-- | This module declares (low-level) data types for Java .class files
-- structures, and Binary instances to read/write them.
module JVM.ClassFile
- (Attribute (..),
+ (-- * About
+ -- $about
+ --
+ -- * Internal class file structures
+ Attribute (..),
FieldType (..),
+ -- * Signatures
FieldSignature, MethodSignature (..), ReturnSignature (..),
ArgumentSignature (..),
+ -- * Stage types
+ File, Direct,
+ -- * Staged structures
Pool, Link,
Method (..), Field (..), Class (..),
Constant (..),
- Pointers, Resolved,
- NameType (..),
- HasSignature (..), HasAttributes (..),
AccessFlag (..), AccessFlags,
Attributes (..),
- className
+ defaultClass,
+ -- * Misc
+ HasSignature (..), HasAttributes (..),
+ NameType (..),
+ fieldNameType, methodNameType,
+ lookupField, lookupMethod,
+ toString,
+ className,
+ apsize, arsize, arlist
)
where
import Control.Monad
+import Control.Monad.Trans (lift)
import Control.Applicative
+import qualified Control.Monad.State as St
import Data.Binary
import Data.Binary.IEEE754
import Data.Binary.Get
import Data.Binary.Put
import Data.Char
import Data.List
+import Data.Default
import qualified Data.Set as S
import qualified Data.Map as M
import qualified Data.ByteString.Lazy as B
import Codec.Binary.UTF8.String hiding (encode, decode)
+-- $about
+--
+-- Java .class file uses constants pool, which stores almost all source-code-level
+-- constants (strings, integer literals etc), and also all identifiers (class,
+-- method, field names etc). All other structures contain indexes of constants in
+-- the pool instead of constants theirself.
+--
+-- It's not convient to use that indexes programmatically. So, .class file is represented
+-- at two stages: File and Direct. At File stage, all data structures contain only indexes,
+-- not constants theirself. When we read a class from a file, we get structure at File stage.
+-- We only can write File stage structure to file.
+--
+-- At Direct stage, structures conain constants, not indexes. Convertion functions (File <-> Direct)
+-- are located in the JVM.Converter module.
+--
+
-- | Read one-byte Char
getChar8 :: Get Char
getChar8 = do
toString :: B.ByteString -> String
toString bstr = decodeString $ map (chr . fromIntegral) $ B.unpack bstr
-type family Link s a
+-- | File stage
+data File = File
-data Pointers = Pointers
+-- | Direct representation stage
+data Direct = Direct
-data Resolved = Resolved
+-- | Link to some object
+type family Link stage a
-type instance Link Pointers a = Word16
+-- | At File stage, Link contain index of object in the constants pool.
+type instance Link File a = Word16
-type instance Link Resolved a = a
+-- | At Direct stage, Link contain object itself.
+type instance Link Direct a = a
+-- | Object (class, method, field …) access flags
type family AccessFlags stage
-type instance AccessFlags Pointers = Word16
+-- | At File stage, access flags are represented as Word16
+type instance AccessFlags File = Word16
+
+-- | At Direct stage, access flags are represented as set of flags.
+type instance AccessFlags Direct = S.Set AccessFlag
+
+-- | Object (class, method, field) attributes
+data family Attributes stage
+
+-- | At File stage, attributes are represented as list of Attribute structures.
+data instance Attributes File = AP {attributesList :: [Attribute]}
+ deriving (Eq, Show)
+
+instance Default (Attributes File) where
+ def = AP []
+
+-- | At Direct stage, attributes are represented as a Map.
+data instance Attributes Direct = AR (M.Map B.ByteString B.ByteString)
+ deriving (Eq, Show)
+
+instance Default (Attributes Direct) where
+ def = AR M.empty
-type instance AccessFlags Resolved = S.Set AccessFlag
+-- | Size of attributes set at Direct stage
+arsize :: Attributes Direct -> Int
+arsize (AR m) = M.size m
-type family Attributes stage
+-- | Associative list of attributes at Direct stage
+arlist :: Attributes Direct -> [(B.ByteString, B.ByteString)]
+arlist (AR m) = M.assocs m
-type instance Attributes Pointers = [Attribute]
-type instance Attributes Resolved = M.Map B.ByteString B.ByteString
+-- | Size of attributes set at File stage
+apsize :: Attributes File -> Int
+apsize (AP list) = length list
-- | Access flags. Used for classess, methods, variables.
data AccessFlag =
| ACC_ABSTRACT -- ^ 0x0400
deriving (Eq, Show, Ord, Enum)
-class HasSignature a where
+-- | Fields and methods have signatures.
