src/greetings.c', Env.C),
Call('recursive_b', './src/greetings.c', Env.C),
Call('new_Greeter', './src/helloworld.c', Env.C),
Call('recursive_a', './src/greetings.c', Env.C),
Call('addInt', './src/helloworld.c', Env.C),
Call('greet_b', './src/helloworld.c', Env.C),
Call('main', './src/helloworld.c', Env.C),
Call('GreeterSayHi', './src/helloworld.c', Env.C)
]
# Act
graph = self.target.load_call_graph()
actual = graph.nodes()
match = (all([i in actual for i in expected])
and all([i in expected for i in actual]))
# Assert
self.assertCountEqual(expected, actual)
for (_, attrs) in graph.nodes(data=True):
self.assertTrue('tested' in attrs)
self.assertTrue('defense' not in attrs)
self.assertTrue('dangerous' not in attrs)
self.assertTrue('vulnerable' not in attrs)
def test_nodes(self):
# Arrange
expected = [
Call('GreeterSayHiTo', './src/helloworld.c', Environments.C),
Call('greet_a', './src/helloworld.c', Environments.C),
Call('greet', './src/greetings.c', Environments.C),
Call('recursive_b', './src/greetings.c', Environments.C),
Call('new_Greeter', './src/helloworld.c', Environments.C),
Call('recursive_a', './src/greetings.c', Environments.C),
Call('addInt', './src/helloworld.c', Environments.C),
Call('greet_b', './src/helloworld.c', Environments.C),
Call('main', './src/helloworld.c', Environments.C),
Call('GreeterSayHi', './src/helloworld.c', Environments.C)
]
# Act
actual = self.target.nodes
# Assert
self.assertCountEqual(expected, [i for (i, _) in actual])
for (_, attrs) in actual:
self.assertTrue('tested' in attrs)
self.assertTrue('defense' not in attrs)
self.assertTrue('dangerous' not in attrs)
self.assertTrue('vulnerable' not in attrs)
def load_call_graph(self):
"""
Description.
Comments.
Returns:
A call graph.
"""
call_graph = nx.DiGraph()
if self.app_packages:
condition_to_add = lambda line: line.startswith("M:") and self._contains_call_in_package(line)
else:
condition_to_add = lambda line: line.startswith("M:")
with open(self.source) as raw_call_graph:
# line is like this:
# M:com.example.kevin.helloandroid.Greeter:sayHelloInSpanish (M)java.lang.StringBuilder:toString.
for line in raw_call_graph:
if condition_to_add(line):
caller, callee = line.split(" ")
call_graph.add_edge(Call.from_javacg(caller), Call.from_javacg(callee))
return call_graph
def test_assign_page_rank(self):
# Arrange
expected = {
Call('greet_a', './src/helloworld.c', Environments.C):
0.12789113913543346,
Call('main', './src/helloworld.c', Environments.C):
0.2671500027198321,
Call('greet', './src/greetings.c', Environments.C):
0.08747233694516567,
Call('addInt', './src/helloworld.c', Environments.C):
0.052845759753949534,
Call('greet_b', './src/helloworld.c', Environments.C):
0.12789113913543343,
Call('GreeterSayHiTo', './src/helloworld.c', Environments.C):
0.052845759753949534,
Call('recursive_b', './src/greetings.c', Environments.C):
0.0891061715241686,
Call('recursive_a', './src/greetings.c', Environments.C):
0.08910617152416858,
Call('new_Greeter', './src/helloworld.c', Environments.C):
0.052845759753949534,
Call('GreeterSayHi', './src/helloworld.c', Environments.C):
0.052845759753949534
}
# Act
self.target.assign_page_rank()
actual = nx.get_node_attributes(self.target.call_graph, 'page_rank')
# Assert
self.assertEqual(len(expected), len(actual))
for i in expected:
self.assertAlmostEqual(expected[i], actual[i])
def test_load_call_graph_edges(self):
# Act
expected = [(Call('main', 'multigprof.c',
Env.C), Call('factorial', 'multigprof.c', Env.C)),
(Call('factorial', 'multigprof.c',
Env.C), Call('main', 'multigprof.c', Env.C)),
(Call('factorial', 'multigprof.c',
Env.C), Call('factorial', 'multigprof.c', Env.C)),
(Call('main', 'multigprof.c',
Env.C), Call('fibonacci', 'multigprof.c', Env.C)),
(Call('fibonacci', 'multigprof.c',
Env.C), Call('main', 'multigprof.c', Env.C))]
# Act
test_graph = self.test_loader.load_call_graph()
edges = test_graph.edges()
all_edges_found = all([c in edges for c in expected])
# Assert
self.assertEqual(len(expected), len(edges))
self.assertTrue(all_edges_found)
for (u, v, attrs) in test_graph.edges(data=True):
self.assertTrue('gprof' in attrs)
self.assertTrue('cflow' not in attrs)
self.assertTrue('call' in attrs or 'return' in attrs)
def load_call_graph(self, granularity=Granularity.FUNC):
"""
Description.
