%
-% (c) The GRASP Project, Glasgow University, 1992-1996
+% (c) The GRASP Project, Glasgow University, 1992-1998
%
\section[PrimRep]{Primitive machine-level kinds of things.}
, getPrimRepSizeInBytes
, retPrimRepSize
, showPrimRep
+ , primRepString
, showPrimRepToUser
- , ppPrimRep
- , guessPrimRep
- , decodePrimRep
) where
#include "HsVersions.h"
-import Util
+import Constants ( dOUBLE_SIZE, iNT64_SIZE, wORD64_SIZE, wORD_SIZE )
import Outputable
-
--- Oh dear.
--- NOTE: we have to reach out and grab this header file
--- in our current source/build tree, and not the one supplied
--- by whoever's compiling us.
-#include "../../includes/GhcConstants.h"
\end{code}
%************************************************************************
| CostCentreRep -- Pointer to a cost centre
| CharRep -- Machine characters
- | IntRep -- integers (at least 32 bits)
+ | Int8Rep -- 8 bit integers
+ | IntRep -- integers (same size as ptr on this arch)
| WordRep -- ditto (but *unsigned*)
| AddrRep -- addresses ("C pointers")
| FloatRep -- floats
| DoubleRep -- doubles
| Word64Rep -- guaranteed to be 64 bits (no more, no less.)
| Int64Rep -- guaranteed to be 64 bits (no more, no less.)
-
- | ForeignObjRep -- This has to be a special kind because ccall
- -- generates special code when passing/returning
- -- one of these. [ADR]
-
- | StablePtrRep -- We could replace this with IntRep but maybe
- -- there's some documentation gain from having
- -- it special? [ADR]
+
+ -- Perhaps all sized integers and words should be primitive types.
+
+ -- Int8Rep is currently used to simulate some old CharRep usages
+ -- when Char changed size from 8 to 31 bits. It does not correspond
+ -- to a Haskell unboxed type, in particular it's not used by Int8.
+
+ | WeakPtrRep
+ | ForeignObjRep
+ | BCORep
+
+ | StablePtrRep -- guaranteed to be represented by a pointer
+
+ | StableNameRep -- A stable name is a real heap object, unpointed,
+ -- with one field containing an index into the
+ -- stable pointer table. It has to be a heap
+ -- object so the garbage collector can track these
+ -- objects and reclaim stable pointer entries.
+
+ | ThreadIdRep -- Really a pointer to a TSO
| ArrayRep -- Primitive array of Haskell pointers
| ByteArrayRep -- Primitive array of bytes (no Haskell pointers)
+ | PrimPtrRep -- Used for MutVars and MVars;
+ -- a pointer to a primitive object
+ -- ToDo: subsumes WeakPtrRep, ThreadIdRep,
+ -- StableNameRep, ForeignObjRep, and BCORep ?
+
| VoidRep -- Occupies no space at all!
-- (Primitive states are mapped onto this)
deriving (Eq, Ord)
-- Kinds are used in PrimTyCons, which need both Eq and Ord
\end{code}
+These pretty much correspond to the C types declared in StgTypes.h,
+with the following exceptions:
+
+ - when an Array or ByteArray is passed to C, we again pass a pointer
+ to the contents. The actual type that is passed is StgPtr for
+ ArrayRep, and StgByteArray (probably a char *) for ByteArrayRep.
+
+These hacks are left until the final printing of the C, in
+PprAbsC.lhs.
+
%************************************************************************
%* *
\subsection[PrimRep-predicates]{Follow-ness, sizes, and such---on @PrimitiveKinds@}
isFollowableRep :: PrimRep -> Bool
isFollowableRep PtrRep = True
-isFollowableRep ArrayRep = True
-isFollowableRep ByteArrayRep = True
--- why is a ForeignObj followable? 4/96 SOF
---
--- A: they're followable because these objects
--- should be lugged around by the storage manager
--- (==> registers containing them are live) -- 3/97 SOF
-isFollowableRep ForeignObjRep = True
+isFollowableRep ArrayRep = True -- all heap objects:
+isFollowableRep ByteArrayRep = True -- ''
+isFollowableRep WeakPtrRep = True -- ''
+isFollowableRep ForeignObjRep = True -- ''
+isFollowableRep StableNameRep = True -- ''
+isFollowableRep PrimPtrRep = True -- ''
+isFollowableRep ThreadIdRep = True -- pointer to a TSO
-isFollowableRep StablePtrRep = False
--- StablePtrs aren't followable because they are just indices into a
--- table for which explicit allocation/ deallocation is required.
-
-isFollowableRep other = False
+isFollowableRep other = False
separateByPtrFollowness :: (a -> PrimRep) -> [a] -> ([a], [a])
\begin{code}
getPrimRepSize :: PrimRep -> Int
-getPrimRepSize DoubleRep = DOUBLE_SIZE -- "words", of course
-getPrimRepSize Word64Rep = WORD64_SIZE
-getPrimRepSize Int64Rep = INT64_SIZE
+getPrimRepSize DoubleRep = dOUBLE_SIZE -- "words", of course
+getPrimRepSize Word64Rep = wORD64_SIZE
+getPrimRepSize Int64Rep = iNT64_SIZE
--getPrimRepSize FloatRep = 1
--getPrimRepSize CharRep = 1 -- ToDo: count in bytes?