+class (Binary (Signature a), Show (Signature a), Eq (Signature a))
+ => HasSignature a where
type Signature a
instance HasSignature Field where
ntName :: B.ByteString,
ntSignature :: Signature a }
-instance Show (Signature a) => Show (NameType a) where
+instance (HasSignature a) => Show (NameType a) where
show (NameType n t) = toString n ++ ": " ++ show t
-deriving instance Eq (Signature a) => Eq (NameType a)
+deriving instance HasSignature a => Eq (NameType a)
-instance (Binary (Signature a)) => Binary (NameType a) where
+instance HasSignature a => Binary (NameType a) where
put (NameType n t) = putLazyByteString n >> put t
get = NameType <$> get <*> get
-- | Constant pool item
data Constant stage =
- CClass B.ByteString
- | CField {refClass :: Link stage B.ByteString, fieldNameType :: Link stage (NameType Field)}
- | CMethod {refClass :: Link stage B.ByteString, nameType :: Link stage (NameType Method)}
- | CIfaceMethod {refClass :: Link stage B.ByteString, nameType :: Link stage (NameType Method)}
+ CClass (Link stage B.ByteString)
+ | CField (Link stage B.ByteString) (Link stage (NameType Field))
+ | CMethod (Link stage B.ByteString) (Link stage (NameType Method))
+ | CIfaceMethod (Link stage B.ByteString) (Link stage (NameType Method))
| CString (Link stage B.ByteString)
| CInteger Word32
| CFloat Float
- | CLong Integer
+ | CLong Word64
| CDouble Double
| CNameType (Link stage B.ByteString) (Link stage B.ByteString)
| CUTF8 {getString :: B.ByteString}
| CUnicode {getString :: B.ByteString}
-className :: Constant Resolved -> B.ByteString
+-- | Name of the CClass. Error on any other constant.
+className :: Constant Direct -> B.ByteString
className (CClass s) = s
className x = error $ "Not a class: " ++ show x
-instance Show (Constant Resolved) where
+instance Show (Constant Direct) where
show (CClass name) = "class " ++ toString name
show (CField cls nt) = "field " ++ toString cls ++ "." ++ show nt
show (CMethod cls nt) = "method " ++ toString cls ++ "." ++ show nt
classAttributes :: Attributes stage -- ^ Class attributes
}
-deriving instance Eq (Constant Pointers)
-deriving instance Eq (Constant Resolved)
-deriving instance Show (Constant Pointers)
-
-instance Binary (Class Pointers) where
+deriving instance Eq (Class File)
+deriving instance Eq (Class Direct)
+deriving instance Show (Class File)
+deriving instance Show (Class Direct)
+
+deriving instance Eq (Constant File)
+deriving instance Eq (Constant Direct)
+deriving instance Show (Constant File)
+
+-- | Default (empty) class file definition.
+defaultClass :: (Default (AccessFlags stage), Default (Link stage B.ByteString), Default (Attributes stage))
+ => Class stage
+defaultClass = Class {
+ magic = 0xCAFEBABE,
+ minorVersion = 0,
+ majorVersion = 50,
+ constsPoolSize = 0,
+ constsPool = def,
+ accessFlags = def,
+ thisClass = def,
+ superClass = def,
+ interfacesCount = 0,
+ interfaces = [],
+ classFieldsCount = 0,
+ classFields = [],
+ classMethodsCount = 0,
+ classMethods = [],
+ classAttributesCount = 0,
+ classAttributes = def }
+
+instance Binary (Class File) where
put (Class {..}) = do
put magic
put minorVersion
put majorVersion
- put constsPoolSize
- forM_ (M.elems constsPool) put
+ putPool constsPool
put accessFlags
put thisClass
put superClass
put classMethodsCount
forM_ classMethods put
put classAttributesCount
- forM_ classAttributes put
+ forM_ (attributesList classAttributes) put
get = do
magic <- get
+ when (magic /= 0xCAFEBABE) $
+ fail $ "Invalid .class file MAGIC value: " ++ show magic
minor <- get
major <- get
- poolsize <- get
- pool <- replicateM (fromIntegral poolsize - 1) get
