%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[PrelVals]{Prelude values the compiler ``knows about''}
\begin{code}
+module PrelVals where
+
#include "HsVersions.h"
-module PrelVals where
+import {-# SOURCE #-} CoreUnfold ( mkUnfolding )
-import Ubiq
-import IdLoop ( UnfoldingGuidance(..) )
-import PrelLoop
+import Id ( Id, mkVanillaId, setIdInfo, mkTemplateLocals )
-- friends:
import PrelMods
-- others:
import CoreSyn -- quite a bit
---import CoreUnfold ( UnfoldingGuidance(..), mkMagicUnfolding )
import IdInfo -- quite a bit
-import Literal ( mkMachInt )
---import NameTypes ( mkPreludeCoreName )
-import PrimOp ( PrimOp(..) )
-import SpecEnv ( SpecEnv(..), nullSpecEnv )
---import Type ( mkSigmaTy, mkFunTys, GenType(..) )
-import TyVar ( alphaTyVar, betaTyVar )
+import Module ( Module )
+import Name ( mkWiredInIdName, mkSrcVarOcc )
+import Type
+import Var ( TyVar )
+import Demand ( wwStrict )
import Unique -- lots of *Keys
-import Util ( panic )
-
--- only used herein:
-mkPreludeId = panic "PrelVals:Id.mkPreludeId"
-mkSpecId = panic "PrelVals:Id.mkSpecId"
-mkTemplateLocals = panic "PrelVals:Id.mkTemplateLocals"
-specialiseTy = panic "PrelVals:specialiseTy"
-
-pcMiscPrelId :: Unique{-IdKey-} -> FAST_STRING -> FAST_STRING -> Type -> IdInfo -> Id
-pcMiscPrelId key mod name ty info
- = mkPreludeId key (mkPreludeCoreName mod name) ty info
+import IOExts
\end{code}
%************************************************************************
%* *
-\subsection[PrelVals-error-related]{@error@ and friends; @trace@}
+\subsection{Un-definable}
%* *
%************************************************************************
-GHC randomly injects these into the code.
+These two can't be defined in Haskell.
-@patError#@ is just a version of @error@ for pattern-matching
-failures. It knows various ``codes'' which expand to longer
-strings---this saves space!
-@absent#@ is a thing we put in for ``absent'' arguments. They jolly
-well shouldn't be yanked on, but if one is, then you will get a
-friendly message from @absent#@ (rather a totally random crash).
+unsafeCoerce# isn't so much a PrimOp as a phantom identifier, that
+just gets expanded into a type coercion wherever it occurs. Hence we
+add it as a built-in Id with an unfolding here.
-@parError#@ is a special version of @error@ which the compiler does
-not know to be a bottoming Id. It is used in the @_par_@ and @_seq_@
-templates, but we don't ever expect to generate code for it.
+The type variables we use here are "open" type variables: this means
+they can unify with both unlifted and lifted types. Hence we provide
+another gun with which to shoot yourself in the foot.
\begin{code}
-pc_bottoming_Id key mod name ty
- = pcMiscPrelId key mod name ty bottoming_info
- where
- bottoming_info = noIdInfo `addInfo` mkBottomStrictnessInfo
- -- these "bottom" out, no matter what their arguments
-
-eRROR_ID
- = pc_bottoming_Id errorIdKey pRELUDE_BUILTIN SLIT("error") errorTy
-
-pAT_ERROR_ID
- = pc_bottoming_Id patErrorIdKey pRELUDE_BUILTIN SLIT("patError#") errorTy
-
-aBSENT_ERROR_ID
- = pc_bottoming_Id absentErrorIdKey pRELUDE_BUILTIN SLIT("absent#")
- (mkSigmaTy [alphaTyVar] [] alphaTy)
-
-pAR_ERROR_ID
- = pcMiscPrelId parErrorIdKey pRELUDE_BUILTIN SLIT("parError#")
- (mkSigmaTy [alphaTyVar] [] alphaTy) noIdInfo
-
-errorTy :: Type
-errorTy = mkSigmaTy [alphaTyVar] [] (mkFunTys [mkListTy charTy] alphaTy)
-\end{code}
-
-We want \tr{_trace} (NB: name not in user namespace) to be wired in
-because we don't want the strictness analyser to get ahold of it,
-decide that the second argument is strict, evaluate that first (!!),
-and make a jolly old mess. Having \tr{_trace} wired in also helps when
-attempting to re-export it---because it's in \tr{PreludeBuiltin}, it
-won't get an \tr{import} declaration in the interface file, so the
-importing-subsequently module needs to know it's magic.
