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|
module ContractProver where
import Directory ( doesFileExist )
import Integer ( ilog )
import IOExts
import List ( deleteBy, elemIndex, find, init, intersect, isSuffixOf
, maximum, minimum, nub, partition, splitOn, union )
import Maybe ( catMaybes, isJust )
import ReadShowTerm ( showTerm )
import State
import System ( exitWith, getArgs, getEnviron, system )
import Contract.Names
import Contract.Usage ( checkContractUsage )
import FilePath ( (</>) )
import FlatCurry.Files
import FlatCurry.Types
import qualified FlatCurry.Goodies as FCG
import FlatCurry.Annotated.Files ( readTypedFlatCurry, typedFlatCurryFileName )
import FlatCurry.Annotated.Goodies
import FlatCurry.Annotated.Types
import FlatCurry.Annotated.TypeSubst ( substRule )
import ShowFlatCurry ( showCurryModule )
import ESMT
import Curry2SMT
import FlatCurry.Typed.Build
import FlatCurry.Typed.Read
import FlatCurry.Typed.Goodies
import FlatCurry.Typed.Names
import FlatCurry.Typed.Simplify ( simpProg, simpFuncDecl, simpExpr )
import FlatCurry.Typed.Types
import PackageConfig ( packagePath )
import ToolOptions
import VerifierState
banner :: String
banner = unlines [bannerLine, bannerText, bannerLine]
where
bannerText = "Contract Checking/Verification Tool (Version of 06/09/19)"
bannerLine = take (length bannerText) (repeat '=')
contractCheckerModule :: String
contractCheckerModule = packagePath </> "include" </> "ContractChecker"
main :: IO ()
main = do
args <- getArgs
(opts,progs) <- processOptions banner args
let optname = optName opts
if not (null optname)
then putStrLn $ "Precondition for '" ++ optname ++ "':\n" ++
encodeContractName (optname ++ "'pre") ++ "\n" ++
"Postcondition for '" ++ optname ++ "':\n" ++
encodeContractName (optname ++ "'post")
else do
when (optVerb opts > 0) $ putStrLn banner
z3exists <- fileInPath "z3"
unless (z3exists || not (optVerify opts)) $ putStrLn $ unlines $
[ "WARNING: CONTRACT VERIFICATION SKIPPED:"
, "The SMT solver Z3 is required for the verifier"
, "but the program 'z3' is not found in the PATH!"]
let opts' = if z3exists then opts else opts { optVerify = False }
mapM_ (proveContracts opts') progs
proveContracts :: Options -> String -> IO ()
proveContracts opts mainmodname = do
prog <- readTypedFlatCurryWithSpec opts mainmodname
let errs = checkContractUsage (progName prog)
(map (\fd -> (snd (funcName fd), funcType fd)) (progFuncs prog))
if null errs
then proveContractsInProg opts prog
else do putStr $ unlines (map showOpError errs)
exitWith 1
where
showOpError (qf,err) =
snd qf ++ " (module " ++ fst qf ++ "): " ++ err
proveContractsInProg :: Options -> TAProg -> IO ()
proveContractsInProg opts oprog = do
let sprog = simpProg oprog
printWhenAll opts $ unlines $
["ORIGINAL PROGRAM:", line, showCurryModule (unAnnProg oprog), line,
"SIMPLIFIED PROGRAM:", line, showCurryModule (unAnnProg sprog), line]
