[refinement] Move symbolic execution code in its own module.

refinement/macaw-refinement.cabal

@@ -68,6 +68,7 @@ library
   other-modules: Data.Macaw.Refinement.FuncBlockUtils
                  Data.Macaw.Refinement.Path
                  Data.Macaw.Refinement.Target
+                 Data.Macaw.Refinement.SymbolicExecution
                  Data.Macaw.Refinement.UnknownTransfer
 
   default-language: Haskell2010

refinement/src/Data/Macaw/Refinement.hs

@@ -25,7 +25,6 @@ import qualified Data.Macaw.Memory as MM
 import qualified Data.Macaw.Symbolic as MS
 import           Data.Macaw.Refinement.Target
 import           Data.Macaw.Refinement.UnknownTransfer
-import           Data.Parameterized.Classes
 
 ----------------------------------------------------------------------
 -- * Discovery Entrypoints

refinement/src/Data/Macaw/Refinement/SymbolicExecution.hs

@@ -0,0 +1,296 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE ImplicitParams #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE TypeOperators #-}
+
+module Data.Macaw.Refinement.SymbolicExecution
+  ( RefinementContext(..)
+  , withDefaultRefinementContext
+  , smtSolveTransfer
+  )
+where
+
+import           Control.Lens
+import           Control.Monad.ST ( RealWorld, stToIO )
+import           Control.Monad.IO.Class ( MonadIO, liftIO )
+import qualified Data.Macaw.BinaryLoader as MBL
+import qualified Data.Macaw.CFG as M
+import qualified Data.Macaw.Discovery as M
+import qualified Data.Macaw.Symbolic as MS
+import qualified Data.Macaw.Symbolic.Memory as MS
+import           Data.Maybe
+import qualified Data.Map as Map
+import qualified Data.Parameterized.Context as Ctx
+import           Data.Parameterized.Nonce
+import           Data.Proxy
+import           GHC.TypeNats
+import qualified Lang.Crucible.Backend as C
+import qualified Lang.Crucible.Backend.Online as C
+import qualified Lang.Crucible.CFG.Core as C
+import qualified Lang.Crucible.FunctionHandle as C
+import qualified Lang.Crucible.LLVM.DataLayout as LLVM
+import qualified Lang.Crucible.LLVM.Intrinsics as LLVM
+import qualified Lang.Crucible.LLVM.MemModel as LLVM
+import qualified Lang.Crucible.Simulator as C
+import qualified Lang.Crucible.Simulator.GlobalState as C
+import qualified System.IO as IO
+import qualified What4.Concrete as W
+import qualified What4.Expr.GroundEval as W
+import qualified What4.Interface as W
+import qualified What4.ProgramLoc as W
+import qualified What4.Protocol.Online as W
+import qualified What4.Protocol.SMTLib2 as W
+import qualified What4.SatResult as W
+import qualified What4.Solver.Z3 as W
+
+data RefinementContext arch t solver fp = RefinementContext
+  { symbolicBackend :: C.OnlineBackend t solver fp
+  , archVals :: MS.ArchVals arch
+  , handleAllocator :: C.HandleAllocator RealWorld
+  , nonceGenerator :: NonceGenerator IO t
+  , extensionImpl :: C.ExtensionImpl (MS.MacawSimulatorState (C.OnlineBackend t solver fp)) (C.OnlineBackend t solver fp) (MS.MacawExt arch)
+  , memVar :: C.GlobalVar LLVM.Mem
+  , mem :: LLVM.MemImpl (C.OnlineBackend t solver fp)
+  , memPtrTable :: MS.MemPtrTable (C.OnlineBackend t solver fp) (M.ArchAddrWidth arch)
+  , globalMappingFn :: MS.GlobalMap (C.OnlineBackend t solver fp) (M.ArchAddrWidth arch)
+  }
+
+withDefaultRefinementContext
+  :: forall arch a bin
+   . (MS.SymArchConstraints arch, 16 <= M.ArchAddrWidth arch)
+  => MBL.LoadedBinary arch bin
+  -> (forall t . RefinementContext arch t (W.Writer W.Z3) (C.Flags C.FloatIEEE) -> IO a)
+  -> IO a
+withDefaultRefinementContext loaded_binary k = do
+  handle_alloc <- C.newHandleAllocator
+  withIONonceGenerator $ \nonce_gen ->
+    C.withZ3OnlineBackend nonce_gen C.NoUnsatFeatures $ \sym ->
+      case MS.archVals (Proxy @arch) of
+        Just arch_vals -> do
+
+          mem_var <- stToIO $ LLVM.mkMemVar handle_alloc
+
+          (mem, mem_ptr_table) <- MS.newGlobalMemory
+            (Proxy @arch)
+            sym
+            LLVM.LittleEndian