--getPrimRepSize ArrayRep = 1 -- Listed specifically for *documentation*
retPrimRepSize = getPrimRepSize RetRep
--- size in bytes, ToDo: cpp in the right vals.
+-- sizes in bytes.
-- (used in some settings to figure out how many bytes
-- we have to push onto the stack when calling external
--- entry points (e.g., stdcalling on win32))
+-- entry points (e.g., stdcalling on win32)
getPrimRepSizeInBytes :: PrimRep -> Int
getPrimRepSizeInBytes pr =
case pr of
- CharRep -> 1
- IntRep -> 4
- AddrRep -> 4
- FloatRep -> 4
- DoubleRep -> 8
- Word64Rep -> 8
- Int64Rep -> 8
- ForeignObjRep -> 4
- StablePtrRep -> 4
- ArrayRep -> 4
- ByteArrayRep -> 4
- _ -> panic "getPrimRepSize: ouch - this wasn't supposed to happen!"
+ CharRep -> 4
+ Int8Rep -> 1
+ IntRep -> wORD_SIZE
+ AddrRep -> wORD_SIZE
+ FloatRep -> wORD_SIZE
+ DoubleRep -> dOUBLE_SIZE * wORD_SIZE
+ Word64Rep -> wORD64_SIZE * wORD_SIZE
+ Int64Rep -> iNT64_SIZE * wORD_SIZE
+ WeakPtrRep -> wORD_SIZE
+ ForeignObjRep -> wORD_SIZE
+ StablePtrRep -> wORD_SIZE
+ StableNameRep -> wORD_SIZE
+ ArrayRep -> wORD_SIZE
+ ByteArrayRep -> wORD_SIZE
+ _ -> panic "getPrimRepSize: ouch - this wasn't supposed to happen!"
\end{code}
showPrimRep :: PrimRep -> String
showPrimRepToUser :: PrimRep -> String
--- dumping PrimRep tag for unfoldings
-ppPrimRep :: PrimRep -> SDoc
-
-guessPrimRep :: String -> PrimRep -- a horrible "inverse" function
-decodePrimRep :: Char -> PrimRep -- of equal nature
-
-ppPrimRep k =
- char
- (case k of
- PtrRep -> 'P'
- CodePtrRep -> 'p'
- DataPtrRep -> 'd'
- CostCentreRep -> 'c' -- Pointer to a cost centre
- RetRep -> 'R'
- CharRep -> 'C'
- IntRep -> 'I'
- Int64Rep -> 'i'
- WordRep -> 'W'
- Word64Rep -> 'w'
- AddrRep -> 'A'
- FloatRep -> 'F'
- DoubleRep -> 'D'
- ArrayRep -> 'a'
- ByteArrayRep -> 'b'
- StablePtrRep -> 'S'
- ForeignObjRep -> 'f'
- VoidRep -> 'V'
- _ -> panic "ppPrimRep")
-
-showPrimRep PtrRep = "P_" -- short for StgPtr
-
-showPrimRep CodePtrRep = "P_" -- DEATH to StgFunPtr! (94/02/22 WDP)
- -- but aren't code pointers and function pointers different sizes
- -- on some machines (eg 80x86)? ADR
- -- Are you trying to ruin my life, or what? (WDP)
-
-showPrimRep DataPtrRep = "D_"
-showPrimRep RetRep = "StgRetAddr"
-showPrimRep CostCentreRep = "CostCentre"
-showPrimRep CharRep = "StgChar"
-showPrimRep IntRep = "I_" -- short for StgInt
-showPrimRep WordRep = "W_" -- short for StgWord
-showPrimRep Int64Rep = "LI_" -- short for StgLongInt
-showPrimRep Word64Rep = "LW_" -- short for StgLongWord
-showPrimRep AddrRep = "StgAddr"
-showPrimRep FloatRep = "StgFloat"
-showPrimRep DoubleRep = "StgDouble"
-showPrimRep ArrayRep = "StgArray" -- see comment below
-showPrimRep ByteArrayRep = "StgByteArray"
-showPrimRep StablePtrRep = "StgStablePtr"
-showPrimRep ForeignObjRep = "StgPtr" -- see comment below
-showPrimRep VoidRep = "!!VOID_KIND!!"
