\begin{code}
module TcEnv(
- TcId, TcIdSet,
- TyThing(..), TyThingDetails(..), TcTyThing(..),
+ TyThing(..), TyThingDetails(..), TcTyThing(..), TcId,
- -- Getting stuff from the environment
- TcEnv, initTcEnv,
- tcEnvTyCons, tcEnvClasses, tcEnvIds, tcEnvTcIds, tcEnvTyVars,
- getTcGEnv,
-
-- Instance environment, and InstInfo type
- tcGetInstEnv, tcSetInstEnv,
- InstInfo(..), pprInstInfo,
+ tcGetInstEnv,
+ InstInfo(..), pprInstInfo, pprInstInfoDetails,
simpleInstInfoTy, simpleInstInfoTyCon,
+ InstBindings(..),
-- Global environment
- tcExtendGlobalEnv, tcExtendGlobalValEnv, tcExtendGlobalTypeEnv,
- tcLookupTyCon, tcLookupClass, tcLookupGlobalId, tcLookupDataCon,
- tcLookupGlobal_maybe, tcLookupGlobal, tcLookupSyntaxId, tcLookupSyntaxName,
+ tcExtendGlobalEnv,
+ tcExtendGlobalValEnv,
+ tcExtendGlobalTypeEnv,
+ tcLookupTyCon, tcLookupClass, tcLookupDataCon,
+ tcLookupGlobal_maybe, tcLookupGlobal, tcLookupGlobalId,
+ getInGlobalScope,
-- Local environment
- tcExtendKindEnv, tcLookupLocalIds, tcInLocalScope,
- tcExtendTyVarEnv, tcExtendTyVarEnvForMeths,
- tcExtendLocalValEnv, tcLookup, tcLookup_maybe, tcLookupId,
+ tcExtendKindEnv,
+ tcExtendTyVarEnv, tcExtendTyVarEnv2,
+ tcExtendLocalValEnv, tcExtendLocalValEnv2,
+ tcLookup, tcLookupLocalIds, tcLookup_maybe,
+ tcLookupId,
+ lclEnvElts, getInLocalScope, findGlobals,
+
+ -- Instance environment
+ tcExtendLocalInstEnv, tcExtendInstEnv, tcExtendTempInstEnv, tcWithTempInstEnv,
+
+ -- Rules
+ tcExtendRules,
-- Global type variables
- tcGetGlobalTyVars, tcExtendGlobalTyVars,
+ tcGetGlobalTyVars,
- -- Random useful things
- RecTcEnv, tcAddImportedIdInfo, tcLookupRecId, tcLookupRecId_maybe,
+ -- Template Haskell stuff
+ checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel,
+ topIdLvl,
+
+ -- Arrow stuff
+ checkProcLevel,
-- New Ids
- newLocalId, newSpecPragmaId,
- newDFunName,
+ newLocalName, newDFunName,
-- Misc
- isLocalThing, tcSetEnv
+ isLocalThing
) where
#include "HsVersions.h"
import RnHsSyn ( RenamedMonoBinds, RenamedSig )
-import TcMonad
-import TcType ( TcKind, TcType, TcTyVar, TcTyVarSet,
- zonkTcTyVarsAndFV
+import HsSyn ( RuleDecl(..), ifaceRuleDeclName )
+import TcRnMonad
+import TcMType ( zonkTcType, zonkTcTyVar, zonkTcTyVarsAndFV )
+import TcType ( Type, ThetaType, TcKind, TcTyVar, TcTyVarSet,
+ tyVarsOfType, tyVarsOfTypes, tcSplitDFunTy, mkGenTyConApp,
+ getDFunTyKey, tcTyConAppTyCon, tyVarBindingInfo,
+ tidyOpenType, tidyOpenTyVar
)
-import Id ( idName, mkSpecPragmaId, mkUserLocal, isDataConWrapId_maybe )
-import IdInfo ( vanillaIdInfo )
-import Var ( TyVar, Id, idType, lazySetIdInfo, idInfo )
+import qualified Type ( getTyVar_maybe )
+import Rules ( extendRuleBase )
+import Id ( idName, isLocalId )
+import Var ( TyVar, Id, idType )
import VarSet
-import Type ( Type, ThetaType,
- tyVarsOfTypes, splitDFunTy,
- getDFunTyKey, tyConAppTyCon
- )
+import VarEnv
+import CoreSyn ( IdCoreRule )
import DataCon ( DataCon )
-import TyCon ( TyCon )
+import TyCon ( TyCon, DataConDetails )
import Class ( Class, ClassOpItem )
-import Name ( Name, OccName, NamedThing(..),
- nameOccName, getSrcLoc, mkLocalName, isLocalName,
- nameIsLocalOrFrom
+import Name ( Name, NamedThing(..),
+ getSrcLoc, mkInternalName, nameIsLocalOrFrom
)
-import NameEnv ( NameEnv, lookupNameEnv, nameEnvElts, elemNameEnv,
- extendNameEnvList, emptyNameEnv, plusNameEnv )
+import NameEnv
import OccName ( mkDFunOcc, occNameString )
-import HscTypes ( DFunId,
- PackageTypeEnv, TypeEnv,
- extendTypeEnvList, extendTypeEnvWithIds,
- typeEnvTyCons, typeEnvClasses, typeEnvIds,
- HomeSymbolTable
- )
+import HscTypes ( DFunId, TypeEnv, extendTypeEnvList, lookupType,
+ TyThing(..), ExternalPackageState(..) )
+import Rules ( RuleBase )
+import BasicTypes ( EP )
import Module ( Module )
-import InstEnv ( InstEnv, emptyInstEnv )
-import HscTypes ( lookupType, TyThing(..) )
-import Util ( zipEqual )
+import InstEnv ( InstEnv, extendInstEnv )
import SrcLoc ( SrcLoc )
-import qualified PrelNames
import Outputable
-
-import IOExts ( newIORef )
+import Maybe ( isJust )
+import List ( partition )
\end{code}
+
%************************************************************************
%* *
-\subsection{TcEnv}
+ Arrow notation proc levels
%* *
%************************************************************************
\begin{code}
-type TcId = Id -- Type may be a TcType
-type TcIdSet = IdSet
-
-data TcEnv
- = TcEnv {
- tcSyntaxMap :: PrelNames.SyntaxMap, -- The syntax map (usually the identity)
-
- tcGST :: Name -> Maybe TyThing, -- The type environment at the moment we began this compilation
-
- tcInsts :: InstEnv, -- All instances (both imported and in this module)
-
