-{-# LANGUAGE FlexibleContexts, TypeFamilies, OverloadedStrings, TypeSynonymInstances, FlexibleInstances #-}
+{-# LANGUAGE FlexibleContexts, TypeFamilies, OverloadedStrings, TypeSynonymInstances, FlexibleInstances, MultiParamTypeClasses, UndecidableInstances, GeneralizedNewtypeDeriving, ScopedTypeVariables #-}
-- | This module defines Generate monad, which helps generating JVM code and
-- creating Java class constants pool.
module JVM.Builder.Monad
generate, generateIO
) where
+import Prelude hiding (catch)
import Control.Monad.State as St
+import Control.Monad.Exception
import Data.Word
import Data.List
import Data.Binary
import JVM.Common () -- import instances only
import JVM.ClassFile
import JVM.Assembler
+import JVM.Exceptions
import Java.ClassPath
-- | Generator state
data GState = GState {
- generated :: [Instruction], -- ^ Already generated code (in current method)
+ generated :: [Instruction], -- ^ Already generated code (in current method)
currentPool :: Pool Direct, -- ^ Already generated constants pool
doneMethods :: [Method Direct], -- ^ Already generated class methods
currentMethod :: Maybe (Method Direct), -- ^ Current method
- stackSize :: Word16, -- ^ Maximum stack size for current method
- locals :: Word16, -- ^ Maximum number of local variables for current method
+ stackSize :: Word16, -- ^ Maximum stack size for current method
+ locals :: Word16, -- ^ Maximum number of local variables for current method
classPath :: [Tree CPEntry]
}
deriving (Eq,Show)
locals = 0,
classPath = []}
-class (Monad m, MonadState GState m) => Generator m where
+class (Monad (g e), MonadState GState (g e)) => Generator e g where
+ throwG :: (Exception x, Throws x e) => x -> g e a
-- | Generate monad
-type GenerateIO a = StateT GState IO a
+newtype Generate e a = Generate {
+ runGenerate :: EMT e (State GState) a }
+ deriving (Monad, MonadState GState)
-type Generate a = State GState a
+instance MonadState st (EMT e (StateT st IO)) where
+ get = lift St.get
+ put x = lift (St.put x)
-instance Generator (StateT GState IO) where
+instance MonadState st (EMT e (State st)) where
+ get = lift St.get
+ put x = lift (St.put x)
-instance Generator (State GState) where
+-- | IO version of Generate monad
+newtype GenerateIO e a = GenerateIO {
+ runGenerateIO :: EMT e (StateT GState IO) a }
+ deriving (Monad, MonadState GState, MonadIO)
+
+instance MonadIO (EMT e (StateT GState IO)) where
+ liftIO action = lift $ liftIO action
+
+instance Generator e GenerateIO where
+ throwG e = GenerateIO (throw e)
+
+instance (MonadState GState (EMT e (State GState))) => Generator e Generate where
+ throwG e = Generate (throw e)
+
+execGenerateIO cp (GenerateIO emt) = do
+ let caught = emt `catch` (\(e :: SomeException) -> fail $ show e)
+ execStateT (runEMT caught) (emptyGState {classPath = cp})
+
+execGenerate cp (Generate emt) = do
+ let caught = emt `catch` (\(e :: SomeException) -> fail $ show e)
+ execState (runEMT caught) (emptyGState {classPath = cp})
-- | Update ClassPath
-withClassPath :: ClassPath () -> GenerateIO ()
+withClassPath :: ClassPath () -> GenerateIO e ()
withClassPath cp = do
res <- liftIO $ execClassPath cp
st <- St.get
in (pool', size)
-- | Add a constant to pool
-addItem :: (Generator g) => Constant Direct -> g Word16
+addItem :: (Generator e g) => Constant Direct -> g e Word16
addItem c = do
pool <- St.gets currentPool
case lookupPool c pool of
lookupPool c pool =
fromIntegral `fmap` findIndex (== c) (M.elems pool)
-addNT :: (Generator g, HasSignature a) => NameType a -> g Word16
+addNT :: (Generator e g, HasSignature a) => NameType a -> g e Word16
addNT (NameType name sig) = do
let bsig = encode sig
x <- addItem (CNameType name bsig)
addItem (CUTF8 bsig)
return x
-addSig :: (Generator g) => MethodSignature -> g Word16
+addSig :: (Generator e g) => MethodSignature -> g e Word16
addSig c@(MethodSignature args ret) = do
let bsig = encode c
addItem (CUTF8 bsig)
-- | Add a constant into pool
-addToPool :: (Generator g) => Constant Direct -> g Word16
+addToPool :: (Generator e g) => Constant Direct -> g e Word16
addToPool c@(CClass str) = do
addItem (CUTF8 str)
addItem c
addItem c
addToPool c = addItem c
-putInstruction :: (Generator g) => Instruction -> g ()
+putInstruction :: (Generator e g) => Instruction -> g e ()
putInstruction instr = do
st <- St.get
let code = generated st
St.put $ st {generated = code ++ [instr]}
-- | Generate one (zero-arguments) instruction
-i0 :: (Generator g) => Instruction -> g ()
+i0 :: (Generator e g) => Instruction -> g e ()
i0 = putInstruction
-- | Generate one one-argument instruction
-i1 :: (Generator g) => (Word16 -> Instruction) -> Constant Direct -> g ()
+i1 :: (Generator e g) => (Word16 -> Instruction) -> Constant Direct -> g e ()
i1 fn c = do
ix <- addToPool c
i0 (fn ix)
-- | Generate one one-argument instruction
-i8 :: (Generator g) => (Word8 -> Instruction) -> Constant Direct -> g ()
+i8 :: (Generator e g) => (Word8 -> Instruction) -> Constant Direct -> g e ()
i8 fn c = do
ix <- addToPool c
i0 (fn $ fromIntegral ix)
-- | Set maximum stack size for current method
-setStackSize :: (Generator g) => Word16 -> g ()
+setStackSize :: (Generator e g) => Word16 -> g e ()
setStackSize n = do
st <- St.get
St.put $ st {stackSize = n}
-- | Set maximum number of local variables for current method
-setMaxLocals :: (Generator g) => Word16 -> g ()
+setMaxLocals :: (Generator e g) => Word16 -> g e ()
setMaxLocals n = do
st <- St.get
St.put $ st {locals = n}
-- | Start generating new method
-startMethod :: (Generator g) => [AccessFlag] -> B.ByteString -> MethodSignature -> g ()
+startMethod :: (Generator e g) => [AccessFlag] -> B.ByteString -> MethodSignature -> g e ()
startMethod flags name sig = do
addToPool (CString name)
addSig sig
currentMethod = Just method }
-- | End of method generation
-endMethod :: (Generator g) => g ()
+endMethod :: (Generator e g, Throws UnexpectedEndMethod e) => g e ()
endMethod = do
m <- St.gets currentMethod
code <- St.gets genCode
case m of
- Nothing -> fail "endMethod without startMethod!"
