Add slithir.operation.unroll as a general util (slither.utils.utils). Use unroll on fix_phi operations

slither/slithir/operations/operation.py

@@ -1,6 +1,7 @@
 import abc
 from slither.core.context.context import Context
 from slither.core.children.child_node import ChildNode
+from slither.utils.utils import unroll
 
 class AbstractOperation(abc.ABC):
 
@@ -30,11 +31,6 @@ class Operation(Context, ChildNode, AbstractOperation):
         return self.read
 
     # if array inside the parameters
-    def _unroll(self, l):
+    @staticmethod
-        ret = []
+    def _unroll(l):
-        for x in l:
+        return unroll(l)
-            if not isinstance(x, list):
-                ret += [x]
-            else:
-                ret += self._unroll(x)
-        return ret

slither/solc_parsing/declarations/function.py

@@ -29,6 +29,7 @@ from slither.visitors.expression.has_conditional import HasConditional
 from slither.core.declarations.contract import Contract
 
 from slither.slithir.variables import StateIRVariable, LocalIRVariable, Constant
+from slither.utils.utils import unroll
 
 logger = logging.getLogger("FunctionSolc")
 
@@ -971,6 +972,7 @@ class FunctionSolc(Function):
                         idx = self.parameters.index(ir.lvalue.non_ssa_version)
                         # find non ssa version of that index
                         additional = [n.ir.arguments[idx] for n in self.reachable_from_nodes]
+                        additional = unroll(additional)
                         additional = [a for a in additional if not isinstance(a, Constant)]
                         ir.rvalues = list(set(additional + ir.rvalues))
                 if isinstance(ir, PhiCallback):

slither/utils/utils.py

@@ -0,0 +1,8 @@
+def unroll(l):
+    ret = []
+    for x in l:
+        if not isinstance(x, list):
+            ret += [x]
+        else:
+            ret += unroll(x)
+    return ret