- tcGEnv :: TypeEnv, -- The global type environment we've accumulated while
- {- NameEnv TyThing-} -- compiling this module:
- -- types and classes (both imported and local)
- -- imported Ids
- -- (Ids defined in this module start in the local envt,
- -- though they move to the global envt during zonking)
-
- tcLEnv :: NameEnv TcTyThing, -- The local type environment: Ids and TyVars
- -- defined in this module
-
- tcTyVars :: TcRef TcTyVarSet -- The "global tyvars"
- -- Namely, the in-scope TyVars bound in tcLEnv, plus the tyvars
- -- mentioned in the types of Ids bound in tcLEnv
- -- Why mutable? see notes with tcGetGlobalTyVars
- }
-
+checkProcLevel :: TcId -> ProcLevel -> TcM ()
+checkProcLevel id id_lvl
+ = do { banned <- getBannedProcLevels
+ ; checkTc (not (id_lvl `elem` banned))
+ (procLevelErr id id_lvl) }
+
+procLevelErr id id_lvl
+ = hang (ptext SLIT("Command-bound variable") <+> quotes (ppr id) <+> ptext SLIT("is not in scope here"))
+ 4 (ptext SLIT("Reason: it is used in the left argument of (-<)"))
\end{code}
+
-The Global-Env/Local-Env story
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-During type checking, we keep in the GlobalEnv
- * All types and classes
- * All Ids derived from types and classes (constructors, selectors)
- * Imported Ids
-
-At the end of type checking, we zonk the local bindings,
-and as we do so we add to the GlobalEnv
- * Locally defined top-level Ids
-
-Why? Because they are now Ids not TcIds. This final GlobalEnv is
-used thus:
- a) fed back (via the knot) to typechecking the
- unfoldings of interface signatures
-
- b) used to augment the GlobalSymbolTable
-
+%************************************************************************
+%* *
+ Meta level
+%* *
+%************************************************************************
\begin{code}
-data TcTyThing
- = AGlobal TyThing -- Used only in the return type of a lookup
- | ATcId TcId -- Ids defined in this module
- | ATyVar TyVar -- Type variables
- | AThing TcKind -- Used temporarily, during kind checking
--- Here's an example of how the AThing guy is used
--- Suppose we are checking (forall a. T a Int):
--- 1. We first bind (a -> AThink kv), where kv is a kind variable.
--- 2. Then we kind-check the (T a Int) part.
--- 3. Then we zonk the kind variable.
--- 4. Now we know the kind for 'a', and we add (a -> ATyVar a::K) to the environment
-
-initTcEnv :: PrelNames.SyntaxMap -> HomeSymbolTable -> PackageTypeEnv -> IO TcEnv
-initTcEnv syntax_map hst pte
- = do { gtv_var <- newIORef emptyVarSet ;
- return (TcEnv { tcSyntaxMap = syntax_map,
- tcGST = lookup,
- tcGEnv = emptyNameEnv,
- tcInsts = emptyInstEnv,
- tcLEnv = emptyNameEnv,
- tcTyVars = gtv_var
- })}
+instance Outputable ThStage where
+ ppr Comp = text "Comp"
+ ppr (Brack l _ _) = text "Brack" <+> int l
+ ppr (Splice l) = text "Splice" <+> int l
+
+
+thLevel :: ThStage -> ThLevel
+thLevel Comp = topLevel
+thLevel (Splice l) = l
+thLevel (Brack l _ _) = l
+
+
+checkWellStaged :: SDoc -- What the stage check is for
+ -> ThLevel -- Binding level
+ -> ThStage -- Use stage
+ -> TcM () -- Fail if badly staged, adding an error
+checkWellStaged pp_thing bind_lvl use_stage
+ | bind_lvl <= use_lvl -- OK!
+ = returnM ()
+
+ | bind_lvl == topLevel -- GHC restriction on top level splices
+ = failWithTc $
+ sep [ptext SLIT("GHC stage restriction:") <+> pp_thing,
+ nest 2 (ptext SLIT("is used in a top-level splice, and must be imported, not defined locally"))]
+
+ | otherwise -- Badly staged
+ = failWithTc $
+ ptext SLIT("Stage error:") <+> pp_thing <+>
+ hsep [ptext SLIT("is bound at stage") <+> ppr bind_lvl,
+ ptext SLIT("but used at stage") <+> ppr use_lvl]
where
- lookup name | isLocalName name = Nothing
- | otherwise = lookupType hst pte name
-
-
-tcEnvClasses env = typeEnvClasses (tcGEnv env)
-tcEnvTyCons env = typeEnvTyCons (tcGEnv env)
-tcEnvIds env = typeEnvIds (tcGEnv env)
-tcEnvTyVars env = [tv | ATyVar tv <- nameEnvElts (tcLEnv env)]
-tcEnvTcIds env = [id | ATcId id <- nameEnvElts (tcLEnv env)]
-
-getTcGEnv (TcEnv { tcGEnv = genv }) = genv
-
-tcInLocalScope :: TcEnv -> Name -> Bool
-tcInLocalScope env v = v `elemNameEnv` (tcLEnv env)
-
--- This data type is used to help tie the knot
--- when type checking type and class declarations
-data TyThingDetails = SynTyDetails Type
- | DataTyDetails ThetaType [DataCon] [Id]
- | ClassDetails ThetaType [Id] [ClassOpItem] DataCon
+ use_lvl = thLevel use_stage
+
+
+topIdLvl :: Id -> ThLevel
+-- Globals may either be imported, or may be from an earlier "chunk"
+-- (separated by declaration splices) of this module. The former
+-- *can* be used inside a top-level splice, but the latter cannot.
