def program_to_text(program):
"""Generate a text (CFG nodes + assignments) version of a program.
For debugging only.
Args:
program: An instance of cfg.Program
Returns:
A string representing all of the data for this program.
"""
s = StringIO.StringIO()
seen = set()
for node in utils.order_nodes(program.cfg_nodes):
seen.add(node)
s.write("%s\n" % node.Label())
s.write(" From: %s\n" % ", ".join(n.Label() for n in node.incoming))
s.write(" To: %s\n" % ", ".join(n.Label() for n in node.outgoing))
s.write("\n")
variables = set(value.variable for value in node.bindings)
for var in sorted(variables, key=lambda v: v.id):
# If a variable is bound in more than one node then it will be listed
# redundantly multiple times. One alternative would be to only list the
# values that occur in the given node, and then also list the other nodes
# that assign the same variable.
# Write the variable, indenting by two spaces.
s.write(" %s\n" % _pretty_variable(var).replace("\n", "\n "))
s.write("\n")
return s.getvalue()
def program_to_text(program):
"""Generate a text (CFG nodes + assignments) version of a program.
For debugging only.
Args:
program: An instance of cfg.Program
Returns:
A string representing all of the data for this program.
"""
s = StringIO.StringIO()
seen = set()
for node in utils.order_nodes(program.cfg_nodes):
seen.add(node)
s.write("%s\n" % node.Label())
s.write(" From: %s\n" % ", ".join(n.Label() for n in node.incoming))
s.write(" To: %s\n" % ", ".join(n.Label() for n in node.outgoing))
s.write("\n")
variables = set(value.variable for value in node.bindings)
for var in sorted(variables, key=lambda v: v.id):
# If a variable is bound in more than one node then it will be listed
# redundantly multiple times. One alternative would be to only list the
# values that occur in the given node, and then also list the other nodes
# that assign the same variable.
# Write the variable, indenting by two spaces.
s.write(" %s\n" % _pretty_variable(var).replace("\n", "\n "))
s.write("\n")
return s.getvalue()
def testOrderNodes4(self):
# n1 --> n3 --> n2
# ^ |
# +------+
n1 = self.prog.NewCFGNode("n1")
n3 = n1.ConnectNew("n3")
n2 = n3.ConnectNew("n2")
n3.ConnectTo(n1)
order = utils.order_nodes([n1, n2, n3])
self.assertItemsEqual([n1, n3, n2], order)
def testOrderNodes4(self):
# n1 --> n3 --> n2
# ^ |
# +------+
n1 = self.prog.NewCFGNode("n1")
n3 = n1.ConnectNew("n3")
n2 = n3.ConnectNew("n2")
n3.ConnectTo(n1)
order = utils.order_nodes([n1, n2, n3])
self.assertItemsEqual([n1, n3, n2], order)
def testOrderNodes6(self):
# +-------------------+
# | v
# n1 --> n2 --> n3 --> n5
# ^ |
# +------n4
n1 = self.prog.NewCFGNode("n1")
n2 = n1.ConnectNew("n2")
n3 = n2.ConnectNew("n3")
n4 = n3.ConnectNew("n4")
n4.ConnectTo(n2)
n5 = n3.ConnectNew("n5")
n1.ConnectTo(n5)
order = utils.order_nodes([n1, n5, n4, n3, n2])
self.assertItemsEqual([n1, n2, n3, n4, n5], order)
def testOrderNodes6(self):
# +-------------------+
# | v
# n1 --> n2 --> n3 --> n5
# ^ |
# +------n4
n1 = self.prog.NewCFGNode("n1")
n2 = n1.ConnectNew("n2")
n3 = n2.ConnectNew("n3")
n4 = n3.ConnectNew("n4")
n4.ConnectTo(n2)
n5 = n3.ConnectNew("n5")
n1.ConnectTo(n5)
order = utils.order_nodes([n1, n5, n4, n3, n2])
self.assertItemsEqual([n1, n2, n3, n4, n5], order)
def program_to_pseudocode(program):
"""Generate a pseudocode (CFG nodes + assignments) version of a program.
For debugging only.
Args:
program: An instance of cfg.Program
Returns:
A string, the "pseudocode" of this program.
"""
s = StringIO.StringIO()
seen = set()
for node in utils.order_nodes(program.cfg_nodes):
seen.add(node)
s.write("<%d>%s\n" % (node.id, node.name))
for value in node.values:
s.write(" %s\n" % pretty_assignment(value))
overwritten = False
for cfg_node, source_sets in value.origins:
if node != cfg_node:
overwritten = True
continue
if source_sets == [set()]:
pass # don't print trivially true source_sets
else:
src = utils.pretty_dnf([[pretty_assignment(v, short=True)
for v in source_set]
for source_set in source_sets])
s.write(" from: %s\n" % src)
if overwritten:
s.write(" (also set to this value in other nodes)\n")
for out in node.outgoing:
s.write(" jump to <%d>%s\n" % (out.id, out.name))
# "stray" nodes are nodes that are unreachable in the CFG.
stray_nodes = set(program.cfg_nodes) - seen
if stray_nodes:
s.write("Stray nodes:\n")
for node in stray_nodes:
s.write("<%d>%s\n" % (node.id, node.name))
return s.getvalue()
def program_to_pseudocode(program):
"""Generate a pseudocode (CFG nodes + assignments) version of a program.
For debugging only.
Args:
program: An instance of cfg.Program
Returns:
A string, the "pseudocode" of this program.