vstref <- newIORef (initVState (makeVerifyInfo opts (progFuncs sprog)))
modifyIORef vstref (addProgToState sprog)
prog1 <- verifyPostConditions opts oprog vstref
prog2 <- verifyPreConditions opts prog1 vstref
prog3 <- addPreConditions opts prog2 vstref
let unewprog = unAnnProg prog3
mname = progName prog3
printWhenAll opts $ unlines $
["TRANSFORMED PROGRAM WITH CONTRACT CHECKING:", line,
showCurryModule unewprog, line]
vst2 <- readIORef vstref
when (areContractsAdded vst2) $ do
when (optFCY opts) $
writeTransformedFCY opts (flatCurryFileName mname) unewprog
when (optTFCY opts) $
writeTransformedTFCY opts (typedFlatCurryFileName mname) prog3
printWhenStatus opts (showStats vst2)
where
line = take 78 (repeat '-')
writeTransformedFCY :: Options -> String -> Prog -> IO ()
writeTransformedFCY opts progfile prog = do
ccprog <- readFlatCurry contractCheckerModule
let rnmccprog = FCG.rnmProg (FCG.progName prog) ccprog
ccimps = FCG.progImports rnmccprog
ccfuncs = FCG.progFuncs rnmccprog
writeFCY progfile
(FCG.updProgFuncs (++ ccfuncs)
(FCG.updProgImports (`union` ccimps) prog))
printWhenStatus opts $ "Transformed program written to: " ++ progfile
writeTransformedTFCY :: Options -> String -> TAProg -> IO ()
writeTransformedTFCY opts progfile prog = do
ccprog <- readTypedFlatCurry contractCheckerModule
let rnmccprog = rnmProg (progName prog) ccprog
ccimps = progImports rnmccprog
ccfuncs = progFuncs rnmccprog
writeTFCY progfile
(updProgFuncs (++ ccfuncs)
(updProgImports (`union` ccimps) prog))
printWhenStatus opts $ "Transformed program written to: " ++ progfile
where
writeTFCY file tprog = writeFile file (showTerm tprog)
data TransState = TransState
{ preCond :: Term
, freshVar :: Int
, varTypes :: [(Int,TypeExpr)]
}
makeTransState :: Int -> [(Int,TypeExpr)] -> TransState
makeTransState = TransState tTrue
incFreshVarIndex :: TransState -> TransState
incFreshVarIndex st = st { freshVar = freshVar st + 1 }
addVarTypes :: [(Int,TypeExpr)] -> TransState -> TransState
addVarTypes vts st = st { varTypes = vts ++ varTypes st }
addPreConditionCheck :: TypeExpr -> CombType -> QName -> TypeExpr -> [TAExpr]
-> TAExpr
addPreConditionCheck ty ct qf@(mn,fn) tys args =
AComb ty FuncCall
((mn, "checkPreCond"),
FuncType ty (FuncType boolType (FuncType stringType (FuncType tt ty))))
[ AComb ty ct (toNoCheckQName qf,tys) args
, AComb boolType ct (toPreCondQName qf, pctype) args
, string2TFCY fn
, tupleExpr args
]
where
argtypes = map annExpr args
tt = tupleType argtypes
pctype = foldr FuncType boolType argtypes
toNoCheckQName :: (String,String) -> (String,String)
toNoCheckQName (mn,fn) = (mn, fn ++ "'NOCHECK")
fromNoCheckQName :: (String,String) -> (String,String)
fromNoCheckQName (mn,fn) =
(mn, let rf = reverse fn
in reverse (drop (if take 8 rf == "KCEHCON'" then 8 else 0) rf))
addPostConditionCheck :: QName -> TARule -> TAExpr
addPostConditionCheck _ (AExternal _ _) =
error $ "Trying to add postcondition to external function!"
