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Split VirtualMachine module

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Bartłomiej Przemysław Pluta
2021-11-09 18:25:15 +01:00
parent 3faa4f4abf
commit bfb231d483
10 changed files with 212 additions and 193 deletions
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99
app/VirtualMachine/Instruction.hs Normal file
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module VirtualMachine.Instruction where
import Data.Char (chr)
import Data.Word (Word8)
import Control.Monad.Trans (liftIO)
import Control.Monad.Trans.Except (ExceptT, except, runExceptT)
import Control.Monad.State (execState, evalState)
import qualified Data.Map as M
import qualified Data.Sequence as S
import VirtualMachine.VM (VM(..), Op(..), push, pop, forward, getAt, getPc, getFp, getStackSize, setPc, setFp)
type Params = [Int]
type Pops = [Int]
type Pushes = S.Seq Int
data Instruction = Simple { _op :: Op, _noParams :: Int, _noPops :: Int, _sAction :: Params -> Pops -> Pushes }
| Complex { _op :: Op, _noParams :: Int, _noPops :: Int, _cAction :: VM -> Params -> Pops -> ExceptT String IO VM }
instance Show Instruction where
show (Simple op noParams noPops _) = (show op) ++ "(S," ++ (show noParams) ++ "," ++ (show noPops) ++ ")"
show (Complex op noParams noPops _) = (show op) ++ "(C," ++ (show noParams) ++ "," ++ (show noPops) ++ ")"
data Unit = Instr { _instr :: Instruction }
| Byte { _byte :: Word8 }
deriving (Show)
instructions :: [Instruction]
instructions = [ Simple { _op = Nop, _noParams = 0, _noPops = 0, _sAction = (\_ _ -> S.empty) }
, Simple { _op = Push, _noParams = 1, _noPops = 0, _sAction = (\params _ -> S.fromList params) }
, Simple { _op = Pop, _noParams = 0, _noPops = 1, _sAction = (\_ _ -> S.empty) }
, Simple { _op = Dup, _noParams = 0, _noPops = 1, _sAction = (\_ [x] -> S.fromList [x, x]) }
, Simple { _op = Swap, _noParams = 0, _noPops = 2, _sAction = (\_ [x, y] -> S.fromList [y, x]) }
, Simple { _op = Add, _noParams = 0, _noPops = 2, _sAction = (\_ [x, y] -> S.fromList [y + x]) }
, Simple { _op = Sub, _noParams = 0, _noPops = 2, _sAction = (\_ [x, y] -> S.fromList [y - x]) }
, Simple { _op = Mul, _noParams = 0, _noPops = 2, _sAction = (\_ [x, y] -> S.fromList [y * x]) }
, Simple { _op = Div, _noParams = 0, _noPops = 2, _sAction = (\_ [x, y] -> S.fromList [y `div` x]) }
, Simple { _op = Neg, _noParams = 0, _noPops = 1, _sAction = (\_ [x] -> S.fromList [-x]) }
, Simple { _op = Not, _noParams = 0, _noPops = 1, _sAction = (\_ [x] -> S.fromList [if x /= 0 then 0 else 1]) }
, Complex { _op = Halt, _noParams = 0, _noPops = 1, _cAction = (\vm _ _ -> except $ Right $ vm { _halt = True }) }
, Complex { _op = Call, _noParams = 1, _noPops = 0, _cAction = call }
, Complex { _op = Ret, _noParams = 0, _noPops = 0, _cAction = ret }
, Complex { _op = Jmp, _noParams = 1, _noPops = 0, _cAction = (\vm [x] _ -> except $ Right $ vm { _pc = x}) }
, Complex { _op = Je, _noParams = 1, _noPops = 1, _cAction = jumpIf (==) }
, Complex { _op = Jne, _noParams = 1, _noPops = 1, _cAction = jumpIf (/=) }
, Complex { _op = Jg, _noParams = 1, _noPops = 1, _cAction = jumpIf (>) }
, Complex { _op = Jl, _noParams = 1, _noPops = 1, _cAction = jumpIf (<) }
, Complex { _op = Jge, _noParams = 1, _noPops = 1, _cAction = jumpIf (>=) }
, Complex { _op = Jle, _noParams = 1, _noPops = 1, _cAction = jumpIf (<=) }
