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Optimize genDelay and genValue
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arcz committed Jan 2, 2023
1 parent f99462a commit 29a046f
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Showing 4 changed files with 31 additions and 28 deletions.
24 changes: 12 additions & 12 deletions lib/Echidna/ABI.hs
Original file line number Diff line number Diff line change
Expand Up @@ -19,10 +19,11 @@ import Data.Hashable (Hashable(..))
import Data.HashMap.Strict (HashMap)
import Data.HashMap.Strict qualified as M
import Data.HashSet (HashSet, fromList, union)
import Data.HashSet qualified as H
import Data.Set (Set)
import Data.Set qualified as Set
import Data.List (intercalate)
import Data.List.NonEmpty qualified as NE
import Data.Maybe (fromMaybe, catMaybes)
import Data.Maybe (fromMaybe, catMaybes, mapMaybe)
import Data.Text (Text)
import Data.Text qualified as T
import Data.Text.Encoding (encodeUtf8)
Expand Down Expand Up @@ -108,28 +109,20 @@ data GenDict = GenDict { _pSynthA :: Float
-- ^ Default seed to use if one is not provided in EConfig
, _rTypes :: Text -> Maybe AbiType
-- ^ Return types of any methods we scrape return values from
, _dictValues :: Set W256
}

makeLenses 'GenDict

hashMapBy :: (Hashable k, Hashable a, Eq k, Ord a) => (a -> k) -> [a] -> HashMap k (HashSet a)
hashMapBy f = M.fromListWith union . fmap (\v -> (f v, fromList [v]))

gaddConstants :: [AbiValue] -> GenDict -> GenDict
gaddConstants l = constants <>~ hashMapBy abiValueType l

gaddCalls :: [SolCall] -> GenDict -> GenDict
gaddCalls c = wholeCalls <>~ hashMapBy (fmap $ fmap abiValueType) c

defaultDict :: GenDict
defaultDict = mkGenDict 0 [] [] 0 (const Nothing)

dictValues :: GenDict -> [W256]
dictValues g = catMaybes $ concatMap (\(_,h) -> map fromValue $ H.toList h) $ M.toList $ g ^. constants
where fromValue (AbiUInt _ n) = Just (fromIntegral n)
fromValue (AbiInt _ n) = Just (fromIntegral n)
fromValue _ = Nothing

deriving anyclass instance Hashable AbiType
deriving anyclass instance Hashable AbiValue
deriving anyclass instance Hashable Addr
Expand All @@ -143,7 +136,14 @@ mkGenDict :: Float -- ^ Percentage of time to mutate instead of synthesize.
-> (Text -> Maybe AbiType)
-- ^ A return value typing rule
-> GenDict
mkGenDict p vs cs = GenDict p (hashMapBy abiValueType vs) (hashMapBy (fmap $ fmap abiValueType) cs)
mkGenDict p vs cs s tr =
GenDict p (hashMapBy abiValueType vs) (hashMapBy (fmap $ fmap abiValueType) cs) s tr (mkDictValues vs)

mkDictValues :: [AbiValue] -> Set W256
mkDictValues vs = Set.fromList $ mapMaybe fromValue vs
where fromValue (AbiUInt _ n) = Just (fromIntegral n)
fromValue (AbiInt _ n) = Just (fromIntegral n)
fromValue _ = Nothing

-- Generation (synthesis)