+-- Hence we give the former impLevel, but the latter topLevel
+-- E.g. this is bad:
+-- x = [| foo |]
+-- $( f x )
+-- By the time we are prcessing the $(f x), the binding for "x"
+-- will be in the global env, not the local one.
+topIdLvl id | isLocalId id = topLevel
+ | otherwise = impLevel
+
+-- Indicates the legal transitions on bracket( [| |] ).
+bracketOK :: ThStage -> Maybe ThLevel
+bracketOK (Brack _ _ _) = Nothing -- Bracket illegal inside a bracket
+bracketOK stage = (Just (thLevel stage + 1))
+
+-- Indicates the legal transitions on splice($).
+spliceOK :: ThStage -> Maybe ThLevel
+spliceOK (Splice _) = Nothing -- Splice illegal inside splice
+spliceOK stage = Just (thLevel stage - 1)
+
+tcMetaTy :: Name -> TcM Type
+-- Given the name of a Template Haskell data type,
+-- return the type
+-- E.g. given the name "Expr" return the type "Expr"
+tcMetaTy tc_name
+ = tcLookupTyCon tc_name `thenM` \ t ->
+ returnM (mkGenTyConApp t [])
+ -- Use mkGenTyConApp because it might be a synonym
\end{code}
%************************************************************************
%* *
-\subsection{Basic lookups}
+\subsection{TyThingDetails}
%* *
%************************************************************************
-\begin{code}
-lookup_global :: TcEnv -> Name -> Maybe TyThing
- -- Try the global envt and then the global symbol table
-lookup_global env name
- = case lookupNameEnv (tcGEnv env) name of
- Just thing -> Just thing
- Nothing -> tcGST env name
-
-lookup_local :: TcEnv -> Name -> Maybe TcTyThing
- -- Try the local envt and then try the global
-lookup_local env name
- = case lookupNameEnv (tcLEnv env) name of
- Just thing -> Just thing
- Nothing -> case lookup_global env name of
- Just thing -> Just (AGlobal thing)
- Nothing -> Nothing
-\end{code}
+This data type is used to help tie the knot
+ when type checking type and class declarations
\begin{code}
-type RecTcEnv = TcEnv
--- This environment is used for getting the 'right' IdInfo
--- on imported things and for looking up Ids in unfoldings
--- The environment doesn't have any local Ids in it
-
-tcAddImportedIdInfo :: RecTcEnv -> Id -> Id
-tcAddImportedIdInfo env id
- = id `lazySetIdInfo` new_info
- -- The Id must be returned without a data dependency on maybe_id
- where
- new_info = case tcLookupRecId_maybe env (idName id) of
- Nothing -> pprTrace "tcAddIdInfo" (ppr id) vanillaIdInfo
- Just imported_id -> idInfo imported_id
- -- ToDo: could check that types are the same
-
-tcLookupRecId_maybe :: RecTcEnv -> Name -> Maybe Id
-tcLookupRecId_maybe env name = case lookup_global env name of
- Just (AnId id) -> Just id
- other -> Nothing
-
-tcLookupRecId :: RecTcEnv -> Name -> Id
-tcLookupRecId env name = case lookup_global env name of
- Just (AnId id) -> id
- Nothing -> pprPanic "tcLookupRecId" (ppr name)
+data TyThingDetails = SynTyDetails Type
+ | DataTyDetails ThetaType (DataConDetails DataCon) [Id] (Maybe (EP Id))
+ | ClassDetails ThetaType [Id] [ClassOpItem] DataCon Name
+ -- The Name is the Name of the implicit TyCon for the class
+ | ForeignTyDetails -- Nothing yet
\end{code}
+
%************************************************************************
%* *
\subsection{Making new Ids}
Constructing new Ids
\begin{code}
-newLocalId :: OccName -> TcType -> SrcLoc -> NF_TcM TcId
-newLocalId name ty loc
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkUserLocal name uniq ty loc)
-
-newSpecPragmaId :: Name -> TcType -> NF_TcM TcId
-newSpecPragmaId name ty
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkSpecPragmaId (nameOccName name) uniq ty (getSrcLoc name))
+newLocalName :: Name -> TcM Name
+newLocalName name -- Make a clone
+ = newUnique `thenM` \ uniq ->
+ returnM (mkInternalName uniq (getOccName name) (getSrcLoc name))
\end{code}
-Make a name for the dict fun for an instance decl.
-It's a *local* name for the moment. The CoreTidy pass
-will globalise it.
