def cfg(func):
"""
Compute the control flow graph for `func`
"""
cfg = Graph()
for block in func.blocks:
# Deduce CFG edges from block terminator
op = block.terminator
if op.opcode == ops.jump:
targets = [op.args[0]]
elif op.opcode == ops.cbranch:
cond, ifbb, elbb = op.args
targets = [ifbb, elbb]
elif op.opcode == ops.ret:
targets = []
else:
assert op.opcode == ops.exc_throw # exc_throw
targets = [block.get_metadata('exc_target') or 'pykit.exit']
# Add edges
for target in targets:
cfg.add_edge(block, target)
return cfg
def makedag():
dag = Graph()
dag.add_edge("a", "b")
dag.add_edge("b", "c")
dag.add_edge("c", "d")
dag.add_edge("d", "e")
dag.add_edge("a", "d")
dag.add_edge("d", "e")
dag.add_edge("b", "e")
return dag
