Integers: Add type check, change operator in assert conditions

mythril/analysis/modules/integer.py

@@ -62,6 +62,10 @@ def _check_integer_overflow(statespace, state, node):
 
         # An integer overflow is possible if op0 + op1 or op0 * op1 > MAX_UINT
 
+        allowed_types = [int, BitVecRef, BitVecNumRef]
+
+        if type(op0) in allowed_types and type(op1) in allowed_types:
+
             if instruction['opcode'] == "ADD":
                 expr = op0 + op1
             else:
@@ -127,7 +131,6 @@ def _check_integer_underflow(statespace, state, node):
 
         logging.debug("[INTEGER_UNDERFLOW] Checking SUB {0}, {1} at address {2}".format(str(op0), str(op1),
                                                                                         str(instruction['address'])))
-
         allowed_types = [int, BitVecRef, BitVecNumRef]
 
         if type(op0) in allowed_types and type(op1) in allowed_types:
@@ -175,14 +178,16 @@ def _check_usage(state, expression):
 
 def _check_jumpi(state, expression):
     """ Check if conditional jump is dependent on the result of expression"""
-    assert state.get_current_instruction()['opcode'] is 'JUMPI'
+    logging.info(state.get_current_instruction()['opcode'])
+    assert state.get_current_instruction()['opcode'] == 'JUMPI'
     condition = state.mstate.stack[-2]
     return str(expression) in str(condition)
 
 
 def _check_sstore(state, expression):
     """ Check if store operation is dependent on the result of expression"""
-    assert state.get_current_instruction()['opcode'] is 'SSTORE'
+    logging.info(state.get_current_instruction()['opcode'])
+    assert state.get_current_instruction()['opcode'] == 'SSTORE'
     value = state.mstate.stack[-2]
     return str(expression) in str(value)