Expand Down
1 change: 1 addition & 0 deletions lib/Echidna/Campaign.hs
Original file line number Diff line number Diff line change
Expand Up @@ -253,6 +253,7 @@ callseq ic v w ql = do
additions = H.unionWith S.union diffs results
-- append to the constants dictionary
modifying (hasLens . genDict . constants) . H.unionWith S.union $ additions
modifying (hasLens . genDict . dictValues) . DS.union $ mkDictValues $ S.toList $ S.unions $ H.elems additions
where
-- Given a list of transactions and a return typing rule, this checks whether we know the return
-- type for each function called, and if we do, tries to parse the return value as a value of that
Expand Down
28 changes: 12 additions & 16 deletions lib/Echidna/Transaction.hs
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@ import Data.Has (Has(..))
import Data.HashMap.Strict qualified as M
import Data.Map (Map, toList)
import Data.Maybe (mapMaybe)
import Data.Set (Set)
import Data.Vector qualified as V
import EVM hiding (value)
import EVM.ABI (abiValueType)
Expand Down Expand Up @@ -52,7 +53,7 @@ genTxM memo m = do
World ss hmm lmm ps _ <- view hasLens
genDict <- use hasLens
mm <- getSignatures hmm lmm
let ns = dictValues genDict
let ns = _dictValues genDict
s' <- rElem ss
r' <- rElem $ NE.fromList (mapMaybe (toContractA mm) (toList m))
c' <- genInteractionsM genDict (snd r')
Expand All @@ -66,26 +67,21 @@ genTxM memo m = do
let metadata = lookupBytecodeMetadata memo bc
(addr,) <$> M.lookup metadata mm

genDelay :: MonadRandom m => W256 -> [W256] -> m W256
genDelay :: MonadRandom m => W256 -> Set W256 -> m W256
genDelay mv ds = do
let ds' = (`mod` (mv + 1)) <$> ds
x <- rElem (0 NE.:| ds')
y <- randValue
fromIntegral <$> oftenUsually x (fromIntegral y)
where randValue = getRandomR (1 :: Integer, fromIntegral mv)
join $ oftenUsually fromDict randValue
where randValue = fromIntegral <$> getRandomR (1 :: Integer, fromIntegral mv)
fromDict = (`mod` (mv + 1)) <$> rElem' ds

genValue :: MonadRandom m => W256 -> [W256] -> [FunctionHash] -> SolCall -> m W256
genValue :: MonadRandom m => W256 -> Set W256 -> [FunctionHash] -> SolCall -> m W256
genValue mv ds ps sc =
if sig `elem` ps then do
let ds' = (`mod` (mv + 1)) <$> ds
x <- rElem (0 NE.:| ds')
y <- randValue
fromIntegral <$> oftenUsually x (fromIntegral y)
if sig `elem` ps then
join $ oftenUsually fromDict randValue
else do
g <- usuallyVeryRarely (pure 0) randValue -- once in a while, this will generate value in a non-payable function
fromIntegral <$> g
where randValue = getRandomR (0 :: Integer, fromIntegral mv)
join $ usuallyVeryRarely (pure 0) randValue -- once in a while, this will generate value in a non-payable function
where randValue = fromIntegral <$> getRandomR (0 :: Integer, fromIntegral mv)
sig = (hashSig . encodeSig . signatureCall) sc
fromDict = (`mod` (mv + 1)) <$> rElem' ds

-- | Check if a 'Transaction' is as \"small\" (simple) as possible (using ad-hoc heuristics).
canShrinkTx :: Tx -> Bool
Expand Down
6 changes: 6 additions & 0 deletions lib/Echidna/Types/Random.hs
Original file line number Diff line number Diff line change
Expand Up @@ -3,13 +3,19 @@ module Echidna.Types.Random where
import Prelude hiding ((!!))
import Control.Monad.Random.Strict (MonadRandom, getRandomR, weighted)
import Data.List.NonEmpty ((!!), NonEmpty(..))
import Data.Set (Set)
import Data.Set qualified as S

type Seed = Int

-- | Get a random element of a non-empty list.
rElem :: MonadRandom m => NonEmpty a -> m a
rElem l = (l !!) <$> getRandomR (0, length l - 1)

-- | Get a random element of a Set
rElem' :: MonadRandom m => Set a -> m a
rElem' v = (`S.elemAt` v) <$> getRandomR (0, length v - 1)

oftenUsually :: MonadRandom m => a -> a -> m a
oftenUsually u r = weighted [(u, 10), (r, 1)]

Expand Down

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