addPostConditionCheck qf@(mn,fn) (ARule ty lhs rhs) =
AComb ty FuncCall
((mn, "checkPostCond"),
FuncType ty (FuncType (FuncType ty boolType)
(FuncType stringType (FuncType tt ty))))
[ rhs
, AComb boolType (FuncPartCall 1) (toPostCondQName qf, ty) args
, string2TFCY fn
, tupleExpr args
]
where
args = map (\ (i,t) -> AVar t i) lhs
tt = tupleType (map annExpr args)
addPreConditions :: Options -> TAProg -> IORef VState -> IO TAProg
addPreConditions _ prog vstref = do
newfuns <- mapM addPreCondition (progFuncs prog)
return (updProgFuncs (const (concat newfuns)) prog)
where
addPreCondition fdecl@(AFunc qf ar vis fty rule) = do
ti <- readVerifyInfoRef vstref
return $
if toPreCondQName qf `elem` map funcName (preConds ti)
then let newrule = checkPreCondRule qf rule
in [updFuncRule (const newrule) fdecl,
AFunc (toNoCheckQName qf) ar vis fty rule]
else [fdecl]
checkPreCondRule :: QName -> TARule -> TARule
checkPreCondRule qn (ARule rty rargs _) =
ARule rty rargs (addPreConditionCheck rty FuncCall qn rty
(map (\ (v,t) -> AVar t v) rargs))
checkPreCondRule qn (AExternal _ _) = error $
"addPreConditions: cannot add precondition to external operation '" ++
snd qn ++ "'!"
verifyPreConditions :: Options -> TAProg -> IORef VState -> IO TAProg
verifyPreConditions opts prog vstref = do
newfuns <- mapM (provePreCondition opts vstref) (progFuncs prog)
return (updProgFuncs (const newfuns) prog)
provePreCondition :: Options -> IORef VState -> TAFuncDecl -> IO TAFuncDecl
provePreCondition opts vstref fdecl = do
ti <- readVerifyInfoRef vstref
printWhenIntermediate opts $
"Operation to be checked: " ++ snd (funcName fdecl)
newrule <- optPreConditionInRule opts ti (funcName fdecl)
(funcRule fdecl) vstref
return (updFuncRule (const newrule) fdecl)
optPreConditionInRule :: Options -> VerifyInfo -> QName -> TARule
-> IORef VState -> IO TARule
optPreConditionInRule _ _ _ rl@(AExternal _ _) _ = return rl
optPreConditionInRule opts ti qn@(_,fn) (ARule rty rargs rhs) vstref = do
let targs = zip [1..] (map snd rargs)
s0 = makeTransState (maximum (0 : map fst rargs ++ allVars rhs) + 1) rargs
(precondformula,s1) = preCondExpOf ti qn targs s0
s2 = s1 { preCond = precondformula }
newrhs <- optPreCondInExp s2 rhs
return (ARule rty rargs newrhs)
where
optPreCondInExp pts exp = case exp of
AComb ty ct (qf,tys) args ->
if qf == ("Prelude","?") && length args == 2
then optPreCondInExp pts (AOr ty (args!!0) (args!!1))
else do
nargs <- mapM (optPreCondInExp pts) args
if toPreCondQName qf `elem` map funcName (preConds ti)
then do
printWhenIntermediate opts $ "Checking call to " ++ snd qf
let ((bs,_) ,pts1) = normalizeArgs nargs pts
(bindexps ,pts2) = mapS (binding2SMT True ti) bs pts1
(precondcall,pts3) = preCondExpOf ti qf
(zip (map fst bs) (map annExpr args)) pts2
let title = "SMT script to verify precondition of '" ++ snd qf ++
"' in function '" ++ fn ++ "'"
pcproof <- checkImplication opts vstref title (varTypes pts3)
(preCond pts) (tConj bindexps) precondcall
let pcvalid = isJust pcproof
modifyIORef vstref
(addPreCondToStats (snd qf ++ "("++fn++")") pcvalid)
if pcvalid
then do
printWhenStatus opts $
fn ++ ": PRECONDITION OF '" ++ snd qf ++ "': VERIFIED"