, Complex { _op = Out, _noParams = 0, _noPops = 1, _cAction = output }
, Complex { _op = Dbg, _noParams = 0, _noPops = 0, _cAction = debug }
]
instructionByOp :: M.Map Op Instruction
instructionByOp = M.fromList $ map (\i -> (_op i, i)) instructions
call :: VM -> Params -> Pops -> ExceptT String IO VM
call vm (addr:_) _ = except $ return $ flip execState vm $ do
fp <- getFp
fp' <- getStackSize
retAddr <- getPc >>= return . (+2)
push [retAddr, fp]
setPc addr
setFp fp'
return ()
call _ [] _ = except $ Left $ "Address excepted"
ret :: VM -> Params -> Pops -> ExceptT String IO VM
ret vm _ _ = do
let fp = _fp vm
let stack = _stack vm
let stackSize = S.length stack
let stack' = _stack $ execState (pop (stackSize - fp)) vm
fp' <- except $ evalState (runExceptT (getAt (stackSize - fp - 1) "Cannot determine previous frame pointer (fp)")) vm
retAddr <- except $ evalState (runExceptT (getAt (stackSize - fp - 2) "Cannot determine return address" )) vm
return vm { _fp = fp', _pc = retAddr, _stack = stack' }
debug :: VM -> Params -> Pops -> ExceptT String IO VM
debug vm _ _ = do
liftIO $ print vm
return vm { _pc = _pc vm + 1 }
jumpIf :: (Int -> Int -> Bool) -> VM -> Params -> Pops -> ExceptT String IO VM
jumpIf predicate vm (addr:_) (top:_) = except $ Right $ vm { _pc = pc }
where pc = if top `predicate` 0 then addr else _pc vm + 1
jumpIf _ _ [] _ = except $ Left "Address expected"
jumpIf _ _ _ [] = except $ Left "Empty stack - nothing to compare"
output :: VM -> Params -> Pops -> ExceptT String IO VM
output vm _ (char:_) = do
liftIO $ putStr $ [chr char]
return (execState (forward 1) vm)
output _ _ [] = except $ Left $ "Empty stack - nothing to output"

88
app/VirtualMachine/Interpreter.hs Normal file
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module VirtualMachine.Interpreter where
import Data.Word (Word8)
import Control.Monad.Trans.Except (ExceptT, except)
import Control.Monad.State (runState, execState)
import qualified Data.Map as M
import qualified Data.ByteString as B
import VirtualMachine.VM (VM(..), Op, empty, pop, pushS, forward, getPc)
import VirtualMachine.Instruction (Instruction(..), Unit(..), instructionByOp)
parseInstr :: [Word8] -> Either String (Instruction, [Word8])
parseInstr (opCode:rest) = do
let op = toEnum . fromIntegral $ opCode :: Op
instr <- case M.lookup op instructionByOp of
(Just i) -> Right i
Nothing -> Left "Unknown instruction"
let noParams = _noParams instr
let params = map fromIntegral $ take noParams rest :: [Word8]
if length params == noParams
then return (instr, params)
else Left $ "Expected " ++ (show noParams) ++ " parameter(s), got " ++ (show $ length params) ++ " for operator '" ++ (show op) ++ "'"
parseInstr [] = Left "Unexpected end of the file"
parse :: [Word8] -> Either String [Unit]
parse [] = Right []
parse code = do
(instr, params) <- parseInstr code
let paramBytes = map Byte params
let noParams = _noParams instr
rest <- parse (drop (noParams + 1) code)
return $ [Instr instr] ++ paramBytes ++ rest
interpret :: VM -> [Unit] -> ExceptT String IO VM
interpret vm@VM { _halt = True} _ = except $ Right $ vm
interpret vm units = do
vm' <- interpretUnit vm units
interpret vm' units
interpretUnit :: VM -> [Unit] -> ExceptT String IO VM
interpretUnit _ [] = except $ Left "Nothing to interpret"
interpretUnit vm units