+Make a name for the dict fun for an instance decl. It's a *local*
+name for the moment. The CoreTidy pass will externalise it. Even in
+--make and ghci stuff, we rebuild the instance environment each time,
+so the dfun id is internal to begin with, and external when compiling
+other modules
\begin{code}
-newDFunName :: Class -> [Type] -> SrcLoc -> NF_TcM Name
+newDFunName :: Class -> [Type] -> SrcLoc -> TcM Name
newDFunName clas (ty:_) loc
- = tcGetUnique `thenNF_Tc` \ uniq ->
- returnNF_Tc (mkLocalName uniq (mkDFunOcc dfun_string) loc)
+ = newUnique `thenM` \ uniq ->
+ returnM (mkInternalName uniq (mkDFunOcc dfun_string) loc)
where
-- Any string that is somewhat unique will do
dfun_string = occNameString (getOccName clas) ++ occNameString (getDFunTyKey ty)
\begin{code}
tcExtendGlobalEnv :: [TyThing] -> TcM r -> TcM r
+ -- Given a mixture of Ids, TyCons, Classes, perhaps from the
+ -- module being compiled, perhaps from a package module,
+ -- extend the global environment, and update the EPS
tcExtendGlobalEnv things thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- ge' = extendTypeEnvList (tcGEnv env) things
- in
- tcSetEnv (env {tcGEnv = ge'}) thing_inside
+ = do { eps <- getEps
+ ; hpt <- getHpt
+ ; env <- getGblEnv
+ ; let mod = tcg_mod env
+ (lcl_things, pkg_things) = partition (isLocalThing mod) things
+ ge' = extendTypeEnvList (tcg_type_env env) lcl_things
+ eps' = eps { eps_PTE = extendTypeEnvList (eps_PTE eps) pkg_things }
+ ; setEps eps'
+ ; setGblEnv (env {tcg_type_env = ge'}) thing_inside }
+tcExtendGlobalValEnv :: [Id] -> TcM a -> TcM a
+ -- Same deal as tcExtendGlobalEnv, but for Ids
+tcExtendGlobalValEnv ids thing_inside
+ = tcExtendGlobalEnv [AnId id | id <- ids] thing_inside
tcExtendGlobalTypeEnv :: TypeEnv -> TcM r -> TcM r
+ -- Top-level things of the interactive context
+ -- No need to extend the package env
tcExtendGlobalTypeEnv extra_env thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- ge' = tcGEnv env `plusNameEnv` extra_env
- in
- tcSetEnv (env {tcGEnv = ge'}) thing_inside
-
-tcExtendGlobalValEnv :: [Id] -> TcM a -> TcM a
-tcExtendGlobalValEnv ids thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- ge' = extendTypeEnvWithIds (tcGEnv env) ids
- in
- tcSetEnv (env {tcGEnv = ge'}) thing_inside
+ = do { env <- getGblEnv
+ ; let ge' = tcg_type_env env `plusNameEnv` extra_env
+ ; setGblEnv (env {tcg_type_env = ge'}) thing_inside }
\end{code}
\begin{code}
-tcLookupGlobal_maybe :: Name -> NF_TcM (Maybe TyThing)
+tcLookupGlobal_maybe :: Name -> TcRn m (Maybe TyThing)
+-- This is a rather heavily-used function, so I've inlined a few things (e.g. getEps)
+-- Notice that for imported things we read the current version from the EPS
+-- mutable variable. This is important in situations like
+-- ...$(e1)...$(e2)...
+-- where the code that e1 expands to might import some defns that
+-- also turn out to be needed by the code that e2 expands to.
tcLookupGlobal_maybe name
- = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (lookup_global env name)
+ = do { env <- getGblEnv
+ ; if nameIsLocalOrFrom (tcg_mod env) name then
+ -- Defined in this module
+ return (lookupNameEnv (tcg_type_env env) name)
+ else
+ do { env <- getTopEnv
+ ; eps <- readMutVar (top_eps env)
+ ; return (lookupType (top_hpt env) (eps_PTE eps) name) }}
\end{code}
A variety of global lookups, when we know what we are looking for.
\begin{code}
-tcLookupGlobal :: Name -> NF_TcM TyThing
+tcLookupGlobal :: Name -> TcM TyThing
tcLookupGlobal name
- = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_thing ->
+ = tcLookupGlobal_maybe name `thenM` \ maybe_thing ->
case maybe_thing of
- Just thing -> returnNF_Tc thing
+ Just thing -> returnM thing
other -> notFound "tcLookupGlobal" name
-tcLookupGlobalId :: Name -> NF_TcM Id
+tcLookupGlobalId :: Name -> TcM Id
+-- Never used for Haskell-source DataCons, hence no ADataCon case
tcLookupGlobalId name
- = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_id ->
- case maybe_id of
- Just (AnId id) -> returnNF_Tc id
- other -> notFound "tcLookupGlobalId" name
-
+ = tcLookupGlobal_maybe name `thenM` \ maybe_thing ->