+            MS.ConcreteMutable
+            (MBL.memoryImage loaded_binary)
+
+          let ?ptrWidth = W.knownNat
+          (base_ptr, allocated_mem) <- LLVM.doMallocUnbounded
+            sym
+            LLVM.GlobalAlloc
+            LLVM.Mutable
+            "flat memory"
+            mem
+            LLVM.noAlignment
+          let Right mem_name = W.userSymbol "mem"
+          mem_array <- W.freshConstant sym mem_name W.knownRepr
+          initialized_mem <- LLVM.doArrayStoreUnbounded
+            sym
+            allocated_mem
+            base_ptr
+            LLVM.noAlignment
+            mem_array
+
+          let global_mapping_fn = \sym' mem' base off -> do
+                flat_mem_ptr <- LLVM.ptrAdd sym' W.knownNat base_ptr off
+                MS.mapRegionPointers
+                  mem_ptr_table
+                  flat_mem_ptr
+                  sym'
+                  mem'
+                  base
+                  off
+
+          MS.withArchEval arch_vals sym $ \arch_eval_fns -> do
+            let ext_impl = MS.macawExtensions
+                  arch_eval_fns
+                  mem_var
+                  global_mapping_fn
+                  (MS.LookupFunctionHandle $ \_ _ _ -> undefined)
+
+            k $ RefinementContext
+              { symbolicBackend = sym
+              , archVals = arch_vals
+              , handleAllocator = handle_alloc
+              , nonceGenerator = nonce_gen
+              , extensionImpl = ext_impl
+              , memVar = mem_var
+              , mem = initialized_mem
+              , memPtrTable = mem_ptr_table
+              , globalMappingFn = global_mapping_fn
+              }
+        Nothing -> fail $ "unsupported architecture"
+
+smtSolveTransfer
+  :: ( MS.SymArchConstraints arch
+     , 16 <= M.ArchAddrWidth arch
+     , C.IsSymInterface (C.OnlineBackend t solver fp)
+     , W.OnlineSolver t solver
+     , MonadIO m
+     )
+  => RefinementContext arch t solver fp
+  -> M.DiscoveryState arch
+  -> [M.ParsedBlock arch ids]
+  -> m [M.ArchSegmentOff arch]
+smtSolveTransfer RefinementContext{..} discovery_state blocks = do
+  let ?ptrWidth = W.knownNat
+
+  let Right stack_name = W.userSymbol "stack"
+  stack_array <- liftIO $ W.freshConstant symbolicBackend stack_name C.knownRepr
+  stack_size <- liftIO $ W.bvLit symbolicBackend ?ptrWidth $ 2 * 1024 * 1024
+  (stack_base_ptr, mem1) <- liftIO $ LLVM.doMalloc
+    symbolicBackend
+    LLVM.StackAlloc
+    LLVM.Mutable
+    "stack_alloc"
+    mem
+    stack_size
+    LLVM.noAlignment
+
+  mem2 <- liftIO $ LLVM.doArrayStore
+    symbolicBackend
+    mem1
+    stack_base_ptr
+    LLVM.noAlignment
+    stack_array
+    stack_size
+  init_sp_val <- liftIO $
+    LLVM.ptrAdd symbolicBackend C.knownRepr stack_base_ptr stack_size
+
+  let entry_addr = M.segoffAddr $ M.pblockAddr $ head blocks
+  ip_base <- liftIO $ W.natLit symbolicBackend $
+    fromIntegral $ M.addrBase entry_addr
+  ip_off <- liftIO $ W.bvLit symbolicBackend W.knownNat $
+    M.memWordToUnsigned $ M.addrOffset entry_addr
+  entry_ip_val <- liftIO $ fromJust <$>
+    globalMappingFn symbolicBackend mem2 ip_base ip_off
+
+  init_regs <- initRegs archVals symbolicBackend entry_ip_val init_sp_val
+  some_cfg <- liftIO $ stToIO $ MS.mkBlockPathCFG
+    (MS.archFunctions archVals)
+    handleAllocator
+    Map.empty
+    (W.BinaryPos "" . maybe 0 fromIntegral . M.segoffAsAbsoluteAddr)
+    blocks
+  case some_cfg of
+    C.SomeCFG cfg -> do
+      let sim_context = C.initSimContext
+            symbolicBackend
+            LLVM.llvmIntrinsicTypes
+            handleAllocator
+            IO.stderr
+            C.emptyHandleMap
+            extensionImpl
+            MS.MacawSimulatorState
+      let global_state = C.insertGlobal memVar mem2 C.emptyGlobals
+      let simulation = C.regValue <$> C.callCFG cfg init_regs
+      let handle_return_type = C.handleReturnType $ C.cfgHandle cfg
+      let initial_state = C.InitialState
+            sim_context
