def test_ControlFlowGraph_node_name_changes_hash(): """Test that hash depends on node name.""" g1 = control_flow_graph.ControlFlowGraph() g1.add_node(0, name="A", entry=True) g2 = control_flow_graph.ControlFlowGraph() g2.add_node(0, name="B", entry=True) assert hash(g1) != hash(g2)
def test_ControlFlowGraph_IsomorphicHash_equivalency(): """Test equivalent hashes, despite different attributes.""" # Graph 1: A --> B g1 = control_flow_graph.ControlFlowGraph(name="foo") g1.add_node(0, name="A", entry=True) g1.add_node(1, name="B", exit=True) g1.add_edge(0, 1) # Graph 2: C --> D g2 = control_flow_graph.ControlFlowGraph(name="bar") g2.add_node(0, name="C", entry=True) g2.add_node(1, name="D", exit=True) g2.add_edge(0, 1) assert g1.IsomorphicHash() == g2.IsomorphicHash()
def test_ControlFlowGraph_unequal_graph_names_are_equal(): """Test that graph names are not used in comparison.""" # Graph 1: A --> B g1 = control_flow_graph.ControlFlowGraph(name="foo") g1.add_node(0, name="A", entry=True) g1.add_node(1, name="B", exit=True) g1.add_edge(0, 1) # Graph 2: A --> B g2 = control_flow_graph.ControlFlowGraph(name="bar") g2.add_node(0, name="A", entry=True) g2.add_node(1, name="B", exit=True) g2.add_edge(0, 1) assert g1 == g2
def test_ControlFlowGraph_unequal_edge_data(): """Test that edge data is used in comparison.""" # Graph 1: A --> B g1 = control_flow_graph.ControlFlowGraph(name="foo") g1.add_node(0, name="A", exit=True) g1.add_node(1, name="B") g1.add_edge(0, 1) # Graph 2: A --> B g2 = control_flow_graph.ControlFlowGraph(name="bar") g2.add_node(0, name="A") g2.add_node(1, name="B", entry=True) g2.add_edge(0, 1) assert g1 != g2
def test_ControlFlowGraph_equal(): """Test that equal graphs can be compared.""" # Graph 1: A --> B g1 = control_flow_graph.ControlFlowGraph() g1.add_node(0, name="A", entry=True) g1.add_node(1, name="B", exit=True) g1.add_edge(0, 1) # Graph 2: A --> B g2 = control_flow_graph.ControlFlowGraph() g2.add_node(0, name="A", entry=True) g2.add_node(1, name="B", exit=True) g2.add_edge(0, 1) assert g1 == g2
def test_ControlFlowGraph_equivalent_hashes(): """Test equivalent hashes, despite different graph names.""" # Graph 1: A --> B g1 = control_flow_graph.ControlFlowGraph(name="foo") g1.add_node(0, name="A", entry=True) g1.add_node(1, name="B", exit=True) g1.add_edge(0, 1) # Graph 2: A --> B g2 = control_flow_graph.ControlFlowGraph(name="bar") g2.add_node(0, name="A", entry=True) g2.add_node(1, name="B", exit=True) g2.add_edge(0, 1) assert hash(g1) == hash(g2)
def test_ControlFlowGraph_unequal_edges(): """Test that graphs with unequal edges are not equal.""" # Graph 1: A --> B g1 = control_flow_graph.ControlFlowGraph() g1.add_node(0, name="A", entry=True) g1.add_node(1, name="B", exit=True) g1.add_edge(0, 1) # Graph 2: B --> A g2 = control_flow_graph.ControlFlowGraph() g2.add_node(0, name="A", entry=True) g2.add_node(1, name="B", exit=True) g2.add_edge(1, 0) assert g1 != g2
def test_ControlFlowGraph_edge_density(): """Test edge density property.""" # Graph: # # +----> B -----+ # | | # | v # A D # | ^ # | | # +----> C -----+ g = control_flow_graph.ControlFlowGraph() g.add_node(0, name="A", entry=True) g.add_node(1, name="B") g.add_node(2, name="C") g.add_node(3, name="D", exit=True) g.add_edge(0, 1) g.add_edge(0, 2) g.add_edge(1, 3) g.add_edge(2, 3) assert g.edge_density == pytest.approx(1 / 4) # Add A -> D path. g.add_edge(0, 3) assert g.edge_density == pytest.approx(5 / 16)
def test_ControlFlowGraph_validate_empty_graph():
"""Test that empty graph is invalid."""