+ case maybe_thing of
+ Just (AnId id) -> returnM id
+ other -> notFound "tcLookupGlobal (id)" name
+
tcLookupDataCon :: Name -> TcM DataCon
tcLookupDataCon con_name
- = tcLookupGlobalId con_name `thenNF_Tc` \ con_id ->
- case isDataConWrapId_maybe con_id of
- Just data_con -> returnTc data_con
- Nothing -> failWithTc (badCon con_id)
-
+ = tcLookupGlobal_maybe con_name `thenM` \ maybe_thing ->
+ case maybe_thing of
+ Just (ADataCon data_con) -> returnM data_con
+ other -> notFound "tcLookupDataCon" con_name
-tcLookupClass :: Name -> NF_TcM Class
+tcLookupClass :: Name -> TcM Class
tcLookupClass name
- = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_clas ->
+ = tcLookupGlobal_maybe name `thenM` \ maybe_clas ->
case maybe_clas of
- Just (AClass clas) -> returnNF_Tc clas
+ Just (AClass clas) -> returnM clas
other -> notFound "tcLookupClass" name
-tcLookupTyCon :: Name -> NF_TcM TyCon
+tcLookupTyCon :: Name -> TcM TyCon
tcLookupTyCon name
- = tcLookupGlobal_maybe name `thenNF_Tc` \ maybe_tc ->
+ = tcLookupGlobal_maybe name `thenM` \ maybe_tc ->
case maybe_tc of
- Just (ATyCon tc) -> returnNF_Tc tc
+ Just (ATyCon tc) -> returnM tc
other -> notFound "tcLookupTyCon" name
-tcLookupId :: Name -> NF_TcM Id
-tcLookupId name
- = tcLookup name `thenNF_Tc` \ thing ->
- case thing of
- ATcId tc_id -> returnNF_Tc tc_id
- AGlobal (AnId id) -> returnNF_Tc id
- other -> pprPanic "tcLookupId" (ppr name)
-tcLookupLocalIds :: [Name] -> NF_TcM [TcId]
-tcLookupLocalIds ns
- = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (map (lookup (tcLEnv env)) ns)
- where
- lookup lenv name = case lookupNameEnv lenv name of
- Just (ATcId id) -> id
- other -> pprPanic "tcLookupLocalIds" (ppr name)
-
-tcLookupSyntaxId :: Name -> NF_TcM Id
--- Lookup a name like PrelNum.fromInt, and return the corresponding Id,
--- after mapping through the SyntaxMap. This may give us the Id for
--- (say) MyPrelude.fromInteger
-tcLookupSyntaxId name
- = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (case lookup_global env (tcSyntaxMap env name) of
- Just (AnId id) -> id
- other -> pprPanic "tcLookupSyntaxId" (ppr name))
-
-tcLookupSyntaxName :: Name -> NF_TcM Name
-tcLookupSyntaxName name
- = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (tcSyntaxMap env name)
+getInGlobalScope :: TcRn m (Name -> Bool)
+-- Get all things in the global environment; used for deciding what
+-- rules to suck in. Anything defined in this module (nameIsLocalOrFrom)
+-- is certainly in the envt, so we don't bother to look.
+getInGlobalScope
+ = do { mod <- getModule
+ ; eps <- getEps
+ ; hpt <- getHpt
+ ; return (\n -> nameIsLocalOrFrom mod n ||
+ isJust (lookupType hpt (eps_PTE eps) n)) }
\end{code}
%************************************************************************
\begin{code}
-tcLookup_maybe :: Name -> NF_TcM (Maybe TcTyThing)
+tcLookup_maybe :: Name -> TcM (Maybe TcTyThing)
tcLookup_maybe name
- = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (lookup_local env name)
-
-tcLookup :: Name -> NF_TcM TcTyThing
+ = getLclEnv `thenM` \ local_env ->
+ case lookupNameEnv (tcl_env local_env) name of
+ Just thing -> returnM (Just thing)
+ Nothing -> tcLookupGlobal_maybe name `thenM` \ mb_res ->
+ returnM (case mb_res of
+ Just thing -> Just (AGlobal thing)
+ Nothing -> Nothing)
+
+tcLookup :: Name -> TcM TcTyThing
tcLookup name
- = tcLookup_maybe name `thenNF_Tc` \ maybe_thing ->
+ = tcLookup_maybe name `thenM` \ maybe_thing ->
case maybe_thing of
- Just thing -> returnNF_Tc thing
+ Just thing -> returnM thing
other -> notFound "tcLookup" name
-- Extract the IdInfo from an IfaceSig imported from an interface file
-\end{code}
+tcLookupId :: Name -> TcM Id
+-- Used when we aren't interested in the binding level
+-- Never a DataCon. (Why does that matter? see TcExpr.tcId)
+tcLookupId name
+ = tcLookup name `thenM` \ thing ->
+ case thing of
+ ATcId tc_id _ _ -> returnM tc_id
+ AGlobal (AnId id) -> returnM id
+ other -> pprPanic "tcLookupId" (ppr name)
+
+tcLookupLocalIds :: [Name] -> TcM [TcId]
+-- We expect the variables to all be bound, and all at
+-- the same level as the lookup. Only used in one place...
