{- |

Module : $Header$

Description : static analysis of CASL specification libraries

Copyright : (c) Till Mossakowski, Uni Bremen 2002-2006

License : similar to LGPL, see HetCATS/LICENSE.txt or LIZENZ.txt

Maintainer : till@informatik.uni-bremen.de

Stability : provisional

Portability : non-portable(Logic)

Static analysis of CASL specification libraries

Follows the verification semantics sketched in Chap. IV:6

of the CASL Reference Manual.

-}

module Static.AnalysisLibrary

( anaLib

, anaLibExt

, ana_LIB_DEFN

) where

import Proofs.Automatic

import Logic.Logic

import Logic.Coerce

import Logic.Grothendieck

import Data.Graph.Inductive.Graph

import Syntax.AS_Structured

import Syntax.AS_Library

import Static.GTheory

import Static.DevGraph

import Static.AnalysisStructured

import Static.AnalysisArchitecture

import Comorphisms.LogicGraph

import Common.AS_Annotation hiding (isAxiom, isDef)

import Common.GlobalAnnotations

import Common.ConvertGlobalAnnos

import Common.AnalyseAnnos

import Common.Result

import Common.ResultT

import Common.Keywords

import Common.Id

import Common.DocUtils

import qualified Data.Map as Map

import Driver.Options

import Driver.ReadFn

import Driver.WriteFn

import Data.List

import Control.Monad

import Control.Monad.Trans

import System.Directory

import System.Time

-- | lookup an env or read and analyze a file

anaLib :: HetcatsOpts -> FilePath -> IO (Maybe (LIB_NAME, LibEnv))

anaLib opts fname = do

fname' <- existsAnSource opts {intype = GuessIn} $ rmSuffix fname

case fname' of

Nothing -> anaLibExt opts fname emptyLibEnv

Just file ->

if isSuffixOf prfSuffix file then do

putIfVerbose opts 0 $ "a matching source file for proof history '"

++ file ++ "' not found."

return Nothing

else anaLibExt opts file emptyLibEnv

-- | read a file and extended the current library environment

anaLibExt :: HetcatsOpts -> FilePath -> LibEnv -> IO (Maybe (LIB_NAME, LibEnv))

anaLibExt opts file libEnv = do

Result ds res <- runResultT $ anaLibFileOrGetEnv logicGraph opts

libEnv (fileToLibName opts file) file

showDiags opts ds

case res of

Nothing -> return Nothing

Just (ln, lenv) -> do

let nEnv = if hasPrfOut opts then automatic ln lenv else lenv

dg = lookupDGraph ln nEnv

ga = globalAnnos dg

writeSpecFiles opts file nEnv ga (ln, globalEnv dg)

putIfVerbose opts 3 $ showGlobalDoc ga ga ""

return $ Just (ln, nEnv)

-- | parsing and static analysis for files

-- Parameters: logic graph, default logic, file name

anaSourceFile :: LogicGraph -> HetcatsOpts -> LibEnv -> FilePath

-> ResultT IO (LIB_NAME, LibEnv)

anaSourceFile lgraph opts libenv fname = ResultT $ do

fname' <- existsAnSource opts {intype = GuessIn} fname

case fname' of

Nothing -> do

return $ fail $ "a file for input '" ++ fname ++ "' not found."

Just file ->

if any (flip isSuffixOf file) [envSuffix, prfSuffix] then

fail $ "a matching source file for '" ++ fname ++ "' not found."

else do

curDir <- getCurrentDirectory

input <- readFile file

mt <- getModificationTime file

-- when switching to ghc 6.6.1 with System.FilePath use:

-- combine curDir file

let absolutePath = if "/" `isPrefixOf` file

then file

else curDir ++ '/':file

putIfVerbose opts 2 $ "Reading file " ++ absolutePath

runResultT $ anaString lgraph opts libenv input absolutePath mt

-- | parsing and static analysis for string (=contents of file)

-- Parameters: logic graph, default logic, contents of file, filename

anaString :: LogicGraph -> HetcatsOpts -> LibEnv -> String

-> FilePath -> ClockTime -> ResultT IO (LIB_NAME, LibEnv)

anaString lgraph opts libenv input file mt = do

let Result ds mast = read_LIB_DEFN_M lgraph opts file input mt

case mast of

Just ast@(Lib_defn ln _ _ ans) -> case analysis opts of

Skip -> do

lift $ putIfVerbose opts 1 $

"Skipping static analysis of library " ++ show ln

ga <- liftR $ addGlobalAnnos emptyGlobalAnnos ans

case gui opts of

Only -> return ()