return $ AComb ty ct (toNoCheckQName qf, tys) nargs
else do
printWhenStatus opts $
fn ++ ": PRECOND CHECK ADDED TO '" ++ snd qf ++ "'"
return $ AComb ty ct (qf,tys) nargs
else return $ AComb ty ct (qf,tys) nargs
ACase ty ct e brs -> do
ne <- optPreCondInExp pts e
let freshvar = freshVar pts
(be,pts1) = binding2SMT True ti (freshvar,ne) (incFreshVarIndex pts)
pts2 = pts1 { preCond = tConj [preCond pts, be]
, varTypes = (freshvar,annExpr ne) : varTypes pts1 }
nbrs <- mapM (optPreCondInBranch pts2 freshvar) brs
return $ ACase ty ct ne nbrs
AOr ty e1 e2 -> do
ne1 <- optPreCondInExp pts e1
ne2 <- optPreCondInExp pts e2
return $ AOr ty ne1 ne2
ALet ty bs e -> do
nes <- mapM (optPreCondInExp pts) (map snd bs)
ne <- optPreCondInExp pts e
return $ ALet ty (zip (map fst bs) nes) ne
AFree ty fvs e -> do
ne <- optPreCondInExp pts e
return $ AFree ty fvs ne
ATyped ty e et -> do
ne <- optPreCondInExp pts e
return $ ATyped ty ne et
_ -> return exp
optPreCondInBranch pts dvar branch = do
let (ABranch p e, pts1) = renamePatternVars pts branch
let npts = pts1 { preCond = tConj [preCond pts1, tEquVar dvar (pat2SMT p)] }
ne <- optPreCondInExp npts e
return (ABranch p ne)
renamePatternVars :: TransState -> TABranchExpr -> (TABranchExpr,TransState)
renamePatternVars pts (ABranch p e) =
if isConsPattern p
then let args = map fst (patArgs p)
minarg = minimum (0 : args)
maxarg = maximum (0 : args)
fv = freshVar pts
rnm i = if i `elem` args then i - minarg + fv else i
nargs = map (\ (v,t) -> (rnm v,t)) (patArgs p)
in (ABranch (updPatArgs (map (\ (v,t) -> (rnm v,t))) p)
(rnmAllVars rnm e),
pts { freshVar = fv + maxarg - minarg + 1
, varTypes = nargs ++ varTypes pts })
else (ABranch p e, pts)
verifyPostConditions :: Options -> TAProg -> IORef VState -> IO TAProg
verifyPostConditions opts prog vstref = do
ti <- readVerifyInfoRef vstref
let fdecls = progFuncs prog
newfuns <- provePostConds ti (postConds ti) fdecls
return $ updProgFuncs (const newfuns) prog
where
provePostConds _ [] fdecls = return fdecls
provePostConds ti (pof:pofs) fdecls =
provePostCondition opts ti pof fdecls vstref >>= provePostConds ti pofs
provePostCondition :: Options -> VerifyInfo -> TAFuncDecl -> [TAFuncDecl]
-> IORef VState -> IO [TAFuncDecl]
provePostCondition opts ti postfun allfuns vstref = do
maybe (putStrLn ("Postcondition: " ++ pcname ++ "\n" ++
"Operation of this postcondition not found!") >>
return allfuns)
(\checkfun -> provePC (simpFuncDecl checkfun))
(find (\fd -> toPostCondName (snd (funcName fd)) ==
decodeContractName pcname)
allfuns)
where
pcname = snd (funcName postfun)
provePC checkfun = do
let (postmn,postfn) = funcName postfun
mainfunc = snd (funcName checkfun)
orgqn = (postmn, reverse (drop 5 (reverse postfn)))
let farity = funcArity checkfun
ftype = funcType checkfun
targsr = zip [1..] (argTypes ftype ++ [resultType ftype])
(bodyformula,s0) = extractPostConditionProofObligation ti [1 .. farity]
(farity+1) (funcRule checkfun)
(precondformula,s1) = preCondExpOf ti orgqn (init targsr) s0
(postcondformula,s2) = (applyFunc postfun targsr `bindS`
pred2smt) s1
let title = "verify postcondition of '" ++ mainfunc ++ "'..."