| pc >= progSize = except $ Left $ "PC (=" ++ (show pc) ++ ") exceeds program size (=" ++ (show progSize) ++ ")"
| otherwise = case unit of
(Instr instr) -> dispatchInstr vm units instr
(Byte _) -> except $ Left $ "PC (=" ++ (show pc) ++ ") currently points to the data byte rather than instruction"
where
pc = _pc vm
progSize = length units
unit = units !! pc
dispatchInstr :: VM -> [Unit] -> Instruction -> ExceptT String IO VM
dispatchInstr vm units instr = case instr of
Simple {} -> except $ Right $ interpretSimple vm units instr
Complex {} -> interpretComplex vm units instr
interpretSimple :: VM -> [Unit] -> Instruction -> VM
interpretSimple vm units instr = flip execState vm $ do
pc <- getPc
let noParams = _noParams instr
let noPops = _noPops instr
let paramBytes = take noParams $ drop (pc + 1) $ units
let params = map (fromIntegral . _byte) paramBytes
let action = _sAction instr
pops <- pop noPops
let pushes = action params pops
pushS pushes
forward $ noParams + 1
return ()
interpretComplex :: VM -> [Unit] -> Instruction -> ExceptT String IO VM
interpretComplex vm units instr = action vm' params pops
where
pc = _pc vm
noParams = _noParams instr
noPops = _noPops instr
paramBytes = take noParams $ drop (pc + 1) $ units
params = map (fromIntegral . _byte) paramBytes
(pops, vm') = runState (pop noPops) vm
action = _cAction instr
run :: B.ByteString -> ExceptT String IO VM
run code = (return $ B.unpack code) >>= (except . parse) >>= interpret empty

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app/VirtualMachine/VM.hs Normal file
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module VirtualMachine.VM where
import Data.Foldable (toList)
import Control.Monad.State (State, get, put)
import Control.Monad.Trans.Except (ExceptT, except)
import qualified Data.Sequence as S
data VM = VM { _pc :: Int
, _fp :: Int
, _stack :: S.Seq Int
, _halt :: Bool
} deriving (Show, Eq)
data Op = Nop -- 0x00
| Halt -- 0x01
| Push -- 0x02
| Pop -- 0x03
| Dup -- 0x04
| Swap -- 0x05
| Add -- 0x06
| Sub -- 0x07
| Mul -- 0x08
| Div -- 0x09
| Neg -- 0x0a
| Not -- 0x0b
| Call -- 0x0c
| Ret -- 0x0d
| Jmp -- 0x0e
| Je -- 0x0f
| Jne -- 0x10
| Jg -- 0x11
| Jl -- 0x12
| Jge -- 0x13
| Jle -- 0x14
| Ld -- 0x15
| In -- 0x16
| Out -- 0x17
| Dbg -- 0x18
deriving (Eq, Ord, Enum, Show, Read, Bounded)
empty :: VM
empty = VM { _pc = 0
, _fp = -1
, _stack = S.empty
, _halt = False
}
-------------------------------------------------------------------------------
push :: [Int] -> State VM ()
push = pushS . S.fromList
pushS :: S.Seq Int -> State VM ()
pushS numbers = do
vm <- get
put vm { _stack = numbers <> _stack vm }
return ()
pop :: Int -> State VM [Int]
pop count = do
vm <- get
let stack = _stack vm
put vm { _stack = S.drop count $ stack }
return $ toList $ S.take count $ stack
getAt :: Int -> String -> ExceptT String (State VM) Int
getAt index err = do
vm <- get
let stack = _stack vm
case (stack S.!? index) of
(Just i) -> return i
Nothing -> except $ Left err
getPc :: State VM Int
getPc = get >>= (return . _pc)
getFp :: State VM Int
getFp = get >>= (return . _fp)
getStackSize :: State VM Int
getStackSize = get >>= (return . length . _stack)
setPc :: Int -> State VM ()
setPc pc' = do
vm <- get
put vm { _pc = pc' }
setFp :: Int -> State VM ()
setFp fp' = do
vm <- get
put vm { _fp = fp' }
forward :: Int -> State VM ()
forward offset = do
vm <- get
put vm { _pc = _pc vm + offset }
return ()