- af <- get
+ when (major > 50) $
+ fail $ "Too new .class file format: " ++ show major
+ poolsize <- getWord16be
+ pool <- getPool (poolsize - 1)
+ af <- get
this <- get
super <- get
interfacesCount <- get
ifaces <- replicateM (fromIntegral interfacesCount) get
- classFieldsCount <- get
+ classFieldsCount <- getWord16be
classFields <- replicateM (fromIntegral classFieldsCount) get
classMethodsCount <- get
classMethods <- replicateM (fromIntegral classMethodsCount) get
asCount <- get
as <- replicateM (fromIntegral $ asCount) get
- let pool' = M.fromList $ zip [1..] pool
- return $ Class magic minor major poolsize pool' af this super
- interfacesCount ifaces classFieldsCount classFields classMethodsCount classMethods asCount as
+ return $ Class magic minor major poolsize pool af this super
+ interfacesCount ifaces classFieldsCount classFields
+ classMethodsCount classMethods asCount (AP as)
-- | Field signature format
data FieldType =
return (x: next)
Nothing -> return []
-instance Binary (Constant Pointers) where
- put (CClass i) = putWord8 7 >> put i
- put (CField i j) = putWord8 9 >> put i >> put j
- put (CMethod i j) = putWord8 10 >> put i >> put j
- put (CIfaceMethod i j) = putWord8 11 >> put i >> put j
- put (CString i) = putWord8 8 >> put i
- put (CInteger x) = putWord8 3 >> put x
- put (CFloat x) = putWord8 4 >> putFloat32be x
- put (CLong x) = putWord8 5 >> put x
- put (CDouble x) = putWord8 6 >> putFloat64be x
- put (CNameType i j) = putWord8 12 >> put i >> put j
- put (CUTF8 bs) = do
- putWord8 1
- put (fromIntegral (B.length bs) :: Word16)
- putLazyByteString bs
- put (CUnicode bs) = do
- putWord8 2
- put (fromIntegral (B.length bs) :: Word16)
- putLazyByteString bs
+long (CLong _) = True
+long (CDouble _) = True
+long _ = False
- get = do
- !offset <- bytesRead
- tag <- getWord8
- case tag of
- 1 -> do
- l <- get
- bs <- getLazyByteString (fromIntegral (l :: Word16))
- return $ CUTF8 bs
- 2 -> do
- l <- get
- bs <- getLazyByteString (fromIntegral (l :: Word16))
- return $ CUnicode bs
- 3 -> CInteger <$> get
- 4 -> CFloat <$> getFloat32be
- 5 -> CLong <$> get
- 6 -> CDouble <$> getFloat64be
- 7 -> CClass <$> get
- 8 -> CString <$> get
- 9 -> CField <$> get <*> get
- 10 -> CMethod <$> get <*> get
- 11 -> CIfaceMethod <$> get <*> get
- 12 -> CNameType <$> get <*> get
- _ -> fail $ "Unknown constants pool entry tag: " ++ show tag
+putPool :: Pool File -> Put
+putPool pool = do
+ let list = M.elems pool
+ d = length $ filter long list
+ putWord16be $ fromIntegral (M.size pool + d + 1)
+ forM_ list putC
+ where
+ putC (CClass i) = putWord8 7 >> put i
+ putC (CField i j) = putWord8 9 >> put i >> put j
+ putC (CMethod i j) = putWord8 10 >> put i >> put j
+ putC (CIfaceMethod i j) = putWord8 11 >> put i >> put j
+ putC (CString i) = putWord8 8 >> put i
+ putC (CInteger x) = putWord8 3 >> put x
+ putC (CFloat x) = putWord8 4 >> putFloat32be x
+ putC (CLong x) = putWord8 5 >> put x
+ putC (CDouble x) = putWord8 6 >> putFloat64be x
+ putC (CNameType i j) = putWord8 12 >> put i >> put j
+ putC (CUTF8 bs) = do
+ putWord8 1
+ put (fromIntegral (B.length bs) :: Word16)
+ putLazyByteString bs
+ putC (CUnicode bs) = do
+ putWord8 2
+ put (fromIntegral (B.length bs) :: Word16)
+ putLazyByteString bs
+
+getPool :: Word16 -> Get (Pool File)
+getPool n = do
+ items <- St.evalStateT go 1
+ return $ M.fromList items
+ where
+ go :: St.StateT Word16 Get [(Word16, Constant File)]
+ go = do
+ i <- St.get
+ if i > n
+ then return []
+ else do
+ c <- lift getC
+ let i' = if long c
+ then i+2
+ else i+1
+ St.put i'
+ next <- go
+ return $ (i,c): next
+
+ getC = do
