%
-% (c) The AQUA Project, Glasgow University, 1994-1996
+% (c) The AQUA Project, Glasgow University, 1998
%
\section[StdIdInfo]{Standard unfoldings}
\begin{code}
module MkId (
- mkImportedId,
- mkUserId,
- mkUserLocal, mkSysLocal,
+ mkSpecPragmaId, mkWorkerId,
- mkDataCon, mkTupleCon,
-
- mkDictFunId,
- mkMethodSelId, mkSuperDictSelId, mkDefaultMethodId,
+ mkDictFunId, mkDefaultMethodId,
+ mkDictSelId,
+ mkDataConId,
mkRecordSelId,
-
- mkPrimitiveId,
- mkWorkerId
-
+ mkNewTySelId,
+ mkPrimitiveId,
+
+ -- And some particular Ids; see below for why they are wired in
+ wiredInIds,
+ unsafeCoerceId, realWorldPrimId,
+ eRROR_ID, rEC_SEL_ERROR_ID, pAT_ERROR_ID, rEC_CON_ERROR_ID,
+ rEC_UPD_ERROR_ID, iRREFUT_PAT_ERROR_ID, nON_EXHAUSTIVE_GUARDS_ERROR_ID,
+ nO_METHOD_BINDING_ERROR_ID, aBSENT_ERROR_ID, pAR_ERROR_ID
) where
#include "HsVersions.h"
-import {-# SOURCE #-} CoreUnfold ( mkUnfolding )
-import Type
-import CoreSyn
-import Literal
-import TysWiredIn ( tupleCon )
-import Name ( mkLocalName, mkSysLocalName, mkCompoundName,
- occNameString, Name, OccName, NamedThing(..)
+import TysPrim ( openAlphaTyVars, alphaTyVar, alphaTy,
+ intPrimTy, realWorldStatePrimTy
+ )
+import TysWiredIn ( boolTy, charTy, mkListTy )
+import PrelMods ( pREL_ERR, pREL_GHC )
+import Type ( Type, ThetaType,
+ mkDictTy, mkTyConApp, mkTyVarTys, mkFunTys, mkFunTy, mkSigmaTy,
+ isUnLiftedType, mkForAllTys, mkTyVarTy, tyVarsOfTypes,
+ splitSigmaTy, splitFunTy_maybe, splitAlgTyConApp,
+ splitFunTys, splitForAllTys, unUsgTy,
+ mkUsgTy, UsageAnn(..)
+ )
+import Module ( Module )
+import CoreUnfold ( mkTopUnfolding, mkCompulsoryUnfolding )
+import Subst ( mkTopTyVarSubst, substTheta )
+import TyCon ( TyCon, isNewTyCon, tyConDataCons, isDataTyCon )
+import Class ( Class, classBigSig, classTyCon, classTyVars, classSelIds )
+import Var ( Id, TyVar )
+import VarSet ( isEmptyVarSet )
+import Const ( Con(..) )
+import Name ( mkDerivedName, mkWiredInIdName, mkLocalName,
+ mkWorkerOcc, mkSuperDictSelOcc,
+ Name, NamedThing(..),
)
-import Id ( idType, fIRST_TAG,
- mkTemplateLocals, mkId, mkVanillaId,
- dataConStrictMarks, dataConFieldLabels, dataConArgTys,
- recordSelectorFieldLabel, dataConSig,
- StrictnessMark(..),
- Id, IdDetails(..), GenId
+import OccName ( mkSrcVarOcc )
+import PrimOp ( PrimOp(DataToTagOp), primOpSig, mkPrimOpIdName )
+import Demand ( wwStrict )
+import DataCon ( DataCon, StrictnessMark(..), dataConStrictMarks, dataConFieldLabels,
+ dataConArgTys, dataConSig, dataConRawArgTys
)
-import IdInfo ( noIdInfo,
- exactArity, setUnfoldingInfo,
+import Id ( idType, mkId,
+ mkVanillaId, mkTemplateLocals,
+ mkTemplateLocal, setInlinePragma
+ )
+import IdInfo ( vanillaIdInfo, mkIdInfo,
+ exactArity, setUnfoldingInfo, setCafInfo,
setArityInfo, setInlinePragInfo,
- InlinePragInfo(..), IdInfo
+ mkStrictnessInfo, setStrictnessInfo,
+ IdFlavour(..), InlinePragInfo(..), CafInfo(..), IdInfo
)
-import Class ( Class, classBigSig, classTyCon )
import FieldLabel ( FieldLabel, FieldLabelTag, mkFieldLabel, fieldLabelName,
firstFieldLabelTag, allFieldLabelTags
)
-import TyVar ( TyVar )
-import TyCon ( TyCon, isNewTyCon, tyConDataCons, isDataTyCon )
-import PrelVals ( rEC_SEL_ERROR_ID )
+import CoreSyn
import Maybes
-import SrcLoc ( SrcLoc )
import BasicTypes ( Arity )
-import Unique ( Unique )
+import Unique
import Maybe ( isJust )
import Outputable
import Util ( assoc )
+import List ( nub )
\end{code}
%************************************************************************
%* *
-\subsection{Easy ones}
+\subsection{Wired in Ids}
%* *
%************************************************************************
\begin{code}
-mkImportedId :: Name -> ty -> IdInfo -> GenId ty
-mkImportedId name ty info = mkId name ty (VanillaId True) info
-
--- SysLocal: for an Id being created by the compiler out of thin air...