_ -> lift $ write_LIB_DEFN ga file opts ast

liftR $ Result ds Nothing

_ -> do

let libstring = show $ getLIB_ID ln

if libstring == libraryS then return ()

else do

if isSuffixOf libstring (rmSuffix file) then return () else

lift $ putIfVerbose opts 1 $

"### file name '" ++ file

++ "' does not match library name '" ++

libstring ++ "'"

lift $ putIfVerbose opts 1 $ "Analyzing library " ++ show ln

(_,ld, _, lenv) <- ana_LIB_DEFN lgraph opts libenv ast

case Map.lookup ln lenv of

Nothing -> error $ "anaString: missing library: " ++ show ln

Just dg -> lift $ do

case gui opts of

Only -> return ()

_ -> write_LIB_DEFN (globalAnnos dg) file opts ld

when (hasEnvOut opts)

(writeFileInfo opts ln file ld dg)

return (ln, lenv)

Nothing -> liftR $ Result ds Nothing

-- lookup/read a library

anaLibFile :: LogicGraph -> HetcatsOpts -> LibEnv -> LIB_NAME

-> ResultT IO (LIB_NAME, LibEnv)

anaLibFile lgraph opts libenv ln =

let lnstr = show ln in case Map.lookup ln libenv of

Just _ -> do

analyzing opts $ "from " ++ lnstr

return (ln, libenv)

Nothing -> do

putMessageIORes opts 1 $ "Downloading " ++ lnstr ++ " ..."

res <- anaLibFileOrGetEnv lgraph

(if recurse opts then opts else opts { outtypes = [] })

libenv ln $ libNameToFile opts ln

putMessageIORes opts 1 $ "... loaded " ++ lnstr

return res

-- lookup/read a library

anaLibFileOrGetEnv :: LogicGraph -> HetcatsOpts -> LibEnv

-> LIB_NAME -> FilePath -> ResultT IO (LIB_NAME, LibEnv)

anaLibFileOrGetEnv lgraph opts libenv libname file = ResultT $ do

let env_file = rmSuffix file ++ envSuffix

recent_env_file <- checkRecentEnv opts env_file file

if recent_env_file

then do

mgc <- readVerbose opts libname env_file

case mgc of

Nothing -> runResultT $ do

lift $ putIfVerbose opts 1 $ "Deleting " ++ env_file

anaSourceFile lgraph opts libenv file

Just (ld, gc) -> do

write_LIB_DEFN (globalAnnos gc) file opts ld

-- get all DGRefs from DGraph

Result ds mEnv <- runResultT $ foldl

( \ ioLibEnv labOfDG -> let node = snd labOfDG in

if isDGRef node then do

let ln = dgn_libname node

p_libEnv <- ioLibEnv

if Map.member ln p_libEnv then

return p_libEnv

else fmap snd $ anaLibFile lgraph

opts p_libEnv ln

else ioLibEnv)

(return $ Map.insert libname gc libenv)

$ labNodesDG gc

return $ Result ds $ fmap

( \ rEnv -> (libname, rEnv)) mEnv

else runResultT $ anaSourceFile lgraph opts libenv file

-- | analyze a LIB_DEFN

-- Parameters: logic graph, default logic, opts, library env, LIB_DEFN

-- call this function as follows:

-- do Result diags res <- runResultT (ana_LIB_DEFN ...)

-- mapM_ (putStrLn . show) diags

ana_LIB_DEFN :: LogicGraph -> HetcatsOpts -> LibEnv -> LIB_DEFN

-> ResultT IO (LIB_NAME,LIB_DEFN, DGraph, LibEnv)

ana_LIB_DEFN lgraph opts libenv (Lib_defn ln alibItems pos ans) = do

gannos <- showDiags1 opts $ liftR $ addGlobalAnnos emptyGlobalAnnos ans

(libItems', dg, libenv', _) <-

foldl ana (do

dg <- lift $ emptyDGwithMVar

return ([], dg { globalAnnos = gannos }, libenv, lgraph))