Comments.
Returns:
A call graph.
"""
call_graph = nx.DiGraph()
if self.app_packages:
def condition_to_add(line):
return (line.startswith("M:")
and self._contains_call_in_package(line))
else:
def condition_to_add(line):
return line.startswith("M:")
with open(self.source) as raw_call_graph:
# line is like this:
# M:com.example.kevin.helloandroid.Greeter:sayHelloInSpanish (M)jav
# a.lang.StringBuilder:toString.
for line in raw_call_graph:
if condition_to_add(line):
caller, callee = line.split(" ")
call_graph.add_edge(Call.from_javacg(caller, granularity),
Call.from_javacg(callee, granularity))
return call_graph
def test_equal(self):
# Arrange
cflow_line = 'getchar()'
test_call_1 = Call.from_cflow(cflow_line)
test_call_2 = Call.from_cflow(cflow_line)
# Assert
self.assertEqual(test_call_1, test_call_2)
def test_equal(self):
# Arrange
cflow_line = 'getchar()'
test_call_1 = Call.from_cflow(cflow_line)
test_call_2 = Call.from_cflow(cflow_line)
# Assert
self.assertEqual(test_call_1, test_call_2)
def test_load_call_graph_nodes(self):
# Arrange
expected = [
Call('opt_progress', './ffmpeg_opt.c', Environments.C),
Call('get_preset_file_2', './ffmpeg_opt.c', Environments.C),
Call('dump_attachment', './ffmpeg_opt.c', Environments.C),
Call('open_output_file', './ffmpeg_opt.c', Environments.C),
Call('init_input', './libavformat/utils.c', Environments.C),
Call('avio_open2', './libavformat/aviobuf.c', Environments.C),
Call('ffurl_open', './libavformat/avio.c', Environments.C),
Call('biquad_s16', './libavfilter/af_biquads.c', Environments.C),
Call('av_log', './libavutil/log.c', Environments.C)
]
# Act
graph = self.target.load_call_graph()
actual = graph.nodes()
# Assert
self.assertCountEqual(expected, actual)
for (_, attrs) in graph.nodes(data=True):
self.assertTrue('tested' in attrs)
self.assertTrue('defense' not in attrs)
self.assertTrue('dangerous' not in attrs)
self.assertTrue('vulnerable' not in attrs)
def test_not_equal(self):
# Arrange
cflow_line_1 = 'getchar()'
cflow_line_2 = (
'xstrdup() <char *xstrdup (const char *str) at ./cyrus/lib/xmalloc'
'.c:89> (R):')
test_call_1 = Call.from_cflow(cflow_line_1)
test_call_2 = Call.from_cflow(cflow_line_2)
# Assert
self.assertNotEqual(test_call_1, test_call_2)
def test_get_nodes(self):
# Arrange
expected = [
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE),
]
# Act
actual = self.target.get_nodes(attribute='exit')
# Assert
self.assertCountEqual(expected, actual)
def test_node_attribute_tested(self):
# Arrange
expected = [
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE)
]
# Act
actual = [i for (i, attrs) in self.target.nodes if 'tested' in attrs]
# Assert
self.assertCountEqual(expected, actual)
def test_exit_points(self):
# Arrange
expected = [
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE)
]
# Act
actual = self.target.exit_points
# Assert
self.assertCountEqual(expected, actual)
def test_not_equal(self):
# Arrange
cflow_line_1 = 'getchar()'
cflow_line_2 = (
'xstrdup() <char *xstrdup (const char *str) at ./cyrus/lib/xmalloc'
'.c:89> (R):'
)
test_call_1 = Call.from_cflow(cflow_line_1)
test_call_2 = Call.from_cflow(cflow_line_2)
# Assert
self.assertNotEqual(test_call_1, test_call_2)
def test_get_ancestors(self):
# Arrange
expected = [
Call('', './src/helloworld.c', Env.C, Gran.FILE),
]
call = Call('', './src/greetings.c', Env.C, Gran.FILE)
# Act
actual = self.target.get_ancestors(call)
# Assert
self.assertCountEqual(expected, actual)
def test_get_shortest_path_length_with_entry(self):
# Arrange
expected = {Call('', './src/helloworld.c', Env.C, Gran.FILE): 1}
call = Call('', './src/greetings.c', Env.C, Gran.FILE)
# Act
actual = self.target.get_shortest_path_length(call, 'entry')
# Assert
self.assertCountEqual(expected, actual)
self.assertAlmostEqual(stat.mean(expected.values()),
stat.mean(expected.values()),
places=4)
def test_get_shortest_path_length_with_entry(self):
# Arrange
expected = {Call('greet_b', './src/helloworld.c', Environments.C): 2}
call = Call('functionPtr', './src/helloworld.c', Environments.C)
# Act
actual = self.target.get_shortest_path_length(call, 'entry')