+            global_state
+            C.defaultAbortHandler
+            (C.runOverrideSim handle_return_type simulation)
+      let execution_features = []
+      exec_res <- liftIO $ C.executeCrucible execution_features initial_state
+      case exec_res of
+        C.FinishedResult _ res -> do
+          let res_regs = res ^. C.partialValue . C.gpValue
+          case C.regValue $ (MS.lookupReg archVals) res_regs M.ip_reg of
+            LLVM.LLVMPointer res_ip_base res_ip_off -> do
+              ip_off_ground_vals <- genModels symbolicBackend res_ip_off 10
+
+              ip_base_mem_word <-
+                case MS.lookupAllocationBase memPtrTable res_ip_base of
+                  Just alloc -> return $ MS.allocationBase alloc
+                  Nothing
+                    | Just (W.ConcreteNat 0) <- W.asConcrete res_ip_base ->
+                      return $ M.memWord 0
+                    | otherwise ->
+                      fail $ "unexpected ip base: "
+                        ++ show (W.printSymExpr res_ip_base)
+
+              return $ mapMaybe
+                (\off -> M.resolveAbsoluteAddr (M.memory discovery_state) $
+                  M.memWord $ fromIntegral $
+                    M.memWordToUnsigned ip_base_mem_word + off)
+                ip_off_ground_vals
+        C.AbortedResult _ aborted_res -> case aborted_res of
+          C.AbortedExec reason _ ->
+            fail $ "simulation abort: " ++ show (C.ppAbortExecReason reason)
+          C.AbortedExit code ->
+            fail $ "simulation halt: " ++ show code
+          C.AbortedBranch{} ->
+            fail $ "simulation abort branch"
+        C.TimeoutResult{} -> fail $ "simulation timeout"
+
+initRegs
+  :: forall arch sym m
+    . (MS.SymArchConstraints arch, C.IsSymInterface sym, MonadIO m)
+  => MS.ArchVals arch
+  -> sym
+  -> C.RegValue sym (LLVM.LLVMPointerType (M.ArchAddrWidth arch))
+  -> C.RegValue sym (LLVM.LLVMPointerType (M.ArchAddrWidth arch))
+  -> m (C.RegMap sym (MS.MacawFunctionArgs arch))
+initRegs arch_vals sym ip_val sp_val = do
+  let reg_types = MS.crucArchRegTypes $ MS.archFunctions $ arch_vals
+  reg_vals <- Ctx.traverseWithIndex (freshSymVar sym "reg") reg_types
+  let reg_struct = C.RegEntry (C.StructRepr reg_types) reg_vals
+  return $ C.RegMap $ Ctx.singleton $
+    (MS.updateReg arch_vals)
+      ((MS.updateReg arch_vals) reg_struct M.ip_reg ip_val)
+      M.sp_reg
+      sp_val
+
+freshSymVar
+  :: (C.IsSymInterface sym, MonadIO m)
+  => sym
+  -> String
+  -> Ctx.Index ctx tp
+  -> C.TypeRepr tp
+  -> m (C.RegValue' sym tp)
+freshSymVar sym prefix idx tp =
+  liftIO $ C.RV <$> case W.userSymbol $ prefix ++ show (Ctx.indexVal idx) of
+    Right symbol -> case tp of
+      LLVM.LLVMPointerRepr w ->
+        LLVM.llvmPointer_bv sym
+          =<< W.freshConstant sym symbol (W.BaseBVRepr w)
+      C.BoolRepr ->
+        W.freshConstant sym symbol W.BaseBoolRepr
+      _ -> fail $ "unsupported variable type: " ++ show tp
+    Left err -> fail $ show err
+
+genModels
+  :: ( C.IsSymInterface (C.OnlineBackend t solver fp)
+     , W.OnlineSolver t solver
+     , KnownNat w
+     , 1 <= w
+     , MonadIO m
+     )
+  => C.OnlineBackend t solver fp
+  -> W.SymBV (C.OnlineBackend t solver fp) w
+  -> Int
+  -> m [W.GroundValue (W.BaseBVType w)]
+genModels sym expr count
+  | count > 0 = liftIO $ do
+    solver_proc <- C.getSolverProcess sym
+    W.checkAndGetModel solver_proc "gen next model" >>= \case
+      W.Sat (W.GroundEvalFn{..}) -> do
+        next_ground_val <- groundEval expr
+        next_bv_val <- W.bvLit sym W.knownNat next_ground_val
+        not_current_ground_val <- W.bvNe sym expr next_bv_val
+        C.addAssumption sym $ C.LabeledPred not_current_ground_val $
+          C.AssumptionReason W.initializationLoc "assume different model"
+        more_ground_vals <- genModels sym expr (count - 1)
+        return $ next_ground_val : more_ground_vals
+      _ -> return []
+  | otherwise = return []

