%
+% (c) The University of Glasgow 2006
% (c) The AQUA Project, Glasgow University, 1998
%
-\section[StdIdInfo]{Standard unfoldings}
This module contains definitions for the IdInfo for things that
have a standard form, namely:
* primitive operations
\begin{code}
+{-# OPTIONS_GHC -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/WorkingConventions#Warnings
+-- for details
+
module MkId (
mkDictFunId, mkDefaultMethodId,
mkDictSelId,
mkDataConIds,
mkRecordSelId,
- mkPrimOpId, mkFCallId,
+ mkPrimOpId, mkFCallId, mkTickBoxOpId, mkBreakPointOpId,
mkReboxingAlt, wrapNewTypeBody, unwrapNewTypeBody,
+ wrapFamInstBody, unwrapFamInstScrut,
mkUnpackCase, mkProductBox,
-- And some particular Ids; see below for why they are wired in
#include "HsVersions.h"
-
-import BasicTypes ( Arity, StrictnessMark(..), isMarkedUnboxed, isMarkedStrict )
-import Rules ( mkSpecInfo )
-import TysPrim ( openAlphaTyVars, alphaTyVar, alphaTy,
- realWorldStatePrimTy, addrPrimTy
- )
-import TysWiredIn ( charTy, mkListTy )
-import PrelRules ( primOpRules )
-import Type ( TyThing(..), mkForAllTy, tyVarsOfTypes,
- newTyConInstRhs, mkTopTvSubst, substTyVar, substTy )
-import TcGadt ( gadtRefine, refineType, emptyRefinement )
-import HsBinds ( ExprCoFn(..), isIdCoercion )
-import Coercion ( mkSymCoercion, mkUnsafeCoercion, isEqPred )
-import TcType ( Type, ThetaType, mkDictTy, mkPredTys, mkPredTy,
- mkTyConApp, mkTyVarTys, mkClassPred, isPredTy,
- mkFunTys, mkFunTy, mkSigmaTy, tcSplitSigmaTy, tcEqType,
- isUnLiftedType, mkForAllTys, mkTyVarTy, tyVarsOfType,
- tcSplitFunTys, tcSplitForAllTys, dataConsStupidTheta
- )
-import CoreUtils ( exprType, dataConOrigInstPat, mkCoerce )
-import CoreUnfold ( mkTopUnfolding, mkCompulsoryUnfolding )
-import Literal ( nullAddrLit, mkStringLit )
-import TyCon ( TyCon, isNewTyCon, tyConDataCons, FieldLabel,
- tyConStupidTheta, isProductTyCon, isDataTyCon,
- isRecursiveTyCon, isFamInstTyCon,
- tyConFamInst_maybe, tyConFamilyCoercion_maybe,
- newTyConCo )
-import Class ( Class, classTyCon, classSelIds )
-import Var ( Id, TyVar, Var, setIdType )
-import VarSet ( isEmptyVarSet, subVarSet, varSetElems )
-import Name ( mkFCallName, mkWiredInName, Name, BuiltInSyntax(..))
-import OccName ( mkOccNameFS, varName )
-import PrimOp ( PrimOp, primOpSig, primOpOcc, primOpTag )
-import ForeignCall ( ForeignCall )
-import DataCon ( DataCon, DataConIds(..), dataConTyCon,
- dataConUnivTyVars,
- dataConFieldLabels, dataConRepArity, dataConResTys,
- dataConRepArgTys, dataConRepType, dataConFullSig,
- dataConStrictMarks, dataConExStricts,
- splitProductType, isVanillaDataCon, dataConFieldType,
- deepSplitProductType,
- )
-import Id ( idType, mkGlobalId, mkVanillaGlobal, mkSysLocal,
- mkTemplateLocals, mkTemplateLocalsNum, mkExportedLocalId,
- mkTemplateLocal, idName
- )
-import IdInfo ( IdInfo, noCafIdInfo, setUnfoldingInfo,
- setArityInfo, setSpecInfo, setCafInfo,
- setAllStrictnessInfo, vanillaIdInfo,
- GlobalIdDetails(..), CafInfo(..)
