Add support of Type for SSA (abi.decode() takes a type as argument)

slither/analyses/data_dependency/data_dependency.py

@@ -9,6 +9,7 @@ from slither.slithir.variables import (Constant, LocalIRVariable,
                                        ReferenceVariable, ReferenceVariableSSA,
                                        StateIRVariable, TemporaryVariable,
                                        TemporaryVariableSSA, TupleVariableSSA)
+from slither.core.solidity_types.type import Type
 
 ###################################################################################
 ###################################################################################
@@ -261,7 +262,7 @@ def compute_dependency_function(function):
 def convert_variable_to_non_ssa(v):
     if isinstance(v, (LocalIRVariable, StateIRVariable, TemporaryVariableSSA, ReferenceVariableSSA, TupleVariableSSA)):
         return v.non_ssa_version
-    assert isinstance(v, (Constant, SolidityVariable, Contract, Enum, SolidityFunction, Structure, Function))
+    assert isinstance(v, (Constant, SolidityVariable, Contract, Enum, SolidityFunction, Structure, Function, Type))
     return v
 
 def convert_to_non_ssa(data_depencies):

slither/slithir/utils/ssa.py

@@ -4,6 +4,7 @@ from slither.core.cfg.node import NodeType
 from slither.core.declarations import (Contract, Enum, Function,
                                        SolidityFunction, SolidityVariable,
                                        SolidityVariableComposed, Structure)
+from slither.core.solidity_types.type import Type
 from slither.core.variables.local_variable import LocalVariable
 from slither.core.variables.state_variable import StateVariable
 from slither.slithir.operations import (Assignment, Balance, Binary, Condition,
@@ -468,7 +469,8 @@ def get(variable, local_variables_instances, state_variables_instances, temporar
                                  Enum,
                                  SolidityFunction,
                                  Structure,
-                                 Function))
+                                 Function,
+                                 Type)) # type for abi.decode(.., t)
     return variable
 
 def get_variable(ir, f, *instances):