Added ProgramCounterException to display a clearer message when pc is out of bounds.

mythril/laser/ethereum/evm_exceptions.py

@@ -35,3 +35,9 @@ class OutOfGasException(VmException):
     """A VM exception denoting the current execution has run out of gas."""
 
     pass
+
+
+class ProgramCounterException(VmException):
+    """A VM exception denoting an invalid PC value (No stop instruction is reached)."""
+
+    pass

mythril/laser/ethereum/state/global_state.py

@@ -9,6 +9,7 @@ from mythril.laser.ethereum.cfg import Node
 from mythril.laser.ethereum.state.environment import Environment
 from mythril.laser.ethereum.state.machine_state import MachineState
 from mythril.laser.ethereum.state.annotation import StateAnnotation
+from mythril.laser.ethereum.evm_exceptions import ProgramCounterException
 
 if TYPE_CHECKING:
     from mythril.laser.ethereum.state.world_state import WorldState
@@ -88,6 +89,10 @@ class GlobalState:
         """
 
         instructions = self.environment.code.instruction_list
+        if self.mstate.pc >= len(instructions):
+            raise ProgramCounterException(
+                "PC: {} can not be reached.".format(self.mstate.pc)
+            )
         return instructions[self.mstate.pc]
 
     @property