- )
-import NewDemand ( mkStrictSig, DmdResult(..),
- mkTopDmdType, topDmd, evalDmd, lazyDmd, retCPR,
- Demand(..), Demands(..) )
-import DmdAnal ( dmdAnalTopRhs )
+import Rules
+import TysPrim
+import TysWiredIn
+import PrelRules
+import Type
+import TypeRep
+import TcGadt
+import Coercion
+import TcType
+import CoreUtils
+import CoreUnfold
+import Literal
+import TyCon
+import Class
+import VarSet
+import Name
+import OccName
+import PrimOp
+import ForeignCall
+import DataCon
+import Id
+import Var ( Var, TyVar, mkCoVar)
+import IdInfo
+import NewDemand
+import DmdAnal
import CoreSyn
-import Unique ( mkBuiltinUnique, mkPrimOpIdUnique )
-import Maybe ( fromJust )
+import Unique
import Maybes
import PrelNames
-import Util ( dropList, isSingleton )
+import BasicTypes hiding ( SuccessFlag(..) )
+import Util
import Outputable
import FastString
-import ListSetOps ( assoc, minusList )
-\end{code}
+import ListSetOps
+import Module
+\end{code}
%************************************************************************
%* *
Making an explicit case expression allows the simplifier to eliminate
it in the (common) case where the constructor arg is already evaluated.
-[Wrappers for data instance tycons]
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Note [Wrappers for data instance tycons]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In the case of data instances, the wrapper also applies the coercion turning
the representation type into the family instance type to cast the result of
the wrapper. For example, consider the declarations
data family Map k :: * -> *
data instance Map (a, b) v = MapPair (Map a (Pair b v))
-The tycon to which the datacon MapPair belongs gets a unique internal name of
-the form :R123Map, and we call it the representation tycon. In contrast, Map
-is the family tycon (accessible via tyConFamInst_maybe). The wrapper and work
-of MapPair get the types
-
- $WMapPair :: forall a b v. Map a (Map a b v) -> Map (a, b) v
- $wMapPair :: forall a b v. Map a (Map a b v) -> :R123Map a b v
-
-which implies that the wrapper code will have to apply the coercion moving
-between representation and family type. It is accessible via
+The tycon to which the datacon MapPair belongs gets a unique internal
+name of the form :R123Map, and we call it the representation tycon.
+In contrast, Map is the family tycon (accessible via
+tyConFamInst_maybe). A coercion allows you to move between
+representation and family type. It is accessible from :R123Map via
tyConFamilyCoercion_maybe and has kind
Co123Map a b v :: {Map (a, b) v :=: :R123Map a b v}
+The wrapper and worker of MapPair get the types
+
+ -- Wrapper
+ $WMapPair :: forall a b v. Map a (Map a b v) -> Map (a, b) v
+ $WMapPair a b v = MapPair a b v `cast` sym (Co123Map a b v)
+
+ -- Worker
+ MapPair :: forall a b v. Map a (Map a b v) -> :R123Map a b v
+
This coercion is conditionally applied by wrapFamInstBody.
+It's a bit more complicated if the data instance is a GADT as well!
+
+ data instance T [a] where
+ T1 :: forall b. b -> T [Maybe b]
+Hence
+ Co7T a :: T [a] ~ :R7T a
+
+Now we want
+
+ -- Wrapper
+ $WT1 :: forall b. b -> T [Maybe b]
+ $WT1 b v = T1 (Maybe b) b (Maybe b) v
+ `cast` sym (Co7T (Maybe b))
+
+ -- Worker
+ T1 :: forall c b. (c ~ Maybe b) => b -> :R7T c
+
\begin{code}
mkDataConIds :: Name -> Name -> DataCon -> DataConIds
mkDataConIds wrap_name wkr_name data_con
- | isNewTyCon tycon
- = DCIds Nothing nt_work_id -- Newtype, only has a worker
+ | isNewTyCon tycon -- Newtype, only has a worker
+ = DCIds Nothing nt_work_id
- | any isMarkedStrict all_strict_marks -- Algebraic, needs wrapper
- || not (null eq_spec)
- || isFamInstTyCon tycon
+ | any isMarkedStrict all_strict_marks -- Algebraic, needs wrapper
+ || not (null eq_spec) -- NB: LoadIface.ifaceDeclSubBndrs
+ || isFamInstTyCon tycon -- depends on this test
= DCIds (Just alg_wrap_id) wrk_id
- | otherwise -- Algebraic, no wrapper
+ | otherwise -- Algebraic, no wrapper
= DCIds Nothing wrk_id
where
(univ_tvs, ex_tvs, eq_spec,
- theta, orig_arg_tys) = dataConFullSig data_con
- tycon = dataConTyCon data_con
-
- ----------- Wrapper --------------
- -- We used to include the stupid theta in the wrapper's args
- -- but now we don't. Instead the type checker just injects these
- -- extra constraints where necessary.