-\begin{code}
-tRACE_ID
- = pcMiscPrelId traceIdKey pRELUDE_BUILTIN SLIT("_trace") traceTy
- (noIdInfo `addInfo` pcGenerateSpecs traceIdKey tRACE_ID noIdInfo traceTy)
+unsafeCoerceId
+ = pcMiscPrelId unsafeCoerceIdKey pREL_GHC SLIT("unsafeCoerce#") ty
+ (mk_inline_unfolding template)
where
- traceTy = mkSigmaTy [alphaTyVar] [] (mkFunTys [mkListTy charTy, alphaTy] alphaTy)
-\end{code}
-
-%************************************************************************
-%* *
-\subsection[PrelVals-Integer-support]{To support @Integer@ and @String@ literals}
-%* *
-%************************************************************************
-
-\begin{code}
-packStringForCId
- = pcMiscPrelId packCStringIdKey{-ToDo:rename-} pRELUDE_PS SLIT("_packStringForC")
- (mkFunTys [stringTy] byteArrayPrimTy) noIdInfo
-
---------------------------------------------------------------------
-
-unpackCStringId
- = pcMiscPrelId unpackCStringIdKey pRELUDE_BUILTIN SLIT("unpackPS#")
- (mkFunTys [addrPrimTy{-a char *-}] stringTy) noIdInfo
--- Andy says:
--- (FunTy addrPrimTy{-a char *-} stringTy) (noIdInfo `addInfo` mkArityInfo 1)
--- but I don't like wired-in IdInfos (WDP)
-
-unpackCString2Id -- for cases when a string has a NUL in it
- = pcMiscPrelId unpackCString2IdKey pRELUDE_BUILTIN SLIT("unpackPS2#")
- (mkFunTys [addrPrimTy{-a char *-}, intPrimTy{-length-}] stringTy)
- noIdInfo
-
---------------------------------------------------------------------
-unpackCStringAppendId
- = pcMiscPrelId unpackCStringAppendIdKey pRELUDE_BUILTIN SLIT("unpackAppendPS#")
- (mkFunTys [addrPrimTy{-a "char *" pointer-},stringTy] stringTy)
- ((noIdInfo
- `addInfo_UF` mkMagicUnfolding unpackCStringAppendIdKey)
- `addInfo` mkArityInfo 2)
-
-unpackCStringFoldrId
- = pcMiscPrelId unpackCStringFoldrIdKey pRELUDE_BUILTIN SLIT("unpackFoldrPS#")
- (mkSigmaTy [alphaTyVar] []
- (mkFunTys [addrPrimTy{-a "char *" pointer-},
- mkFunTys [charTy, alphaTy] alphaTy,
- alphaTy]
- alphaTy))
- ((noIdInfo
- `addInfo_UF` mkMagicUnfolding unpackCStringFoldrIdKey)
- `addInfo` mkArityInfo 3)
+ (alphaTyVar:betaTyVar:_) = openAlphaTyVars
+ alphaTy = mkTyVarTy alphaTyVar
+ betaTy = mkTyVarTy betaTyVar
+ ty = mkForAllTys [alphaTyVar,betaTyVar] (mkFunTy alphaTy betaTy)
+ [x] = mkTemplateLocals [alphaTy]
+ template = mkLams [alphaTyVar,betaTyVar,x] $
+ Note (Coerce betaTy alphaTy) (Var x)
\end{code}
-OK, this is Will's idea: we should have magic values for Integers 0,
-+1, +2, and -1 (go ahead, fire me):
-\begin{code}
-integerZeroId
- = pcMiscPrelId integerZeroIdKey pRELUDE_CORE SLIT("__integer0") integerTy noIdInfo
-integerPlusOneId
- = pcMiscPrelId integerPlusOneIdKey pRELUDE_CORE SLIT("__integer1") integerTy noIdInfo
-integerPlusTwoId
- = pcMiscPrelId integerPlusTwoIdKey pRELUDE_CORE SLIT("__integer2") integerTy noIdInfo
-integerMinusOneId
- = pcMiscPrelId integerMinusOneIdKey pRELUDE_CORE SLIT("__integerm1") integerTy noIdInfo