--- UserLocal: an Id with a name the user might recognize...
-mkSysLocal :: FAST_STRING -> Unique -> (GenType flexi) -> SrcLoc -> GenId (GenType flexi)
-mkUserLocal :: OccName -> Unique -> (GenType flexi) -> SrcLoc -> GenId (GenType flexi)
-
-mkSysLocal str uniq ty loc
- = mkVanillaId (mkSysLocalName uniq str loc) ty noIdInfo
+wiredInIds
+ = [ -- These error-y things are wired in because we don't yet have
+ -- a way to express in an interface file that the result type variable
+ -- is 'open'; that is can be unified with an unboxed type
+ --
+ -- [The interface file format now carry such information, but there's
+ -- no way yet of expressing at the definition site for these error-reporting
+ -- functions that they have an 'open' result type. -- sof 1/99]
+
+ aBSENT_ERROR_ID
+ , eRROR_ID
+ , iRREFUT_PAT_ERROR_ID
+ , nON_EXHAUSTIVE_GUARDS_ERROR_ID
+ , nO_METHOD_BINDING_ERROR_ID
+ , pAR_ERROR_ID
+ , pAT_ERROR_ID
+ , rEC_CON_ERROR_ID
+ , rEC_UPD_ERROR_ID
+
+ -- These two can't be defined in Haskell
+ , realWorldPrimId
+ , unsafeCoerceId
+ , getTagId
+ ]
+\end{code}
-mkUserLocal occ uniq ty loc
- = mkVanillaId (mkLocalName uniq occ loc) ty noIdInfo
+%************************************************************************
+%* *
+\subsection{Easy ones}
+%* *
+%************************************************************************
-mkUserId :: Name -> GenType flexi -> GenId (GenType flexi)
-mkUserId name ty
- = mkVanillaId name ty noIdInfo
+\begin{code}
+mkSpecPragmaId occ uniq ty loc
+ = mkId (mkLocalName uniq occ loc) ty (mkIdInfo SpecPragmaId)
+ -- Maybe a SysLocal? But then we'd lose the location
mkDefaultMethodId dm_name rec_c ty
- = mkVanillaId dm_name ty noIdInfo
+ = mkVanillaId dm_name ty
-mkDictFunId dfun_name full_ty clas itys
- = mkVanillaId dfun_name full_ty noIdInfo
-
-mkWorkerId uniq unwrkr ty info
- = mkVanillaId name ty info
- where
- name = mkCompoundName name_fn uniq (getName unwrkr)
- name_fn wkr_str = SLIT("$w") _APPEND_ wkr_str
+mkWorkerId uniq unwrkr ty
+ = mkVanillaId (mkDerivedName mkWorkerOcc (getName unwrkr) uniq) ty
\end{code}
-
%************************************************************************
%* *
\subsection{Data constructors}
%************************************************************************
\begin{code}
-mkDataCon :: Name
- -> [StrictnessMark] -> [FieldLabel]
- -> [TyVar] -> ThetaType
- -> [TyVar] -> ThetaType
- -> [TauType] -> TyCon
- -> Id
- -- can get the tag and all the pieces of the type from the Type
-
-mkDataCon name stricts fields tvs ctxt con_tvs con_ctxt args_tys tycon
- = ASSERT(length stricts == length args_tys)
- data_con
- where
- -- NB: data_con self-recursion; should be OK as tags are not
- -- looked at until late in the game.