- wrap_tvs = (univ_tvs `minusList` map fst eq_spec) ++ ex_tvs
- subst = mkTopTvSubst eq_spec
- dict_tys = mkPredTys theta
- result_ty_args = map (substTyVar subst) univ_tvs
- result_ty = case tyConFamInst_maybe tycon of
- -- ordinary constructor
- Nothing -> mkTyConApp tycon result_ty_args
- -- family instance constructor
- Just (familyTyCon,
- instTys) ->
- mkTyConApp familyTyCon (map (substTy subst) instTys)
- wrap_ty = mkForAllTys wrap_tvs $ mkFunTys dict_tys $
- mkFunTys orig_arg_tys $ result_ty
- -- NB: watch out here if you allow user-written equality
- -- constraints in data constructor signatures
+ eq_theta, dict_theta, orig_arg_tys, res_ty) = dataConFullSig data_con
+ tycon = dataConTyCon data_con -- The representation TyCon (not family)
----------- Worker (algebraic data types only) --------------
-- The *worker* for the data constructor is the function that
-- even if arity = 0
wkr_sig = mkStrictSig (mkTopDmdType (replicate wkr_arity topDmd) cpr_info)
+ -- Note [Data-con worker strictness]
-- Notice that we do *not* say the worker is strict
-- even if the data constructor is declared strict
-- e.g. data T = MkT !(Int,Int)
nt_work_info = noCafIdInfo -- The NoCaf-ness is set by noCafIdInfo
`setArityInfo` 1 -- Arity 1
`setUnfoldingInfo` newtype_unf
- newtype_unf = ASSERT( isVanillaDataCon data_con &&
- isSingleton orig_arg_tys )
+ newtype_unf = -- The assertion below is no longer correct:
+ -- there may be a dict theta rather than a singleton orig_arg_ty
+ -- ASSERT( isVanillaDataCon data_con &&
+ -- isSingleton orig_arg_tys )
+ --
-- No existentials on a newtype, but it can have a context
-- e.g. newtype Eq a => T a = MkT (...)
mkCompulsoryUnfolding $
mkLams wrap_tvs $ Lam id_arg1 $
- wrapNewTypeBody tycon result_ty_args
+ wrapNewTypeBody tycon res_ty_args
(Var id_arg1)
- id_arg1 = mkTemplateLocal 1 (head orig_arg_tys)
+ id_arg1 = mkTemplateLocal 1
+ (if null orig_arg_tys
+ then ASSERT(not (null $ dataConDictTheta data_con)) mkPredTy $ head (dataConDictTheta data_con)
+ else head orig_arg_tys
+ )
+
+ ----------- Wrapper --------------
+ -- We used to include the stupid theta in the wrapper's args
+ -- but now we don't. Instead the type checker just injects these
+ -- extra constraints where necessary.
