Add exception handler to tod module and adapt tests

mythril/analysis/modules/transaction_order_independence.py

@@ -75,7 +75,10 @@ def _get_storage_variable(storage, state):
 def _can_change(constraints, variable):
     """ Checks if the variable can change given some constraints """
     _constraints = copy.deepcopy(constraints)
+    try:
         model = solver.get_model(_constraints)
+    except UnsatError:
+        return False
     initial_value = int(str(model.eval(variable, model_completion=True)))
     return _try_constraints(constraints, [variable != initial_value]) is not None
 

tests/testdata/outputs_expected/calls.sol.o.json

@@ -42,6 +42,14 @@
             "address": 912,
             "debug": "<DEBUG-DATA>"
         },
+        {
+            "title": "Transaction order dependence",
+            "description": "A possible transaction order independence vulnerability exists in function _function_0xd24b08cc. The value or direction of the call statement is determined from a tainted storage location",
+            "function": "_function_0xd24b08cc",
+            "type": "Warning",
+            "address": 779,
+            "debug": "<DEBUG-DATA>"
+        },
         {
             "title": "Unchecked CALL return value",
             "description": "The return value of an external call is not checked. Note that execution continue even if the called contract throws.",

tests/testdata/outputs_expected/calls.sol.o.markdown

@@ -55,6 +55,17 @@ The contract account state is changed after an external call. Consider that the
 
 This contract executes a message call to an address provided as a function argument. Generally, it is not recommended to call user-supplied adresses using Solidity's call() construct. Note that attackers might leverage reentrancy attacks to exploit race conditions or manipulate this contract's state.
 
+## Transaction order dependence
+
+- Type: Warning
+- Contract: Unknown
+- Function name: `_function_0xd24b08cc`
+- PC address: 779
+
+### Description
+
+A possible transaction order independence vulnerability exists in function _function_0xd24b08cc. The value or direction of the call statement is determined from a tainted storage location
+
 ## Unchecked CALL return value
 
 - Type: Informational

tests/testdata/outputs_expected/calls.sol.o.text

@@ -38,6 +38,14 @@ PC address: 912
 This contract executes a message call to an address provided as a function argument. Generally, it is not recommended to call user-supplied adresses using Solidity's call() construct. Note that attackers might leverage reentrancy attacks to exploit race conditions or manipulate this contract's state.
 --------------------
 
+==== Transaction order dependence ====
+Type: Warning
+Contract: Unknown
+Function name: _function_0xd24b08cc
+PC address: 779
+A possible transaction order independence vulnerability exists in function _function_0xd24b08cc. The value or direction of the call statement is determined from a tainted storage location
+--------------------
+
 ==== Unchecked CALL return value ====
 Type: Informational
 Contract: Unknown

tests/testdata/outputs_expected/weak_random.sol.o.json

@@ -33,6 +33,14 @@
             "type": "Informational",
             "address": 146,
             "debug": "<DEBUG-DATA>"
+        },
+        {
+            "title": "Transaction order dependence",
+            "description": "A possible transaction order independence vulnerability exists in function _function_0xe9874106. The value or direction of the call statement is determined from a tainted storage location",
+            "function": "_function_0xe9874106",
+            "type": "Warning",
+            "address": 1285,
+            "debug": "<DEBUG-DATA>"
         }
     ]
 }

tests/testdata/outputs_expected/weak_random.sol.o.markdown

@@ -49,3 +49,14 @@ A reachable exception (opcode 0xfe) has been detected. This can be caused by typ
 ### Description
 
 A reachable exception (opcode 0xfe) has been detected. This can be caused by type errors, division by zero, out-of-bounds array access, or assert violations. This is acceptable in most situations. Note however that `assert()` should only be used to check invariants. Use `require()` for regular input checking. 
+
+## Transaction order dependence
+
+- Type: Warning
+- Contract: Unknown
+- Function name: `_function_0xe9874106`
+- PC address: 1285
+
+### Description
+
+A possible transaction order independence vulnerability exists in function _function_0xe9874106. The value or direction of the call statement is determined from a tainted storage location

tests/testdata/outputs_expected/weak_random.sol.o.text

@@ -36,3 +36,11 @@ PC address: 146
 A reachable exception (opcode 0xfe) has been detected. This can be caused by type errors, division by zero, out-of-bounds array access, or assert violations. This is acceptable in most situations. Note however that `assert()` should only be used to check invariants. Use `require()` for regular input checking. 
 --------------------
 
+==== Transaction order dependence ====
+Type: Warning
+Contract: Unknown
+Function name: _function_0xe9874106
+PC address: 1285
+A possible transaction order independence vulnerability exists in function _function_0xe9874106. The value or direction of the call statement is determined from a tainted storage location
+--------------------
+