- data_con = mkId name data_con_ty details (dataConInfo data_con)
- details = AlgConId data_con_tag stricts fields tvs ctxt con_tvs con_ctxt args_tys tycon
-
- data_con_tag = assoc "mkDataCon" (data_con_family `zip` [fIRST_TAG..]) data_con
- data_con_family = tyConDataCons tycon
- data_con_ty = mkSigmaTy (tvs++con_tvs) (ctxt++con_ctxt)
- (mkFunTys args_tys (mkTyConApp tycon (mkTyVarTys tvs)))
-
-
-mkTupleCon :: Arity -> Name -> Type -> Id
-mkTupleCon arity name ty
- = con_id
+mkDataConId :: DataCon -> Id
+mkDataConId data_con
+ = mkId (getName data_con)
+ id_ty
+ (dataConInfo data_con)
where
- con_id = mkId name ty (TupleConId arity) (dataConInfo con_id)
+ (tyvars, theta, ex_tyvars, ex_theta, arg_tys, tycon) = dataConSig data_con
+ id_ty = mkSigmaTy (tyvars ++ ex_tyvars)
+ (theta ++ ex_theta)
+ (mkFunTys arg_tys (mkTyConApp tycon (mkTyVarTys tyvars)))
\end{code}
We're going to build a constructor that looks like:
* We have to check that we can construct Data dictionaries for
the types a and Int. Once we've done that we can throw d1 away too.
-* We use (case p of ...) to evaluate p, rather than "seq" because
+* We use (case p of q -> ...) to evaluate p, rather than "seq" because
all that matters is that the arguments are evaluated. "seq" is
very careful to preserve evaluation order, which we don't need
to be here.
+ You might think that we could simply give constructors some strictness
+ info, like PrimOps, and let CoreToStg do the let-to-case transformation.
+ But we don't do that because in the case of primops and functions strictness
+ is a *property* not a *requirement*. In the case of constructors we need to
+ do something active to evaluate the argument.
+
+ Making an explicit case expression allows the simplifier to eliminate
+ it in the (common) case where the constructor arg is already evaluated.
+
\begin{code}
-dataConInfo :: Id -> IdInfo
-
-dataConInfo con_id
- = setInlinePragInfo IWantToBeINLINEd $
- -- Always inline constructors if possible
- setArityInfo (exactArity (length locals)) $
- setUnfoldingInfo unfolding $
- noIdInfo
+dataConInfo :: DataCon -> IdInfo
+
+dataConInfo data_con
+ = mkIdInfo (ConstantId (DataCon data_con))
+ `setArityInfo` exactArity (n_dicts + n_ex_dicts + n_id_args)
+ `setUnfoldingInfo` unfolding
where
- unfolding = mkUnfolding con_rhs
+ unfolding = mkTopUnfolding (Note InlineMe con_rhs)
+ -- The dictionary constructors of a class don't get a binding,
+ -- but they are always saturated, so they should always be inlined.
- (tyvars, theta, con_tyvars, con_theta, arg_tys, tycon) = dataConSig con_id
+ (tyvars, theta, ex_tyvars, ex_theta, orig_arg_tys, tycon)
+ = dataConSig data_con
+ rep_arg_tys = dataConRawArgTys data_con
+ all_tyvars = tyvars ++ ex_tyvars
dict_tys = [mkDictTy clas tys | (clas,tys) <- theta]
- con_dict_tys = [mkDictTy clas tys | (clas,tys) <- con_theta]
+ ex_dict_tys = [mkDictTy clas tys | (clas,tys) <- ex_theta]
+
n_dicts = length dict_tys
+ n_ex_dicts = length ex_dict_tys
+ n_id_args = length orig_arg_tys
+ n_rep_args = length rep_arg_tys
+
result_ty = mkTyConApp tycon (mkTyVarTys tyvars)
- locals = mkTemplateLocals (dict_tys ++ con_dict_tys ++ arg_tys)
- data_args = drop n_dicts locals
- (data_arg1:_) = data_args -- Used for newtype only
- strict_marks = dataConStrictMarks con_id
- strict_args = [arg | (arg,MarkedStrict) <- data_args `zip` strict_marks]
- -- NB: we can't call mkTemplateLocals twice, because it
- -- always starts from the same unique.