+ wrap_tvs = (univ_tvs `minusList` map fst eq_spec) ++ ex_tvs
+ res_ty_args = substTyVars (mkTopTvSubst eq_spec) univ_tvs
+ eq_tys = mkPredTys eq_theta
+ dict_tys = mkPredTys dict_theta
+ wrap_ty = mkForAllTys wrap_tvs $ mkFunTys eq_tys $ mkFunTys dict_tys $
+ mkFunTys orig_arg_tys $ res_ty
+ -- NB: watch out here if you allow user-written equality
+ -- constraints in data constructor signatures
----------- Wrappers for algebraic data types --------------
alg_wrap_id = mkGlobalId (DataConWrapId data_con) wrap_name wrap_ty alg_wrap_info
alg_wrap_info = noCafIdInfo -- The NoCaf-ness is set by noCafIdInfo
- `setArityInfo` alg_arity
+ `setArityInfo` wrap_arity
-- It's important to specify the arity, so that partial
-- applications are treated as values
- `setUnfoldingInfo` alg_unf
+ `setUnfoldingInfo` wrap_unf
`setAllStrictnessInfo` Just wrap_sig
all_strict_marks = dataConExStricts data_con ++ dataConStrictMarks data_con
-- ...(let w = C x in ...(w p q)...)...
-- we want to see that w is strict in its two arguments
- alg_unf = mkTopUnfolding $ Note InlineMe $
+ wrap_unf = mkTopUnfolding $ Note InlineMe $
mkLams wrap_tvs $
+ mkLams eq_args $
mkLams dict_args $ mkLams id_args $
foldr mk_case con_app
(zip (dict_args ++ id_args) all_strict_marks)
i3 []
- con_app _ rep_ids = wrapFamInstBody tycon result_ty_args $
- Var wrk_id `mkTyApps` result_ty_args
- `mkVarApps` ex_tvs
- `mkTyApps` map snd eq_spec
+ con_app _ rep_ids = wrapFamInstBody tycon res_ty_args $
+ Var wrk_id `mkTyApps` res_ty_args
+ `mkVarApps` ex_tvs
+ `mkTyApps` map snd eq_spec -- Equality evidence
+ `mkVarApps` eq_args
`mkVarApps` reverse rep_ids
(dict_args,i2) = mkLocals 1 dict_tys
(id_args,i3) = mkLocals i2 orig_arg_tys
- alg_arity = i3-1
+ wrap_arity = i3-1
+ (eq_args,_) = mkCoVarLocals i3 eq_tys
+
+ mkCoVarLocals i [] = ([],i)
+ mkCoVarLocals i (x:xs) = let (ys,j) = mkCoVarLocals (i+1) xs
+ y = mkCoVar (mkSysTvName (mkBuiltinUnique i) FSLIT("dc_co")) x
+ in (y:ys,j)
mk_case
:: (Id, StrictnessMark) -- Arg, strictness
MarkedStrict
| isUnLiftedType (idType arg) -> body i (arg:rep_args)
| otherwise ->
- Case (Var arg) arg result_ty [(DEFAULT,[], body i (arg:rep_args))]
+ Case (Var arg) arg res_ty [(DEFAULT,[], body i (arg:rep_args))]
MarkedUnboxed
-> unboxProduct i (Var arg) (idType arg) the_body
mkLocals i tys = (zipWith mkTemplateLocal [i..i+n-1] tys, i+n)
where
n = length tys
-
--- If the type constructor is a representation type of a data instance, wrap
--- the expression into a cast adjusting the expression type, which is an
--- instance of the representation type, to the corresponding instance of the
--- family instance type.
---
-wrapFamInstBody :: TyCon -> [Type] -> CoreExpr -> CoreExpr
-wrapFamInstBody tycon args result_expr
- | Just co_con <- tyConFamilyCoercion_maybe tycon
- = mkCoerce (mkSymCoercion (mkTyConApp co_con args)) result_expr
- | otherwise
- = result_expr
-
\end{code}
of the result type; there may be other tyvars in the constructor's
type (e.g. 'b' in T2).
-\begin{code}
+Note [Selector running example]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+It's OK to combine GADTs and type families. Here's a running example:
--- Steps for handling "naughty" vs "non-naughty" selectors:
--- 1. Determine naughtiness by comparing field type vs result type
--- 2. Install naughty ones with selector_ty of type _|_ and fill in mzero for info
--- 3. If it's not naughty, do the normal plan.
