liquidhaskell-0.3.0.0: src/Language/Haskell/Liquid/DiffCheck.hs
-- | This module contains the code for Incremental checking, which finds the
-- part of a target file (the subset of the @[CoreBind]@ that have been
-- modified since it was last checked, as determined by a diff against
-- a saved version of the file.
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE FlexibleInstances #-}
module Language.Haskell.Liquid.DiffCheck (
-- * Changed binders + Unchanged Errors
DiffCheck (..)
-- * Use previously saved info to generate DiffCheck target
, slice
-- * Use target binders to generate DiffCheck target
, thin
-- * Save current information for next time
, saveResult
)
where
import Control.Applicative ((<$>), (<*>))
import Data.Aeson
import qualified Data.Text as T
import Data.Algorithm.Diff
import Data.Monoid (mempty)
import Data.Maybe (listToMaybe, mapMaybe, fromMaybe)
import Data.Hashable
import qualified Data.IntervalMap.FingerTree as IM
import CoreSyn
import Name
import SrcLoc
import Var
import qualified Data.HashSet as S
import qualified Data.HashMap.Strict as M
import qualified Data.List as L
import System.Directory (copyFile, doesFileExist)
import Language.Fixpoint.Types (FixResult (..))
import Language.Fixpoint.Files
import Language.Haskell.Liquid.Types (AnnInfo (..), Error, TError (..), Output (..))
import Language.Haskell.Liquid.GhcInterface
import Language.Haskell.Liquid.GhcMisc
import Text.Parsec.Pos (sourceName, sourceLine, sourceColumn, SourcePos, newPos)
import Text.PrettyPrint.HughesPJ (text, render, Doc)
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as LB
-------------------------------------------------------------------------
-- Data Types -----------------------------------------------------------
-------------------------------------------------------------------------
-- | Main type of value returned for diff-check.
data DiffCheck = DC { newBinds :: [CoreBind]
, oldOutput :: !(Output Doc)
}
data Def = D { start :: Int -- ^ line at which binder definition starts
, end :: Int -- ^ line at which binder definition ends
, binder :: Var -- ^ name of binder
}
deriving (Eq, Ord)
-- | Variable dependencies "call-graph"
type Deps = M.HashMap Var (S.HashSet Var)
-- | Map from saved-line-num ---> current-line-num
type LMap = IM.IntervalMap Int Int
-- | Intervals of line numbers that have been re-checked
type ChkItv = IM.IntervalMap Int ()
instance Show Def where
show (D i j x) = showPpr x ++ " start: " ++ show i ++ " end: " ++ show j
-- | `slice` returns a subset of the @[CoreBind]@ of the input `target`
-- file which correspond to top-level binders whose code has changed
-- and their transitive dependencies.
-------------------------------------------------------------------------
slice :: FilePath -> [CoreBind] -> IO (Maybe DiffCheck)
-------------------------------------------------------------------------
slice target cbs = ifM (doesFileExist saved) (Just <$> dc) (return Nothing)
where
saved = extFileName Saved target
dc = sliceSaved target saved cbs
sliceSaved :: FilePath -> FilePath -> [CoreBind] -> IO DiffCheck
sliceSaved target saved cbs
= do (is, lm) <- lineDiff target saved
res <- loadResult target
return $ sliceSaved' is lm (DC cbs res)
sliceSaved' :: [Int] -> LMap -> DiffCheck -> DiffCheck
sliceSaved' is lm dc = DC cbs' res'
where
cbs' = thin cbs $ diffVars is dfs
res' = adjustOutput lm cm res
cm = checkedItv chDfs
dfs = coreDefs cbs
chDfs = coreDefs cbs'
DC cbs res = dc
-- | @thin@ returns a subset of the @[CoreBind]@ given which correspond
-- to those binders that depend on any of the @Var@s provided.
-------------------------------------------------------------------------
thin :: [CoreBind] -> [Var] -> [CoreBind]
-------------------------------------------------------------------------
thin cbs xs = filterBinds cbs ys
where
ys = dependentVars (coreDeps cbs) $ S.fromList xs
-------------------------------------------------------------------------
filterBinds :: [CoreBind] -> S.HashSet Var -> [CoreBind]
-------------------------------------------------------------------------
filterBinds cbs ys = filter f cbs
where
f (NonRec x _) = x `S.member` ys
f (Rec xes) = any (`S.member` ys) $ fst <$> xes
-------------------------------------------------------------------------
coreDefs :: [CoreBind] -> [Def]
-------------------------------------------------------------------------
coreDefs cbs = L.sort [D l l' x | b <- cbs
, x <- bindersOf b
, isGoodSrcSpan (getSrcSpan x)
, (l, l') <- coreDef b]
coreDef b = meetSpans b eSp vSp
where
eSp = lineSpan b $ catSpans b $ bindSpans b
vSp = lineSpan b $ catSpans b $ getSrcSpan <$> bindersOf b
-- | `meetSpans` cuts off the start-line to be no less than the line at which
-- the binder is defined. Without this, i.e. if we ONLY use the ticks and
-- spans appearing inside the definition of the binder (i.e. just `eSp`)
-- then the generated span can be WAY before the actual definition binder,
-- possibly due to GHC INLINE pragmas or dictionaries OR ...