printWhenIntermediate opts $ "Trying to " ++ title
pcproof <- checkImplication opts vstref ("SMT script to " ++ title)
(varTypes s2) (tConj [precondformula, bodyformula]) tTrue
postcondformula
modifyIORef vstref (addPostCondToStats mainfunc (isJust pcproof))
maybe
(do printWhenStatus opts $ mainfunc ++ ": POSTCOND CHECK ADDED"
return (map (addPostConditionTo (funcName postfun)) allfuns) )
(\proof -> do
unless (optNoProof opts) $
writeFile ("PROOF_" ++ showQNameNoDots orgqn ++ "_" ++
"SatisfiesPostCondition.smt") proof
printWhenStatus opts $ mainfunc ++ ": POSTCONDITION VERIFIED"
return allfuns )
pcproof
addPostConditionTo :: QName -> TAFuncDecl -> TAFuncDecl
addPostConditionTo pfname fdecl = let fn = funcName fdecl in
if toPostCondQName fn == pfname
then updFuncBody (const (addPostConditionCheck fn (funcRule fdecl))) fdecl
else fdecl
extractPostConditionProofObligation :: VerifyInfo -> [Int] -> Int -> TARule
-> (Term,TransState)
extractPostConditionProofObligation _ _ _ (AExternal _ s) =
(tComb ("External: " ++ s) [], makeTransState 0 [])
extractPostConditionProofObligation ti args resvar (ARule ty orgargs orgexp) =
let exp = rnmAllVars renameRuleVar orgexp
rtype = resType (length orgargs) ty
state0 = makeTransState (maximum (resvar : allVars exp) + 1)
((resvar, rtype) : zip args (map snd orgargs))
in binding2SMT True ti (resvar,exp) state0
where
maxArgResult = maximum (resvar : args)
renameRuleVar r = maybe (r + maxArgResult + 1)
(args!!)
(elemIndex r (map fst orgargs))
resType n te = if n==0
then te
else case te of FuncType _ rt -> resType (n-1) rt
_ -> error "Internal errror: resType!"
preCondExpOf :: VerifyInfo -> QName -> [(Int,TypeExpr)] -> State TransState Term
preCondExpOf ti qf args =
maybe (returnS tTrue)
(\fd -> applyFunc fd args `bindS` pred2smt)
(find (\fd -> decodeContractQName (funcName fd)
== toPreCondQName (fromNoCheckQName qf))
(preConds ti))
postCondExpOf :: VerifyInfo -> QName -> [(Int,TypeExpr)]
-> State TransState Term
postCondExpOf ti qf args =
maybe (returnS tTrue)
(\fd -> applyFunc fd args `bindS` pred2smt)
(find (\fd -> decodeContractQName (funcName fd)
== toPostCondQName (fromNoCheckQName qf))
(postConds ti))
applyFunc :: TAFuncDecl -> [(Int,TypeExpr)] -> State TransState TAExpr
applyFunc fdecl targs s0 =
let tsub = maybe (error $ "applyFunc: types\n" ++
show (argTypes (funcType fdecl)) ++ "\n" ++
show (map snd targs) ++ "\ndo not match!")
id
(matchTypes (argTypes (funcType fdecl)) (map snd targs))
(ARule _ orgargs orgexp) = substRule tsub (funcRule fdecl)
exp = rnmAllVars (renameRuleVar orgargs) orgexp
s1 = s0 { freshVar = max (freshVar s0)
(maximum (0 : args ++ allVars exp) + 1) }
in (simpExpr $ applyArgs exp (drop (length orgargs) args), s1)
where
args = map fst targs
renameRuleVar orgargs r = maybe (r + freshVar s0)
(args!!)
