def convert_expression_to_slithir(self):
for func in self.functions + self.modifiers:
try:
func.generate_slithir_and_analyze()
except AttributeError:
# This can happens for example if there is a call to an interface
# And the interface is redefined due to contract's name reuse
# But the available version misses some functions
self.log_incorrect_parsing(
f'Impossible to generate IR for {self.name}.{func.name}')
all_ssa_state_variables_instances = dict()
for contract in self.inheritance:
for v in contract.state_variables_declared:
new_var = StateIRVariable(v)
all_ssa_state_variables_instances[v.canonical_name] = new_var
self._initial_state_variables.append(new_var)
for v in self.variables:
if v.contract == self:
new_var = StateIRVariable(v)
all_ssa_state_variables_instances[v.canonical_name] = new_var
self._initial_state_variables.append(new_var)
for func in self.functions + self.modifiers:
func.generate_slithir_ssa(all_ssa_state_variables_instances)
def update_lvalue(new_ir, node, local_variables_instances,
all_local_variables_instances, state_variables_instances,
all_state_variables_instances):
if isinstance(new_ir, OperationWithLValue):
lvalue = new_ir.lvalue
update_through_ref = False
if isinstance(new_ir, (Assignment, Binary)):
if isinstance(lvalue, ReferenceVariable):
update_through_ref = True
while isinstance(lvalue, ReferenceVariable):
lvalue = lvalue.points_to
if isinstance(lvalue, (LocalIRVariable, StateIRVariable)):
if isinstance(lvalue, LocalIRVariable):
new_var = LocalIRVariable(lvalue)
new_var.index = all_local_variables_instances[
lvalue.name].index + 1
all_local_variables_instances[lvalue.name] = new_var
local_variables_instances[lvalue.name] = new_var
else:
new_var = StateIRVariable(lvalue)
new_var.index = all_state_variables_instances[
lvalue.canonical_name].index + 1
all_state_variables_instances[lvalue.canonical_name] = new_var
state_variables_instances[lvalue.canonical_name] = new_var
if update_through_ref:
phi_operation = Phi(new_var, {node})
phi_operation.rvalues = [lvalue]
node.add_ssa_ir(phi_operation)
if not isinstance(new_ir.lvalue, ReferenceVariable):
new_ir.lvalue = new_var
else:
to_update = new_ir.lvalue
while isinstance(to_update.points_to, ReferenceVariable):
to_update = to_update.points_to
to_update.points_to = new_var
def convert_expression_to_slithir(self):
for func in self.functions + self.modifiers:
func.generate_slithir_and_analyze()
all_ssa_state_variables_instances = dict()
for contract in self.inheritance:
for v in contract.state_variables_declared:
new_var = StateIRVariable(v)
all_ssa_state_variables_instances[v.canonical_name] = new_var
self._initial_state_variables.append(new_var)
for v in self.variables:
if v.contract == self:
new_var = StateIRVariable(v)
all_ssa_state_variables_instances[v.canonical_name] = new_var
self._initial_state_variables.append(new_var)
for func in self.functions + self.modifiers:
func.generate_slithir_ssa(all_ssa_state_variables_instances)
def convert_expression_to_slithir_ssa(self):
"""
Assume generate_slithir_and_analyze was called on all functions
:return:
"""
from slither.slithir.variables import StateIRVariable
all_ssa_state_variables_instances = dict()
for contract in self.inheritance:
for v in contract.state_variables_declared:
new_var = StateIRVariable(v)
all_ssa_state_variables_instances[v.canonical_name] = new_var
self._initial_state_variables.append(new_var)
for v in self.variables:
if v.contract == self:
new_var = StateIRVariable(v)
all_ssa_state_variables_instances[v.canonical_name] = new_var
self._initial_state_variables.append(new_var)
for func in self.functions + self.modifiers:
func.generate_slithir_ssa(all_ssa_state_variables_instances)
def add_ssa_ir(function, all_state_variables_instances):
'''
Add SSA version of the IR
Args:
function
all_state_variables_instances
'''
if not function.is_implemented:
return
init_definition = dict()
for v in function.parameters + function.returns:
if v.name:
init_definition[v.name] = (v, function.entry_point)