-\end{code}
-%************************************************************************
-%* *
-\subsection[PrelVals-parallel]{@seq@ and @par@: for parallel operation (only)}
-%* *
-%************************************************************************
-
-\begin{code}
---------------------------------------------------------------------
--- seqId :: "_seq_", used w/ GRIP, etc., is really quite similar to
--- dangerousEval
-{-
- OLDER:
- _seq_ = /\ a b -> \ x y -> case x of { _ -> y }
-
- OLD:
- _seq_ = /\ a b -> \ x y -> case seq# x y of { _Lift y' -> y' }
-
- NEW (95/05):
- _seq_ = /\ a b -> \ x::a y::b -> case seq# x of { 0# -> parError#; _ -> y; }
-
--}
-
-seqId = pcMiscPrelId seqIdKey pRELUDE_BUILTIN SLIT("_seq_")
- (mkSigmaTy [alphaTyVar, betaTyVar] []
- (mkFunTys [alphaTy, betaTy] betaTy))
- (noIdInfo `addInfo_UF` (mkUnfolding EssentialUnfolding seq_template))
- where
- [x, y, z]
- = mkTemplateLocals [
- {-x-} alphaTy,
- {-y-} betaTy,
- {-z-} intPrimTy
- ]
-
- seq_template
- = mkLam [alphaTyVar, betaTyVar] [x, y] (
- Case (Prim SeqOp [TyArg alphaTy, VarArg x]) (
- PrimAlts
- [(mkMachInt 0, mkTyApp (Var pAR_ERROR_ID) [betaTy])]
- (BindDefault z (Var y))))
-
---------------------------------------------------------------------
--- parId :: "_par_", also used w/ GRIP, etc.
-{-
- OLDER:
-
- par = /\ a b -> \ x y -> case (par# (case x of { _ -> () })) of { _ -> y }
-
- OLD:
-
- _par_ = /\ a b -> \ x y -> case par# x y of { _Lift y' -> y' }
-
- NEW (95/05):
-
- _par_ = /\ a b -> \ x::a y::b -> case par# x of { 0# -> parError#; _ -> y; }
-
--}
-parId = pcMiscPrelId parIdKey pRELUDE_BUILTIN SLIT("_par_")
- (mkSigmaTy [alphaTyVar, betaTyVar] []
- (mkFunTys [alphaTy, betaTy] betaTy))
- (noIdInfo `addInfo_UF` (mkUnfolding EssentialUnfolding par_template))
- where
- [x, y, z]
- = mkTemplateLocals [
- {-x-} alphaTy,
- {-y-} betaTy,
- {-z-} intPrimTy
- ]
-
- par_template
- = mkLam [alphaTyVar, betaTyVar] [x, y] (
- Case (Prim ParOp [TyArg alphaTy, VarArg x]) (
- PrimAlts
- [(mkMachInt 0, mkTyApp (Var pAR_ERROR_ID) [betaTy])]
- (BindDefault z (Var y))))
-
--- forkId :: "_fork_", for *required* concurrent threads
-{-
- _fork_ = /\ a b -> \ x::a y::b -> case fork# x of { 0# -> parError#; _ -> y; }
--}
-forkId = pcMiscPrelId forkIdKey pRELUDE_BUILTIN SLIT("_fork_")
- (mkSigmaTy [alphaTyVar, betaTyVar] []
- (mkFunTys [alphaTy, betaTy] betaTy))
- (noIdInfo `addInfo_UF` (mkUnfolding EssentialUnfolding fork_template))
- where
- [x, y, z]
- = mkTemplateLocals [
- {-x-} alphaTy,
- {-y-} betaTy,
- {-z-} intPrimTy
- ]
-
- fork_template
- = mkLam [alphaTyVar, betaTyVar] [x, y] (
- Case (Prim ForkOp [TyArg alphaTy, VarArg x]) (
- PrimAlts
- [(mkMachInt 0, mkTyApp (Var pAR_ERROR_ID) [betaTy])]
- (BindDefault z (Var y))))
-
-\end{code}
+@realWorld#@ used to be a magic literal, \tr{void#}. If things get
+nasty as-is, change it back to a literal (@Literal@).