-
- con_app | isNewTyCon tycon
- = ASSERT( length arg_tys == 1)
- Note (Coerce result_ty (head arg_tys)) (Var data_arg1)
- | otherwise
- = Con con_id (map TyArg (mkTyVarTys tyvars) ++ map VarArg data_args)
+ mkLocals i n tys = (zipWith mkTemplateLocal [i..i+n-1] tys, i+n)
+ (dict_args, i1) = mkLocals 1 n_dicts dict_tys
+ (ex_dict_args,i2) = mkLocals i1 n_ex_dicts ex_dict_tys
+ (id_args,i3) = mkLocals i2 n_id_args orig_arg_tys
- con_rhs = mkTyLam tyvars $
- mkValLam locals $
- foldr mk_case con_app strict_args
+ (id_arg1:_) = id_args -- Used for newtype only
+ strict_marks = dataConStrictMarks data_con
- mk_case arg body | isUnpointedType (idType arg)
- = body -- "!" on unboxed arg does nothing
- | otherwise
- = Case (Var arg) (AlgAlts [] (BindDefault arg body))
- -- This case shadows "arg" but that's fine
+ con_app i rep_ids
+ | isNewTyCon tycon
+ = ASSERT( length orig_arg_tys == 1 )
+ Note (Coerce result_ty (head orig_arg_tys)) (Var id_arg1)
+ | otherwise
+ = mkConApp data_con
+ (map Type (mkTyVarTys all_tyvars) ++
+ map Var (reverse rep_ids))
+
+ con_rhs = mkLams all_tyvars $ mkLams dict_args $
+ mkLams ex_dict_args $ mkLams id_args $
+ foldr mk_case con_app
+ (zip (ex_dict_args++id_args) strict_marks) i3 []
+
+ mk_case
+ :: (Id, StrictnessMark) -- arg, strictness
+ -> (Int -> [Id] -> CoreExpr) -- body
+ -> Int -- next rep arg id
+ -> [Id] -- rep args so far
+ -> CoreExpr
+ mk_case (arg,strict) body i rep_args
+ = case strict of
+ NotMarkedStrict -> body i (arg:rep_args)
+ MarkedStrict
+ | isUnLiftedType (idType arg) -> body i (arg:rep_args)
+ | otherwise ->
+ Case (Var arg) arg [(DEFAULT,[], body i (arg:rep_args))]
+
+ MarkedUnboxed con tys ->
+ Case (Var arg) arg [(DataCon con, con_args,
+ body i' (reverse con_args++rep_args))]
+ where n_tys = length tys
+ (con_args,i') = mkLocals i (length tys) tys
\end{code}
= ASSERT( null theta && isDataTyCon tycon )
sel_id
where
- sel_id = mkId (fieldLabelName field_label) selector_ty
- (RecordSelId field_label) info
+ sel_id = mkId (fieldLabelName field_label) selector_ty info
- info = exactArity 1 `setArityInfo` (
- unfolding `setUnfoldingInfo`
- noIdInfo)
+ info = mkIdInfo (RecordSelId field_label)
+ `setArityInfo` exactArity 1
+ `setUnfoldingInfo` unfolding
+
-- ToDo: consider adding further IdInfo
- unfolding = mkUnfolding sel_rhs
+ unfolding = mkTopUnfolding sel_rhs
(tyvars, theta, tau) = splitSigmaTy selector_ty
(data_ty,rhs_ty) = expectJust "StdIdInfoRec" (splitFunTy_maybe tau)
[data_id] = mkTemplateLocals [data_ty]
alts = map mk_maybe_alt data_cons
- sel_rhs = mkTyLam tyvars $
- mkValLam [data_id] $
- Case (Var data_id)
- -- if any of the constructors don't have the label, ...