+tcLookupLocalIds ns
+ = getLclEnv `thenM` \ env ->
+ returnM (map (lookup (tcl_env env) (thLevel (tcl_th_ctxt env))) ns)
+ where
+ lookup lenv lvl name
+ = case lookupNameEnv lenv name of
+ Just (ATcId id lvl1 _) -> ASSERT( lvl == lvl1 ) id
+ other -> pprPanic "tcLookupLocalIds" (ppr name)
+
+lclEnvElts :: TcLclEnv -> [TcTyThing]
+lclEnvElts env = nameEnvElts (tcl_env env)
+
+getInLocalScope :: TcM (Name -> Bool)
+ -- Ids only
+getInLocalScope = getLclEnv `thenM` \ env ->
+ let
+ lcl_env = tcl_env env
+ in
+ return (`elemNameEnv` lcl_env)
+\end{code}
\begin{code}
tcExtendKindEnv :: [(Name,TcKind)] -> TcM r -> TcM r
tcExtendKindEnv pairs thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- le' = extendNameEnvList (tcLEnv env) [(n, AThing k) | (n,k) <- pairs]
+ = updLclEnv upd thing_inside
+ where
+ upd lcl_env = lcl_env { tcl_env = extend (tcl_env lcl_env) }
+ extend env = extendNameEnvList env [(n, AThing k) | (n,k) <- pairs]
-- No need to extend global tyvars for kind checking
- in
- tcSetEnv (env {tcLEnv = le'}) thing_inside
tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r
-tcExtendTyVarEnv tyvars thing_inside
- = tcGetEnv `thenNF_Tc` \ env@(TcEnv {tcLEnv = le, tcTyVars = gtvs}) ->
+tcExtendTyVarEnv tvs thing_inside
+ = tc_extend_tv_env [(getName tv, ATyVar tv) | tv <- tvs] tvs thing_inside
+
+tcExtendTyVarEnv2 :: [(TyVar,TcTyVar)] -> TcM r -> TcM r
+tcExtendTyVarEnv2 tv_pairs thing_inside
+ = tc_extend_tv_env [(getName tv1, ATyVar tv2) | (tv1,tv2) <- tv_pairs]
+ [tv | (_,tv) <- tv_pairs]
+ thing_inside
+
+tc_extend_tv_env binds tyvars thing_inside
+ = getLclEnv `thenM` \ env@(TcLclEnv {tcl_env = le, tcl_tyvars = gtvs}) ->
let
- le' = extendNameEnvList le [ (getName tv, ATyVar tv) | tv <- tyvars]
+ le' = extendNameEnvList le binds
new_tv_set = mkVarSet tyvars
in
-- It's important to add the in-scope tyvars to the global tyvar set
-- Here, g mustn't be generalised. This is also important during
-- class and instance decls, when we mustn't generalise the class tyvars
-- when typechecking the methods.
- tc_extend_gtvs gtvs new_tv_set `thenNF_Tc` \ gtvs' ->
- tcSetEnv (env {tcLEnv = le', tcTyVars = gtvs'}) thing_inside
-
--- This variant, tcExtendTyVarEnvForMeths, takes *two* bunches of tyvars:
--- the signature tyvars contain the original names
--- the instance tyvars are what those names should be mapped to
--- It's needed when typechecking the method bindings of class and instance decls
--- It does *not* extend the global tyvars; tcMethodBind does that for itself
-
-tcExtendTyVarEnvForMeths :: [TyVar] -> [TcTyVar] -> TcM r -> TcM r
-tcExtendTyVarEnvForMeths sig_tyvars inst_tyvars thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- let
- le' = extendNameEnvList (tcLEnv env) stuff
- stuff = [ (getName sig_tv, ATyVar inst_tv)
- | (sig_tv, inst_tv) <- zipEqual "tcMeth" sig_tyvars inst_tyvars
- ]
- in
- tcSetEnv (env {tcLEnv = le'}) thing_inside
+ tc_extend_gtvs gtvs new_tv_set `thenM` \ gtvs' ->
+ setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs'}) thing_inside
\end{code}
\begin{code}
-tcExtendLocalValEnv :: [(Name,TcId)] -> TcM a -> TcM a
-tcExtendLocalValEnv names_w_ids thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
+tcExtendLocalValEnv :: [TcId] -> TcM a -> TcM a
+tcExtendLocalValEnv ids thing_inside
+ = getLclEnv `thenM` \ env ->
+ let
+ extra_global_tyvars = tyVarsOfTypes [idType id | id <- ids]
+ th_lvl = thLevel (tcl_th_ctxt env)
+ proc_lvl = proc_level (tcl_arrow_ctxt env)
+ extra_env = [(idName id, ATcId id th_lvl proc_lvl) | id <- ids]
+ le' = extendNameEnvList (tcl_env env) extra_env
+ in
+ tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' ->
+ setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs'}) thing_inside
+
+tcExtendLocalValEnv2 :: [(Name,TcId)] -> TcM a -> TcM a
+tcExtendLocalValEnv2 names_w_ids thing_inside
+ = getLclEnv `thenM` \ env ->
let
extra_global_tyvars = tyVarsOfTypes [idType id | (name,id) <- names_w_ids]
- extra_env = [(name, ATcId id) | (name,id) <- names_w_ids]
- le' = extendNameEnvList (tcLEnv env) extra_env
+ th_lvl = thLevel (tcl_th_ctxt env)
+ proc_lvl = proc_level (tcl_arrow_ctxt env)
+ extra_env = [(name, ATcId id th_lvl proc_lvl) | (name,id) <- names_w_ids]
+ le' = extendNameEnvList (tcl_env env) extra_env
in
- tc_extend_gtvs (tcTyVars env) extra_global_tyvars `thenNF_Tc` \ gtvs' ->
- tcSetEnv (env {tcLEnv = le', tcTyVars = gtvs'}) thing_inside
+ tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' ->
+ setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs'}) thing_inside
+\end{code}
+
+
+\begin{code}
+-----------------------
+-- findGlobals looks at the value environment and finds values
+-- whose types mention the offending type variable. It has to be
+-- careful to zonk the Id's type first, so it has to be in the monad.
+-- We must be careful to pass it a zonked type variable, too.