\begin{code}
-#ifdef GRAN
-
-parLocalId = pcMiscPrelId parLocalIdKey pRELUDE_BUILTIN SLIT("_parLocal_")
- (mkSigmaTy [alphaTyVar, betaTyVar] []
- (mkFunTys [intPrimTy, alphaTy, betaTy] betaTy))
- (noIdInfo `addInfo_UF` (mkUnfolding EssentialUnfolding parLocal_template))
- where
- [w, x, y, z]
- = mkTemplateLocals [
- {-w-} intPrimTy,
- {-x-} alphaTy,
- {-y-} betaTy,
- {-z-} betaTy
- ]
-
- parLocal_template
- = mkLam [alphaTyVar, betaTyVar] [w, x, y] (
- Case (Prim ParLocalOp [TyArg alphaTy, TyArg betaTy, VarArg x, VarArg w, VarArg y]) (
- AlgAlts
- [(liftDataCon, [z], Var z)]
- (NoDefault)))
-
-parGlobalId = pcMiscPrelId parGlobalIdKey pRELUDE_BUILTIN SLIT("_parGlobal_")
- (mkSigmaTy [alphaTyVar, betaTyVar] []
- (mkFunTys [intPrimTy,alphaTy,betaTy] betaTy))
- (noIdInfo `addInfo_UF` (mkUnfolding EssentialUnfolding parGlobal_template))
- where
- [w, x, y, z]
- = mkTemplateLocals [
- {-w-} intPrimTy,
- {-x-} alphaTy,
- {-y-} betaTy,
- {-z-} betaTy
- ]
-
- parGlobal_template
- = mkLam [alphaTyVar, betaTyVar] [w, x, y] (
- Case (Prim ParGlobalOp [TyArg alphaTy, TyArg betaTy, VarArg x, VarArg w, VarArg y]) (
- AlgAlts
- [(liftDataCon, [z], Var z)]
- (NoDefault)))
-
-#endif {-GRAN-}
+realWorldPrimId
+ = pcMiscPrelId realWorldPrimIdKey pREL_GHC SLIT("realWorld#")
+ realWorldStatePrimTy
+ noCafIdInfo
\end{code}
-%************************************************************************
-%* *
-\subsection[PrelVals-deriving]{Values known about mainly for doing derived instance decls}
-%* *
-%************************************************************************
-
-map :: (a -> b) -> [a] -> [b]
- -- this is up in the here-because-of-unfolding list
-
---??showChar :: Char -> ShowS
-showSpace :: ShowS -- non-std: == "showChar ' '"
-showString :: String -> ShowS
-showParen :: Bool -> ShowS -> ShowS
-
-(++) :: [a] -> [a] -> [a]
-readParen :: Bool -> ReadS a -> ReadS a
-lex :: ReadS String
%************************************************************************
%* *
-\subsection[PrelVals-void]{@void#@: Magic value of type @Void#@}
+\subsection[PrelVals-error-related]{@error@ and friends; @trace@}
%* *
%************************************************************************
-I don't think this is available to the user; it's used in the
-simplifier (WDP 94/06).