# We only add phi function for state variable at entry node if
# The state variable is used
# And if the state variables is written in another function (otherwise its stay at index 0)
for (_, variable_instance) in all_state_variables_instances.items():
if is_used_later(function.entry_point, variable_instance):
# rvalues are fixed in solc_parsing.declaration.function
function.entry_point.add_ssa_ir(
Phi(StateIRVariable(variable_instance), set()))
add_phi_origins(function.entry_point, init_definition, dict())
for node in function.nodes:
for (variable, nodes) in node.phi_origins_local_variables.values():
if len(nodes) < 2:
continue
if not is_used_later(node, variable):
continue
node.add_ssa_ir(Phi(LocalIRVariable(variable), nodes))
for (variable, nodes) in node.phi_origins_state_variables.values():
if len(nodes) < 2:
continue
#if not is_used_later(node, variable.name, []):
# continue
node.add_ssa_ir(Phi(StateIRVariable(variable), nodes))
init_local_variables_instances = dict()
for v in function.parameters:
if v.name:
new_var = LocalIRVariable(v)
function.add_parameter_ssa(new_var)
if new_var.is_storage:
fake_variable = LocalIRVariable(v)
fake_variable.name = 'STORAGE_' + fake_variable.name
fake_variable.set_location('reference_to_storage')
new_var.refers_to = {fake_variable}
init_local_variables_instances[
fake_variable.name] = fake_variable
init_local_variables_instances[v.name] = new_var
for v in function.returns:
if v.name:
new_var = LocalIRVariable(v)
function.add_return_ssa(new_var)
if new_var.is_storage:
fake_variable = LocalIRVariable(v)
fake_variable.name = 'STORAGE_' + fake_variable.name
fake_variable.set_location('reference_to_storage')
new_var.refers_to = {fake_variable}
init_local_variables_instances[
fake_variable.name] = fake_variable
init_local_variables_instances[v.name] = new_var
all_init_local_variables_instances = dict(init_local_variables_instances)
init_state_variables_instances = dict(all_state_variables_instances)
initiate_all_local_variables_instances(function.nodes,
init_local_variables_instances,
all_init_local_variables_instances)
generate_ssa_irs(function.entry_point,
dict(init_local_variables_instances),
all_init_local_variables_instances,
dict(init_state_variables_instances),
all_state_variables_instances,
init_local_variables_instances, [])
fix_phi_rvalues_and_storage_ref(function.entry_point,
dict(init_local_variables_instances),
all_init_local_variables_instances,
dict(init_state_variables_instances),
all_state_variables_instances,
init_local_variables_instances)
def generate_ssa_irs(node, local_variables_instances,
all_local_variables_instances, state_variables_instances,
all_state_variables_instances,
init_local_variables_instances, visited):
if node in visited:
return
if node.type in [NodeType.ENDIF, NodeType.ENDLOOP] and any(
not father in visited for father in node.fathers):
return
# visited is shared
visited.append(node)
for ir in node.irs_ssa:
assert isinstance(ir, Phi)
update_lvalue(ir, node, local_variables_instances,
all_local_variables_instances, state_variables_instances,
all_state_variables_instances)
# these variables are lived only during the liveness of the block
# They dont need phi function
temporary_variables_instances = dict()
reference_variables_instances = dict()
for ir in node.irs:
new_ir = copy_ir(ir, local_variables_instances,
state_variables_instances,
temporary_variables_instances,
reference_variables_instances,
all_local_variables_instances)
update_lvalue(new_ir, node, local_variables_instances,
all_local_variables_instances, state_variables_instances,
all_state_variables_instances)
if new_ir:
node.add_ssa_ir(new_ir)
if isinstance(ir, (InternalCall, HighLevelCall,
InternalDynamicCall, LowLevelCall)):
if isinstance(ir, LibraryCall):
continue
for variable in all_state_variables_instances.values():
if not is_used_later(node, variable):
continue
new_var = StateIRVariable(variable)
new_var.index = all_state_variables_instances[
