SlithIR:

- Add .used attributes to all operators, it returns all the variables used
 - Use ABC for Operation

slither/slithir/operations/high_level_call.py

@@ -58,7 +58,9 @@ class HighLevelCall(Call, OperationWithLValue):
 
     @property
     def read(self):
-        return [self.destination]
+        all_read = [self.destination, self.call_gas, self.call_value] + self.arguments
+        # remove None
+        return [x for x in all_read if x]
 
     @property
     def destination(self):

slither/slithir/operations/internal_dynamic_call.py

@@ -19,7 +19,7 @@ class InternalDynamicCall(Call, OperationWithLValue):
 
     @property
     def read(self):
-        return list(self.arguments)
+        return list(self.arguments) + [self.function]
 
     @property
     def function(self):

slither/slithir/operations/low_level_call.py

@@ -50,7 +50,9 @@ class LowLevelCall(Call, OperationWithLValue):
 
     @property
     def read(self):
-        return [self.destination]
+        all_read = [self.destination, self.call_gas, self.call_value] + self.arguments
+        # remove None
+        return [x for x in all_read if x]
 
     @property
     def destination(self):

slither/slithir/operations/lvalue.py

@@ -14,6 +14,10 @@ class OperationWithLValue(Operation):
     def lvalue(self):
         return self._lvalue
 
+    @property
+    def used(self):
+        return self.read + [self.lvalue]
+
     @lvalue.setter
     def lvalue(self, lvalue):
         self._lvalue = lvalue

slither/slithir/operations/operation.py

@@ -1,9 +1,29 @@
+import abc
 from slither.core.context.context import Context
-class Operation(Context):
+
+class AbstractOperation(abc.ABC):
 
     @property
+    @abc.abstractmethod
     def read(self):
         """
-            Must be ovveriden
+            Return the list of variables READ
+        """
+        pass
+
+    @property
+    @abc.abstractmethod
+    def used(self):
+        """
+            Return the list of variables used
+        """
+        pass
+
+class Operation(Context, AbstractOperation):
+
+    @property
+    def used(self):
+        """
+            By default used is all the variables read
         """
-        raise Exception('Not overrided {}'.format(type(self)))
+        return self.read

slither/slithir/operations/send.py

@@ -23,7 +23,7 @@ class Send(Call, OperationWithLValue):
 
     @property
     def read(self):
-        return [self.destination]
+        return [self.destination, self.call_value]
 
     @property
     def destination(self):

slither/slithir/operations/transfer.py

@@ -18,7 +18,7 @@ class Transfer(Call):
 
     @property
     def read(self):
-        return [self.destination]
+        return [self.destination, self.call_value]
 
     @property
     def destination(self):