2 % (c) The University of Glasgow 2000-2006
4 ByteCodeLink: Bytecode assembler and linker
7 {-# OPTIONS -optc-DNON_POSIX_SOURCE #-}
10 -- The above warning supression flag is a temporary kludge.
11 -- While working on this module you are encouraged to remove it and fix
12 -- any warnings in the module. See
13 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
18 ClosureEnv, emptyClosureEnv, extendClosureEnv,
19 linkBCO, lookupStaticPtr, lookupName
23 #include "HsVersions.h"
40 import GHC.Word ( Word(..) )
42 import Data.Array.Base
43 import GHC.Arr ( STArray(..) )
45 import Control.Monad ( zipWithM )
46 import Control.Monad.ST ( stToIO )
49 import GHC.Arr ( Array(..) )
50 import GHC.IOBase ( IO(..) )
51 import GHC.Ptr ( Ptr(..), castPtr )
52 import GHC.Base ( writeArray#, RealWorld, Int(..), Word# )
58 %************************************************************************
60 \subsection{Linking interpretables into something we can run}
62 %************************************************************************
65 type ClosureEnv = NameEnv (Name, HValue)
66 newtype HValue = HValue Any
68 emptyClosureEnv = emptyNameEnv
70 extendClosureEnv :: ClosureEnv -> [(Name,HValue)] -> ClosureEnv
71 extendClosureEnv cl_env pairs
72 = extendNameEnvList cl_env [ (n, (n,v)) | (n,v) <- pairs]
76 %************************************************************************
78 \subsection{Linking interpretables into something we can run}
80 %************************************************************************
84 data BCO# = BCO# ByteArray# -- instrs :: Array Word16#
85 ByteArray# -- literals :: Array Word32#
86 PtrArray# -- ptrs :: Array HValue
87 ByteArray# -- itbls :: Array Addr#
90 linkBCO :: ItblEnv -> ClosureEnv -> UnlinkedBCO -> IO HValue
92 = do BCO bco# <- linkBCO' ie ce ul_bco
93 -- SDM: Why do we need mkApUpd0 here? I *think* it's because
94 -- otherwise top-level interpreted CAFs don't get updated
95 -- after evaluation. A top-level BCO will evaluate itself and
96 -- return its value when entered, but it won't update itself.
97 -- Wrapping the BCO in an AP_UPD thunk will take care of the
100 -- Update: the above is true, but now we also have extra invariants:
101 -- (a) An AP thunk *must* point directly to a BCO
102 -- (b) A zero-arity BCO *must* be wrapped in an AP thunk
103 -- (c) An AP is always fully saturated, so we *can't* wrap
104 -- non-zero arity BCOs in an AP thunk.
106 if (unlinkedBCOArity ul_bco > 0)
107 then return (unsafeCoerce# bco#)
108 else case mkApUpd0# bco# of { (# final_bco #) -> return final_bco }
111 linkBCO' :: ItblEnv -> ClosureEnv -> UnlinkedBCO -> IO BCO
112 linkBCO' ie ce (UnlinkedBCO nm arity insns_barr bitmap literalsSS ptrsSS)
113 -- Raises an IO exception on failure
114 = do let literals = ssElts literalsSS
117 linked_literals <- mapM (lookupLiteral ie) literals
119 let n_literals = sizeSS literalsSS
120 n_ptrs = sizeSS ptrsSS
122 ptrs_arr <- mkPtrsArray ie ce n_ptrs ptrs
125 !ptrs_parr = case ptrs_arr of Array _lo _hi _n parr -> parr
127 literals_arr = listArray (0, n_literals-1) linked_literals
128 :: UArray Word16 Word
129 !literals_barr = case literals_arr of UArray _lo _hi _n barr -> barr
133 newBCO insns_barr literals_barr ptrs_parr arity# bitmap
136 -- we recursively link any sub-BCOs while making the ptrs array
137 mkPtrsArray :: ItblEnv -> ClosureEnv -> Word16 -> [BCOPtr] -> IO (Array Word16 HValue)
138 mkPtrsArray ie ce n_ptrs ptrs = do
139 marr <- newArray_ (0, n_ptrs-1)
141 fill (BCOPtrName n) i = do
142 ptr <- lookupName ce n
143 unsafeWrite marr i ptr
144 fill (BCOPtrPrimOp op) i = do
145 ptr <- lookupPrimOp op
146 unsafeWrite marr i ptr
147 fill (BCOPtrBCO ul_bco) i = do
148 BCO bco# <- linkBCO' ie ce ul_bco
149 writeArrayBCO marr i bco#
150 fill (BCOPtrBreakInfo brkInfo) i =
151 unsafeWrite marr i (unsafeCoerce# brkInfo)
152 fill (BCOPtrArray brkArray) i =
153 unsafeWrite marr i (unsafeCoerce# brkArray)
154 zipWithM fill ptrs [0..]
157 newtype IOArray i e = IOArray (STArray RealWorld i e)
159 instance MArray IOArray e IO where
160 getBounds (IOArray marr) = stToIO $ getBounds marr
161 getNumElements (IOArray marr) = stToIO $ getNumElements marr
162 newArray lu init = stToIO $ do
163 marr <- newArray lu init; return (IOArray marr)
164 newArray_ lu = stToIO $ do
165 marr <- newArray_ lu; return (IOArray marr)
166 unsafeRead (IOArray marr) i = stToIO (unsafeRead marr i)
167 unsafeWrite (IOArray marr) i e = stToIO (unsafeWrite marr i e)
169 -- XXX HACK: we should really have a new writeArray# primop that takes a BCO#.