g = control_flow_graph.ControlFlowGraph()
with test.Raises(control_flow_graph.NotEnoughNodes) as e_ctx:
g.ValidateControlFlowGraph()
assert str(e_ctx.value) == "Function `cfg` has no nodes"
assert not g.IsValidControlFlowGraph()
def test_ControlFlowGraph_IsValidControlFlowGraph_irreducible_loop(): """Test that an irreducible graph is valid.""" g = control_flow_graph.ControlFlowGraph() # Graph: # +-------+ # | | # v | # A------->B+----->C # | | ^ # | | | # | v | # | D | # | | # +----------------+ g.add_node(0, name="A", entry=True) g.add_node(1, name="B") g.add_node(2, name="C") g.add_node(3, name="D", exit=True) g.add_edge(0, 1) g.add_edge(0, 2) g.add_edge(1, 2) g.add_edge(2, 1) g.add_edge(1, 3) assert g.ValidateControlFlowGraph() == g assert g.IsValidControlFlowGraph()
def test_ControlFlowGraph_undirected_diameter(): """Test undirected_diameter property.""" # Graph: # # +----> B -----+ # | | # | v # A D # | ^ # | | # +----> C -----+ g = control_flow_graph.ControlFlowGraph() g.add_node(0, name="A", entry=True) g.add_node(1, name="B") g.add_node(2, name="C") g.add_node(3, name="D", exit=True) g.add_edge(0, 1) g.add_edge(0, 2) g.add_edge(1, 3) g.add_edge(2, 3) assert g.undirected_diameter == 2 # Increase the diameter by adding a new E node and D -> E path. g.add_node(4, name="E") g.add_edge(3, 4) assert g.undirected_diameter == 3
def test_ControlFlowGraph_IsValidControlFlowGraph_exit_block_has_output():
"""Test that an if-else loop graph is valid."""
g = control_flow_graph.ControlFlowGraph()
# Graph:
#
# +----> B -----+
# | |
# | v
# A<-----------+D
# | ^
# | |
# +----> C -----+
g.add_node(0, name="A", entry=True)
g.add_node(1, name="B")
g.add_node(2, name="C")
g.add_node(3, name="D", exit=True)
g.add_edge(0, 1)
g.add_edge(0, 2)
g.add_edge(1, 3)
g.add_edge(2, 3)
g.add_edge(3, 0)
with test.Raises(control_flow_graph.InvalidNodeDegree) as e_ctx:
g.ValidateControlFlowGraph()
assert str(e_ctx.value) == "Exit block outdegree(D) = 1 in function `cfg`"
assert not g.IsValidControlFlowGraph()
def test_ControlFlowGraph_node_attribute_changes_hash(): """Test that hash depends on node attributes.""" g1 = control_flow_graph.ControlFlowGraph() g1.add_node(0, name="A") g2 = g1.copy() assert hash(g1) == hash(g2) g2.nodes[0]["entry"] = True assert hash(g1) != hash(g2)
def test_ControlFlowGraph_IsValidControlFlowGraph_disconnected_graph():
"""A disconnected graph is not valid."""
g = control_flow_graph.ControlFlowGraph()
g.add_node(0, name="A", entry=True)
g.add_node(1, name="B", exit=True)
g.add_node(2, name="C")
g.add_edge(0, 1)
with test.Raises(control_flow_graph.UnconnectedNode) as e_ctx:
g.ValidateControlFlowGraph()
assert str(e_ctx.value) == "Unconnected node 'C'"
assert not g.IsValidControlFlowGraph()
def test_ControlFlowGraph_IsValidControlFlowGraph_no_path_from_entry_to_exit():
"""A disconnected graph is not valid."""
# Graph: A -> B <- C
g = control_flow_graph.ControlFlowGraph()
g.add_node(0, name="A", entry=True)
g.add_node(1, name="B")
g.add_node(2, name="C", exit=True)
g.add_edge(0, 1)
g.add_edge(2, 1)
with test.Raises(control_flow_graph.MalformedControlFlowGraphError) as e_ctx:
g.ValidateControlFlowGraph()
assert str(e_ctx.value) == (
"No path from entry node 'A' to exit node 'C' " "in function `cfg`"
)
assert not g.IsValidControlFlowGraph()
def test_ControlFlowGraph_IsValidControlFlowGraph_invalid_degrees():
"""Test that a graph where two nodes could be fused is invalid."""