"""
s = StringIO.StringIO()
seen = set()
for node in utils.order_nodes(program.cfg_nodes):
seen.add(node)
s.write("<%d>%s\n" % (node.id, node.name))
for value in node.values:
s.write(" %s\n" % pretty_assignment(value))
overwritten = False
for cfg_node, source_sets in value.origins:
if node != cfg_node:
overwritten = True
continue
if source_sets == [set()]:
pass # don't print trivially true source_sets
else:
src = utils.pretty_dnf([[pretty_assignment(v, short=True)
for v in source_set]
for source_set in source_sets])
s.write(" from: %s\n" % src)
if overwritten:
s.write(" (also set to this value in other nodes)\n")
for out in node.outgoing:
s.write(" jump to <%d>%s\n" % (out.id, out.name))
# "stray" nodes are nodes that are unreachable in the CFG.
stray_nodes = set(program.cfg_nodes) - seen
if stray_nodes:
s.write("Stray nodes:\n")
for node in stray_nodes:
s.write("<%d>%s\n" % (node.id, node.name))
return s.getvalue()
def testOrderNodes7(self):
# +---------------------------------+
# | v
# n1 --> n2 --> n3 --> n4 --> n5 --> n6
# ^ | ^ |
# | v | v
# +------n7 +------n8
n1 = self.prog.NewCFGNode("n1")
n2 = n1.ConnectNew("n2")
n3 = n2.ConnectNew("n3")
n4 = n3.ConnectNew("n4")
n5 = n4.ConnectNew("n5")
n6 = n5.ConnectNew("n6")
n7 = n3.ConnectNew("n7")
n7.ConnectTo(n2)
n8 = n5.ConnectNew("n8")
n8.ConnectTo(n4)
n1.ConnectTo(n6)
order = utils.order_nodes([n1, n2, n3, n4, n5, n6, n7, n8])
self.assertItemsEqual([n1, n2, n3, n7, n4, n5, n8, n6], order)
def testOrderNodes7(self):
# +---------------------------------+
# | v
# n1 --> n2 --> n3 --> n4 --> n5 --> n6
# ^ | ^ |
# | v | v
# +------n7 +------n8
n1 = self.prog.NewCFGNode("n1")
n2 = n1.ConnectNew("n2")
n3 = n2.ConnectNew("n3")
n4 = n3.ConnectNew("n4")
n5 = n4.ConnectNew("n5")
n6 = n5.ConnectNew("n6")
n7 = n3.ConnectNew("n7")
n7.ConnectTo(n2)
n8 = n5.ConnectNew("n8")
n8.ConnectTo(n4)
n1.ConnectTo(n6)
order = utils.order_nodes([n1, n2, n3, n4, n5, n6, n7, n8])
self.assertItemsEqual([n1, n2, n3, n7, n4, n5, n8, n6], order)
def compute_order(bytecode):
"""Split bytecode into blocks and order the blocks.
This builds an "ancestor first" ordering of the basic blocks of the bytecode.
Args:
bytecode: A list of instances of opcodes.Opcode. (E.g. returned from
opcodes.dis())
Returns:
A list of Block instances.
"""
blocks = _split_bytecode(bytecode)
first_op_to_block = {block.code[0]: block for block in blocks}
for i, block in enumerate(blocks):
next_block = blocks[i + 1] if i < len(blocks) - 1 else None
last_op = block.code[-1]
if next_block and not last_op.no_next():
block.connect_outgoing(next_block)
if last_op.target:
block.connect_outgoing(first_op_to_block[last_op.target])
if last_op.block_target:
block.connect_outgoing(first_op_to_block[last_op.block_target])
return utils.order_nodes(blocks)
def compute_order(bytecode):
"""Split bytecode into blocks and order the blocks.
This builds an "ancestor first" ordering of the basic blocks of the bytecode.
Args:
bytecode: A list of instances of opcodes.Opcode. (E.g. returned from
opcodes.dis())
Returns:
A list of Block instances.
"""
blocks = _split_bytecode(bytecode)
first_op_to_block = {block.code[0]: block for block in blocks}
for i, block in enumerate(blocks):
next_block = blocks[i + 1] if i < len(blocks) - 1 else None
last_op = block.code[-1]
if next_block and not last_op.no_next():
block.connect_outgoing(next_block)
if last_op.target:
block.connect_outgoing(first_op_to_block[last_op.target])
if last_op.block_target:
block.connect_outgoing(first_op_to_block[last_op.block_target])
return utils.order_nodes(blocks)
def testOrderNodes2(self):
# n1 n2(dead)
n1 = self.prog.NewCFGNode("n1")
n2 = self.prog.NewCFGNode("n2")
order = utils.order_nodes([n1, n2])
self.assertItemsEqual([n1], order)
def testOrderNodes1(self):
# n1 --> n2
n1 = self.prog.NewCFGNode("n1")
n2 = n1.ConnectNew("n2")
order = utils.order_nodes([n1, n2])
self.assertItemsEqual([n1, n2], order)
def testOrderNodes0(self):
order = utils.order_nodes([])
self.assertItemsEqual(order, [])
def testOrderNodes0(self): order = utils.order_nodes([]) self.assertItemsEqual(order, [])
def testOrderNodes1(self):
# n1 --> n2
n1 = self.prog.NewCFGNode("n1")
n2 = n1.ConnectNew("n2")
order = utils.order_nodes([n1, n2])
self.assertItemsEqual([n1, n2], order)
def testOrderNodes2(self):
# n1 n2(dead)
n1 = self.prog.NewCFGNode("n1")
n2 = self.prog.NewCFGNode("n2")
order = utils.order_nodes([n1, n2])
self.assertItemsEqual([n1], order)