+ !offset <- bytesRead
+ tag <- getWord8
+ case tag of
+ 1 -> do
+ l <- get
+ bs <- getLazyByteString (fromIntegral (l :: Word16))
+ return $ CUTF8 bs
+ 2 -> do
+ l <- get
+ bs <- getLazyByteString (fromIntegral (l :: Word16))
+ return $ CUnicode bs
+ 3 -> CInteger <$> get
+ 4 -> CFloat <$> getFloat32be
+ 5 -> CLong <$> get
+ 6 -> CDouble <$> getFloat64be
+ 7 -> CClass <$> get
+ 8 -> CString <$> get
+ 9 -> CField <$> get <*> get
+ 10 -> CMethod <$> get <*> get
+ 11 -> CIfaceMethod <$> get <*> get
+ 12 -> CNameType <$> get <*> get
+ _ -> fail $ "Unknown constants pool entry tag: " ++ show tag
+-- _ -> return $ CInteger 0
-- | Class field format
data Field stage = Field {
fieldAttributesCount :: Word16,
fieldAttributes :: Attributes stage }
-deriving instance Eq (Field Pointers)
-deriving instance Eq (Field Resolved)
-deriving instance Show (Field Pointers)
-deriving instance Show (Field Resolved)
+deriving instance Eq (Field File)
+deriving instance Eq (Field Direct)
+deriving instance Show (Field File)
+deriving instance Show (Field Direct)
+
+lookupField :: B.ByteString -> Class Direct -> Maybe (Field Direct)
+lookupField name cls = look (classFields cls)
+ where
+ look [] = Nothing
+ look (f:fs)
+ | fieldName f == name = Just f
+ | otherwise = look fs
-instance Binary (Field Pointers) where
+fieldNameType :: Field Direct -> NameType Field
+fieldNameType f = NameType (fieldName f) (fieldSignature f)
+
+instance Binary (Field File) where
put (Field {..}) = do
put fieldAccessFlags
put fieldName
put fieldSignature
put fieldAttributesCount
- forM_ fieldAttributes put
+ forM_ (attributesList fieldAttributes) put
get = do
af <- get
- ni <- get
+ ni <- getWord16be
si <- get
- n <- get
+ n <- getWord16be
as <- replicateM (fromIntegral n) get
- return $ Field af ni si n as
+ return $ Field af ni si n (AP as)
-- | Class method format
data Method stage = Method {
- methodAccessFlags :: Attributes stage,
+ methodAccessFlags :: AccessFlags stage,
methodName :: Link stage B.ByteString,
methodSignature :: Link stage MethodSignature,
methodAttributesCount :: Word16,
methodAttributes :: Attributes stage }
-deriving instance Eq (Method Pointers)
-deriving instance Eq (Method Resolved)
-deriving instance Show (Method Pointers)
-deriving instance Show (Method Resolved)
+deriving instance Eq (Method File)
+deriving instance Eq (Method Direct)
+deriving instance Show (Method File)
+deriving instance Show (Method Direct)
+
+methodNameType :: Method Direct -> NameType Method
+methodNameType m = NameType (methodName m) (methodSignature m)
+
+lookupMethod :: B.ByteString -> Class Direct -> Maybe (Method Direct)
+lookupMethod name cls = look (classMethods cls)
+ where
+ look [] = Nothing
+ look (f:fs)
+ | methodName f == name = Just f
+ | otherwise = look fs
-instance Binary (Method Pointers) where
+instance Binary (Method File) where
put (Method {..}) = do
put methodAccessFlags
put methodName
put methodSignature
put methodAttributesCount
- forM_ methodAttributes put
+ forM_ (attributesList methodAttributes) put
get = do
offset <- bytesRead
si <- get
n <- get
as <- replicateM (fromIntegral n) get
- return $ Method af ni si n as
+ return $ Method {
+ methodAccessFlags = af,
+ methodName = ni,
+ methodSignature = si,
+ methodAttributesCount = n,
+ methodAttributes = AP as }
-- | Any (class/ field/ method/ ...) attribute format.
-- Some formats specify special formats for @attributeValue@.
get = do
offset <- bytesRead
- name <- get
+ name <- getWord16be
len <- getWord32be
value <- getLazyByteString (fromIntegral len)
return $ Attribute name len value
projects / hs-java.git / blobdiff