    {-# LANGUAGE MagicHash, RecordWildCards, GeneralizedNewtypeDeriving #-}
    --
    --  (c) The University of Glasgow 2002-2006
    --

    -- | Bytecode assembler types
    module ByteCodeTypes
      ( CompiledByteCode(..), seqCompiledByteCode, FFIInfo(..)
      , UnlinkedBCO(..), BCOPtr(..), BCONPtr(..)
      , ItblEnv, ItblPtr(..)
      , CgBreakInfo(..)
      , ModBreaks (..), BreakIndex, emptyModBreaks
      , CCostCentre
      ) where

    import FastString
    import Id
    import Name
    import NameEnv
    import Outputable
    import PrimOp
    import SizedSeq
    import Type
    import SrcLoc
    import GHCi.BreakArray
    import GHCi.RemoteTypes
    import GHCi.FFI
    import GHCi.InfoTable
    import Control.DeepSeq

    import Foreign
    import Data.Array
    import Data.Array.Base  ( UArray(..) )
    import Data.ByteString (ByteString)
    import Data.IntMap (IntMap)
    import qualified Data.IntMap as IntMap
    import GHC.Stack.CCS

    -- -----------------------------------------------------------------------------
    -- Compiled Byte Code

    data CompiledByteCode = CompiledByteCode
      { bc_bcos   :: [UnlinkedBCO]  -- Bunch of interpretable bindings
      , bc_itbls  :: ItblEnv        -- A mapping from DataCons to their itbls
      , bc_ffis   :: [FFIInfo]      -- ffi blocks we allocated
      , bc_strs   :: [RemotePtr ()] -- malloc'd strings
      , bc_breaks :: Maybe ModBreaks -- breakpoint info (Nothing if we're not
                                     -- creating breakpoints, for some reason)
      }
                    -- ToDo: we're not tracking strings that we malloc'd
    newtype FFIInfo = FFIInfo (RemotePtr C_ffi_cif)
      deriving (Show, NFData)

    instance Outputable CompiledByteCode where
      ppr CompiledByteCode{..} = ppr bc_bcos

    -- Not a real NFData instance, because ModBreaks contains some things
    -- we can't rnf
    seqCompiledByteCode :: CompiledByteCode -> ()
    seqCompiledByteCode CompiledByteCode{..} =
      rnf bc_bcos `seq`
      rnf (nameEnvElts bc_itbls) `seq`
      rnf bc_ffis `seq`
      rnf bc_strs `seq`
      rnf (fmap seqModBreaks bc_breaks)

    type ItblEnv = NameEnv (Name, ItblPtr)
            -- We need the Name in the range so we know which
            -- elements to filter out when unloading a module

    newtype ItblPtr = ItblPtr (RemotePtr StgInfoTable)
      deriving (Show, NFData)

    data UnlinkedBCO
       = UnlinkedBCO {
            unlinkedBCOName   :: !Name,
            unlinkedBCOArity  :: {-# UNPACK #-} !Int,
            unlinkedBCOInstrs :: !(UArray Int Word16),      -- insns
            unlinkedBCOBitmap :: !(UArray Int Word),        -- bitmap
            unlinkedBCOLits   :: !(SizedSeq BCONPtr),       -- non-ptrs
            unlinkedBCOPtrs   :: !(SizedSeq BCOPtr)         -- ptrs
       }

    instance NFData UnlinkedBCO where
      rnf UnlinkedBCO{..} =
        rnf unlinkedBCOLits `seq`
        rnf unlinkedBCOPtrs

    data BCOPtr
      = BCOPtrName   !Name
      | BCOPtrPrimOp !PrimOp
      | BCOPtrBCO    !UnlinkedBCO
      | BCOPtrBreakArray  -- a pointer to this module's BreakArray

    instance NFData BCOPtr where
      rnf (BCOPtrBCO bco) = rnf bco
      rnf x = x `seq` ()

    data BCONPtr
      = BCONPtrWord  {-# UNPACK #-} !Word
      | BCONPtrLbl   !FastString
      | BCONPtrItbl  !Name
      | BCONPtrStr   !ByteString

    instance NFData BCONPtr where
      rnf x = x `seq` ()

    -- | Information about a breakpoint that we know at code-generation time
    data CgBreakInfo
       = CgBreakInfo
       { cgb_vars   :: [(Id,Word16)]
       , cgb_resty  :: Type
       }

    -- Not a real NFData instance because we can't rnf Id or Type
    seqCgBreakInfo :: CgBreakInfo -> ()
    seqCgBreakInfo CgBreakInfo{..} =
      rnf (map snd cgb_vars) `seq`
      seqType cgb_resty

    instance Outputable UnlinkedBCO where
       ppr (UnlinkedBCO nm _arity _insns _bitmap lits ptrs)
          = sep [text "BCO", ppr nm, text "with",
                 ppr (sizeSS lits), text "lits",
                 ppr (sizeSS ptrs), text "ptrs" ]

    instance Outputable CgBreakInfo where
       ppr info = text "CgBreakInfo" <+>
                  parens (ppr (cgb_vars info) <+>
                          ppr (cgb_resty info))

    -- -----------------------------------------------------------------------------
    -- Breakpoints

    -- | Breakpoint index
    type BreakIndex = Int

    -- | C CostCentre type
    data CCostCentre

    -- | All the information about the breakpoints for a module
    data ModBreaks
       = ModBreaks
       { modBreaks_flags :: ForeignRef BreakArray
            -- ^ The array of flags, one per breakpoint,
            -- indicating which breakpoints are enabled.
       , modBreaks_locs :: !(Array BreakIndex SrcSpan)
            -- ^ An array giving the source span of each breakpoint.
       , modBreaks_vars :: !(Array BreakIndex [OccName])
            -- ^ An array giving the names of the free variables at each breakpoint.
       , modBreaks_decls :: !(Array BreakIndex [String])
            -- ^ An array giving the names of the declarations enclosing each breakpoint.
       , modBreaks_ccs :: !(Array BreakIndex (RemotePtr CostCentre))
            -- ^ Array pointing to cost centre for each breakpoint
       , modBreaks_breakInfo :: IntMap CgBreakInfo
            -- ^ info about each breakpoint from the bytecode generator
       }

    seqModBreaks :: ModBreaks -> ()
    seqModBreaks ModBreaks{..} =
      rnf modBreaks_flags `seq`
      rnf modBreaks_locs `seq`
      rnf modBreaks_vars `seq`
      rnf modBreaks_decls `seq`
      rnf modBreaks_ccs `seq`
      rnf (fmap seqCgBreakInfo modBreaks_breakInfo)

    -- | Construct an empty ModBreaks
    emptyModBreaks :: ModBreaks
    emptyModBreaks = ModBreaks
       { modBreaks_flags = error "ModBreaks.modBreaks_array not initialised"
             -- ToDo: can we avoid this?
       , modBreaks_locs  = array (0,-1) []
       , modBreaks_vars  = array (0,-1) []
       , modBreaks_decls = array (0,-1) []
       , modBreaks_ccs = array (0,-1) []
       , modBreaks_breakInfo = IntMap.empty
       }