- (if any (not . isJust) alts then
- AlgAlts (catMaybes alts)
- (BindDefault data_id error_expr)
- else
- AlgAlts (catMaybes alts) NoDefault)
+ the_alts = catMaybes alts
+ default_alt | all isJust alts = [] -- No default needed
+ | otherwise = [(DEFAULT, [], error_expr)]
+
+ sel_rhs = mkLams tyvars $ Lam data_id $
+ Case (Var data_id) data_id (the_alts ++ default_alt)
mk_maybe_alt data_con
= case maybe_the_arg_id of
Nothing -> Nothing
- Just the_arg_id -> Just (data_con, arg_ids, Var the_arg_id)
+ Just the_arg_id -> Just (DataCon data_con, arg_ids, Var the_arg_id)
where
arg_ids = mkTemplateLocals (dataConArgTys data_con tyvar_tys)
-- The first one will shadow data_id, but who cares
field_lbls = dataConFieldLabels data_con
maybe_the_arg_id = assocMaybe (field_lbls `zip` arg_ids) field_label
- error_expr = mkApp (Var rEC_SEL_ERROR_ID) [rhs_ty] [LitArg msg_lit]
+ error_expr = mkApps (Var rEC_SEL_ERROR_ID) [Type (unUsgTy rhs_ty), mkStringLit full_msg]
+ -- preserves invariant that type args are *not* usage-annotated on top. KSW 1999-04.
full_msg = showSDoc (sep [text "No match in record selector", ppr sel_id])
- msg_lit = NoRepStr (_PK_ full_msg)
\end{code}
%************************************************************************
%* *
-\subsection{Dictionary selectors}
+\subsection{Newtype field selectors}
%* *
%************************************************************************
+Possibly overkill to do it this way:
+
\begin{code}
-mkSuperDictSelId :: Unique -> Class -> FieldLabelTag -> Type -> Id
- -- The FieldLabelTag says which superclass is selected
- -- So, for
- -- class (C a, C b) => Foo a b where ...
- -- we get superclass selectors
- -- Foo_sc1, Foo_sc2
-
-mkSuperDictSelId uniq clas index ty
- = mkDictSelId name clas ty
+mkNewTySelId field_label selector_ty = sel_id
where
- name = mkCompoundName name_fn uniq (getName clas)
- name_fn clas_str = clas_str _APPEND_ SLIT("_sc") _APPEND_ (_PK_ (show index))
+ sel_id = mkId (fieldLabelName field_label) selector_ty info
+
+
+ info = mkIdInfo (RecordSelId field_label)
+ `setArityInfo` exactArity 1
+ `setUnfoldingInfo` unfolding
+
+ -- ToDo: consider adding further IdInfo
- -- For method selectors the clean thing to do is
- -- to give the method selector the same name as the class op itself.
-mkMethodSelId name clas ty
- = mkDictSelId name clas ty
+ unfolding = mkTopUnfolding sel_rhs
+
+ (tyvars, theta, tau) = splitSigmaTy selector_ty
+ (data_ty,rhs_ty) = expectJust "StdIdInfoRec" (splitFunTy_maybe tau)
+ -- tau is of form (T a b c -> field-type)
+ (tycon, _, data_cons) = splitAlgTyConApp data_ty
+ tyvar_tys = mkTyVarTys tyvars
+
+ [data_id] = mkTemplateLocals [data_ty]
+ sel_rhs = mkLams tyvars $ Lam data_id $
+ Note (Coerce (unUsgTy rhs_ty) (unUsgTy data_ty)) (Var data_id)
\end{code}
+
+%************************************************************************
+%* *
+\subsection{Dictionary selectors}
+%* *
+%************************************************************************
+
Selecting a field for a dictionary. If there is just one field, then
there's nothing to do.