+
+findGlobals :: TcTyVarSet
+ -> TidyEnv
+ -> TcM (TidyEnv, [SDoc])
+
+findGlobals tvs tidy_env
+ = getLclEnv `thenM` \ lcl_env ->
+ go tidy_env [] (lclEnvElts lcl_env)
+ where
+ go tidy_env acc [] = returnM (tidy_env, acc)
+ go tidy_env acc (thing : things)
+ = find_thing ignore_it tidy_env thing `thenM` \ (tidy_env1, maybe_doc) ->
+ case maybe_doc of
+ Just d -> go tidy_env1 (d:acc) things
+ Nothing -> go tidy_env1 acc things
+
+ ignore_it ty = not (tvs `intersectsVarSet` tyVarsOfType ty)
+
+-----------------------
+find_thing ignore_it tidy_env (ATcId id _ _)
+ = zonkTcType (idType id) `thenM` \ id_ty ->
+ if ignore_it id_ty then
+ returnM (tidy_env, Nothing)
+ else let
+ (tidy_env', tidy_ty) = tidyOpenType tidy_env id_ty
+ msg = sep [ppr id <+> dcolon <+> ppr tidy_ty,
+ nest 2 (parens (ptext SLIT("bound at") <+>
+ ppr (getSrcLoc id)))]
+ in
+ returnM (tidy_env', Just msg)
+
+find_thing ignore_it tidy_env (ATyVar tv)
+ = zonkTcTyVar tv `thenM` \ tv_ty ->
+ if ignore_it tv_ty then
+ returnM (tidy_env, Nothing)
+ else let
+ (tidy_env1, tv1) = tidyOpenTyVar tidy_env tv
+ (tidy_env2, tidy_ty) = tidyOpenType tidy_env1 tv_ty
+ msg = sep [ppr tv1 <+> eq_stuff, nest 2 bound_at]
+
+ eq_stuff | Just tv' <- Type.getTyVar_maybe tv_ty, tv == tv' = empty
+ | otherwise = equals <+> ppr tv_ty
+ -- It's ok to use Type.getTyVar_maybe because ty is zonked by now
+
+ bound_at = tyVarBindingInfo tv
+ in
+ returnM (tidy_env2, Just msg)
\end{code}
%************************************************************************
\begin{code}
-tcExtendGlobalTyVars extra_global_tvs thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- tc_extend_gtvs (tcTyVars env) extra_global_tvs `thenNF_Tc` \ gtvs' ->
- tcSetEnv (env {tcTyVars = gtvs'}) thing_inside
-
tc_extend_gtvs gtvs extra_global_tvs
- = tcReadMutVar gtvs `thenNF_Tc` \ global_tvs ->
- tcNewMutVar (global_tvs `unionVarSet` extra_global_tvs)
+ = readMutVar gtvs `thenM` \ global_tvs ->
+ newMutVar (global_tvs `unionVarSet` extra_global_tvs)
\end{code}
@tcGetGlobalTyVars@ returns a fully-zonked set of tyvars free in the environment.
the environment.
\begin{code}
-tcGetGlobalTyVars :: NF_TcM TcTyVarSet
+tcGetGlobalTyVars :: TcM TcTyVarSet
tcGetGlobalTyVars
- = tcGetEnv `thenNF_Tc` \ (TcEnv {tcTyVars = gtv_var}) ->
- tcReadMutVar gtv_var `thenNF_Tc` \ gbl_tvs ->
- zonkTcTyVarsAndFV (varSetElems gbl_tvs) `thenNF_Tc` \ gbl_tvs' ->
- tcWriteMutVar gtv_var gbl_tvs' `thenNF_Tc_`
- returnNF_Tc gbl_tvs'
+ = getLclEnv `thenM` \ (TcLclEnv {tcl_tyvars = gtv_var}) ->
+ readMutVar gtv_var `thenM` \ gbl_tvs ->
+ zonkTcTyVarsAndFV (varSetElems gbl_tvs) `thenM` \ gbl_tvs' ->
+ writeMutVar gtv_var gbl_tvs' `thenM_`
+ returnM gbl_tvs'
\end{code}
%* *
%************************************************************************
+The TcGblEnv holds a mutable variable containing the current full, instance environment.
+The ExtendInstEnv functions extend this environment by side effect, in case we are
+sucking in new instance declarations deep in the body of a TH splice, which are needed
+in another TH splice. The tcg_insts field of the TcGblEnv contains just the dfuns
+from this module
+
\begin{code}
-tcGetInstEnv :: NF_TcM InstEnv
-tcGetInstEnv = tcGetEnv `thenNF_Tc` \ env ->
- returnNF_Tc (tcInsts env)
+tcGetInstEnv :: TcM InstEnv
+tcGetInstEnv = do { env <- getGblEnv; readMutVar (tcg_inst_env env) }
+
+tcExtendInstEnv :: [DFunId] -> TcM a -> TcM a
+ -- Add instances from local or imported
+ -- instances, and refresh the instance-env cache
+tcExtendInstEnv dfuns thing_inside
+ = do { dflags <- getDOpts
+ ; eps <- getEps
+ ; env <- getGblEnv
+ ; let ie_var = tcg_inst_env env
+ ; inst_env <- readMutVar ie_var
+ ; let
+ -- Extend the total inst-env with the new dfuns
+ (inst_env', errs) = extendInstEnv dflags inst_env dfuns
+
+ -- Sort the ones from this module from the others
+ (lcl_dfuns, pkg_dfuns) = partition (isLocalThing mod) dfuns
+ mod = tcg_mod env
+
+ -- And add the pieces to the right places
+ (eps_inst_env', _) = extendInstEnv dflags (eps_inst_env eps) pkg_dfuns
+ eps' = eps { eps_inst_env = eps_inst_env' }
+
+ env' = env { tcg_insts = lcl_dfuns ++ tcg_insts env }
+
+ ; traceDFuns dfuns
+ ; addErrs errs
+ ; writeMutVar ie_var inst_env'
+ ; setEps eps'
+ ; setGblEnv env' thing_inside }
+
+tcExtendLocalInstEnv :: [InstInfo] -> TcM a -> TcM a
+ -- Special case for local instance decls
+tcExtendLocalInstEnv infos thing_inside
+ = do { dflags <- getDOpts
+ ; env <- getGblEnv
+ ; let ie_var = tcg_inst_env env
+ ; inst_env <- readMutVar ie_var
+ ; let
+ dfuns = map iDFunId infos
+ (inst_env', errs) = extendInstEnv dflags inst_env dfuns
+ env' = env { tcg_insts = dfuns ++ tcg_insts env }
+ ; traceDFuns dfuns
+ ; addErrs errs
+ ; writeMutVar ie_var inst_env'
+ ; setGblEnv env' thing_inside }
+
+tcExtendTempInstEnv :: [DFunId] -> TcM a -> TcM a
+ -- Extend the instance envt, but with *no* permanent
+ -- effect on mutable variables; also ignore errors
+ -- Used during 'deriving' stuff
+tcExtendTempInstEnv dfuns thing_inside
+ = do { dflags <- getDOpts
+ ; env <- getGblEnv
+ ; let ie_var = tcg_inst_env env
+ ; inst_env <- readMutVar ie_var
+ ; let (inst_env', errs) = extendInstEnv dflags inst_env dfuns
+ -- Ignore the errors about duplicate instances.