170 writeArrayBCO :: IOArray Word16 a -> Int -> BCO# -> IO ()
171 writeArrayBCO (IOArray (STArray _ _ _ marr#)) (I# i#) bco# = IO $ \s# ->
172 case (unsafeCoerce# writeArray#) marr# i# bco# s# of { s# ->
176 writeArrayMBA :: IOArray Int a -> Int -> MutableByteArray# a -> IO ()
177 writeArrayMBA (IOArray (STArray _ _ marr#)) (I# i#) mba# = IO $ \s# ->
178 case (unsafeCoerce# writeArray#) marr# i# bco# s# of { s# ->
184 newBCO :: ByteArray# -> ByteArray# -> Array# a -> Int# -> ByteArray# -> IO BCO
185 newBCO instrs lits ptrs arity bitmap
186 = IO $ \s -> case newBCO# instrs lits ptrs arity bitmap s of
187 (# s1, bco #) -> (# s1, BCO bco #)
190 lookupLiteral :: ItblEnv -> BCONPtr -> IO Word
191 lookupLiteral ie (BCONPtrWord lit) = return lit
192 lookupLiteral ie (BCONPtrLbl sym) = do Ptr a# <- lookupStaticPtr sym
193 return (W# (int2Word# (addr2Int# a#)))
194 lookupLiteral ie (BCONPtrItbl nm) = do Ptr a# <- lookupIE ie nm
195 return (W# (int2Word# (addr2Int# a#)))
197 lookupStaticPtr :: FastString -> IO (Ptr ())
198 lookupStaticPtr addr_of_label_string
199 = do let label_to_find = unpackFS addr_of_label_string
200 m <- lookupSymbol label_to_find
202 Just ptr -> return ptr
203 Nothing -> linkFail "ByteCodeLink: can't find label"
206 lookupPrimOp :: PrimOp -> IO HValue
208 = do let sym_to_find = primopToCLabel primop "closure"
209 m <- lookupSymbol sym_to_find
211 Just (Ptr addr) -> case addrToHValue# addr of
212 (# hval #) -> return hval
213 Nothing -> linkFail "ByteCodeLink.lookupCE(primop)" sym_to_find
215 lookupName :: ClosureEnv -> Name -> IO HValue
217 = case lookupNameEnv ce nm of
218 Just (_,aa) -> return aa
220 -> ASSERT2(isExternalName nm, ppr nm)
221 do let sym_to_find = nameToCLabel nm "closure"
222 m <- lookupSymbol sym_to_find
224 Just (Ptr addr) -> case addrToHValue# addr of
225 (# hval #) -> return hval
226 Nothing -> linkFail "ByteCodeLink.lookupCE" sym_to_find
228 lookupIE :: ItblEnv -> Name -> IO (Ptr a)
230 = case lookupNameEnv ie con_nm of
231 Just (_, a) -> return (castPtr (itblCode a))
233 -> do -- try looking up in the object files.
234 let sym_to_find1 = nameToCLabel con_nm "con_info"
235 m <- lookupSymbol sym_to_find1
237 Just addr -> return addr
239 -> do -- perhaps a nullary constructor?
240 let sym_to_find2 = nameToCLabel con_nm "static_info"
241 n <- lookupSymbol sym_to_find2
243 Just addr -> return addr
244 Nothing -> linkFail "ByteCodeLink.lookupIE"
245 (sym_to_find1 ++ " or " ++ sym_to_find2)
247 linkFail :: String -> String -> IO a
249 = ghcError (ProgramError $
251 , "During interactive linking, GHCi couldn't find the following symbol:"
253 , "This may be due to you not asking GHCi to load extra object files,"
254 , "archives or DLLs needed by your current session. Restart GHCi, specifying"
255 , "the missing library using the -L/path/to/object/dir and -lmissinglibname"
256 , "flags, or simply by naming the relevant files on the GHCi command line."
257 , "Alternatively, this link failure might indicate a bug in GHCi."
258 , "If you suspect the latter, please send a bug report to:"
259 , " glasgow-haskell-bugs@haskell.org"
262 -- HACKS!!! ToDo: cleaner
263 nameToCLabel :: Name -> String{-suffix-} -> String
264 nameToCLabel n suffix
265 = if pkgid /= mainPackageId
266 then package_part ++ '_': qual_name
269 pkgid = modulePackageId mod
270 mod = ASSERT( isExternalName n ) nameModule n
271 package_part = unpackFS (zEncodeFS (packageIdFS (modulePackageId mod)))
272 module_part = unpackFS (zEncodeFS (moduleNameFS (moduleName mod)))
273 occ_part = unpackFS (zEncodeFS (occNameFS (nameOccName n)))
274 qual_name = module_part ++ '_':occ_part ++ '_':suffix
277 primopToCLabel :: PrimOp -> String{-suffix-} -> String
278 primopToCLabel primop suffix
279 = let str = "ghczmprim_GHCziPrimopWrappers_" ++ unpackFS (zEncodeFS (occNameFS (primOpOcc primop))) ++ '_':suffix
280 in --trace ("primopToCLabel: " ++ str)