# Assert
self.assertCountEqual(expected, actual)
self.assertAlmostEqual(stat.mean(expected.values()),
stat.mean(expected.values()),
places=4)
def test_load_call_graph_edges_file_granularity(self):
# Arrange
expected = [
(
Call('', './src/helloworld.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE)
),
(
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE)
),
(
Call('', './src/helloworld.c', Env.C, Gran.FILE),
Call('', './src/greetings.c', Env.C, Gran.FILE)
),
(
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/greetings.c', Env.C, Gran.FILE)
)
]
# Act
test_graph = self.test_loader.load_call_graph(granularity=Gran.FILE)
edges = test_graph.edges()
all_edges_found = all([c in edges for c in expected])
# Assert
self.assertEqual(len(expected), len(edges))
self.assertTrue(all_edges_found)
for (u, v, attrs) in test_graph.edges(data=True):
self.assertTrue('cflow' in attrs)
self.assertTrue('gprof' not in attrs)
self.assertTrue('call' in attrs or 'return' in attrs)
def test_get_degree(self):
# Arrange
expected = {
Call('', './src/helloworld.c', Env.C, Gran.FILE): (2, 2),
Call('', './src/greetings.c', Env.C, Gran.FILE): (2, 2)
}
# Act
actual = self.target.get_degree()
match = all([actual[i] == expected[i] for i in actual])
# Assert
self.assertEqual(len(expected), len(actual))
self.assertTrue(match)
def test_get_page_rank(self):
# Arrange
expected = {
Call('', './src/helloworld.c', Env.C, Gran.FILE): 0.5,
Call('', './src/greetings.c', Env.C, Gran.FILE): 0.5
}
# Act
actual = self.target.get_page_rank()
# Assert
self.assertEqual(len(expected), len(actual))
for i in expected:
self.assertAlmostEqual(expected[i], actual[i])
def test_assign_weights(self):
# Arrange
expected = {
(
Call('', './src/helloworld.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE)
): 75,
(
Call('', './src/helloworld.c', Env.C, Gran.FILE),
Call('', './src/greetings.c', Env.C, Gran.FILE)
): 75,
(
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE)
): 25,
(
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/greetings.c', Env.C, Gran.FILE)
): 75
}
# Act
self.target.assign_weights()
actual = nx.get_edge_attributes(self.target.call_graph, 'weight')
# Assert
self.assertCountEqual(expected, actual)
for i in expected:
self.assertEqual(expected[i], actual[i], msg=i)
def test_edges(self):
# Arrange
expected = [
(
Call('', './src/helloworld.c', Env.C, Gran.FILE),
Call('', './src/greetings.c', Env.C, Gran.FILE)
),
(
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE)
),
(
Call('', './src/greetings.c', Env.C, Gran.FILE),
Call('', './src/greetings.c', Env.C, Gran.FILE)
),
(
Call('', './src/helloworld.c', Env.C, Gran.FILE),
Call('', './src/helloworld.c', Env.C, Gran.FILE)
)
]
# Act
actual = self.target.edges
# Assert
self.assertCountEqual(expected, [(i, j) for (i, j, _) in actual])
for (_, _, attrs) in actual:
self.assertTrue('gprof' in attrs)
self.assertTrue('cflow' not in attrs)
self.assertTrue('call' in attrs or 'return' in attrs)
def test_assign_page_rank(self):
# Arrange
expected = {
Call('', './src/helloworld.c', Env.C, Gran.FILE): 0.525,
Call('', './src/greetings.c', Env.C, Gran.FILE): 0.475
}
# Act
self.target.assign_page_rank()
actual = nx.get_node_attributes(self.target.call_graph, 'page_rank')
# Assert
self.assertEqual(len(expected), len(actual))
for i in expected:
self.assertAlmostEqual(expected[i], actual[i])
def test_is_output(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertTrue(test_call.is_output())
def test_function_signature_only_name(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertEqual('', test_call.function_signature)
def test_identity_function_name(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertEqual('printf', test_call.identity)
def test_is_input(self):
# Arrange
cflow_line = 'getchar()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertTrue(test_call.is_input())
def test_is_not_input(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertFalse(test_call.is_input())
def test_is_not_output(self):
# Arrange
cflow_line = 'getchar()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertFalse(test_call.is_output())