-
-showPrimRepToUser pr =
- case pr of
- CharRep -> "StgChar"
- IntRep -> "StgInt"
- WordRep -> "StgWord"
- Int64Rep -> "StgInt64"
- Word64Rep -> "StgWord64"
- AddrRep -> "StgAddr"
- FloatRep -> "StgFloat"
- DoubleRep -> "StgDouble"
- ArrayRep -> "StgArray"
- ByteArrayRep -> "StgByteArray"
- StablePtrRep -> "StgStablePtr"
- ForeignObjRep -> "StgPtr"
- _ -> panic ("showPrimRepToUser: " ++ showPrimRep pr)
-
-
-decodePrimRep ch =
- case ch of
- 'P' -> PtrRep
- 'p' -> CodePtrRep
- 'd' -> DataPtrRep
- 'c' -> CostCentreRep
- 'R' -> RetRep
- 'C' -> CharRep
- 'I' -> IntRep
- 'W' -> WordRep
- 'i' -> Int64Rep
- 'w' -> Word64Rep
- 'A' -> AddrRep
- 'F' -> FloatRep
- 'D' -> DoubleRep
- 'a' -> ArrayRep
- 'b' -> ByteArrayRep
- 'S' -> StablePtrRep
- 'f' -> ForeignObjRep
- 'V' -> VoidRep
- _ -> panic "decodePrimRep"
-
-guessPrimRep "D_" = DataPtrRep
-guessPrimRep "StgRetAddr" = RetRep
-guessPrimRep "StgChar" = CharRep
-guessPrimRep "I_" = IntRep
-guessPrimRep "LI_" = Int64Rep
-guessPrimRep "W_" = WordRep
-guessPrimRep "LW_" = Word64Rep
-guessPrimRep "StgAddr" = AddrRep
-guessPrimRep "StgFloat" = FloatRep
-guessPrimRep "StgDouble" = DoubleRep
-guessPrimRep "StgArray" = ArrayRep
-guessPrimRep "StgByteArray" = ByteArrayRep
-guessPrimRep "StgStablePtr" = StablePtrRep
+
+showPrimRep PtrRep = "P_" -- short for StgPtr
+showPrimRep CodePtrRep = "P_" -- DEATH to StgFunPtr! (94/02/22 WDP)
+showPrimRep DataPtrRep = "D_"
+showPrimRep RetRep = "P_"
+showPrimRep CostCentreRep = "CostCentre"
+showPrimRep CharRep = "C_"
+showPrimRep Int8Rep = "StgInt8"
+showPrimRep IntRep = "I_" -- short for StgInt
+showPrimRep WordRep = "W_" -- short for StgWord
+showPrimRep Int64Rep = "LI_" -- short for StgLongInt
+showPrimRep Word64Rep = "LW_" -- short for StgLongWord
+showPrimRep AddrRep = "StgAddr"
+showPrimRep FloatRep = "StgFloat"
+showPrimRep DoubleRep = "StgDouble"
+showPrimRep ArrayRep = "P_" -- see comment below
+showPrimRep PrimPtrRep = "P_"
+showPrimRep ByteArrayRep = "StgByteArray"
+showPrimRep StablePtrRep = "StgStablePtr"
+showPrimRep StableNameRep = "P_"
+showPrimRep ThreadIdRep = "StgTSO*"
+showPrimRep WeakPtrRep = "P_"
+showPrimRep ForeignObjRep = "StgAddr"
+showPrimRep VoidRep = "!!VOID_KIND!!"
+showPrimRep BCORep = "P_" -- not sure -- JRS 000708
+
+primRepString CharRep = "Char"
+primRepString Int8Rep = "Char" -- To have names like newCharArray#
+primRepString IntRep = "Int"
+primRepString WordRep = "Word"
+primRepString Int64Rep = "Int64"
+primRepString Word64Rep = "Word64"
+primRepString AddrRep = "Addr"
+primRepString FloatRep = "Float"
+primRepString DoubleRep = "Double"
+primRepString WeakPtrRep = "Weak"
+primRepString ForeignObjRep = "ForeignObj"
+primRepString StablePtrRep = "StablePtr"
+primRepString StableNameRep = "StableName"
+primRepString other = pprPanic "primRepString" (ppr other)
+
+showPrimRepToUser pr = primRepString pr
\end{code}
-All local C variables of @ArrayRep@ are declared in C as type
-@StgArray@. The coercion to a more precise C type is done just before
-indexing (by the relevant C primitive-op macro).
-
-Nota Bene. There are three types associated with @ForeignObj@ (MallocPtr++):
-\begin{itemize}
-\item
-@StgForeignObjClosure@ is the type of the thing the prim. op @mkForeignObj@ returns.
-{- old comment for MallocPtr
-(This typename is hardwired into @ppr_casm_results@ in
-@PprAbsC.lhs@.)
--}
-
-\item
-@StgForeignObj@ is the type of the thing we give the C world.
-
-\item
-@StgPtr@ is the type of the (pointer to the) heap object which we
-pass around inside the STG machine.
-\end{itemize}
-
-It is really easy to confuse the two. (I'm not sure this choice of
-type names helps.) [ADR]
+Foreign Objects and Arrays are treated specially by the code for
+_ccall_s: we pass a pointer to the contents of the object, not the
+object itself.