Add a handful of type-hint annotations.

This is not exhaustive, just a handful of annotations that
improved my quality-of-life while developing. Note that
I occasionally import type dependencies using the
`if typing.TYPE_CHECKING` construct .. this avoids runtime
circular imports.

greed/factory.py

@@ -1,14 +1,22 @@
+import typing
 import logging
 
 from greed.block import Block
 from greed.sim_manager import SimulationManager
 from greed.state import SymbolicEVMState
 
+if typing.TYPE_CHECKING:
+    from greed.project import Project
+    from greed.TAC import TAC_Statement
+    from greed.function import TAC_Function
+
 
 log = logging.getLogger(__name__)
 
 
 class Factory:
+    project: 'Project'
+
     def __init__(self, project: "Project"):
         self.project = project
 

greed/sim_manager.py

@@ -1,11 +1,14 @@
 import logging
 import os
 import sys
-from typing import Callable
+from typing import Callable, List, Optional, TYPE_CHECKING
 
 from greed import options
 from greed.state import SymbolicEVMState
 
+if TYPE_CHECKING:
+    from greed.exploration_techniques import ExplorationTechnique
+
 log = logging.getLogger(__name__)
 
 
@@ -35,35 +38,35 @@ def set_error(self, s: str):
         self.error += [s]
 
     @property
-    def states(self):
+    def states(self) -> List[SymbolicEVMState]:
         """
         :return: All the states
         """
         return sum(self.stashes.values(), [])
 
     @property
-    def active(self):
+    def active(self) -> List[SymbolicEVMState]:
         """
         :return: Active stash
         """
         return self.stashes['active']
 
     @property
-    def deadended(self):
+    def deadended(self) -> List[SymbolicEVMState]:
         """
         :return: Deadended stash
         """
         return self.stashes['deadended']
 
     @property
-    def found(self):
+    def found(self) -> List[SymbolicEVMState]:
         """
         :return: Found stash
         """
         return self.stashes['found']
 
     @property
-    def one_active(self):
+    def one_active(self) -> Optional[SymbolicEVMState]:
         """
         :return: First element of the active stash, or None if the stash is empty
         """
@@ -73,7 +76,7 @@ def one_active(self):
             return None
 
     @property
-    def one_deadended(self):
+    def one_deadended(self) -> Optional[SymbolicEVMState]:
         """
         :return: First element of the deadended stash, or None if the stash is empty
         """
@@ -83,7 +86,7 @@ def one_deadended(self):
             return None
 
     @property
-    def one_found(self):
+    def one_found(self) -> Optional[SymbolicEVMState]:
         """
         :return: First element of the found stash, or None if the stash is empty
         """
@@ -146,7 +149,7 @@ def step(self, find: Callable[[SymbolicEVMState], bool] = lambda s: False,
         for s in self.stashes['pruned'] + self.stashes['unsat'] + self.stashes['errored']:
             s.solver.dispose_context()
 
-    def single_step_state(self, state: SymbolicEVMState):
+    def single_step_state(self, state: SymbolicEVMState) -> List[SymbolicEVMState]:
         log.debug(f"Stepping {state}")
         log.debug(state.curr_stmt)
 

greed/state.py

@@ -1,5 +1,6 @@
 import datetime
 import logging
+import typing
 
 from greed import options as opt
 from greed.memory import LambdaMemory, PartialConcreteStorage
@@ -11,9 +12,28 @@
 
 log = logging.getLogger(__name__)
 
+if typing.TYPE_CHECKING:
+    from greed.project import Project
+
 
 class SymbolicEVMState:
     uuid_generator = UUIDGenerator()
+    xid: int
+    project: "Project"
+    code: bytes
+    uuid: int
+    active_plugins: typing.Dict[str, SimStatePlugin]
+    _pc: str
+    trace: typing.List[str]
+    memory: LambdaMemory
+    options: typing.Dict[str, typing.Any]
+    registers: typing.Dict[str, typing.Any]
+
+    # default plugins
+    solver: SimStateSolver
+    globals: SimStateGlobals
+    inspect: SimStateInspect
+
 
     def __init__(self, xid, project, partial_init=False, init_ctx=None, options=None, max_calldatasize=None, partial_concrete_storage=False):
         self.xid = xid
@@ -158,7 +178,7 @@ def set_init_ctx(self, init_ctx=None):
             self.ctx["CALLVALUE"] = BVV(init_ctx["CALLVALUE"], 256)
 
     @property
-    def pc(self):
+    def pc(self) -> str:
         return self._pc
 
     @property
@@ -170,7 +190,7 @@ def constraints(self):
         return self.solver.constraints
 
     @pc.setter
-    def pc(self, value):
+    def pc(self, value: str):
         self._pc = value
 
     def set_next_pc(self):

greed/state_plugins/solver.py

@@ -3,11 +3,14 @@
 from greed import options
 from greed.solver.shortcuts import *
 from greed.state_plugins import SimStatePlugin
+from greed.solver.solver import Solver
 
 log = logging.getLogger(__name__)
 
 
 class SimStateSolver(SimStatePlugin):
+    _solver: Solver
+
     def __init__(self, partial_init=False):
         super(SimStateSolver, self).__init__()
 
@@ -41,14 +44,14 @@ def _add_assertions(self, assertions):
         # Adding the constraints to the backend
         self._solver.add_assertions(assertions)
 
-    def push(self):
+    def push(self) -> int:
         self._curr_frame_level += 1
         self._path_constraints[self._curr_frame_level] = set()
         self._memory_constraints[self._curr_frame_level] = set()
         self._solver.push()
         return self._curr_frame_level
 
-    def pop(self):
+    def pop(self) -> int:
         if self._curr_frame_level == 0:
             log.fatal("Cannot pop() level 0 frame")
             return self._curr_frame_level
@@ -184,7 +187,7 @@ def eval_memory_at(self, array, offset, length, raw=False):
         else:
             return f"{int_value:0{bv_unsigned_value(length)*2}x}"
 
-    def copy(self):
+    def copy(self) -> 'SimStateSolver':
         new_solver = SimStateSolver(partial_init=True)
         new_solver._solver = self._solver.copy()