def test_identity_function_name_file_granularity(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line, granularity=Granularity.FILE)
# Assert
self.assertEqual('', test_call.identity)
def test_get_entry_point_reachability_non_entry(self):
# Arrange
call = Call('', './src/greetings.c', Env.C, Gran.FILE)
# Assert
self.assertRaises(Exception, self.target.get_entry_point_reachability,
call)
def test_is_not_output(self):
# Arrange
cflow_line = 'getchar()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertFalse(test_call.is_output())
def test_is_output(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertTrue(test_call.is_output())
def test_is_not_input(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertFalse(test_call.is_input())
def test_identity_function_name_file_granularity(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line, granularity=Granularity.FILE)
# Assert
self.assertEqual('', test_call.identity)
def test_identity_function_name(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertEqual('printf', test_call.identity)
def test_is_input(self):
# Arrange
cflow_line = 'getchar()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertTrue(test_call.is_input())
def test_function_signature_only_name(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertEqual('', test_call.function_signature)
def test_in_stdlib(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertTrue(test_call.in_stdlib())
def load_call_graph(self):
"""
Generates the Call Graph as a networkx.DiGraph object.
Invokes the call grap generation software (cflow) and creates a networkx.DiGraph instance that represents
the analyzed source code's Call Graph.
Args:
is_reverse: Boolean specifying whether the graph generation software (cflow) should use the reverse
algorithm.
Returns:
None
"""
call_graph = nx.DiGraph()
is_first_line = True
parent = Stack()
if os.path.isfile(self.source):
raw_call_graph = open(self.source)
readline = lambda: raw_call_graph.readline()
elif os.path.isdir(self.source):
raw_call_graph = self._exec_cflow(self.is_reverse)
readline = lambda: raw_call_graph.stdout.readline().decode(encoding='UTF-8')
while True:
line = readline()
if line == '':
break
current = Call.from_cflow(line)
if not is_first_line:
if current.level > previous.level:
parent.push(previous)
elif current.level < previous.level:
for t in range(previous.level - current.level):
parent.pop()
if parent.top:
call_graph.add_node(current, {'tested': False})
call_graph.add_node(parent.top, {'tested': False})
# Edge weight can be any arbitrary number greater than
# that used as the weight for the edges in the gprof
# call graph.
if not self.is_reverse:
call_graph.add_edge(parent.top, current,
{'cflow': 'cflow'}, weight=1)
else:
call_graph.add_edge(current, parent.top,
{'cflow': 'cflow'}, weight=1)
previous = current
is_first_line = False
return call_graph
def test_in_stdlib(self):
# Arrange
cflow_line = 'printf()'
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertTrue(test_call.in_stdlib())
def test_is_not_input_no_leaf(self):
# Arrange
cflow_line = (
'xstrdup() <char *xstrdup (const char *str) at ./cyrus/lib/xmalloc'
'.c:89> (R):'
)
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertFalse(test_call.is_input())
def test_function_signature_full(self):
# Arrange
cflow_line = (
'xstrdup() <char *xstrdup (const char *str) at ./cyrus/lib/xmalloc'
'.c:89> (R):'
)
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertEqual('./cyrus/lib/xmalloc.c', test_call.function_signature)
def test_identity_full_file_granularity(self):
# Arrange
cflow_line = (
'xstrdup() <char *xstrdup (const char *str) at ./cyrus/lib/xmalloc'
'.c:89> (R):'
)
test_call = Call.from_cflow(cflow_line, granularity=Granularity.FILE)
# Assert
self.assertEqual('./cyrus/lib/xmalloc.c', test_call.identity)
def test_identity_full(self):
# Arrange
cflow_line = (
'xstrdup() <char *xstrdup (const char *str) at ./cyrus/lib/xmalloc'
'.c:89> (R):'
)
test_call = Call.from_cflow(cflow_line)
# Assert
self.assertEqual('xstrdup ./cyrus/lib/xmalloc.c', test_call.identity)
def load_call_graph(self):
"""
Generates the Call Graph as a networkx.DiGraph object.