g = control_flow_graph.ControlFlowGraph()
# Graph:
#
# A --> B --> C
g.add_node(0, name="A", entry=True)
g.add_node(1, name="B")
g.add_node(2, name="C", exit=True)
g.add_edge(0, 1)
g.add_edge(1, 2)
with test.Raises(control_flow_graph.InvalidNodeDegree) as e_ctx:
g.ValidateControlFlowGraph()
assert str(e_ctx.value) == "outdegree(A) = 1, indegree(B) = 1"
assert not g.IsValidControlFlowGraph()
def test_ControlFlowGraph_IsValidControlFlowGraph_while_loop(): """Test that a while loop graph is valid.""" g = control_flow_graph.ControlFlowGraph() # Graph: # # +--------+ # | | # v | # A+------>B C # | ^ # | | # +----------------+ g.add_node(0, name="A", entry=True) g.add_node(1, name="B") g.add_node(2, name="C", exit=True) g.add_edge(0, 1) g.add_edge(1, 0) g.add_edge(0, 2) assert g.ValidateControlFlowGraph() == g assert g.IsValidControlFlowGraph()
def test_ControlFlowGraph_exit_block(): """Test exit block.""" g = control_flow_graph.ControlFlowGraph() # Graph: # # +----> B -----+ # | | # | v # A D # | ^ # | | # +----> C -----+ g.add_node(0, name="A", entry=True) g.add_node(1, name="B") g.add_node(2, name="C") g.add_node(3, name="D", exit=True) g.add_edge(0, 1) g.add_edge(0, 2) g.add_edge(1, 3) g.add_edge(2, 3) assert g.exit_blocks == [3]
def test_ControlFlowGraph_IsValidControlFlowGraph_if_else_loop(): """Test that an if-else loop graph is valid.""" g = control_flow_graph.ControlFlowGraph() # Graph: # # +----> B -----+ # | | # | v # A D # | ^ # | | # +----> C -----+ g.add_node(0, name="A", entry=True) g.add_node(1, name="B") g.add_node(2, name="C") g.add_node(3, name="D", exit=True) g.add_edge(0, 1) g.add_edge(0, 2) g.add_edge(1, 3) g.add_edge(2, 3) assert g.ValidateControlFlowGraph() == g assert g.IsValidControlFlowGraph()
def test_ControlFlowGraph_IsValidControlFlowGraph_while_loop_with_exit(): """Test that a while loop with an if branch exit is valid.""" g = control_flow_graph.ControlFlowGraph() # Graph: # # +----------------+ # | | # v | # A+------>B+----->C D # | | ^ # | | | # +------->+---------------+ g.add_node(0, name="A", entry=True) g.add_node(1, name="B") g.add_node(2, name="C") g.add_node(3, name="D", exit=True) g.add_edge(0, 1) g.add_edge(1, 2) g.add_edge(2, 0) g.add_edge(0, 3) g.add_edge(1, 3) assert g.ValidateControlFlowGraph() == g assert g.IsValidControlFlowGraph()
def test_ControlFlowGraph_IsValidControlFlowGraph_unamed_nodes():
"""Test that all nodes in a graph must have a name."""
g = control_flow_graph.ControlFlowGraph()
# Graph:
#
# +----> B -----+
# | |
# | v
# A D
# | ^
# | |
# +----> -----+
g.add_node(0, name="A", entry=True)
g.add_node(1, name="B")
g.add_node(2)
g.add_node(3, name="D", exit=True)
g.add_edge(0, 1)
g.add_edge(0, 2)
g.add_edge(1, 3)
g.add_edge(2, 3)
with test.Raises(control_flow_graph.MissingNodeName) as e_ctx:
g.ValidateControlFlowGraph()
assert str(e_ctx.value) == "Node 2 has no name in function `cfg`"
assert not g.IsValidControlFlowGraph()
def test_ControlFlowGraph_IsValidControlFlowGraph_duplicate_names():
"""Test that duplicate names is an error."""
g = control_flow_graph.ControlFlowGraph()
# Graph:
#
# +----> B -----+
# | |
# | v
# A D
# | ^
# | |
# +----> B -----+
g.add_node(0, name="A", entry=True)
g.add_node(1, name="B")
g.add_node(2, name="B")
g.add_node(3, name="D", exit=True)
g.add_edge(0, 1)
g.add_edge(0, 2)
g.add_edge(1, 3)
g.add_edge(2, 3)
with test.Raises(control_flow_graph.DuplicateNodeName) as e_ctx:
g.ValidateControlFlowGraph()
assert str(e_ctx.value) == "Duplicate node name 'B' in function `cfg`"
assert not g.IsValidControlFlowGraph()
def test_ControlFlowGraph_validate_one_node(): """Test that single-node graph is valid.""" g = control_flow_graph.ControlFlowGraph() g.add_node(0, name="A", entry=True, exit=True) g.ValidateControlFlowGraph()