mkDictSelId name clas ty
= sel_id
where
- sel_id = mkId name ty (RecordSelId field_lbl) info
+ sel_id = mkId name ty info
field_lbl = mkFieldLabel name ty tag
- tag = assoc "MkId.mkDictSelId" ((sc_sel_ids ++ op_sel_ids) `zip` allFieldLabelTags) sel_id
+ tag = assoc "MkId.mkDictSelId" (classSelIds clas `zip` allFieldLabelTags) sel_id
- info = setInlinePragInfo IWantToBeINLINEd $
- setUnfoldingInfo unfolding noIdInfo
- -- The always-inline thing means we don't need any other IdInfo
+ info = mkIdInfo (RecordSelId field_lbl)
+ `setUnfoldingInfo` unfolding
+
+ -- We no longer use 'must-inline' on record selectors. They'll
+ -- inline like crazy if they scrutinise a constructor
- unfolding = mkUnfolding rhs
+ unfolding = mkTopUnfolding rhs
- (tyvars, _, sc_sel_ids, op_sel_ids, defms) = classBigSig clas
+ tyvars = classTyVars clas
tycon = classTyCon clas
[data_con] = tyConDataCons tycon
dict_ty = mkDictTy clas tyvar_tys
(dict_id:arg_ids) = mkTemplateLocals (dict_ty : arg_tys)
- rhs | isNewTyCon tycon = mkLam tyvars [dict_id] $
+ rhs | isNewTyCon tycon = mkLams tyvars $ Lam dict_id $
Note (Coerce (head arg_tys) dict_ty) (Var dict_id)
- | otherwise = mkLam tyvars [dict_id] $
- Case (Var dict_id) $
- AlgAlts [(data_con, arg_ids, Var the_arg_id)] NoDefault
+ | otherwise = mkLams tyvars $ Lam dict_id $
+ Case (Var dict_id) dict_id
+ [(DataCon data_con, arg_ids, Var the_arg_id)]
\end{code}
%* *
%************************************************************************
-
\begin{code}
-mkPrimitiveId name ty prim_op
- = mkId name ty (PrimitiveId prim_op) info
+mkPrimitiveId :: PrimOp -> Id
+mkPrimitiveId prim_op
+ = id
where
-
- info = setUnfoldingInfo unfolding $
- setInlinePragInfo IMustBeINLINEd $
- -- The pragma @IMustBeINLINEd@ says that this Id absolutely
+ (tyvars,arg_tys,res_ty) = primOpSig prim_op
+ ty = mkForAllTys tyvars (mkFunTys arg_tys res_ty)
+ name = mkPrimOpIdName prim_op id
+ id = mkId name ty info
+
+ info = mkIdInfo (ConstantId (PrimOp prim_op))
+ `setUnfoldingInfo` unfolding
+
+ unfolding = mkCompulsoryUnfolding rhs
+ -- The mkCompulsoryUnfolding says that this Id absolutely
-- must be inlined. It's only used for primitives,
-- because we don't want to make a closure for each of them.
- noIdInfo
- unfolding = mkUnfolding rhs
+ args = mkTemplateLocals arg_tys
+ rhs = mkLams tyvars $ mkLams args $
+ mkPrimApp prim_op (map Type (mkTyVarTys tyvars) ++ map Var args)
+\end{code}
- (tyvars, tau) = splitForAllTys ty
- (arg_tys, _) = splitFunTys tau
- args = mkTemplateLocals arg_tys
- rhs = mkLam tyvars args $
- Prim prim_op
- ([TyArg (mkTyVarTy tv) | tv <- tyvars] ++
- [VarArg v | v <- args])
+%************************************************************************
+%* *
+\subsection{DictFuns}
+%* *
+%************************************************************************
+
+\begin{code}
+mkDictFunId :: Name -- Name to use for the dict fun;
+ -> Class
+ -> [TyVar]
+ -> [Type]
+ -> ThetaType
+ -> Id
+
+mkDictFunId dfun_name clas inst_tyvars inst_tys inst_decl_theta
+ = mkVanillaId dfun_name dfun_ty
+ where
+ (class_tyvars, sc_theta, _, _) = classBigSig clas
+ sc_theta' = substTheta (mkTopTyVarSubst class_tyvars inst_tys) sc_theta
+
+ dfun_theta = case inst_decl_theta of
+ [] -> [] -- If inst_decl_theta is empty, then we don't
+ -- want to have any dict arguments, so that we can
+ -- expose the constant methods.
+
+ other -> nub (inst_decl_theta ++ filter not_const sc_theta')
+ -- Otherwise we pass the superclass dictionaries to
+ -- the dictionary function; the Mark Jones optimisation.
+ --
+ -- NOTE the "nub". I got caught by this one:
+ -- class Monad m => MonadT t m where ...
+ -- instance Monad m => MonadT (EnvT env) m where ...
+ -- Here, the inst_decl_theta has (Monad m); but so
+ -- does the sc_theta'!
+ --
+ -- NOTE the "not_const". I got caught by this one too:
+ -- class Foo a => Baz a b where ...
+ -- instance Wob b => Baz T b where..
+ -- Now sc_theta' has Foo T
+
+ dfun_ty = mkSigmaTy inst_tyvars dfun_theta (mkDictTy clas inst_tys)
+
+ not_const (clas, tys) = not (isEmptyVarSet (tyVarsOfTypes tys))
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection{Un-definable}
+%* *
+%************************************************************************
+
+These two can't be defined in Haskell.
+
+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.