(elemIndex r (map fst orgargs))
applyArgs e [] = e
applyArgs e (v:vs) =
let e_v = AComb failed FuncCall
(pre "apply", failed) [e, AVar failed v]
in applyArgs e_v vs
pred2smt :: TAExpr -> State TransState Term
pred2smt exp = case exp of
AVar _ i -> returnS (TSVar i)
ALit _ l -> returnS (lit2SMT l)
AComb _ ct (qf,ftype) args ->
if qf == pre "not" && length args == 1
then pred2smt (head args) `bindS` \barg -> returnS (tNot barg)
else mapS pred2smt args `bindS` \bargs ->
returnS (TComb (cons2SMT (ct /= ConsCall || not (null bargs))
False qf ftype) bargs)
_ -> error $ "Translation of some Boolean expressions into SMT " ++
"not yet supported:\n" ++ show (unAnnExpr exp)
binding2SMT :: Bool -> VerifyInfo -> (Int,TAExpr) -> State TransState Term
binding2SMT odemanded vi (oresvar,oexp) =
exp2smt odemanded (oresvar, simpExpr oexp)
where
exp2smt demanded (resvar,exp) = case exp of
AVar _ i -> returnS $ if resvar==i then tTrue
else tEquVar resvar (TSVar i)
ALit _ l -> returnS (tEquVar resvar (lit2SMT l))
AComb ty ct (qf,_) args ->
if qf == pre "?" && length args == 2
then exp2smt demanded (resvar, AOr ty (args!!0) (args!!1))
else normalizeArgs args `bindS` \ (bs,nargs) ->
mapS (exp2smt (isPrimOp qf || optStrict (toolOpts vi)))
bs `bindS` \bindexps ->
comb2smt qf ty ct nargs bs bindexps
ALet _ bs e ->
getS `bindS` \ts ->
putS (addVarTypes (map fst bs) ts) `bindS_`
mapS (exp2smt False)
(map (\ ((i,_),ae) -> (i,ae)) bs) `bindS` \bindexps ->
exp2smt demanded (resvar,e) `bindS` \bexp ->
returnS (tConj (bindexps ++ [bexp]))
AOr _ e1 e2 ->
exp2smt demanded (resvar,e1) `bindS` \bexp1 ->
exp2smt demanded (resvar,e2) `bindS` \bexp2 ->
returnS (tDisj [bexp1, bexp2])
ACase _ _ e brs ->
getS `bindS` \ts ->
let freshvar = freshVar ts in
putS (addVarTypes [(freshvar, annExpr e)] (incFreshVarIndex ts)) `bindS_`
exp2smt demanded (freshvar,e) `bindS` \argbexp ->
mapS branch2smt (map (\b->(freshvar,b)) brs) `bindS` \bbrs ->
returnS (tConj [argbexp, tDisj bbrs])
ATyped _ e _ -> exp2smt demanded (resvar,e)
AFree _ _ _ -> error "Free variables not yet supported!"
where
comb2smt qf rtype ct nargs bs bindexps
| qf == pre "otherwise"
= returnS (tEquVar resvar tTrue)
| ct == ConsCall
= returnS (tConj (bindexps ++
[tEquVar resvar
(TComb (cons2SMT (null nargs) False qf rtype)
(map arg2smt nargs))]))
| qf == pre "apply"
=
returnS tTrue
| isPrimOp qf
= returnS (tConj (bindexps ++
[tEquVar resvar (TComb (cons2SMT True False qf rtype)
(map arg2smt nargs))]))
| otherwise
= let targs = zip (map fst bs) (map annExpr nargs) in
preCondExpOf vi qf targs `bindS` \precond ->
postCondExpOf vi qf (targs ++ [(resvar,rtype)]) `bindS` \postcond ->
returnS (tConj (bindexps ++ if demanded then [precond,postcond] else []))
branch2smt (cvar, (ABranch p e)) =
exp2smt demanded (resvar,e) `bindS` \branchbexp ->
getS `bindS` \ts ->
putS ts { varTypes = patvars ++ varTypes ts} `bindS_`
returnS (tConj [ tEquVar cvar (pat2SMT p), branchbexp])
where
patvars = if isConsPattern p
then patArgs p
else []
arg2smt e = case e of AVar _ i -> TSVar i
ALit _ l -> lit2SMT l
_ -> error $ "Not normalized: " ++ show e
normalizeArgs :: [TAExpr] -> State TransState ([(Int,TAExpr)],[TAExpr])
normalizeArgs [] = returnS ([],[])
normalizeArgs (e:es) = case e of
AVar _ i -> normalizeArgs es `bindS` \ (bs,nes) ->
returnS ((i,e):bs, e:nes)