refinement/src/Data/Macaw/Refinement/UnknownTransfer.hs

@@ -1,13 +1,8 @@
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GADTs #-}
-{-# LANGUAGE ImplicitParams #-}
 {-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeOperators #-}
 -- | This module uses symbolic evaluation to refine the discovered CFG
 -- and resolve unknown transfer classify failures.
@@ -117,8 +112,7 @@ where
 import           GHC.TypeLits
 
 import Control.Lens
-import Control.Monad ( foldM, forM )
-import Control.Monad.ST ( RealWorld, stToIO )
+import Control.Monad ( forM )
 import Control.Monad.IO.Class ( MonadIO, liftIO )
 import qualified Data.Macaw.BinaryLoader as MBL
 import qualified Data.Macaw.CFG as MC
@@ -142,32 +136,13 @@ import Data.Macaw.Refinement.FuncBlockUtils ( BlockIdentifier(..), blockID
 import Data.Macaw.Refinement.Path ( FuncBlockPath(..)
                                   , buildFuncPath, pathDepth, pathForwardTrails
                                   , pathTo, takePath )
+import Data.Macaw.Refinement.SymbolicExecution ( withDefaultRefinementContext
+                                               , smtSolveTransfer
+                                               )
 import qualified Data.Macaw.Symbolic as MS
-import qualified Data.Macaw.Symbolic.Memory as MSM
 import Data.Maybe
 import qualified Data.Map as Map
-import qualified Data.Parameterized.Context as Ctx
-import Data.Parameterized.Nonce
 import Data.Parameterized.Some
-import Data.Proxy ( Proxy(..) )
-import qualified Lang.Crucible.Backend as C
-import qualified Lang.Crucible.Backend.Online as C
-import qualified Lang.Crucible.CFG.Core as C
-import qualified Lang.Crucible.FunctionHandle as C
-import qualified Lang.Crucible.LLVM.DataLayout as LLVM
-import qualified Lang.Crucible.LLVM.Intrinsics as LLVM
-import qualified Lang.Crucible.LLVM.MemModel as LLVM
-import qualified Lang.Crucible.Simulator as C
-import qualified Lang.Crucible.Simulator.GlobalState as C
-import           System.IO as IO
-import qualified What4.Concrete as W
-import qualified What4.Expr.GroundEval as W
-import qualified What4.Interface as W
-import qualified What4.ProgramLoc as W
-import qualified What4.Protocol.Online as W
-import qualified What4.Protocol.SMTLib2 as W
-import qualified What4.SatResult as W
-import qualified What4.Solver.Z3 as W
 
 import           Text.PrettyPrint.ANSI.Leijen as PP hiding ((<$>))
 
