def _insert_dummy_exit_node(cfg: CFG) -> CFG:
dummy_exit_node = pg.ProgramGraphNode(index=sys.maxsize, is_artificial=True)
exit_nodes = cfg.exit_nodes
if not exit_nodes and len(cfg.nodes) == 1:
exit_nodes = cfg.nodes
cfg.add_node(dummy_exit_node)
for exit_node in exit_nodes:
cfg.add_edge(exit_node, dummy_exit_node)
return cfg
def _insert_dummy_entry_node(cfg: CFG) -> CFG:
dummy_entry_node = pg.ProgramGraphNode(index=-1, is_artificial=True)
entry_node = cfg.entry_node
if not entry_node and len(cfg.nodes) == 1:
entry_node = cfg.nodes.pop() # There is only one candidate to pop
elif not entry_node:
entry_node = [n for n in cfg.nodes if n.index == 0][0]
cfg.add_node(dummy_entry_node)
cfg.add_edge(dummy_entry_node, entry_node)
return cfg
def _create_augmented_graph(graph: cfg.CFG) -> cfg.CFG:
entry_node = graph.entry_node
assert entry_node, "Cannot work with CFG without entry node"
exit_nodes = graph.exit_nodes
augmented_graph = graph.copy()
start_node = pg.ProgramGraphNode(index=-sys.maxsize, is_artificial=True)
augmented_graph.add_node(start_node)
augmented_graph.add_edge(start_node, entry_node)
for exit_node in exit_nodes:
augmented_graph.add_edge(start_node, exit_node)
return augmented_graph
def _create_nodes(
blocks: ControlFlowGraph,
) -> Tuple[Dict[int, List[int]], Dict[int, pg.ProgramGraphNode]]:
nodes: Dict[int, pg.ProgramGraphNode] = {}
edges: Dict[int, List[int]] = {}
for node_index, block in enumerate(blocks):
node = pg.ProgramGraphNode(index=node_index, basic_block=block)
nodes[node_index] = node
if node_index not in edges:
edges[node_index] = []
next_block = block.next_block
if next_block:
next_index = blocks.get_block_index(next_block)
edges[node_index].append(next_index)
if target_block := block.get_jump():
next_index = blocks.get_block_index(target_block)
edges[node_index].append(next_index)