_ -> getS `bindS` \ts ->
let fvar = freshVar ts
nts = addVarTypes [(fvar,annExpr e)] (incFreshVarIndex ts)
in putS nts `bindS_`
normalizeArgs es `bindS` \ (bs,nes) ->
returnS ((fvar,e):bs, AVar (annExpr e) fvar : nes)
unzipBranches :: [TABranchExpr] -> ([TAPattern],[TAExpr])
unzipBranches [] = ([],[])
unzipBranches (ABranch p e : brs) = (p:xs,e:ys)
where (xs,ys) = unzipBranches brs
checkImplication :: Options -> IORef VState -> String -> [(Int,TypeExpr)]
-> Term -> Term -> Term -> IO (Maybe String)
checkImplication opts vstref scripttitle vartypes assertion impbindings imp =
if optVerify opts
then checkImplicationWithSMT opts vstref scripttitle vartypes
assertion impbindings imp
else return Nothing
checkImplicationWithSMT :: Options -> IORef VState -> String -> [(Int,TypeExpr)]
-> Term -> Term -> Term -> IO (Maybe String)
checkImplicationWithSMT opts vstref scripttitle vartypes
assertion impbindings imp = do
let allsyms = catMaybes
(map (\n -> maybe Nothing Just (untransOpName n))
(map qidName
(allQIdsOfTerm (tConj [assertion, impbindings, imp]))))
unless (null allsyms) $ printWhenIntermediate opts $
"Translating operations into SMT: " ++ unwords (map showQName allsyms)
(smtfuncs,fdecls,ndinfo) <- funcs2SMT opts vstref allsyms
smttypes <- genSMTTypes vstref vartypes fdecls [assertion,impbindings,imp]
let freshvar = maximum (map fst vartypes) + 1
([assertionC,impbindingsC,impC],newix) =
nondetTransL ndinfo freshvar [assertion,impbindings,imp]
smt = smttypes ++
[ EmptyLine, smtfuncs, EmptyLine
, Comment "Free variables:" ] ++
map typedVar2SMT
(vartypes ++ map toChoiceVar [freshvar .. newix-1]) ++
[ EmptyLine
, Comment "Boolean formula of assertion (known properties):"
, sAssert assertionC, EmptyLine
, Comment "Bindings of implication:"
, sAssert impbindingsC, EmptyLine
, Comment "Assert negated implication:"
, sAssert (tNot impC), EmptyLine
, Comment "check satisfiability:"
, CheckSat
, Comment "if unsat, we can omit this part of the contract check"
]
smtstdtypes <- readInclude "Prelude.smt"
smtchoice <- if or (map snd ndinfo)
then readInclude "Prelude_Choice.smt"
else return ""
let smtprelude = smtstdtypes ++ smtchoice
callSMT opts $ "; " ++ scripttitle ++ "\n\n" ++ smtprelude ++ showSMT smt
where
readInclude f = readFile (packagePath </> "include" </> f)
toChoiceVar i = (i, TCons (pre "Choice") [])
genSMTTypes :: IORef VState -> [(Int,TypeExpr)] -> [TAFuncDecl] -> [Term]
-> IO [Command]
genSMTTypes vstref vartypes fdecls smtterms = do
let
alltypes = concatMap typesOfFunc fdecls ++ map snd vartypes
alltcons = foldr union [] (map tconsOfTypeExpr alltypes)
allsorts = concatMap sortIdsOfSort (concatMap sortsOfTerm smtterms)
(pretypes,usertypes) = partition ((== "Prelude") . fst) alltcons
presorts = nub (filter (`notElem` (map tcons2SMT pretypes)) allsorts) ++
map tcons2SMT pretypes
vst <- readIORef vstref
let udecls = map (maybe (error "Internal error: some datatype not found!") id)
(map (tdeclOf vst) usertypes)
return $ concatMap preludeSort2SMT presorts ++
[ EmptyLine ] ++
(if null udecls
then []
else [ Comment "User-defined datatypes:" ] ++
map tdecl2SMT udecls)
callSMT :: Options -> String -> IO (Maybe String)
callSMT opts smtinput = do
printWhenIntermediate opts $ "SMT SCRIPT:\n" ++ showWithLineNums smtinput
printWhenIntermediate opts $ "CALLING Z3..."