+ Nothing -> throwG UnexpectedEndMethod
Just method -> do
let method' = method {methodAttributes = AR $ M.fromList [("Code", encodeMethod code)],
methodAttributesCount = 1}
doneMethods = doneMethods st ++ [method']}
-- | Generate new method
-newMethod :: (Generator g)
- => [AccessFlag] -- ^ Access flags for method (public, static etc)
- -> B.ByteString -- ^ Method name
- -> [ArgumentSignature] -- ^ Signatures of method arguments
- -> ReturnSignature -- ^ Method return signature
- -> g () -- ^ Generator for method code
- -> g (NameType Method)
+newMethod :: (Generator e g, Throws UnexpectedEndMethod e)
+ => [AccessFlag] -- ^ Access flags for method (public, static etc)
+ -> B.ByteString -- ^ Method name
+ -> [ArgumentSignature] -- ^ Signatures of method arguments
+ -> ReturnSignature -- ^ Method return signature
+ -> g e () -- ^ Generator for method code
+ -> g e (NameType Method)
newMethod flags name args ret gen = do
let sig = MethodSignature args ret
startMethod flags name sig
return (NameType name sig)
-- | Get a class from current ClassPath
-getClass :: String -> GenerateIO (Class Direct)
+getClass :: (Throws ENotLoaded e, Throws ENotFound e)
+ => String -> GenerateIO e (Class Direct)
getClass name = do
cp <- St.gets classPath
res <- liftIO $ getEntry cp name
case res of
- Just (NotLoaded p) -> fail $ "Class file was not loaded: " ++ p
+ Just (NotLoaded p) -> throwG (ClassFileNotLoaded p)
Just (Loaded _ c) -> return c
- Just (NotLoadedJAR p c) -> fail $ "Class was not loaded from JAR " ++ p ++ ": " ++ c
+ Just (NotLoadedJAR p c) -> throwG (JARNotLoaded p c)
Just (LoadedJAR _ c) -> return c
- Nothing -> fail $ "No such class in ClassPath: " ++ name
+ Nothing -> throwG (ClassNotFound name)
-- | Get class field signature from current ClassPath
-getClassField :: String -> B.ByteString -> GenerateIO (NameType Field)
+getClassField :: (Throws ENotFound e, Throws ENotLoaded e)
+ => String -> B.ByteString -> GenerateIO e (NameType Field)
getClassField clsName fldName = do
cls <- getClass clsName
case lookupField fldName cls of
Just fld -> return (fieldNameType fld)
- Nothing -> fail $ "No such field in class " ++ clsName ++ ": " ++ toString fldName
+ Nothing -> throwG (FieldNotFound clsName fldName)
-- | Get class method signature from current ClassPath
-getClassMethod :: String -> B.ByteString -> GenerateIO (NameType Method)
+getClassMethod :: (Throws ENotFound e, Throws ENotLoaded e)
+ => String -> B.ByteString -> GenerateIO e (NameType Method)
getClassMethod clsName mName = do
cls <- getClass clsName
case lookupMethod mName cls of
Just m -> return (methodNameType m)
- Nothing -> fail $ "No such method in class " ++ clsName ++ ": " ++ toString mName
+ Nothing -> throwG (MethodNotFound clsName mName)
-- | Convert Generator state to method Code.
genCode :: GState -> Code
len = fromIntegral $ B.length $ encodeInstructions (generated st)
-- | Start class generation.
-initClass :: (Generator g) => B.ByteString -> g Word16
+initClass :: (Generator e g) => B.ByteString -> g e Word16
initClass name = do
addToPool (CClass "java/lang/Object")
addToPool (CClass name)
addToPool (CString "Code")
-- | Generate a class
-generateIO :: [Tree CPEntry] -> B.ByteString -> GenerateIO () -> IO (Class Direct)
generateIO cp name gen = do
let generator = do
initClass name
gen
- res <- execStateT generator (emptyGState {classPath = cp})
+ res <- execGenerateIO cp generator
let code = genCode res
d = defaultClass :: Class Direct
return $ d {
classMethods = doneMethods res }
-- | Generate a class
-generate :: [Tree CPEntry] -> B.ByteString -> Generate () -> Class Direct
generate cp name gen =
let generator = do
initClass name
gen
- res = execState generator (emptyGState {classPath = cp})
+ res = execGenerate cp generator
code = genCode res
d = defaultClass :: Class Direct
in d {
projects / hs-java.git / blobdiff