Address review comments

lib/Echidna/Exec.hs

@@ -7,7 +7,7 @@ module Echidna.Exec where
 import Optics.Core
 import Optics.State.Operators
 
-import Control.Monad (when, forM_)
+import Control.Monad (when)
 import Control.Monad.Catch (MonadThrow(..))
 import Control.Monad.State.Strict (MonadState(get, put), execState, runStateT, MonadIO(liftIO), gets, modify', execStateT)
 import Control.Monad.Reader (MonadReader, ask, asks)
@@ -287,23 +287,20 @@ execTxWithCov tx = do
  addCoverage !vm = do
  let (pc, opIx, depth) = currentCovLoc vm
  contract = currentContract vm
+ contractSize = BS.length . forceBuf . fromJust . view bytecode $ contract
 
  maybeCovVec <- lookupUsingCodehashOrInsert env.codehashMap contract env.dapp env.coverageRef $ do
- let size = BS.length . forceBuf . fromJust . view bytecode $ contract
- if size == 0 then pure Nothing else do
+ if contractSize == 0 then pure Nothing else do
  -- IO for making a new vec
- vec <- VMut.new size
  -- We use -1 for opIx to indicate that the location was not covered
- forM_ [0..size-1] $ \i -> VMut.write vec i (-1, 0, 0)
+ vec <- VMut.replicate contractSize (-1, 0, 0)
  pure $ Just vec
 
  statsRef <- getTLS env.statsRef
  maybeStatsVec <- lookupUsingCodehashOrInsert env.codehashMap contract env.dapp statsRef $ do
- let size = BS.length . forceBuf . fromJust . view bytecode $ contract
- if size == 0 then pure Nothing else do
+ if contractSize == 0 then pure Nothing else do
  -- IO for making a new vec
- vec <- VMut.new size
- forM_ [0..size-1] $ \i -> VMut.write vec i (0, 0)
+ vec <- VMut.replicate contractSize (0, 0)
  pure $ Just vec
 
  case maybeCovVec of
@@ -320,7 +317,8 @@ execTxWithCov tx = do
  (_, depths, results) | depth < 64 && not (depths `testBit` depth) -> do
  VMut.write vec pc (opIx, depths `setBit` depth, results `setBit` fromEnum Stop)
  writeIORef covContextRef (True, Just (vec, pc))
- _ -> modifyIORef' covContextRef $ \(new, _) -> (new, Just (vec, pc))
+ _ ->
+ modifyIORef' covContextRef $ \(new, _) -> (new, Just (vec, pc))
 
  -- | Get the VM's current execution location
  currentCovLoc vm = (vm.state.pc, fromMaybe 0 $ vmOpIx vm, length vm.frames)

lib/Echidna/Output/Source.hs

@@ -9,7 +9,7 @@ import Data.ByteString qualified as BS
 import Data.Foldable
 import Data.IORef (readIORef, IORef)
 import Data.List (nub, sort)
-import Data.Maybe (fromMaybe, mapMaybe, isJust, fromJust)
+import Data.Maybe (fromMaybe, mapMaybe)
 import Data.Map (Map)
 import Data.Map qualified as Map
 import Data.Sequence qualified as Seq
@@ -42,15 +42,15 @@ zipSumStats v1 v2 = do
  vec2 <- v2
  return [(exec1 + exec2, revert1 + revert2) | (exec1, revert1) <- vec1 | (exec2, revert2) <- vec2]
 
-mvToList :: (VU.Unbox a) => VU.IOVector a -> IO [a]
-mvToList = fmap U.toList . U.freeze
-
 combineStats :: TLS (IORef StatsMap) -> IO StatsMapV
 combineStats statsRef = do
  threadStats' <- allTLS statsRef
  threadStats <- mapM readIORef threadStats' :: IO [StatsMap]
- statsLists <- pure $ map (\(m :: StatsMap) -> Map.map (\(x :: VU.IOVector StatsInfo) -> mvToList x) m) threadStats :: IO [Map EVM.Types.W256 (IO [StatsInfo])]
+ let statsLists = map (Map.map mvToList) threadStats :: [Map EVM.Types.W256 (IO [StatsInfo])]
  traverse (U.fromList <$>) $ Map.unionsWith zipSumStats statsLists
+ where
+ mvToList :: (VU.Unbox a) => VU.IOVector a -> IO [a]
+ mvToList = fmap U.toList . U.freeze
 
 saveCoverages
  :: Env
@@ -199,8 +199,7 @@ srcMapCov sc covMap statMap contracts = do
  updateLine (Just (r, q)) = Just ((<> unpackTxResults txResults) r, max q execQty)
  updateLine Nothing = Just (unpackTxResults txResults, execQty)
  fileStats = Map.lookup c.runtimeCodehash statMap
- idxStats | isJust fileStats = fromJust fileStats U.! opIx
- | otherwise = (0, 0)
+ idxStats = maybe (0, 0) (U.! opIx) fileStats
  execQty = fst idxStats
  Nothing -> acc
  Nothing -> acc

lib/Echidna/Types/Coverage.hs

@@ -20,10 +20,13 @@ type CoverageMap = Map W256 (IOVector CoverageInfo)
 
 -- | Map with the statistic information needed for source code printing.
 -- Indexed by contracts' compile-time codehash; see `CodehashMap`.
+-- Used during runtime data collection
 type StatsMap = Map W256 (IOVector StatsInfo)
 
 -- | Map with the statistic information needed for source code printing.
 -- Indexed by contracts' compile-time codehash; see `CodehashMap`.
+-- Used during statistics summarization (combining multiple `StatsMap`)
+-- and coverage report generation.
 type StatsMapV = Map W256 (Vector StatsInfo)
 
 -- | Basic coverage information