(map item alibItems)

return (ln,

Lib_defn ln

(map (uncurry replaceAnnoted)

(zip (reverse libItems') alibItems))

pos

ans,

dg,

Map.insert ln dg libenv')

where

ana res1 libItem = do

(libItems', dg1, libenv1, lG) <- res1

let newLG = case libItems' of

[] -> lG { currentLogic = defLogic opts }

Logic_decl (Logic_name logTok _) _ : _ ->

lG { currentLogic = tokStr logTok }

_ -> lG

l1 <- lookupLogic "current logic" (currentLogic newLG) newLG

ResultT (do

Result diags2 res <-

runResultT $ ana_LIB_ITEM newLG opts libenv1 dg1 l1 libItem

runResultT $ showDiags1 opts (liftR (Result diags2 res))

let mRes = case res of

Just (libItem', dg1', libenv1') ->

Just (libItem' : libItems', dg1', libenv1', newLG)

Nothing -> Nothing

if outputToStdout opts then

if hasErrors diags2 then

fail "Stopped due to errors"

else runResultT $ liftR $ Result [] mRes

else runResultT $ liftR $ Result diags2 mRes)

putMessageIORes :: HetcatsOpts -> Int -> String -> ResultT IO ()

putMessageIORes opts i msg =

if outputToStdout opts

then lift $ putIfVerbose opts i msg

else liftR $ message () msg

analyzing :: HetcatsOpts -> String -> ResultT IO ()

analyzing opts msg = putMessageIORes opts 1 $ "Analyzing " ++ msg

alreadyDefined :: String -> String

alreadyDefined str = "Name " ++ str ++ " already defined"

-- | analyze a GENERICITY

ana_GENERICITY :: LogicGraph -> DGraph -> AnyLogic -> HetcatsOpts

-> NODE_NAME -> GENERICITY

-> Result (GENERICITY, GenericitySig, DGraph)

ana_GENERICITY lg dg l opts name

gen@(Genericity params@(Params psps) imps@(Imported isps) pos) =

case psps of

[] -> do -- no parameter ...

when (not (null isps))

(plain_error () "Parameterless specifications must not have imports"

pos)

return (gen, (EmptyNode l, [], EmptyNode l), dg)

_ -> do

(imps',nsigI,dg') <- ana_IMPORTS lg dg l opts (extName "I" name) imps

case psps of

[asp] -> do -- one parameter ...

(sp', nsigP, dg'') <- ana_SPEC lg dg' nsigI name opts (item asp)

return (Genericity (Params [replaceAnnoted sp' asp]) imps' pos,

(nsigI, [nsigP], JustNode nsigP), dg'')

_ -> do -- ... and more parameters

(params',nsigPs,dg'') <-

ana_PARAMS lg dg' nsigI opts (inc name) params

let adj = adjustPos pos

gsigmaP <- adj $ gsigManyUnion lg (map getSig nsigPs)

G_sign lidP gsigP indP <- return gsigmaP

let node_contents = newNodeLab name DGFormalParams

$ noSensGTheory lidP gsigP indP

node = getNewNodeDG dg''

dg''' = insNodeDG (node,node_contents) dg''

inslink dgres (NodeSig n sigma) = do

dgl <- dgres

incl <- adj $ ginclusion lg sigma gsigmaP

return (insLEdgeNubDG (n,node,DGLink

{ dgl_morphism = incl

, dgl_type = GlobalDef

, dgl_origin = DGFormalParams

, dgl_id = defaultEdgeID

}) dgl)

dg4 <- foldl inslink (return dg''') nsigPs

return (Genericity params' imps' pos,

(nsigI, nsigPs, JustNode $ NodeSig node gsigmaP), dg4)

ana_PARAMS :: LogicGraph -> DGraph -> MaybeNode

-> HetcatsOpts -> NODE_NAME -> PARAMS

-> Result (PARAMS, [NodeSig], DGraph)

ana_PARAMS lg dg nsigI opts name (Params asps) = do

(sps',pars,dg',_) <- foldl ana (return ([], [], dg, name))

$ map item asps

return (Params (map (uncurry replaceAnnoted)