+ data instance T [a] where
+ T1 { fld :: b } :: T [Maybe b]
+The representation type looks like this
+ data :R7T a where
+ T1 { fld :: b } :: :R7T (Maybe b)
+
+and there's coercion from the family type to the representation type
+ :CoR7T a :: T [a] ~ :R7T a
+
+The selector we want for fld looks like this:
+
+ fld :: forall b. T [Maybe b] -> b
+ fld = /\b. \(d::T [Maybe b]).
+ case d `cast` :CoR7T (Maybe b) of
+ T1 (x::b) -> x
+
+The scrutinee of the case has type :R7T (Maybe b), which can be
+gotten by appying the eq_spec to the univ_tvs of the data con.
+
+\begin{code}
mkRecordSelId :: TyCon -> FieldLabel -> Id
mkRecordSelId tycon field_label
-- Assumes that all fields with the same field label have the same type
| is_naughty = naughty_id
| otherwise = sel_id
where
- is_naughty = not (tyVarsOfType field_ty `subVarSet` res_tv_set)
- sel_id_details = RecordSelId tycon field_label is_naughty
+ is_naughty = not (tyVarsOfType field_ty `subVarSet` data_tv_set)
+ sel_id_details = RecordSelId { sel_tycon = tycon, sel_label = field_label, sel_naughty = is_naughty }
+ -- For a data type family, the tycon is the *instance* TyCon
- -- Escapist case here for naughty construcotrs
+ -- Escapist case here for naughty constructors
-- We give it no IdInfo, and a type of forall a.a (never looked at)
naughty_id = mkGlobalId sel_id_details field_label forall_a_a noCafIdInfo
forall_a_a = mkForAllTy alphaTyVar (mkTyVarTy alphaTyVar)
data_cons_w_field = filter has_field data_cons -- Can't be empty!
has_field con = field_label `elem` dataConFieldLabels con
- con1 = head data_cons_w_field
- res_tys = dataConResTys con1
- res_tv_set = tyVarsOfTypes res_tys
- res_tvs = varSetElems res_tv_set
- data_ty = mkTyConApp tycon res_tys
+ con1 = ASSERT( not (null data_cons_w_field) ) head data_cons_w_field
+ (univ_tvs, _, eq_spec, _, _, _, data_ty) = dataConFullSig con1
+ -- For a data type family, the data_ty (and hence selector_ty) mentions
+ -- only the family TyCon, not the instance TyCon
+ data_tv_set = tyVarsOfType data_ty
+ data_tvs = varSetElems data_tv_set
field_ty = dataConFieldType con1 field_label
-- *Very* tiresomely, the selectors are (unnecessarily!) overloaded over
n_stupid_dicts = length stupid_dict_tys
(field_tyvars,pre_field_theta,field_tau) = tcSplitSigmaTy field_ty
-
- field_theta = filter (not . isEqPred) pre_field_theta
- field_dict_tys = mkPredTys field_theta
- n_field_dict_tys = length field_dict_tys
+ field_theta = filter (not . isEqPred) pre_field_theta
+ field_dict_tys = mkPredTys field_theta
+ n_field_dict_tys = length field_dict_tys
-- If the field has a universally quantified type we have to
-- be a bit careful. Suppose we have
-- data R = R { op :: forall a. Foo a => a -> a }
-- op (R op) = op
selector_ty :: Type
- selector_ty = mkForAllTys res_tvs $ mkForAllTys field_tyvars $
+ selector_ty = mkForAllTys data_tvs $ mkForAllTys field_tyvars $
mkFunTys stupid_dict_tys $ mkFunTys field_dict_tys $
mkFunTy data_ty field_tau
field_dict_ids = mkTemplateLocalsNum field_dict_base field_dict_tys
dict_id_base = field_dict_base + n_field_dict_tys
data_id = mkTemplateLocal dict_id_base data_ty
- arg_base = dict_id_base + 1
