cryptol/sbv/Data/SBV/Provers/CVC4.hs
2014-07-21 15:23:34 -07:00

103 lines
6.0 KiB
Haskell

-----------------------------------------------------------------------------
-- |
-- Module : Data.SBV.Provers.CVC4
-- Copyright : (c) Levent Erkok
-- License : BSD3
-- Maintainer : erkokl@gmail.com
-- Stability : experimental
--
-- The connection to the CVC4 SMT solver
-----------------------------------------------------------------------------
{-# LANGUAGE ScopedTypeVariables #-}
module Data.SBV.Provers.CVC4(cvc4) where
import qualified Control.Exception as C
import Data.Char (isSpace)
import Data.Function (on)
import Data.List (sortBy, intercalate)
import System.Environment (getEnv)
import System.Exit (ExitCode(..))
import Data.SBV.BitVectors.Data
import Data.SBV.SMT.SMT
import Data.SBV.SMT.SMTLib
-- | The description of the CVC4 SMT solver
-- The default executable is @\"cvc4\"@, which must be in your path. You can use the @SBV_CVC4@ environment variable to point to the executable on your system.
-- The default options are @\"--lang smt\"@. You can use the @SBV_CVC4_OPTIONS@ environment variable to override the options.
cvc4 :: SMTSolver
cvc4 = SMTSolver {
name = CVC4
, executable = "cvc4"
, options = ["--lang", "smt"]
, engine = \cfg isSat qinps modelMap skolemMap pgm -> do
execName <- getEnv "SBV_CVC4" `C.catch` (\(_ :: C.SomeException) -> return (executable (solver cfg)))
execOpts <- (words `fmap` getEnv "SBV_CVC4_OPTIONS") `C.catch` (\(_ :: C.SomeException) -> return (options (solver cfg)))
let cfg' = cfg { solver = (solver cfg) {executable = execName, options = addTimeOut (timeOut cfg) execOpts} }
tweaks = case solverTweaks cfg' of
[] -> ""
ts -> unlines $ "; --- user given solver tweaks ---" : ts ++ ["; --- end of user given tweaks ---"]
script = SMTScript {scriptBody = tweaks ++ pgm, scriptModel = Just (cont skolemMap)}
standardSolver cfg' script id (ProofError cfg') (interpretSolverOutput cfg' (extractMap isSat qinps modelMap))
, xformExitCode = cvc4ExitCode
, capabilities = SolverCapabilities {
capSolverName = "CVC4"
, mbDefaultLogic = Just "ALL_SUPPORTED" -- CVC4 is not happy if we don't set the logic, so fall-back to this if necessary
, supportsMacros = True
, supportsProduceModels = True
, supportsQuantifiers = True
, supportsUninterpretedSorts = True
, supportsUnboundedInts = True
, supportsReals = True -- Not quite the same capability as Z3; but works more or less..
, supportsFloats = False
, supportsDoubles = False
}
}
where zero :: Kind -> String
zero KBool = "false"
zero (KBounded _ sz) = "#x" ++ replicate (sz `div` 4) '0'
zero KUnbounded = "0"
zero KReal = "0.0"
zero KFloat = error "SBV.CVC4.zero: Unexpected float value"
zero KDouble = error "SBV.CVC4.zero: Unexpected double value"
zero (KUninterpreted s) = error $ "SBV.CVC4.zero: Unexpected uninterpreted sort: " ++ s
cont skolemMap = intercalate "\n" $ map extract skolemMap
where extract (Left s) = "(echo \"((" ++ show s ++ " " ++ zero (kindOf s) ++ "))\")"
extract (Right (s, [])) = "(get-value (" ++ show s ++ "))"
extract (Right (s, ss)) = "(get-value (" ++ show s ++ concat [' ' : zero (kindOf a) | a <- ss] ++ "))"
addTimeOut Nothing o = o
addTimeOut (Just i) o
| i < 0 = error $ "CVC4: Timeout value must be non-negative, received: " ++ show i
| True = o ++ ["--tlimit=" ++ show i ++ "000"] -- SBV takes seconds, CVC4 wants milli-seconds
-- | CVC4 uses different exit codes to indicate its status, rather than the
-- standard 0 being success and non-0 being failure. Make it palatable to SBV.
-- See <http://cvc4.cs.nyu.edu/wiki/User_Manual#Exit_status> for details.
cvc4ExitCode :: ExitCode -> ExitCode
cvc4ExitCode (ExitFailure n) | n `elem` [10, 20, 0] = ExitSuccess
cvc4ExitCode ec = ec
extractMap :: Bool -> [(Quantifier, NamedSymVar)] -> [(String, UnintKind)] -> [String] -> SMTModel
extractMap isSat qinps _modelMap solverLines =
SMTModel { modelAssocs = map snd $ sortByNodeId $ concatMap (interpretSolverModelLine inps . unstring) solverLines
, modelUninterps = []
, modelArrays = []
}
where sortByNodeId :: [(Int, a)] -> [(Int, a)]
sortByNodeId = sortBy (compare `on` fst)
inps -- for "sat", display the prefix existentials. For completeness, we will drop
-- only the trailing foralls. Exception: Don't drop anything if it's all a sequence of foralls
| isSat = map snd $ if all (== ALL) (map fst qinps)
then qinps
else reverse $ dropWhile ((== ALL) . fst) $ reverse qinps
-- for "proof", just display the prefix universals
| True = map snd $ takeWhile ((== ALL) . fst) qinps
-- CVC4 puts quotes around echo's, go figure. strip them here
unstring s' = case (s, head s, last s) of
(_:tl@(_:_), '"', '"') -> init tl
_ -> s'
where s = reverse . dropWhile isSpace . reverse . dropWhile isSpace $ s'