variable.canonical_name].index + 1
all_state_variables_instances[
variable.canonical_name] = new_var
state_variables_instances[
variable.canonical_name] = new_var
phi_ir = PhiCallback(new_var, {node}, new_ir, variable)
# rvalues are fixed in solc_parsing.declaration.function
node.add_ssa_ir(phi_ir)
if isinstance(new_ir, (Assignment, Binary)):
if isinstance(new_ir.lvalue, LocalIRVariable):
if new_ir.lvalue.is_storage:
if isinstance(new_ir.rvalue, ReferenceVariable):
refers_to = new_ir.rvalue.points_to_origin
new_ir.lvalue.add_refers_to(refers_to)
else:
new_ir.lvalue.add_refers_to(new_ir.rvalue)
for succ in node.dominator_successors:
generate_ssa_irs(succ, dict(local_variables_instances),
all_local_variables_instances,
dict(state_variables_instances),
all_state_variables_instances,
init_local_variables_instances, visited)
for dominated in node.dominance_frontier:
generate_ssa_irs(dominated, dict(local_variables_instances),
all_local_variables_instances,
dict(state_variables_instances),
all_state_variables_instances,
init_local_variables_instances, visited)
def generate_ssa_irs(
node,
local_variables_instances,
all_local_variables_instances,
state_variables_instances,
all_state_variables_instances,
init_local_variables_instances,
visited,
):
if node in visited:
return
if node.type in [NodeType.ENDIF, NodeType.ENDLOOP] and any(
not father in visited for father in node.fathers):
return
# visited is shared
visited.append(node)
for ir in node.irs_ssa:
assert isinstance(ir, Phi)
update_lvalue(
ir,
node,
local_variables_instances,
all_local_variables_instances,
state_variables_instances,
all_state_variables_instances,
)
# these variables are lived only during the liveness of the block
# They dont need phi function
temporary_variables_instances = {}
reference_variables_instances = {}
tuple_variables_instances = {}
for ir in node.irs:
new_ir = copy_ir(
ir,
local_variables_instances,
state_variables_instances,
temporary_variables_instances,
reference_variables_instances,
tuple_variables_instances,
all_local_variables_instances,
)
new_ir.set_expression(ir.expression)
new_ir.set_node(ir.node)
update_lvalue(
new_ir,
node,
local_variables_instances,
all_local_variables_instances,
state_variables_instances,
all_state_variables_instances,
)
if new_ir:
node.add_ssa_ir(new_ir)
if isinstance(ir, (InternalCall, HighLevelCall,
InternalDynamicCall, LowLevelCall)):
if isinstance(ir, LibraryCall):
continue
for variable in all_state_variables_instances.values():
if not is_used_later(node, variable):
continue
new_var = StateIRVariable(variable)
new_var.index = all_state_variables_instances[
variable.canonical_name].index + 1
all_state_variables_instances[
variable.canonical_name] = new_var
state_variables_instances[
variable.canonical_name] = new_var
phi_ir = PhiCallback(new_var, {node}, new_ir, variable)
# rvalues are fixed in solc_parsing.declaration.function
node.add_ssa_ir(phi_ir)
if isinstance(new_ir, (Assignment, Binary)):
if isinstance(new_ir.lvalue, LocalIRVariable):
if new_ir.lvalue.is_storage:
if isinstance(new_ir.rvalue, ReferenceVariable):
refers_to = new_ir.rvalue.points_to_origin
new_ir.lvalue.add_refers_to(refers_to)
# Discard Constant
# This can happen on yul, like
# assembly { var.slot = some_value }
# Here we do not keep track of the references as we do not track
# such low level manipulation
# However we could extend our storage model to do so in the future
elif not isinstance(new_ir.rvalue, Constant):
new_ir.lvalue.add_refers_to(new_ir.rvalue)
for succ in node.dominator_successors:
generate_ssa_irs(
succ,
dict(local_variables_instances),
all_local_variables_instances,
dict(state_variables_instances),
all_state_variables_instances,
init_local_variables_instances,
visited,
)
for dominated in node.dominance_frontier:
generate_ssa_irs(
dominated,
dict(local_variables_instances),
all_local_variables_instances,
dict(state_variables_instances),
all_state_variables_instances,
init_local_variables_instances,
visited,
)