+
+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}
+unsafeCoerceId
+ = pcMiscPrelId unsafeCoerceIdKey pREL_GHC SLIT("unsafeCoerce#") ty info
+ where
+ info = vanillaIdInfo
+ `setUnfoldingInfo` mkCompulsoryUnfolding rhs
+
+
+ ty = mkForAllTys [openAlphaTyVar,openBetaTyVar]
+ (mkFunTy openAlphaTy openBetaTy)
+ [x] = mkTemplateLocals [openAlphaTy]
+ rhs = mkLams [openAlphaTyVar,openBetaTyVar,x] $
+ Note (Coerce openBetaTy openAlphaTy) (Var x)
+\end{code}
+
+
+@getTag#@ is another function which can't be defined in Haskell. It needs to
+evaluate its argument and call the dataToTag# primitive.
+
+\begin{code}
+getTagId
+ = pcMiscPrelId getTagIdKey pREL_GHC SLIT("getTag#") ty info
+ where
+ info = vanillaIdInfo
+ `setUnfoldingInfo` mkCompulsoryUnfolding rhs
+ -- We don't provide a defn for this; you must inline it
+
+ ty = mkForAllTys [alphaTyVar] (mkFunTy alphaTy intPrimTy)
+ [x,y] = mkTemplateLocals [alphaTy,alphaTy]
+ rhs = mkLams [alphaTyVar,x] $
+ Case (Var x) y [ (DEFAULT, [],
+ Con (PrimOp DataToTagOp) [Type alphaTy, 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}
+realWorldPrimId -- :: State# RealWorld
+ = pcMiscPrelId realWorldPrimIdKey pREL_GHC SLIT("realWorld#")
+ realWorldStatePrimTy
+ noCafIdInfo
+\end{code}
+
+
+%************************************************************************
+%* *
+\subsection[PrelVals-error-related]{@error@ and friends; @trace@}
+%* *
+%************************************************************************
+
+GHC randomly injects these into the code.
+
+@patError@ is just a version of @error@ for pattern-matching
+failures. It knows various ``codes'' which expand to longer
+strings---this saves space!
+
+@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).
+
+@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.
+
+\begin{code}
+eRROR_ID
+ = pc_bottoming_Id errorIdKey pREL_ERR SLIT("error") errorTy
+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")
+
+aBSENT_ERROR_ID
+ = pc_bottoming_Id absentErrorIdKey pREL_ERR SLIT("absentErr")
+ (mkSigmaTy [openAlphaTyVar] [] openAlphaTy)
+
+pAR_ERROR_ID
+ = pcMiscPrelId parErrorIdKey pREL_ERR SLIT("parError")
+ (mkSigmaTy [openAlphaTyVar] [] openAlphaTy) noCafIdInfo
+
\end{code}
%************************************************************************
%* *
-\subsection{Catch-all}
+\subsection{Utilities}
%* *
%************************************************************************
\begin{code}
-addStandardIdInfo id
- = pprTrace "addStandardIdInfo missing:" (ppr id) id
+pcMiscPrelId :: Unique{-IdKey-} -> Module -> FAST_STRING -> Type -> IdInfo -> Id
+pcMiscPrelId key mod str ty info
+ = let
+ name = mkWiredInIdName key mod (mkSrcVarOcc str) imp
+ imp = mkId name ty 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.
+
+pc_bottoming_Id key mod name ty
+ = pcMiscPrelId key mod name ty bottoming_info
+ where
+ bottoming_info = noCafIdInfo
+ `setStrictnessInfo` mkStrictnessInfo ([wwStrict], True)
+
+ -- these "bottom" out, no matter what their arguments
+
+generic_ERROR_ID u n = pc_bottoming_Id u pREL_ERR n errorTy
+
+-- Very useful...
+noCafIdInfo = vanillaIdInfo `setCafInfo` NoCafRefs
+
+(openAlphaTyVar:openBetaTyVar:_) = openAlphaTyVars
+openAlphaTy = mkTyVarTy openAlphaTyVar
+openBetaTy = mkTyVarTy openBetaTyVar
+
+errorTy :: Type
+errorTy = mkUsgTy UsMany $
+ mkSigmaTy [openAlphaTyVar] [] (mkFunTys [mkUsgTy UsOnce (mkListTy charTy)]
+ (mkUsgTy UsMany 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}
projects / ghc-hetmet.git / blobdiff