(ecode,out,err) <- evalCmd "z3" ["-smt2", "-in", "-T:2"] smtinput
when (ecode>0) $ do printWhenIntermediate opts $ "EXIT CODE: " ++ show ecode
writeFile "error.smt" smtinput
printWhenIntermediate opts $ "RESULT:\n" ++ out
unless (null err) $ printWhenIntermediate opts $ "ERROR:\n" ++ err
let unsat = let ls = lines out in not (null ls) && head ls == "unsat"
return $ if unsat
then Just $ "; proved by: z3 -smt2 <SMTFILE>\n\n" ++ smtinput
else Nothing
nondetTrans :: [(QName,Bool)] -> Int -> Term -> (Term,Int)
nondetTrans ndinfo ix trm = case trm of
TConst _ -> (trm,ix)
TSVar _ -> (trm,ix)
TComb f args -> let (targs,i1) = nondetTransL ndinfo ix args
in if maybe False
(\qn -> maybe False id (lookup qn ndinfo))
(untransOpName (qidName f))
then (TComb (addChoiceType f) (TSVar i1 : targs), i1+1)
else (TComb f targs, i1)
Forall vs arg -> let (targ,ix1) = nondetTrans ndinfo ix arg
in (Forall vs targ, ix1)
Exists vs arg -> let (targ,ix1) = nondetTrans ndinfo ix arg
in (Exists vs targ, ix1)
ESMT.Let bs e -> let (tbt,ix1) = nondetTransL ndinfo ix (map snd bs)
(te,ix2) = nondetTrans ndinfo ix1 e
in (ESMT.Let (zip (map fst bs) tbt) te, ix2)
where
addChoiceType (Id n) = Id n
addChoiceType (As n tp) = As n (SComb "Func" [SComb "Choice" [], tp])
nondetTransL :: [(QName,Bool)] -> Int -> [Term] -> ([Term],Int)
nondetTransL _ i [] = ([],i)
nondetTransL ndinfo i (t:ts) =
let (t1,i1) = nondetTrans ndinfo i t
(ts1,i2) = nondetTransL ndinfo i1 ts
in (t1:ts1, i2)
axiomatizedOps :: [String]
axiomatizedOps = ["Prelude_null","Prelude_take","Prelude_length"]
typedVar2SMT :: (Int,TypeExpr) -> Command
typedVar2SMT (i,te) = DeclareVar (SV i (polytype2sort te))
tconsOfTypeExpr :: TypeExpr -> [QName]
tconsOfTypeExpr (TVar _) = []
tconsOfTypeExpr (FuncType a b) = union (tconsOfTypeExpr a) (tconsOfTypeExpr b)
tconsOfTypeExpr (TCons qName texps) =
foldr union [qName] (map tconsOfTypeExpr texps)
tconsOfTypeExpr (ForallType _ te) = tconsOfTypeExpr te
fileInPath :: String -> IO Bool
fileInPath file = do
path <- getEnviron "PATH"
dirs <- return $ splitOn ":" path
(liftIO (any id)) $ mapM (doesFileExist . (</> file)) dirs
showQNameNoDots :: QName -> String
showQNameNoDots = map (\c -> if c=='.' then '_' else c) . showQName
showWithLineNums :: String -> String
showWithLineNums txt =
let txtlines = lines txt
maxlog = ilog (length txtlines + 1)
showNum n = (take (maxlog - ilog n) (repeat ' ')) ++ show n ++ ": "
in unlines . map (uncurry (++)) . zip (map showNum [1..]) $ txtlines
|