-\begin{code}
-voidPrimId
- = pcMiscPrelId voidPrimIdKey pRELUDE_BUILTIN SLIT("void#")
- voidPrimTy noIdInfo
-\end{code}
-
-%************************************************************************
-%* *
-\subsection[PrelVals-runST]{@_runST@: Magic start-state-transformer function}
-%* *
-%************************************************************************
+GHC randomly injects these into the code.
-@_runST@ has a non-Haskell-able type:
-\begin{verbatim}
--- _runST :: forall a. (forall s. _ST s a) -> a
--- which is to say ::
--- forall a. (forall s. (_State s -> (a, _State s))) -> a
+@patError@ is just a version of @error@ for pattern-matching
+failures. It knows various ``codes'' which expand to longer
+strings---this saves space!
-_runST a m = case m _RealWorld (S# _RealWorld realWorld#) of
- (r :: a, wild :: _State _RealWorld) -> r
-\end{verbatim}
-We unfold always, just for simplicity:
-\begin{code}
-runSTId
- = pcMiscPrelId runSTIdKey pRELUDE_BUILTIN SLIT("_runST") run_ST_ty id_info
- where
- s_tv = betaTyVar
- s = betaTy
-
- st_ty a = mkSigmaTy [s_tv] [] (mkStateTransformerTy s a)
-
- run_ST_ty
- = mkSigmaTy [alphaTyVar] [] (mkFunTys [st_ty alphaTy] alphaTy)
- -- NB: rank-2 polymorphism! (forall inside the st_ty...)
-
- id_info
- = noIdInfo
- `addInfo` mkArityInfo 1
- `addInfo` mkStrictnessInfo [WwStrict] Nothing
- `addInfo` mkArgUsageInfo [ArgUsage 1]
- -- ABSOLUTELY NO UNFOLDING, e.g.: (mkUnfolding EssentialUnfolding run_ST_template)
- -- see example below
-{- OUT:
- [m, t, r, wild]
- = mkTemplateLocals [
- {-m-} st_ty alphaTy,
- {-t-} realWorldStateTy,
- {-r-} alphaTy,
- {-_-} realWorldStateTy
- ]
-
- run_ST_template
- = mkLam [alphaTyVar] [m] (
- Let (NonRec t (Con stateDataCon [TyArg realWorldTy, VarArg realWorldPrimId])) (
- Case (App (mkTyApp (Var m) [realWorldTy]) (VarArg t)) (
- AlgAlts
- [(mkTupleCon 2, [r, wild], Var r)]
- NoDefault)))
--}
-\end{code}
+@absentErr@ is a thing we put in for ``absent'' arguments. They jolly
+well shouldn't be yanked on, but if one is, then you will get a
+friendly message from @absentErr@ (rather than a totally random
+crash).
-SLPJ 95/04: Why @_runST@ must not have an unfolding; consider:
-\begin{verbatim}
-f x =
- _runST ( \ s -> let
- (a, s') = newArray# 100 [] s
- (_, s'') = fill_in_array_or_something a x s'
- in
- freezeArray# a s'' )
-\end{verbatim}
-If we inline @_runST@, we'll get:
-\begin{verbatim}
-f x = let
- (a, s') = newArray# 100 [] realWorld#{-NB-}
- (_, s'') = fill_in_array_or_something a x s'
- in
- freezeArray# a s''
-\end{verbatim}
-And now the @newArray#@ binding can be floated to become a CAF, which
-is totally and utterly wrong:
-\begin{verbatim}
-f = let
- (a, s') = newArray# 100 [] realWorld#{-NB-} -- YIKES!!!
- in
- \ x ->
- let (_, s'') = fill_in_array_or_something a x s' in
- freezeArray# a s''
-\end{verbatim}
-All calls to @f@ will share a {\em single} array! End SLPJ 95/04.
+@parError@ is a special version of @error@ which the compiler does
+not know to be a bottoming Id. It is used in the @_par_@ and @_seq_@
+templates, but we don't ever expect to generate code for it.