+ scrut_id = mkTemplateLocal (dict_id_base+1) scrut_ty
+ arg_base = dict_id_base + 2
the_alts :: [CoreAlt]
the_alts = map mk_alt data_cons_w_field -- Already sorted by data-con
caf_info | no_default = NoCafRefs
| otherwise = MayHaveCafRefs
- sel_rhs = mkLams res_tvs $ mkLams field_tyvars $
+ sel_rhs = mkLams data_tvs $ mkLams field_tyvars $
mkLams stupid_dict_ids $ mkLams field_dict_ids $
- Lam data_id $ mk_result sel_body
+ Lam data_id $ mk_result sel_body
+
+ scrut_ty_args = substTyVars (mkTopTvSubst eq_spec) univ_tvs
+ scrut_ty = mkTyConApp tycon scrut_ty_args
+ scrut = unwrapFamInstScrut tycon scrut_ty_args (Var data_id)
+ -- First coerce from the type family to the representation type
-- NB: A newtype always has a vanilla DataCon; no existentials etc
- -- res_tys will simply be the dataConUnivTyVars
- sel_body | isNewTyCon tycon = unwrapNewTypeBody tycon res_tys (Var data_id)
- | otherwise = Case (Var data_id) data_id field_ty (default_alt ++ the_alts)
+ -- data_tys will simply be the dataConUnivTyVars
+ sel_body | isNewTyCon tycon = unwrapNewTypeBody tycon scrut_ty_args scrut
+ | otherwise = Case scrut scrut_id field_ty (default_alt ++ the_alts)
mk_result poly_result = mkVarApps (mkVarApps poly_result field_tyvars) field_dict_ids
-- We pull the field lambdas to the top, so we need to
-- foo = /\a. \t:T. case t of { MkT f -> f a }
mk_alt data_con
- = ASSERT2( res_ty `tcEqType` field_ty, ppr data_con $$ ppr res_ty $$ ppr field_ty )
+ = ASSERT2( data_ty `tcEqType` field_ty, ppr data_con $$ ppr data_ty $$ ppr field_ty )
mkReboxingAlt rebox_uniqs data_con (ex_tvs ++ co_tvs ++ arg_vs) rhs
where
-- get pattern binders with types appropriately instantiated
arg_uniqs = map mkBuiltinUnique [arg_base..]
- (ex_tvs, co_tvs, arg_vs) = dataConOrigInstPat arg_uniqs data_con res_tys
+ (ex_tvs, co_tvs, arg_vs) = dataConOrigInstPat arg_uniqs data_con scrut_ty_args
rebox_base = arg_base + length ex_tvs + length co_tvs + length arg_vs
rebox_uniqs = map mkBuiltinUnique [rebox_base..]
-- T1 b' (c : [b]=[b']) (x:Maybe b')
-- -> x `cast` Maybe (sym (right c))
- Succeeded refinement = gadtRefine emptyRefinement ex_tvs co_tvs
- (co_fn, res_ty) = refineType refinement (idType the_arg_id)
+
-- Generate the refinement for b'=b,
-- and apply to (Maybe b'), to get (Maybe b)
-
- rhs = case co_fn of
- ExprCoFn co -> Cast (Var the_arg_id) co
- id_co -> ASSERT(isIdCoercion id_co) Var the_arg_id
+ Succeeded refinement = gadtRefine emptyRefinement ex_tvs co_tvs
+ the_arg_id_ty = idType the_arg_id
+ (rhs, data_ty) = case refineType refinement the_arg_id_ty of
+ Just (co, data_ty) -> (Cast (Var the_arg_id) co, data_ty)
+ Nothing -> (Var the_arg_id, the_arg_id_ty)
field_vs = filter (not . isPredTy . idType) arg_vs
the_arg_id = assoc "mkRecordSelId:mk_alt" (field_lbls `zip` field_vs) field_label
-- C a -> C a
-- for a single-op class (after all, the selector is the identity)
-- But it's type must expose the representation of the dictionary
- -- to gat (say) C a -> (a -> a)
+ -- to get (say) C a -> (a -> a)
info = noCafIdInfo
`setArityInfo` 1
tycon = classTyCon clas
[data_con] = tyConDataCons tycon
tyvars = dataConUnivTyVars data_con
