X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcEnv.lhs;h=5360887b786fd55c40360b095a585a6e225c8317;hb=8655d6ca41df4aa77a559d4067ad3815797b9803;hp=42a6c9b3f98cb8dba1e874df4f4c551bb22374ef;hpb=0596517a9b4b2b32e5d375a986351102ac4540fc;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcEnv.lhs b/ghc/compiler/typecheck/TcEnv.lhs index 42a6c9b..5360887 100644 --- a/ghc/compiler/typecheck/TcEnv.lhs +++ b/ghc/compiler/typecheck/TcEnv.lhs @@ -1,198 +1,540 @@ \begin{code} -#include "HsVersions.h" - module TcEnv( - TcEnv, - - initEnv, getEnv_LocalIds, getEnv_TyCons, getEnv_Classes, - - tcTyVarScope, tcTyVarScopeGivenKinds, tcLookupTyVar, - - tcExtendTyConEnv, tcLookupTyCon, tcLookupTyConByKey, - tcExtendClassEnv, tcLookupClass, tcLookupClassByKey, - - tcExtendGlobalValEnv, tcExtendLocalValEnv, - tcLookupLocalValue, tcLookupLocalValueOK, tcLookupLocalValueByKey, - tcLookupGlobalValue, tcLookupGlobalValueByKey, - - newMonoIds, newLocalIds, newLocalId, - tcGetGlobalTyVars + TyThing(..), TyThingDetails(..), TcTyThing(..), TcId, + + -- Instance environment, and InstInfo type + tcGetInstEnv, + InstInfo(..), pprInstInfo, pprInstInfoDetails, + simpleInstInfoTy, simpleInstInfoTyCon, + InstBindings(..), + + -- Global environment + tcExtendGlobalEnv, + tcExtendGlobalValEnv, + tcExtendGlobalTypeEnv, + tcLookupTyCon, tcLookupClass, tcLookupDataCon, + tcLookupGlobal_maybe, tcLookupGlobal, tcLookupGlobalId, + getInGlobalScope, + + -- Local environment + 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, + + -- Template Haskell stuff + checkWellStaged, spliceOK, bracketOK, tcMetaTy, thLevel, + topIdLvl, + + -- Arrow stuff + checkProcLevel, + + -- New Ids + newLocalName, newDFunName, + + -- Misc + isLocalThing ) where +#include "HsVersions.h" -import Ubiq -import TcMLoop -- for paranoia checking +import RnHsSyn ( RenamedMonoBinds, RenamedSig ) +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 qualified Type ( getTyVar_maybe ) +import Rules ( extendRuleBase ) +import Id ( idName, isLocalId ) +import Var ( TyVar, Id, idType ) +import VarSet +import VarEnv +import CoreSyn ( IdCoreRule ) +import DataCon ( DataCon ) +import TyCon ( TyCon, DataConDetails ) +import Class ( Class, ClassOpItem ) +import Name ( Name, NamedThing(..), + getSrcLoc, mkInternalName, nameIsLocalOrFrom + ) +import NameEnv +import OccName ( mkDFunOcc, occNameString ) +import HscTypes ( DFunId, TypeEnv, extendTypeEnvList, lookupType, + TyThing(..), ExternalPackageState(..) ) +import Rules ( RuleBase ) +import BasicTypes ( EP ) +import Module ( Module ) +import InstEnv ( InstEnv, extendInstEnv ) +import SrcLoc ( SrcLoc ) +import Outputable +import Maybe ( isJust ) +import List ( partition ) +\end{code} -import Id ( Id(..), GenId, idType, mkUserLocal ) -import TcHsSyn ( TcIdBndr(..), TcIdOcc(..) ) -import TcKind ( TcKind, newKindVars, tcKindToKind, kindToTcKind ) -import TcType ( TcType(..), TcMaybe, TcTyVar(..), TcTyVarSet(..), newTyVarTys, zonkTcTyVars ) -import TyVar ( mkTyVar, getTyVarKind, unionTyVarSets, emptyTyVarSet ) -import Type ( tyVarsOfTypes ) -import TyCon ( TyCon, Arity(..), getTyConKind, getSynTyConArity ) -import Class ( Class(..), GenClass, getClassSig ) -import TcMonad +%************************************************************************ +%* * + Arrow notation proc levels +%* * +%************************************************************************ -import Name ( Name(..), getNameShortName ) -import PprStyle -import Pretty -import Unique ( Unique ) -import UniqFM -import Util ( zipWithEqual, zipWith3Equal, zipLazy, panic ) +\begin{code} +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} + -Data type declarations -~~~~~~~~~~~~~~~~~~~~~ +%************************************************************************ +%* * + Meta level +%* * +%************************************************************************ \begin{code} -data TcEnv s = TcEnv - (TyVarEnv s) - (TyConEnv s) - (ClassEnv s) - (ValueEnv Id) -- Globals - (ValueEnv (TcIdBndr s)) -- Locals - (MutableVar s (TcTyVarSet s)) -- Free type variables of locals - -- ...why mutable? see notes with tcGetGlobalTyVars - -type TyVarEnv s = UniqFM (TcKind s, TyVar) -type TyConEnv s = UniqFM (TcKind s, Maybe Arity, TyCon) -- Arity present for Synonyms only -type