-@realWorld#@ used to be a magic literal, \tr{void#}. If things get
-nasty as-is, change it back to a literal (@Literal@).
\begin{code}
-realWorldPrimId
- = pcMiscPrelId realWorldPrimIdKey pRELUDE_BUILTIN SLIT("realWorld#")
- realWorldStatePrimTy
- noIdInfo
-\end{code}
-
-%************************************************************************
-%* *
-\subsection[PrelVals-foldr-build]{Values known about for ``foldr/build''}
-%* *
-%************************************************************************
+pc_bottoming_Id key mod name ty
+ = pcMiscPrelId key mod name ty bottoming_info
+ where
+ bottoming_info = mkStrictnessInfo ([wwStrict], True) False `setStrictnessInfo` noCafIdInfo
+ -- these "bottom" out, no matter what their arguments
-\begin{code}
-buildId
- = pcMiscPrelId buildIdKey pRELUDE_CORE SLIT("_build") buildTy
- ((((noIdInfo
- `addInfo_UF` mkMagicUnfolding buildIdKey)
- `addInfo` mkStrictnessInfo [WwStrict] Nothing)
- `addInfo` mkArgUsageInfo [ArgUsage 2])
- `addInfo` pcGenerateSpecs buildIdKey buildId noIdInfo{-ToDo-} buildTy)
- -- cheating, but since _build never actually exists ...
- where
- -- The type of this strange object is:
- -- \/ a . (\/ b . (a -> b -> b) -> b -> b) -> [a]
+eRROR_ID
+ = pc_bottoming_Id errorIdKey pREL_ERR SLIT("error") errorTy
- buildTy = mkSigmaTy [alphaTyVar] [] (mkFunTys [build_ty] (mkListTy alphaTy))
- where
- build_ty = mkSigmaTy [betaTyVar] []
- (mkFunTys [alphaTy, mkFunTys [betaTy] betaTy, betaTy] betaTy)
-\end{code}
+generic_ERROR_ID u n
+ = pc_bottoming_Id u pREL_ERR n errorTy
-@mkBuild@ is sugar for building a build!
+rEC_SEL_ERROR_ID
+ = generic_ERROR_ID recSelErrIdKey SLIT("patError")
+pAT_ERROR_ID
+ = generic_ERROR_ID patErrorIdKey SLIT("patError")
+rEC_CON_ERROR_ID
+ = generic_ERROR_ID recConErrorIdKey SLIT("recConError")
+rEC_UPD_ERROR_ID
+ = generic_ERROR_ID recUpdErrorIdKey SLIT("recUpdError")
+iRREFUT_PAT_ERROR_ID
+ = generic_ERROR_ID irrefutPatErrorIdKey SLIT("irrefutPatError")
+nON_EXHAUSTIVE_GUARDS_ERROR_ID
+ = generic_ERROR_ID nonExhaustiveGuardsErrorIdKey SLIT("nonExhaustiveGuardsError")
+nO_METHOD_BINDING_ERROR_ID
+ = generic_ERROR_ID noMethodBindingErrorIdKey SLIT("noMethodBindingError")
-@mkbuild ty tv c n e@ $Rightarrow$ @build ty (/\ tv -> \ c n -> e)@
-@ty@ is the type of the list.
-@tv@ is always a new type variable.
-@c,n@ are Id's for the abstract cons and nil, @g@ for let binding the argument argument.