@@ -431,249 +406,3 @@ solve bin (Equation inpDS paths) = do
 --isBetterSolution :: Solution arch -> Solution arch -> Bool
 -- isBetterSolution :: [ArchSegmentOff arch] -> [ArchSegmentOff arch] -> Bool
 -- isBetterSolution = (<)
-
-----------------------------------------------------------------------
--- * Symbolic execution
-
-
-data RefinementContext arch t solver fp = RefinementContext
-  { symbolicBackend :: C.OnlineBackend t solver fp
-  , archVals :: MS.ArchVals arch
-  , handleAllocator :: C.HandleAllocator RealWorld
-  , nonceGenerator :: NonceGenerator IO t
-  , extensionImpl :: C.ExtensionImpl (MS.MacawSimulatorState (C.OnlineBackend t solver fp)) (C.OnlineBackend t solver fp) (MS.MacawExt arch)
-  , memVar :: C.GlobalVar LLVM.Mem
-  , mem :: LLVM.MemImpl (C.OnlineBackend t solver fp)
-  , memPtrTable :: MSM.MemPtrTable (C.OnlineBackend t solver fp) (MC.ArchAddrWidth arch)
-  , globalMappingFn :: MS.GlobalMap (C.OnlineBackend t solver fp) (MC.ArchAddrWidth arch)
-  }
-
-withDefaultRefinementContext
-  :: forall arch a bin
-   . (MS.SymArchConstraints arch, 16 <= MC.ArchAddrWidth arch)
-  => MBL.LoadedBinary arch bin
-  -> (forall t . RefinementContext arch t (W.Writer W.Z3) (C.Flags C.FloatIEEE) -> IO a)
-  -> IO a
-withDefaultRefinementContext loaded_binary k = do
-  handle_alloc <- C.newHandleAllocator
-  withIONonceGenerator $ \nonce_gen ->
-    C.withZ3OnlineBackend nonce_gen C.NoUnsatFeatures $ \sym ->
-      case MS.archVals (Proxy @arch) of
-        Just arch_vals -> do
-
-          mem_var <- stToIO $ LLVM.mkMemVar handle_alloc
-
-          (mem, mem_ptr_table) <- MSM.newGlobalMemory
-            (Proxy @arch)
-            sym
-            LLVM.LittleEndian
-            MSM.ConcreteMutable
-            (MBL.memoryImage loaded_binary)
-
-          let ?ptrWidth = W.knownNat
-          (base_ptr, allocated_mem) <- LLVM.doMallocUnbounded
-            sym
-            LLVM.GlobalAlloc
-            LLVM.Mutable
-            "flat memory"
-            mem
-            LLVM.noAlignment
-          let Right mem_name = W.userSymbol "mem"
-          mem_array <- W.freshConstant sym mem_name W.knownRepr
-          initialized_mem <- LLVM.doArrayStoreUnbounded
-            sym
-            allocated_mem
-            base_ptr
-            LLVM.noAlignment
-            mem_array
-
-          let global_mapping_fn = \sym' mem' base off -> do
-                flat_mem_ptr <- LLVM.ptrAdd sym' W.knownNat base_ptr off
-                MSM.mapRegionPointers
-                  mem_ptr_table
-                  flat_mem_ptr
-                  sym'
-                  mem'
-                  base
-                  off
-
-          MS.withArchEval arch_vals sym $ \arch_eval_fns -> do
-            let ext_impl = MS.macawExtensions
-                  arch_eval_fns
-                  mem_var
-                  global_mapping_fn
-                  (MS.LookupFunctionHandle $ \_ _ _ -> undefined)
-
-            k $ RefinementContext
-              { symbolicBackend = sym
-              , archVals = arch_vals
-              , handleAllocator = handle_alloc
-              , nonceGenerator = nonce_gen
-              , extensionImpl = ext_impl
-              , memVar = mem_var