Invokes the call grap generation software (cflow) and creates a networkx.DiGraph instance that represents
the analyzed source code's Call Graph.
Args:
is_reverse: Boolean specifying whether the graph generation software (cflow) should use the reverse
algorithm.
Returns:
None
"""
call_graph = nx.DiGraph()
header_passed = False
entry = None
is_caller = True
callers = list()
callees = list()
# line_count = 0
with open(self.source) as raw_call_graph:
while True:
line = raw_call_graph.readline()
# line_count += 1
# print(line_count)
# print(line)
if not header_passed:
if line == GprofLoader.header:
header_passed = True
continue
else: # if header_passed:
if self.is_entry_line(line):
try:
entry = Call.from_gprof(line)
except ValueError as e:
raise e
call_graph.add_node(entry, {'tested': False})
is_caller = False
elif line == GprofLoader.separator:
if len(callers) > 0 or len(callees) > 0:
call_graph.node[entry]['tested'] = True
for caller in callers:
call_graph.add_node(caller, {'tested': True})
# Edge weight can be any arbitrary number lesser
# than that used as the weight for the edges
# in the cflow call graph.
call_graph.add_edge(caller, entry,
{'gprof': 'gprof'}, weight=0.5)
callers.clear()
for callee in callees:
call_graph.add_node(callee, {'tested': True})
# Edge weight can be any arbitrary number lesser
# than that used as the weight for the edges
# in the cflow call graph.
call_graph.add_edge(entry, callee,
{'gprof': 'gprof'}, weight=0.5)
callees.clear()
is_caller = True
elif line == GprofLoader.eof:
break
else:
try:
if is_caller:
callers.append(Call.from_gprof(line))
else:
callees.append(Call.from_gprof(line))
except ValueError as e:
self._error_messages.append("Error: " + str(e) + " Input line: " + line)
return call_graph
def load_call_graph(self, granularity=Granularity.FUNC):
"""Load a call graph generated by cflow.
If necessary, the static call graph generation utility (cflow) is
invoked to generate the call graph before attempting to load it.
Parameters
----------
granularity : str
The granularity at which the call graph must be loaded. See
attacksurfacemeter.granularity.Granularity for available choices.
Returns
-------
call_graph : networkx.DiGraph
An object representing the call graph.
"""
call_graph = nx.DiGraph()
parent = Stack()
raw_call_graph = None
if os.path.isfile(self.source):
raw_call_graph = open(self.source)
elif os.path.isdir(self.source):
raw_call_graph = self._exec_cflow()
try:
previous = Call.from_cflow(raw_call_graph.readline(), granularity)
for line in raw_call_graph:
current = Call.from_cflow(line, granularity)
if current.level > previous.level:
parent.push(previous)
elif current.level < previous.level:
for t in range(previous.level - current.level):
parent.pop()
if parent.top:
caller = callee = None
entry = exit = dangerous = defense = False
if self.is_reverse:
caller = current
callee = parent.top
else:
caller = parent.top
callee = current
(caller_attrs, callee_attrs) = utilities.get_node_attrs(
'cflow', caller, callee, self.defenses,
self.vulnerabilities
)
call_graph.add_node(caller, caller_attrs)
if callee_attrs is not None:
call_graph.add_node(callee, callee_attrs)
# Adding the edge caller -- callee
attrs = {'cflow': None, 'call': None}
call_graph.add_edge(caller, callee, attrs)
# Adding the edge callee -- caller with the assumption
# that every call must return
attrs = {'cflow': None, 'return': None}
call_graph.add_edge(callee, caller, attrs)
previous = current
finally:
if raw_call_graph:
raw_call_graph.close()
return call_graph