+ -- We don't want repeated error messages
+ -- They'll appear later, when we do the top-level extendInstEnvs
+ ; writeMutVar ie_var inst_env'
+ ; result <- thing_inside
+ ; writeMutVar ie_var inst_env -- Restore!
+ ; return result }
+
+tcWithTempInstEnv :: TcM a -> TcM a
+-- Run thing_inside, discarding any effects on the instance environment
+tcWithTempInstEnv thing_inside
+ = do { env <- getGblEnv
+ ; let ie_var = tcg_inst_env env
+ ; old_ie <- readMutVar ie_var
+ ; result <- thing_inside
+ ; writeMutVar ie_var old_ie -- Restore
+ ; return result }
+
+traceDFuns dfuns
+ = traceTc (text "Adding instances:" <+> vcat (map pp dfuns))
+ where
+ pp dfun = ppr dfun <+> dcolon <+> ppr (idType dfun)
+\end{code}
-tcSetInstEnv :: InstEnv -> TcM a -> TcM a
-tcSetInstEnv ie thing_inside
- = tcGetEnv `thenNF_Tc` \ env ->
- tcSetEnv (env {tcInsts = ie}) thing_inside
-\end{code}
+
+%************************************************************************
+%* *
+\subsection{Rules}
+%* *
+%************************************************************************
+
+\begin{code}
+tcExtendRules :: [RuleDecl Id] -> TcM a -> TcM a
+ -- Just pop the new rules into the EPS and envt resp
+ -- All the rules come from an interface file, not soruce
+ -- Nevertheless, some may be for this module, if we read
+ -- its interface instead of its source code
+tcExtendRules rules thing_inside
+ = do { eps <- getEps
+ ; env <- getGblEnv
+ ; let
+ (lcl_rules, pkg_rules) = partition is_local_rule rules
+ is_local_rule = isLocalThing mod . ifaceRuleDeclName
+ mod = tcg_mod env
+
+ core_rules = [(id,rule) | IfaceRuleOut id rule <- pkg_rules]
+ eps' = eps { eps_rule_base = addIfaceRules (eps_rule_base eps) core_rules }
+ -- All the rules from an interface are of the IfaceRuleOut form
+
+ env' = env { tcg_rules = lcl_rules ++ tcg_rules env }
+
+ ; setEps eps'
+ ; setGblEnv env' thing_inside }
+
+addIfaceRules :: RuleBase -> [IdCoreRule] -> RuleBase
+addIfaceRules rule_base rules
+ = foldl extendRuleBase rule_base rules
+\end{code}
%************************************************************************
instance c => k (t tvs) where b
+It is used just for *local* instance decls (not ones from interface files).
+But local instance decls includes
+ - derived ones
+ - generic ones
+as well as explicit user written ones.
+
\begin{code}
data InstInfo
= InstInfo {
iDFunId :: DFunId, -- The dfun id
- iBinds :: RenamedMonoBinds, -- Bindings, b
- iPrags :: [RenamedSig] -- User pragmas recorded for generating specialised instances
+ iBinds :: InstBindings
}
-pprInstInfo info = vcat [ptext SLIT("InstInfo:") <+> ppr (idType (iDFunId info)),
- nest 4 (ppr (iBinds info))]
+data InstBindings
+ = VanillaInst -- The normal case
+ RenamedMonoBinds -- Bindings
+ [RenamedSig] -- User pragmas recorded for generating
+ -- specialised instances
+
+ | NewTypeDerived -- Used for deriving instances of newtypes, where the
+ [Type] -- witness dictionary is identical to the argument
+ -- dictionary. Hence no bindings, no pragmas
+ -- The [Type] are the representation types
+ -- See notes in TcDeriv
+
+pprInstInfo info = vcat [ptext SLIT("InstInfo:") <+> ppr (idType (iDFunId info))]
+
+pprInstInfoDetails (InstInfo { iBinds = VanillaInst b _ }) = ppr b
+pprInstInfoDetails (InstInfo { iBinds = NewTypeDerived _}) = text "Derived from the representation type"
simpleInstInfoTy :: InstInfo -> Type
-simpleInstInfoTy info = case splitDFunTy (idType (iDFunId info)) of
+simpleInstInfoTy info = case tcSplitDFunTy (idType (iDFunId info)) of
(_, _, _, [ty]) -> ty
simpleInstInfoTyCon :: InstInfo -> TyCon
-- Gets the type constructor for a simple instance declaration,
-- i.e. one of the form instance (...) => C (T a b c) where ...
-simpleInstInfoTyCon inst = tyConAppTyCon (simpleInstInfoTy inst)
+simpleInstInfoTyCon inst = tcTyConAppTyCon (simpleInstInfoTy inst)
\end{code}
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