-              , mem = initialized_mem
-              , memPtrTable = mem_ptr_table
-              , globalMappingFn = global_mapping_fn
-              }
-        Nothing -> fail $ "unsupported architecture"
-
-freshSymVar
-  :: (C.IsSymInterface sym, MonadIO m)
-  => sym
-  -> String
-  -> Ctx.Index ctx tp
-  -> C.TypeRepr tp
-  -> m (C.RegValue' sym tp)
-freshSymVar sym prefix idx tp =
-  liftIO $ C.RV <$> case W.userSymbol $ prefix ++ show (Ctx.indexVal idx) of
-    Right symbol -> case tp of
-      LLVM.LLVMPointerRepr w ->
-        LLVM.llvmPointer_bv sym
-          =<< W.freshConstant sym symbol (W.BaseBVRepr w)
-      C.BoolRepr ->
-        W.freshConstant sym symbol W.BaseBoolRepr
-      _ -> fail $ "unsupported variable type: " ++ show tp
-    Left err -> fail $ show err
-
-initRegs
-  :: forall arch sym m
-   . (MS.SymArchConstraints arch, C.IsSymInterface sym, MonadIO m)
-  => MS.ArchVals arch
-  -> sym
-  -> C.RegValue sym (LLVM.LLVMPointerType (MC.ArchAddrWidth arch))
-  -> C.RegValue sym (LLVM.LLVMPointerType (MC.ArchAddrWidth arch))
-  -> m (C.RegMap sym (MS.MacawFunctionArgs arch))
-initRegs arch_vals sym ip_val sp_val = do
-  let reg_types = MS.crucArchRegTypes $ MS.archFunctions $ arch_vals
-  reg_vals <- Ctx.traverseWithIndex (freshSymVar sym "reg") reg_types
-  let reg_struct = C.RegEntry (C.StructRepr reg_types) reg_vals
-  return $ C.RegMap $ Ctx.singleton $
-    (MS.updateReg arch_vals)
-      ((MS.updateReg arch_vals) reg_struct MC.ip_reg ip_val)
-      MC.sp_reg
-      sp_val
-
-smtSolveTransfer
-  :: ( MS.SymArchConstraints arch
-     , 16 <= MC.ArchAddrWidth arch
-     , C.IsSymInterface (C.OnlineBackend t solver fp)
-     , W.OnlineSolver t solver
-     , MonadIO m
-     )
-  => RefinementContext arch t solver fp
-  -> DiscoveryState arch
-  -> [ParsedBlock arch ids]
-  -> m [ArchSegmentOff arch]
-smtSolveTransfer RefinementContext{..} discovery_state blocks = do
-  let ?ptrWidth = W.knownNat
-
-  let Right stack_name = W.userSymbol "stack"
-  stack_array <- liftIO $ W.freshConstant symbolicBackend stack_name C.knownRepr
-  stack_size <- liftIO $ W.bvLit symbolicBackend ?ptrWidth $ 2 * 1024 * 1024
-  (stack_base_ptr, mem1) <- liftIO $ LLVM.doMalloc
-    symbolicBackend
-    LLVM.StackAlloc
-    LLVM.Mutable
-    "stack_alloc"
-    mem
-    stack_size
-    LLVM.noAlignment
-
-  mem2 <- liftIO $ LLVM.doArrayStore
-    symbolicBackend
-    mem1
-    stack_base_ptr
-    LLVM.noAlignment
-    stack_array
-    stack_size
-  init_sp_val <- liftIO $ LLVM.ptrAdd symbolicBackend C.knownRepr stack_base_ptr stack_size
-
-  let entry_addr = MC.segoffAddr $ pblockAddr $ head blocks
-  ip_base <- liftIO $ W.natLit symbolicBackend $
-    fromIntegral $ MC.addrBase entry_addr
-  ip_off <- liftIO $ W.bvLit symbolicBackend W.knownNat $
-    MC.memWordToUnsigned $ MC.addrOffset entry_addr
-  entry_ip_val <- liftIO $ fromJust <$>
-    globalMappingFn symbolicBackend mem2 ip_base ip_off
-
-  init_regs <- initRegs archVals symbolicBackend entry_ip_val init_sp_val
-  some_cfg <- liftIO $ stToIO $ MS.mkBlockPathCFG
-    (MS.archFunctions archVals)
-    handleAllocator
-    Map.empty
-    (W.BinaryPos "" . maybe 0 fromIntegral . MC.segoffAsAbsoluteAddr)