-- for an example: see the "INCCHECK: Def" generated by
-- liquid -d benchmarks/bytestring-0.9.2.1/Data/ByteString.hs
-- where `spanEnd` is a single line function around 1092 but where
-- the generated span starts mysteriously at 222 where Data.List is imported.
meetSpans _ Nothing _
= []
meetSpans _ (Just (l,l')) Nothing
= [(l, l')]
meetSpans _ (Just (l,l')) (Just (m,_))
= [(max l m, l')]
lineSpan _ (RealSrcSpan sp) = Just (srcSpanStartLine sp, srcSpanEndLine sp)
lineSpan _ _ = Nothing
catSpans b [] = error $ "DIFFCHECK: catSpans: no spans found for " ++ showPpr b
catSpans b xs = foldr combineSrcSpans noSrcSpan [x | x@(RealSrcSpan z) <- xs, bindFile b == srcSpanFile z]
bindFile (NonRec x _) = varFile x
bindFile (Rec xes) = varFile $ fst $ head xes
varFile b = case getSrcSpan b of
RealSrcSpan z -> srcSpanFile z
_ -> error $ "DIFFCHECK: getFile: no file found for: " ++ showPpr b
bindSpans (NonRec x e) = getSrcSpan x : exprSpans e
bindSpans (Rec xes) = map getSrcSpan xs ++ concatMap exprSpans es
where
(xs, es) = unzip xes
exprSpans (Tick t e)
| isJunkSpan sp = exprSpans e
| otherwise = [sp]
where
sp = tickSrcSpan t
exprSpans (Var x) = [getSrcSpan x]
exprSpans (Lam x e) = getSrcSpan x : exprSpans e
exprSpans (App e a) = exprSpans e ++ exprSpans a
exprSpans (Let b e) = bindSpans b ++ exprSpans e
exprSpans (Cast e _) = exprSpans e
exprSpans (Case e x _ cs) = getSrcSpan x : exprSpans e ++ concatMap altSpans cs
exprSpans _ = []
altSpans (_, xs, e) = map getSrcSpan xs ++ exprSpans e
isJunkSpan (RealSrcSpan _) = False
isJunkSpan _ = True
-------------------------------------------------------------------------
coreDeps :: [CoreBind] -> Deps
-------------------------------------------------------------------------
coreDeps = M.fromList . concatMap bindDep
bindDep b = [(x, ys) | x <- bindersOf b]
where
ys = S.fromList $ freeVars S.empty b
-------------------------------------------------------------------------
dependentVars :: Deps -> S.HashSet Var -> S.HashSet Var
-------------------------------------------------------------------------
dependentVars d = {- tracePpr "INCCHECK: tx changed vars" $ -}
go S.empty {- tracePpr "INCCHECK: seed changed vars" -}
where
pre = S.unions . fmap deps . S.toList
deps x = M.lookupDefault S.empty x d
go seen new
| S.null new = seen
| otherwise = let seen' = S.union seen new
new' = pre new `S.difference` seen'
in go seen' new'
-------------------------------------------------------------------------
diffVars :: [Int] -> [Def] -> [Var]
-------------------------------------------------------------------------
diffVars lines defs' = -- tracePpr ("INCCHECK: diffVars lines = " ++ show lines ++ " defs= " ++ show defs) $
go (L.sort lines) defs
where
defs = L.sort defs'
go _ [] = []
go [] _ = []
go (i:is) (d:ds)
| i < start d = go is (d:ds)
| i > end d = go (i:is) ds
| otherwise = binder d : go (i:is) ds
-------------------------------------------------------------------------
-- Diff Interface -------------------------------------------------------
-------------------------------------------------------------------------
-- | `lineDiff new old` compares the contents of `src` with `dst`
-- and returns the lines of `src` that are different.
-------------------------------------------------------------------------
lineDiff :: FilePath -> FilePath -> IO ([Int], LMap)
-------------------------------------------------------------------------
lineDiff new old = lineDiff' <$> getLines new <*> getLines old
where
getLines = fmap lines . readFile
lineDiff' :: [String] -> [String] -> ([Int], LMap)
lineDiff' new old = (ns, lm)
where
ns = diffLines 1 diff
lm = foldr setShift IM.empty $ diffShifts diff
diff = fmap length <$> getGroupedDiff new old
diffLines _ [] = []
diffLines n (Both i _ : d) = diffLines n' d where n' = n + i -- length ls
diffLines n (First i : d) = [n .. (n' - 1)] ++ diffLines n' d where n' = n + i -- length ls
diffLines n (Second _ : d) = diffLines n d
diffShifts :: [Diff Int] -> [(Int, Int, Int)]
diffShifts = go 1 1
where
go old new (Both n _ : d) = (old, old + n - 1, new - old) : go (old + n) (new + n) d
go old new (Second n : d) = go (old + n) new d
go old new (First n : d) = go old (new + n) d
go _ _ [] = []
instance Functor Diff where
fmap f (First x) = First (f x)
fmap f (Second x) = Second (f x)
fmap f (Both x y) = Both (f x) (f y)
-- | @save@ creates an .saved version of the @target@ file, which will be
-- used to find what has changed the /next time/ @target@ is checked.
