Experimental stuff

mythril/analysis/modules/integer.py

@@ -14,6 +14,7 @@ from mythril.laser.ethereum.util import get_concrete_int
 from mythril.laser.ethereum.state.annotation import StateAnnotation
 from mythril.analysis.modules.base import DetectionModule
 from copy import copy
+from mythril.laser.smt import simplify
 
 from mythril.laser.smt import (
     BVAddNoOverflow,
@@ -77,7 +78,8 @@ class IntegerOverflowUnderflowModule(DetectionModule):
                 "there's a possible state where op1 + op0 > 2^32 - 1"
             ),
             entrypoint="callback",
-            pre_hooks=["ADD", "MUL", "EXP", "SUB", "SSTORE", "JUMPI", "STOP", "RETURN"],
+            # pre_hooks=["ADD", "MUL", "EXP", "SUB", "SSTORE", "JUMPI", "STOP", "RETURN"],
+             pre_hooks=["MUL", "SSTORE", "JUMPI", "STOP", "RETURN"],
         )
 
     def reset_module(self):
@@ -304,27 +306,44 @@ class IntegerOverflowUnderflowModule(DetectionModule):
 
             ostate = annotation.overflowing_state
 
-            try:
             # This check can be disabled if the constraints are to difficult for z3 to solve
             # within any reasonable time.
-                if DISABLE_EFFECT_CHECK:
-                    constraints = ostate.mstate.constraints + [annotation.constraint]
-                else:
-                    constraints = state.mstate.constraints + [annotation.constraint]
+
+            if ostate.get_current_instruction()['address'] != 1587:
+                continue
 
             log.info(
                 "Potential overflow: {} at {}".format(
                     annotation.operator, ostate.get_current_instruction()["address"]
                 )
             )
+            '''
+            if DISABLE_EFFECT_CHECK:
+                constraints = ostate.mstate.constraints + [annotation.constraint]
+            else:
+                constraints = state.mstate.constraints + [annotation.constraint]
+            '''
+
+            try:
+                solver.get_model(state.mstate.constraints)
+                logging.info("get_model(state.mstate.constraints) SUCCEEDED (end state is reachable)")
+            except UnsatError:
+                logging.info("get_model(state.mstate.constraints) failed (end state is unreachable)")
 
+            try:
+                solver.get_model([annotation.constraint])
+                logging.info("get_model([annotation.constraint]) SUCCEEDED (integer can overflow)")
+            except UnsatError:
+                logging.info("get_model([annotation.constraint]) failed (integer cannot overflow)")
+
+            try:
                 transaction_sequence = solver.get_transaction_sequence(
-                    state, constraints
+                    state, state.mstate.constraints + [annotation.constraint]
                     )
 
-                log.info("SAT")
+                log.info("SUCCEEDED: Combined constraints were solved ")
             except UnsatError:
-                log.info("UNSAT")
+                log.info("Solving combined constraints failed")
                 continue
 
             _type = "Underflow" if annotation.operator == "subtraction" else "Overflow"