- arg_tys = ASSERT( isVanillaDataCon data_con ) dataConRepArgTys data_con
+ arg_tys = {- ASSERT( isVanillaDataCon data_con ) -} dataConRepArgTys data_con
+ eq_theta = dataConEqTheta data_con
the_arg_id = assoc "MkId.mkDictSelId" (map idName (classSelIds clas) `zip` arg_ids) name
- pred = mkClassPred clas (mkTyVarTys tyvars)
- (dict_id:arg_ids) = mkTemplateLocals (mkPredTy pred : arg_tys)
+ pred = mkClassPred clas (mkTyVarTys tyvars)
+ dict_id = mkTemplateLocal 1 $ mkPredTy pred
+ (eq_ids,n) = mkCoVarLocals 2 $ mkPredTys eq_theta
+ arg_ids = mkTemplateLocalsNum n arg_tys
- rhs = mkLams tyvars (Lam dict_id rhs_body)
+ mkCoVarLocals i [] = ([],i)
+ mkCoVarLocals i (x:xs) = let (ys,j) = mkCoVarLocals (i+1) xs
+ y = mkCoVar (mkSysTvName (mkBuiltinUnique i) FSLIT("dc_co")) x
+ in (y:ys,j)
+
+ rhs = mkLams tyvars (Lam dict_id rhs_body)
rhs_body | isNewTyCon tycon = unwrapNewTypeBody tycon (map mkTyVarTy tyvars) (Var dict_id)
| otherwise = Case (Var dict_id) dict_id (idType the_arg_id)
- [(DataAlt data_con, arg_ids, Var the_arg_id)]
+ [(DataAlt data_con, eq_ids ++ arg_ids, Var the_arg_id)]
+\end{code}
+
+%************************************************************************
+%* *
+ Wrapping and unwrapping newtypes and type families
+%* *
+%************************************************************************
+
+\begin{code}
wrapNewTypeBody :: TyCon -> [Type] -> CoreExpr -> CoreExpr
-- The wrapper for the data constructor for a newtype looks like this:
-- newtype T a = MkT (a,Int)
-- body of the wrapper, namely
-- e `cast` (CoT [a])
--
--- If a coercion constructor is prodivided in the newtype, then we use
+-- If a coercion constructor is provided in the newtype, then we use
-- it, otherwise the wrap/unwrap are both no-ops
--
+-- If the we are dealing with a newtype *instance*, we have a second coercion
+-- identifying the family instance with the constructor of the newtype
+-- instance. This coercion is applied in any case (ie, composed with the
+-- coercion constructor of the newtype or applied by itself).
+
wrapNewTypeBody tycon args result_expr
- | Just co_con <- newTyConCo tycon
- = mkCoerce (mkSymCoercion (mkTyConApp co_con args)) result_expr
- | otherwise
- = result_expr
+ = wrapFamInstBody tycon args inner
+ where
+ inner
+ | Just co_con <- newTyConCo_maybe tycon
+ = mkCoerce (mkSymCoercion (mkTyConApp co_con args)) result_expr
+ | otherwise
+ = result_expr
+
+-- When unwrapping, we do *not* apply any family coercion, because this will
+-- be done via a CoPat by the type checker. We have to do it this way as
+-- computing the right type arguments for the coercion requires more than just
+-- a spliting operation (cf, TcPat.tcConPat).
unwrapNewTypeBody :: TyCon -> [Type] -> CoreExpr -> CoreExpr
unwrapNewTypeBody tycon args result_expr
- | Just co_con <- newTyConCo tycon
+ | Just co_con <- newTyConCo_maybe tycon
= mkCoerce (mkTyConApp co_con args) result_expr
| otherwise
= result_expr
+-- If the type constructor is a representation type of a data instance, wrap
+-- the expression into a cast adjusting the expression type, which is an
+-- instance of the representation type, to the corresponding instance of the
+-- family instance type.