-------------------------------------------------------------------------
saveResult :: FilePath -> Output Doc -> IO ()
-------------------------------------------------------------------------
saveResult target res
= do copyFile target saveF
B.writeFile errF $ LB.toStrict $ encode res
where
saveF = extFileName Saved target
errF = extFileName Cache target
-------------------------------------------------------------------------
loadResult :: FilePath -> IO (Output Doc)
-------------------------------------------------------------------------
loadResult f = ifM (doesFileExist jsonF) out (return mempty)
where
jsonF = extFileName Cache f
out = (fromMaybe mempty . decode . LB.fromStrict) <$> B.readFile jsonF
-------------------------------------------------------------------------
adjustOutput :: LMap -> ChkItv -> Output Doc -> Output Doc
-------------------------------------------------------------------------
adjustOutput lm cm o = mempty { o_types = adjustTypes lm cm (o_types o) }
{ o_result = adjustResult lm cm (o_result o) }
adjustTypes :: LMap -> ChkItv -> AnnInfo a -> AnnInfo a
adjustTypes lm cm (AI m) = AI $ M.fromList
[(sp', v) | (sp, v) <- M.toList m
, Just sp' <- [adjustSrcSpan lm cm sp]]
adjustResult :: LMap -> ChkItv -> FixResult Error -> FixResult Error
adjustResult lm cm (Unsafe es) = errorsResult Unsafe $ adjustErrors lm cm es
adjustResult lm cm (Crash es z) = errorsResult (`Crash` z) $ adjustErrors lm cm es
adjustResult _ _ r = r
errorsResult _ [] = Safe
errorsResult f es = f es
adjustErrors lm cm = mapMaybe adjustError
where
adjustError (ErrSaved sp msg) = (`ErrSaved` msg) <$> adjustSrcSpan lm cm sp
adjustError e = Just e
-------------------------------------------------------------------------
adjustSrcSpan :: LMap -> ChkItv -> SrcSpan -> Maybe SrcSpan
-------------------------------------------------------------------------
adjustSrcSpan lm cm sp
= do sp' <- adjustSpan lm sp
if isCheckedSpan cm sp'
then Nothing
else Just sp'
isCheckedSpan cm (RealSrcSpan sp) = isCheckedRealSpan cm sp
isCheckedSpan _ _ = False
isCheckedRealSpan cm = not . null . (`IM.search` cm) . srcSpanStartLine
adjustSpan lm (RealSrcSpan rsp) = RealSrcSpan <$> adjustReal lm rsp
adjustSpan _ sp = Just sp
adjustReal lm rsp
| Just δ <- getShift l1 lm = Just $ realSrcSpan f (l1 + δ) c1 (l2 + δ) c2
| otherwise = Nothing
where
(f, l1, c1, l2, c2) = unpackRealSrcSpan rsp
-- | @getShift lm old@ returns @Just δ@ if the line number @old@ shifts by @δ@
-- in the diff and returns @Nothing@ otherwise.
getShift :: Int -> LMap -> Maybe Int
getShift old = fmap snd . listToMaybe . IM.search old
-- | @setShift (lo, hi, δ) lm@ updates the interval map @lm@ appropriately
setShift :: (Int, Int, Int) -> LMap -> LMap
setShift (l1, l2, δ) = IM.insert (IM.Interval l1 l2) δ
checkedItv :: [Def] -> ChkItv
checkedItv chDefs = foldr (`IM.insert` ()) IM.empty is
where
is = [IM.Interval l1 l2 | D l1 l2 _ <- chDefs]
ifM b x y = b >>= \z -> if z then x else y
-------------------------------------------------------------------------
-- | Aeson instances ----------------------------------------------------
-------------------------------------------------------------------------
instance ToJSON SourcePos where
toJSON p = object [ "sourceName" .= f
, "sourceLine" .= l
, "sourceColumn" .= c
]
where
f = sourceName p
l = sourceLine p
c = sourceColumn p
instance FromJSON SourcePos where
parseJSON (Object v) = newPos <$> v .: "sourceName"
<*> v .: "sourceLine"
<*> v .: "sourceColumn"
parseJSON _ = mempty
instance ToJSON (FixResult Error)
instance FromJSON (FixResult Error)
instance ToJSON Doc where
toJSON = String . T.pack . render
instance FromJSON Doc where
parseJSON (String s) = return $ text $ T.unpack s
parseJSON _ = mempty
instance (ToJSON k, ToJSON v) => ToJSON (M.HashMap k v) where
toJSON = toJSON . M.toList
instance (Eq k, Hashable k, FromJSON k, FromJSON v) => FromJSON (M.HashMap k v) where
parseJSON = fmap M.fromList . parseJSON
instance ToJSON a => ToJSON (AnnInfo a)
instance FromJSON a => FromJSON (AnnInfo a)
instance ToJSON (Output Doc)
instance FromJSON (Output Doc)