(zip (reverse sps') asps)),

reverse pars, dg')

where

ana res sp = do

(sps',pars,dg1,n) <- res

(sp',par,dg') <- ana_SPEC lg dg1 nsigI n opts sp

return (sp':sps',par:pars,dg',inc n)

ana_IMPORTS :: LogicGraph -> DGraph -> AnyLogic -> HetcatsOpts

-> NODE_NAME -> IMPORTED -> Result (IMPORTED, MaybeNode, DGraph)

ana_IMPORTS lg dg l opts name imps@(Imported asps) = case asps of

[] -> return (imps, EmptyNode l, dg)

_ -> do

let sp = Union asps nullRange

(Union asps' _, nsig', dg') <-

ana_SPEC lg dg (EmptyNode l) name opts sp

return (Imported asps', JustNode nsig', dg')

-- ??? emptyExplicit stuff needs to be added here

-- | analyse a LIB_ITEM

ana_LIB_ITEM :: LogicGraph -> HetcatsOpts

-> LibEnv -> DGraph -> AnyLogic

-> LIB_ITEM

-> ResultT IO (LIB_ITEM, DGraph, LibEnv)

ana_LIB_ITEM lgraph opts libenv dg l itm = case itm of

Spec_defn spn gen asp pos -> do

let spstr = tokStr spn

analyzing opts $ "spec " ++ spstr

(gen', (imp, params, allparams), dg') <-

liftR (ana_GENERICITY lgraph dg l opts

(extName "P" (makeName spn)) gen)

(sp', body, dg'') <-

liftR (ana_SPEC lgraph dg'

allparams (makeName spn) opts (item asp))

let libItem' = Spec_defn spn gen' (replaceAnnoted sp' asp) pos

genv = globalEnv dg

if Map.member spn genv

then liftR (plain_error (libItem', dg'', libenv)

(alreadyDefined spstr) pos)

else return (libItem',

dg'' { globalEnv = Map.insert spn (SpecEntry

(imp, params, getMaybeSig allparams, body)) genv }

, libenv)

View_defn vn gen vt gsis pos -> do

analyzing opts $ "view " ++ tokStr vn

liftR (ana_VIEW_DEFN lgraph libenv dg l opts vn gen vt gsis pos)

Arch_spec_defn asn asp pos -> do

let asstr = tokStr asn

analyzing opts $ "arch spec " ++ asstr

(archSig, dg', asp') <-

liftR (ana_ARCH_SPEC lgraph dg l opts (item asp))

let asd' = Arch_spec_defn asn (replaceAnnoted asp' asp) pos

genv = globalEnv dg'

if Map.member asn genv

then liftR (plain_error (asd', dg', libenv)

(alreadyDefined asstr) pos)

else return (asd', dg'

{ globalEnv = Map.insert asn (ArchEntry archSig) genv },

libenv)

Unit_spec_defn usn usp pos -> do

let usstr = tokStr usn

analyzing opts $ "unit spec " ++ usstr

(unitSig, dg', usp') <- liftR (ana_UNIT_SPEC lgraph dg l opts

(EmptyNode l) usp)

let usd' = Unit_spec_defn usn usp' pos

genv = globalEnv dg'

if Map.member usn genv

then liftR (plain_error (itm, dg', libenv)

(alreadyDefined usstr) pos)

else return (usd', dg'

{ globalEnv = Map.insert usn (UnitEntry unitSig) genv },

libenv)

Ref_spec_defn rn _ pos -> do

let rnstr = tokStr rn

analyzing opts $ "refinement "

++ rnstr ++ "\n (refinement analysis not implemented yet)"

let genv = globalEnv dg

if Map.member rn genv

then liftR (plain_error (itm, dg, libenv)

(alreadyDefined rnstr)

pos)

else return ( itm, dg { globalEnv = Map.insert rn (RefEntry) genv }

, libenv)

Logic_decl (Logic_name logTok _) _ -> do

logNm <- lookupLogic "LOGIC DECLARATION:" (tokStr logTok) lgraph

putMessageIORes opts 1 $ "logic " ++ show logNm

return (itm, dg, libenv)

Download_items ln items _ -> do

-- we take as the default logic for imported libs

-- the global default logic

(ln', libenv') <- anaLibFile lgraph opts libenv ln

if ln == ln' then case Map.lookup ln libenv' of

Nothing -> error $ "Internal error: did not find library " ++

show ln ++ " available: " ++ show (Map.keys libenv')