+-- See Note [Wrappers for data instance tycons]
+wrapFamInstBody :: TyCon -> [Type] -> CoreExpr -> CoreExpr
+wrapFamInstBody tycon args body
+ | Just co_con <- tyConFamilyCoercion_maybe tycon
+ = mkCoerce (mkSymCoercion (mkTyConApp co_con args)) body
+ | otherwise
+ = body
+unwrapFamInstScrut :: TyCon -> [Type] -> CoreExpr -> CoreExpr
+unwrapFamInstScrut tycon args scrut
+ | Just co_con <- tyConFamilyCoercion_maybe tycon
+ = mkCoerce (mkTyConApp co_con args) scrut
+ | otherwise
+ = scrut
\end{code}
ty = mkForAllTys tyvars (mkFunTys arg_tys res_ty)
name = mkWiredInName gHC_PRIM (primOpOcc prim_op)
(mkPrimOpIdUnique (primOpTag prim_op))
- Nothing (AnId id) UserSyntax
+ (AnId id) UserSyntax
id = mkGlobalId (PrimOpId prim_op) name ty info
info = noCafIdInfo
(arg_tys, _) = tcSplitFunTys tau
arity = length arg_tys
strict_sig = mkStrictSig (mkTopDmdType (replicate arity evalDmd) TopRes)
+
+-- Tick boxes and breakpoints are both represented as TickBoxOpIds,
+-- except for the type:
+--
+-- a plain HPC tick box has type (State# RealWorld)
+-- a breakpoint Id has type forall a.a
+--
+-- The breakpoint Id will be applied to a list of arbitrary free variables,
+-- which is why it needs a polymorphic type.
+
+mkTickBoxOpId :: Unique -> Module -> TickBoxId -> Id
+mkTickBoxOpId uniq mod ix = mkTickBox' uniq mod ix realWorldStatePrimTy
+
+mkBreakPointOpId :: Unique -> Module -> TickBoxId -> Id
+mkBreakPointOpId uniq mod ix = mkTickBox' uniq mod ix ty
+ where ty = mkSigmaTy [openAlphaTyVar] [] openAlphaTy
+
+mkTickBox' uniq mod ix ty = mkGlobalId (TickBoxOpId tickbox) name ty info
+ where
+ tickbox = TickBox mod ix
+ occ_str = showSDoc (braces (ppr tickbox))
+ name = mkTickBoxOpName uniq occ_str
+ info = noCafIdInfo
\end{code}
\begin{code}
mkWiredInIdName mod fs uniq id
- = mkWiredInName mod (mkOccNameFS varName fs) uniq Nothing (AnId id) UserSyntax
+ = mkWiredInName mod (mkOccNameFS varName fs) uniq (AnId id) UserSyntax
unsafeCoerceName = mkWiredInIdName gHC_PRIM FSLIT("unsafeCoerce#") unsafeCoerceIdKey unsafeCoerceId
nullAddrName = mkWiredInIdName gHC_PRIM FSLIT("nullAddr#") nullAddrIdKey nullAddrId
(mkFunTy openAlphaTy openBetaTy)
[x] = mkTemplateLocals [openAlphaTy]
rhs = mkLams [openAlphaTyVar,openBetaTyVar,x] $
--- Note (Coerce openBetaTy openAlphaTy) (Var x)
- Cast (Var x) (mkUnsafeCoercion openAlphaTy openBetaTy)
+ Cast (Var x) (mkUnsafeCoercion openAlphaTy openBetaTy)
-- nullAddr# :: Addr#
-- The reason is is here is because we don't provide
-- not from GHC.Base.hi. This is important, because the strictness
-- analyser will spot it as strict!
--
--- Also no unfolding in lazyId: it gets "inlined" by a HACK in the worker/wrapper pass
+-- Also no unfolding in lazyId: it gets "inlined" by a HACK in the worker/wrapperpass
-- (see WorkWrap.wwExpr)
-- We could use inline phases to do this, but that would be vulnerable to changes in
-- phase numbering....we must inline precisely after strictness analysis.
strict_sig = mkStrictSig (mkTopDmdType [evalDmd] BotRes)
-- These "bottom" out, no matter what their arguments
-
-(openAlphaTyVar:openBetaTyVar:_) = openAlphaTyVars
-openAlphaTy = mkTyVarTy openAlphaTyVar
-openBetaTy = mkTyVarTy openBetaTyVar
\end{code}
projects / ghc-hetmet.git / blobdiff