- c :: a -> b -> b
- n :: b
- v :: (\/ b . (a -> b -> b) -> b -> b) -> [a]
--- \/ a . (\/ b . (a -> b -> b) -> b -> b) -> [a]
-@e@ is the object right inside the @build@
+aBSENT_ERROR_ID
+ = pc_bottoming_Id absentErrorIdKey pREL_ERR SLIT("absentErr")
+ (mkSigmaTy [openAlphaTyVar] [] openAlphaTy)
-\begin{code}
-mkBuild :: Type
- -> TyVar
- -> Id
- -> Id
- -> Id
- -> CoreExpr -- template
- -> CoreExpr -- template
-
-mkBuild ty tv c n g expr
- = Let (NonRec g (mkLam [tv] [c,n] expr))
- (App (mkTyApp (Var buildId) [ty]) (VarArg g))
-\end{code}
+pAR_ERROR_ID
+ = pcMiscPrelId parErrorIdKey pREL_ERR SLIT("parError")
+ (mkSigmaTy [openAlphaTyVar] [] openAlphaTy) noCafIdInfo
-\begin{code}
-augmentId
- = pcMiscPrelId augmentIdKey pRELUDE_CORE SLIT("_augment") augmentTy
- (((noIdInfo
- `addInfo_UF` mkMagicUnfolding augmentIdKey)
- `addInfo` mkStrictnessInfo [WwStrict,WwLazy False] Nothing)
- `addInfo` mkArgUsageInfo [ArgUsage 2,UnknownArgUsage])
- -- cheating, but since _augment never actually exists ...
- where
- -- The type of this strange object is:
- -- \/ a . (\/ b . (a -> b -> b) -> b -> b) -> [a] -> [a]
+openAlphaTy = mkTyVarTy openAlphaTyVar
- augmentTy = mkSigmaTy [alphaTyVar] [] (mkFunTys [aug_ty, mkListTy alphaTy] (mkListTy alphaTy))
- where
- aug_ty = mkSigmaTy [betaTyVar] []
- (mkFunTys [alphaTy, mkFunTys [betaTy] betaTy, betaTy] betaTy)
+errorTy :: Type
+errorTy = mkSigmaTy [openAlphaTyVar] [] (mkFunTys [mkListTy charTy] openAlphaTy)
+ -- Notice the openAlphaTyVar. It says that "error" can be applied
+ -- to unboxed as well as boxed types. This is OK because it never
+ -- returns, so the return type is irrelevant.
\end{code}
-\begin{code}
-foldrId = pcMiscPrelId foldrIdKey pRELUDE_FB{-not "List"-} SLIT("foldr")
- foldrTy idInfo
- where
- foldrTy =
- mkSigmaTy [alphaTyVar, betaTyVar] []
- (mkFunTys [alphaTy, mkFunTys [betaTy] betaTy, betaTy, mkListTy alphaTy] betaTy)
-
- idInfo = (((((noIdInfo
- `addInfo_UF` mkMagicUnfolding foldrIdKey)
- `addInfo` mkStrictnessInfo [WwLazy False,WwLazy False,WwStrict] Nothing)
- `addInfo` mkArityInfo 3)
- `addInfo` mkUpdateInfo [2,2,1])
- `addInfo` pcGenerateSpecs foldrIdKey foldrId noIdInfo{-ToDo-} foldrTy)
-
-foldlId = pcMiscPrelId foldlIdKey pRELUDE_FB{-not "List"-} SLIT("foldl")
- foldlTy idInfo
- where
- foldlTy =
- mkSigmaTy [alphaTyVar, betaTyVar] []
- (mkFunTys [alphaTy, mkFunTys [betaTy] betaTy, alphaTy, mkListTy betaTy] alphaTy)
-
- idInfo = (((((noIdInfo
- `addInfo_UF` mkMagicUnfolding foldlIdKey)
- `addInfo` mkStrictnessInfo [WwLazy False,WwLazy False,WwStrict] Nothing)
- `addInfo` mkArityInfo 3)
- `addInfo` mkUpdateInfo [2,2,1])
- `addInfo` pcGenerateSpecs foldlIdKey foldlId noIdInfo{-ToDo-} foldlTy)
-
--- A bit of magic goes no here. We translate appendId into ++,
--- you have to be carefull when you actually compile append:
--- xs ++ ys = augment (\ c n -> foldr c n xs) ys
--- {- unfold augment -}
--- = foldr (:) ys xs
--- {- fold foldr to append -}
--- = ys `appendId` xs
--- = ys ++ xs -- ugg!