Just dg' -> do

(genv1,dg1) <- liftR (foldl (ana_ITEM_NAME_OR_MAP libenv' ln

$ globalEnv dg')

(return (globalEnv dg, dg))

items)

gannos'' <- liftR $ globalAnnos dg `mergeGlobalAnnos` globalAnnos dg'

return (itm, dg1

{ globalAnnos = gannos''

, globalEnv = genv1 }, libenv')

else liftR $ fail $ "downloaded library '" ++ show ln'

++ "' does not match library name '" ++ shows ln "'"

-- ??? Needs to be generalized to views between different logics

ana_VIEW_DEFN :: LogicGraph -> LibEnv -> DGraph

-> AnyLogic -> HetcatsOpts -> SIMPLE_ID

-> GENERICITY -> VIEW_TYPE -> [G_mapping] -> Range

-> Result (LIB_ITEM, DGraph, LibEnv)

ana_VIEW_DEFN lgraph libenv dg l opts

vn gen vt gsis pos = do

let adj = adjustPos pos

(gen',(imp,params,allparams),dg') <-

ana_GENERICITY lgraph dg l opts (extName "VG" (makeName vn)) gen

(vt', (src,tar), dg'') <-

ana_VIEW_TYPE lgraph dg' l allparams opts

(makeName vn) vt

let gsigmaS = getSig src

gsigmaT = getSig tar

G_sign lidS sigmaS _ <- return gsigmaS

G_sign lidT sigmaT _ <- return gsigmaT

gsis1 <- adj $ homogenizeGM (Logic lidS) gsis

G_symb_map_items_list lid sis <- return gsis1

sigmaS' <- adj $ coerceSign lidS lid "" sigmaS

sigmaT' <- adj $ coerceSign lidT lid "" sigmaT

mor <- if isStructured opts then return (ide lid sigmaS')

else do

rmap <- adj $ stat_symb_map_items lid sis

adj $ induced_from_to_morphism lid rmap sigmaS' sigmaT'

let nodeS = getNode src

nodeT = getNode tar

gmor = gEmbed (G_morphism lid 0 mor 0 0)

link = (nodeS,nodeT,DGLink {

dgl_morphism = gmor,

dgl_type = GlobalThm LeftOpen None LeftOpen,

-- 'LeftOpen' for conserv correct?

dgl_origin = DGView vn,

dgl_id = [getNewEdgeID dg'']})

vsig = (src,gmor,(imp,params,getMaybeSig allparams,tar))

genv = globalEnv dg''

if Map.member vn genv

then plain_error (View_defn vn gen' vt' gsis pos, dg'', libenv)

(alreadyDefined $ tokStr vn)

pos

else return (View_defn vn gen' vt' gsis pos,

(insEdgeDG link dg'')

{ globalEnv = Map.insert vn (ViewEntry vsig) genv }

, libenv)

-- | analyze a VIEW_TYPE

-- The first three arguments give the global context

-- The AnyLogic is the current logic

-- The NodeSig is the signature of the parameter of the view

-- flag, whether just the structure shall be analysed

ana_VIEW_TYPE :: LogicGraph -> DGraph -> AnyLogic

-> MaybeNode -> HetcatsOpts -> NODE_NAME -> VIEW_TYPE

-> Result (VIEW_TYPE, (NodeSig, NodeSig), DGraph)

ana_VIEW_TYPE lg dg l parSig opts name

(View_type aspSrc aspTar pos) = do

(spSrc',srcNsig,dg') <- adjustPos pos $

ana_SPEC lg dg (EmptyNode l) (extName "S" name) opts (item aspSrc)

(spTar',tarNsig,dg'') <- adjustPos pos $

ana_SPEC lg dg' parSig

(extName "T" name) opts (item aspTar)

return (View_type (replaceAnnoted spSrc' aspSrc)

(replaceAnnoted spTar' aspTar)

pos,

(srcNsig, tarNsig), dg'')

ana_ITEM_NAME_OR_MAP :: LibEnv -> LIB_NAME -> GlobalEnv

-> Result (GlobalEnv, DGraph) -> ITEM_NAME_OR_MAP

-> Result (GlobalEnv, DGraph)

ana_ITEM_NAME_OR_MAP libenv ln genv' res itm =

ana_ITEM_NAME_OR_MAP1 libenv ln genv' res $ case itm of

Item_name name -> (name, name)