-    blocks
-  case some_cfg of
-    C.SomeCFG cfg -> do
-      let sim_context = C.initSimContext
-            symbolicBackend
-            LLVM.llvmIntrinsicTypes
-            handleAllocator
-            IO.stderr
-            C.emptyHandleMap
-            extensionImpl
-            MS.MacawSimulatorState
-      let global_state = C.insertGlobal memVar mem2 C.emptyGlobals
-      let simulation = C.regValue <$> C.callCFG cfg init_regs
-      let handle_return_type = C.handleReturnType $ C.cfgHandle cfg
-      let initial_state = C.InitialState
-            sim_context
-            global_state
-            C.defaultAbortHandler
-            (C.runOverrideSim handle_return_type simulation)
-      let execution_features = []
-      exec_res <- liftIO $ C.executeCrucible execution_features initial_state
-      case exec_res of
-        C.FinishedResult _ res -> do
-          let res_regs = res ^. C.partialValue . C.gpValue
-          case C.regValue $ (MS.lookupReg archVals) res_regs MC.ip_reg of
-            LLVM.LLVMPointer res_ip_base res_ip_off -> do
-              ip_off_ground_vals <- genModels symbolicBackend res_ip_off 10
-
-              ip_base_mem_word <- case MSM.lookupAllocationBase memPtrTable res_ip_base of
-                Just alloc -> return $ MSM.allocationBase alloc
-                Nothing
-                  | Just (W.ConcreteNat 0) <- W.asConcrete res_ip_base ->
-                    return $ MC.memWord 0
-                  | otherwise ->
-                    fail $ "unexpected ip base: " ++ show (W.printSymExpr res_ip_base)
-
-              return $ mapMaybe
-                (\off -> MC.resolveAbsoluteAddr (memory discovery_state) $
-                  MC.memWord $ fromIntegral $
-                    MC.memWordToUnsigned ip_base_mem_word + off)
-                ip_off_ground_vals
-        C.AbortedResult _ aborted_res -> case aborted_res of
-          C.AbortedExec reason _ ->
-            fail $ "simulation abort: " ++ show (C.ppAbortExecReason reason)
-          C.AbortedExit code ->
-            fail $ "simulation halt: " ++ show code
-          C.AbortedBranch{} ->
-            fail $ "simulation abort branch"
-        C.TimeoutResult{} -> fail $ "simulation timeout"
-
-genModels
-  :: ( C.IsSymInterface (C.OnlineBackend t solver fp)
-     , W.OnlineSolver t solver
-     , KnownNat w
-     , 1 <= w
-     , MonadIO m
-     )
-  => C.OnlineBackend t solver fp
-  -> W.SymBV (C.OnlineBackend t solver fp) w
-  -> Int
-  -> m [W.GroundValue (W.BaseBVType w)]
-genModels sym expr count
-  | count > 0 = liftIO $ do
-    solver_proc <- C.getSolverProcess sym
-    W.checkAndGetModel solver_proc "gen next model" >>= \case
-      W.Sat (W.GroundEvalFn{..}) -> do
-        next_ground_val <- groundEval expr
-        next_bv_val <- W.bvLit sym W.knownNat next_ground_val
-        not_current_ground_val <- W.bvNe sym expr next_bv_val
-        C.addAssumption sym $ C.LabeledPred not_current_ground_val $
-          C.AssumptionReason W.initializationLoc "assume different model"
-        more_ground_vals <- genModels sym expr (count - 1)
-        return $ next_ground_val : more_ground_vals
-      _ -> return []
-  | otherwise = return []