--- *BUT* you want (++) and not _append in your interfaces.
---
--- So you have to turn *off* unfolding of foldr inside FoldrBuild.hs inside
--- the prelude.
---
-
-appendId
- = pcMiscPrelId appendIdKey pRELUDE_LIST SLIT("++") appendTy idInfo
- where
- appendTy =
- (mkSigmaTy [alphaTyVar] []
- (mkFunTys [mkListTy alphaTy, mkListTy alphaTy] (mkListTy alphaTy)))
- idInfo = (((noIdInfo
- `addInfo` mkStrictnessInfo [WwStrict,WwLazy False] Nothing)
- `addInfo` mkArityInfo 2)
- `addInfo` mkUpdateInfo [1,2])
-\end{code}
%************************************************************************
%* *
-\subsection[PrelUtils-specialisations]{Specialisations for builtin values}
+\subsection{Utilities}
%* *
%************************************************************************
-The specialisations which exist for the builtin values must be recorded in
-their IdInfos.
-
-NOTE: THE USES OF THE pcGenerate... FUNCTIONS MUST CORRESPOND
- TO THE SPECIALISATIONS DECLARED IN THE PRELUDE !!!
-
-HACK: We currently use the same unique for the specialised Ids.
-
-The list @specing_types@ determines the types for which specialised
-versions are created. Note: This should correspond with the
-types passed to the pre-processor with the -genSPECS arg (see ghc.lprl).
-
-ToDo: Create single mkworld definition which is grabbed here and in ghc.lprl
+Note IMustBeINLINEd below. These things have the same status as
+constructor functions, i.e. they will *always* be inlined, wherever
+they occur.
\begin{code}
-pcGenerateSpecs :: Unique -> Id -> IdInfo -> Type -> SpecEnv
-pcGenerateSpecs key id info ty
- = nullSpecEnv
+mk_inline_unfolding expr = setUnfoldingInfo (mkUnfolding expr) $
+ setInlinePragInfo IMustBeINLINEd noIdInfo
-{- LATER:
+exactArityInfo n = exactArity n `setArityInfo` noIdInfo
-pc_gen_specs True key id info ty
+pcMiscPrelId :: Unique{-IdKey-} -> Module -> FAST_STRING -> Type -> IdInfo -> Id
-pc_gen_specs is_id key id info ty
- = mkSpecEnv spec_infos
- where
- spec_infos = [ let spec_ty = specialiseTy ty spec_tys 0
- spec_id = if is_id
- then mkSpecId key {- HACK WARNING: same unique! -}
- id spec_tys spec_ty info
- else panic "SpecData:SpecInfo:SpecId"
- in
- SpecInfo spec_tys (length ctxts) spec_id
- | spec_tys <- specialisations ]
-
- (tyvars, ctxts, _) = splitSigmaTy ty
- no_tyvars = length tyvars
-
- specialisations = if no_tyvars == 0
- then []
- else tail (cross_product no_tyvars specing_types)
-
- -- N.B. tail removes fully polymorphic specialisation
-
-cross_product 0 tys = []
-cross_product 1 tys = map (:[]) tys
-cross_product n tys = concat [map (:cp) tys | cp <- cross_product (n-1) tys]
-
-
-specing_types = [Nothing,
- Just charPrimTy,
- Just doublePrimTy,
- Just intPrimTy ]
--}
+pcMiscPrelId key mod str ty info
+ = let
+ name = mkWiredInIdName key mod (mkSrcVarOcc str) imp
+ imp = mkVanillaId name ty `setIdInfo` info -- the usual case...
+ in
+ imp
+ -- We lie and say the thing is imported; otherwise, we get into
+ -- a mess with dependency analysis; e.g., core2stg may heave in
+ -- random calls to GHCbase.unpackPS__. If GHCbase is the module
+ -- being compiled, then it's just a matter of luck if the definition
+ -- will be in "the right place" to be in scope.
+
+-- very useful...
+noCafIdInfo = NoCafRefs `setCafInfo` noIdInfo
\end{code}
+