Item_name_map old new _ -> (old, new)

-- | Auxiliary function for not yet implemented features

ana_err :: String -> a

ana_err f = error $ "*** Analysis of " ++ f ++ " is not yet implemented!"

ana_ITEM_NAME_OR_MAP1 :: LibEnv -> LIB_NAME -> GlobalEnv

-> Result (GlobalEnv, DGraph) -> (SIMPLE_ID, SIMPLE_ID)

-> Result (GlobalEnv, DGraph)

ana_ITEM_NAME_OR_MAP1 libenv ln genv' res (old, new) = do

(genv,dg) <- res

entry <- maybeToResult nullRange

(tokStr old ++ " not found") (Map.lookup old genv')

case Map.lookup new genv of

Nothing -> return ()

Just _ -> fail (tokStr new ++ " already used")

case entry of

SpecEntry extsig ->

let (dg1,extsig1) = refExtsig libenv ln dg (Just new) extsig

genv1 = Map.insert new (SpecEntry extsig1) genv

in return (genv1,dg1)

ViewEntry vsig ->

let (dg1,vsig1) = refViewsig libenv ln dg vsig

genv1 = Map.insert new (ViewEntry vsig1) genv

in return (genv1,dg1)

ArchEntry _asig -> ana_err "arch spec download"

UnitEntry _usig -> ana_err "unit spec download"

RefEntry -> ana_err "ref spec download"

refNodesig :: LibEnv -> LIB_NAME -> DGraph -> (Maybe SIMPLE_ID, NodeSig)

-> (DGraph, NodeSig)

refNodesig libenv refln dg (name, NodeSig refn sigma@(G_sign lid sig ind)) =

let (ln, n) = getActualParent libenv refln refn

node_contents = newInfoNodeLab (makeMaybeName name)

(newRefInfo ln n) $ noSensGTheory lid sig ind

node = getNewNodeDG dg

in

--(insNode (node,node_contents) dg, NodeSig node sigma)

case (lookupInAllRefNodesDG (ln, n) dg) of

Just existNode -> (dg, NodeSig existNode sigma)

Nothing -> (addToRefNodesDG (node, ln, n)

$ insNodeDG (node,node_contents) dg

, NodeSig node sigma)

{- | get to the actual parent which is not a referenced node, so that

the small chains between nodes in different library can be advoided.

(details see ticket 5)

-}

getActualParent :: LibEnv -> LIB_NAME -> Node -> (LIB_NAME, Node)

getActualParent libenv ln n =

let

dg = lookupDGraph ln libenv

refLab =

lab' $ safeContextDG "Static.AnalysisLibrary.getActualParent" dg n

in

case isDGRef refLab of

-- recursively goes to parent of the current node, but

-- it actually would only be done once

True -> getActualParent libenv (dgn_libname refLab) (dgn_node refLab)

False -> (ln, n)

refNodesigs :: LibEnv -> LIB_NAME -> DGraph -> [(Maybe SIMPLE_ID, NodeSig)]

-> (DGraph, [NodeSig])

refNodesigs libenv ln = mapAccumR (refNodesig libenv ln)

refExtsig :: LibEnv -> LIB_NAME -> DGraph -> Maybe SIMPLE_ID -> ExtGenSig

-> (DGraph, ExtGenSig)

refExtsig libenv ln dg name (imps,params,gsigmaP,body) =

let

params' = map (\x -> (Nothing,x)) params

(dg0, body1) = refNodesig libenv ln dg (name, body)

(dg1, params1) = refNodesigs libenv ln dg0 params'

(dg2, imps1) = case imps of

EmptyNode _ -> (dg1, imps)

JustNode ns -> let

(dg3, nns) = refNodesig libenv ln dg1 (Nothing, ns)

in (dg3, JustNode nns)

in (dg2,(imps1,params1,gsigmaP,body1))

refViewsig :: LibEnv -> LIB_NAME -> DGraph -> (NodeSig, t1, ExtGenSig)

-> (DGraph, (NodeSig, t1, ExtGenSig))

refViewsig libenv ln dg (src,mor,extsig) =

(dg2,(src1,mor,extsig1))

where

(_,[src1]) = refNodesigs libenv ln dg [(Nothing,src)]

(dg2,extsig1) = refExtsig libenv ln dg Nothing extsig