ClassEnv s = UniqFM (TcKind s, Class) -type ValueEnv id = UniqFM id - -initEnv :: MutableVar s (TcTyVarSet s) -> TcEnv s -initEnv mut = TcEnv emptyUFM emptyUFM emptyUFM emptyUFM emptyUFM mut - -getEnv_LocalIds (TcEnv _ _ _ _ ls _) = eltsUFM ls -getEnv_TyCons (TcEnv _ ts _ _ _ _) = [tycon | (_, _, tycon) <- eltsUFM ts] -getEnv_Classes (TcEnv _ _ cs _ _ _) = [clas | (_, clas) <- eltsUFM cs] +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 + 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} -Making new TcTyVars, with knot tying! -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +%************************************************************************ +%* * +\subsection{TyThingDetails} +%* * +%************************************************************************ + +This data type is used to help tie the knot + when type checking type and class declarations + \begin{code} -tcTyVarScopeGivenKinds - :: [Name] -- Names of some type variables - -> [TcKind s] - -> ([TyVar] -> TcM s a) -- Thing to type check in their scope - -> TcM s a -- Result - -tcTyVarScopeGivenKinds names kinds thing_inside - = fixTc (\ ~(rec_tyvars, _) -> - -- Ok to look at names, kinds, but not tyvars! - - tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - let - tve' = addListToUFM tve (names `zip` (kinds `zipLazy` rec_tyvars)) - in - tcSetEnv (TcEnv tve' tce ce gve lve gtvs) - (thing_inside rec_tyvars) `thenTc` \ result -> - - -- Get the tyvar's Kinds from their TcKinds - mapNF_Tc tcKindToKind kinds `thenNF_Tc` \ kinds' -> - - -- Construct the real TyVars - let - tyvars = zipWithEqual mk_tyvar names kinds' - mk_tyvar name kind = mkTyVar (getNameShortName name) (getItsUnique name) kind - in - returnTc (tyvars, result) - ) `thenTc` \ (_,result) -> - returnTc result - -tcTyVarScope names thing_inside - = newKindVars (length names) `thenNF_Tc` \ kinds -> - tcTyVarScopeGivenKinds names kinds thing_inside +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} -The Kind, TyVar, Class and TyCon envs -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +%************************************************************************ +%* * +\subsection{Making new Ids} +%* * +%************************************************************************ -Extending the environments. Notice the uses of @zipLazy@, which makes sure -that the knot-tied TyVars, TyCons and Classes aren't looked at too early. +Constructing new Ids \begin{code} -tcExtendTyConEnv :: [(Name,Maybe Arity)] -> [TyCon] -> TcM s r -> TcM s r -tcExtendTyConEnv names_w_arities tycons scope - = newKindVars (length names_w_arities) `thenNF_Tc` \ kinds -> - tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - let - tce' = addListToUFM tce [ (name, (kind, arity, tycon)) - | ((name,arity), (kind,tycon)) <- names_w_arities `zip` - (kinds `zipLazy` tycons) - ] - in - tcSetEnv (TcEnv tve tce' ce gve lve gtvs) scope +newLocalName :: Name -> TcM Name +newLocalName name -- Make a clone + = newUnique `thenM` \ uniq -> + returnM (mkInternalName uniq (getOccName name) (getSrcLoc name)) +\end{code} -tcExtendClassEnv :: [Name] -> [Class] -> TcM s r -> TcM s r -tcExtendClassEnv names classes scope - = newKindVars (length names) `thenNF_Tc` \ kinds -> - tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - let - ce' = addListToUFM ce (names `zip` (kinds `zipLazy` classes)) - in - tcSetEnv (TcEnv tve tce ce' gve lve gtvs) scope +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 -> TcM Name +newDFunName clas (ty:_) 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) + +newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc) \end{code} +\begin{code} +isLocalThing :: NamedThing a => Module -> a -> Bool +isLocalThing mod thing = nameIsLocalOrFrom mod (getName thing) +\end{code} -Looking up in the environments. +%************************************************************************ +%* * +\subsection{The global environment} +%* * +%************************************************************************ \begin{code} -tcLookupTyVar name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM tve (panic "tcLookupTyVar") name) +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 + = 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 + = 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 -> 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 + = 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} -tcLookupTyCon (WiredInTyCon tc) -- wired in tycons - = returnNF_Tc (kindToTcKind (getTyConKind tc), getSynTyConArity tc, tc) +A variety of global lookups, when we know what we are looking for. +\begin{code} +tcLookupGlobal :: Name -> TcM TyThing +tcLookupGlobal name + = tcLookupGlobal_maybe name `thenM` \ maybe_thing -> + case maybe_thing of + Just thing -> returnM thing + other -> notFound "tcLookupGlobal" name + +tcLookupGlobalId :: Name -> TcM Id +-- Never used for Haskell-source DataCons, hence no ADataCon case +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 + = 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 -> TcM Class +tcLookupClass name + = tcLookupGlobal_maybe name `thenM` \ maybe_clas -> + case maybe_clas of + Just (AClass clas) -> returnM clas + other -> notFound "tcLookupClass" name + +tcLookupTyCon :: Name -> TcM TyCon tcLookupTyCon name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM tce (panic "tcLookupTyCon") name) + = tcLookupGlobal_maybe name `thenM` \ maybe_tc -> + case maybe_tc of + Just (ATyCon tc) -> returnM tc + other -> notFound "tcLookupTyCon" 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} -tcLookupTyConByKey uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - let - (kind, arity, tycon) = lookupWithDefaultUFM_Directly tce (panic "tcLookupTyCon") uniq - in - returnNF_Tc tycon -tcLookupClass name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM ce (panic "tcLookupClass") name) +%************************************************************************ +%* * +\subsection{The local environment} +%* * +%************************************************************************ + +\begin{code} +tcLookup_maybe :: Name -> TcM (Maybe TcTyThing) +tcLookup_maybe name + = 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 `thenM` \ maybe_thing -> + case maybe_thing of + Just thing -> returnM thing + other -> notFound "tcLookup" name + -- Extract the IdInfo from an IfaceSig imported from an interface file + +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} -tcLookupClassByKey uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> +\begin{code} +tcExtendKindEnv :: [(Name,TcKind)] -> TcM r -> TcM r +tcExtendKindEnv pairs thing_inside + = 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 + +tcExtendTyVarEnv :: [TyVar] -> TcM r -> TcM r +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 - (kind, clas) = lookupWithDefaultUFM_Directly ce (panic "tcLookupClas") uniq + le' = extendNameEnvList le binds + new_tv_set = mkVarSet tyvars in - returnNF_Tc clas + -- It's important to add the in-scope tyvars to the global tyvar set + -- as well. Consider + -- f (x::r) = let g y = y::r in ... + -- 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 `thenM` \ gtvs' -> + setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs'}) thing_inside \end{code} - -Extending and consulting the value environment -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ \begin{code} -tcExtendGlobalValEnv ids scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> +tcExtendLocalValEnv :: [TcId] -> TcM a -> TcM a +tcExtendLocalValEnv ids thing_inside + = getLclEnv `thenM` \ env -> let - gve' = addListToUFM_Directly gve [(getItsUnique id, id) | id <- ids] + 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 - tcSetEnv (TcEnv tve tce ce gve' lve gtvs) scope + tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' -> + setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs'}) thing_inside -tcExtendLocalValEnv names ids scope - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - tcReadMutVar gtvs `thenNF_Tc` \ global_tvs -> +tcExtendLocalValEnv2 :: [(Name,TcId)] -> TcM a -> TcM a +tcExtendLocalValEnv2 names_w_ids thing_inside + = getLclEnv `thenM` \ env -> let - lve' = addListToUFM lve (names `zip` ids) - extra_global_tyvars = tyVarsOfTypes (map idType ids) - new_global_tyvars = global_tvs `unionTyVarSets` extra_global_tyvars + extra_global_tyvars = tyVarsOfTypes [idType id | (name,id) <- names_w_ids] + 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 - tcNewMutVar new_global_tyvars `thenNF_Tc` \ gtvs' -> + tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' -> + setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs'}) thing_inside +\end{code} + - tcSetEnv (TcEnv tve tce ce gve lve' gtvs') scope +\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} + + +%************************************************************************ +%* * +\subsection{The global tyvars} +%* * +%************************************************************************ + +\begin{code} +tc_extend_gtvs gtvs 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. @@ -200,94 +542,207 @@ To improve subsequent calls to the same function it writes the zonked set back i the environment. \begin{code} -tcGetGlobalTyVars :: NF_TcM s (TcTyVarSet s) +tcGetGlobalTyVars :: TcM TcTyVarSet tcGetGlobalTyVars - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - tcReadMutVar gtvs `thenNF_Tc` \ global_tvs -> - zonkTcTyVars global_tvs `thenNF_Tc` \ global_tvs' -> - tcWriteMutVar gtvs global_tvs' `thenNF_Tc_` - returnNF_Tc global_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} -\begin{code} -tcLookupLocalValue :: Name -> NF_TcM s (Maybe (TcIdBndr s)) -tcLookupLocalValue name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupUFM lve name) -tcLookupLocalValueByKey :: Unique -> NF_TcM s (Maybe (TcIdBndr s)) -tcLookupLocalValueByKey uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupUFM_Directly lve uniq) +%************************************************************************ +%* * +\subsection{The instance environment} +%* * +%************************************************************************ -tcLookupLocalValueOK :: String -> Name -> NF_TcM s (TcIdBndr s) -tcLookupLocalValueOK err name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM lve (panic err) name) +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 :: 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} -tcLookupGlobalValue :: Name -> NF_TcM s Id -tcLookupGlobalValue (WiredInVal id) -- wired in ids - = returnNF_Tc id +%************************************************************************ +%* * +\subsection{Rules} +%* * +%************************************************************************ -tcLookupGlobalValue name - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM gve def name) - where -#ifdef DEBUG - def = panic ("tcLookupGlobalValue:" ++ ppShow 1000 (ppr PprDebug name)) -#else - def = panic "tcLookupGlobalValue" -#endif +\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} -tcLookupGlobalValueByKey :: Unique -> NF_TcM s Id -tcLookupGlobalValueByKey uniq - = tcGetEnv `thenNF_Tc` \ (TcEnv tve tce ce gve lve gtvs) -> - returnNF_Tc (lookupWithDefaultUFM_Directly gve def uniq) - where -#ifdef DEBUG - def = panic ("tcLookupGlobalValueByKey:" ++ ppShow 1000 (ppr PprDebug uniq)) -#else - def = panic "tcLookupGlobalValueByKey" -#endif +%************************************************************************ +%* * +\subsection{The InstInfo type} +%* * +%************************************************************************ -\end{code} +The InstInfo type summarises the information in an instance declaration + instance c => k (t tvs) where b -Constructing new Ids -~~~~~~~~~~~~~~~~~~~~ +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} -newMonoIds :: [Name] -> Kind -> ([TcIdBndr s] -> TcM s a) -> TcM s a -newMonoIds names kind m - = newTyVarTys no_of_names kind `thenNF_Tc` \ tys -> - tcGetUniques no_of_names `thenNF_Tc` \ uniqs -> - let - new_ids = zipWith3Equal mk_id names uniqs tys - mk_id name uniq ty = mkUserLocal (getOccurrenceName name) uniq ty - (getSrcLoc name) - in - tcExtendLocalValEnv names new_ids (m new_ids) - where - no_of_names = length names - -newLocalId :: FAST_STRING -> TcType s -> NF_TcM s (TcIdOcc s) -newLocalId name ty - = tcGetSrcLoc `thenNF_Tc` \ loc -> - tcGetUnique `thenNF_Tc` \ uniq -> - returnNF_Tc (TcId (mkUserLocal name uniq ty loc)) - -newLocalIds :: [FAST_STRING] -> [TcType s] -> NF_TcM s [TcIdOcc s] -newLocalIds names tys - = tcGetSrcLoc `thenNF_Tc` \ loc -> - tcGetUniques (length names) `thenNF_Tc` \ uniqs -> - let - new_ids = zipWith3Equal mk_id names uniqs tys - mk_id name uniq ty = TcId (mkUserLocal name uniq ty loc) - in - returnNF_Tc new_ids +data InstInfo + = InstInfo { + iDFunId :: DFunId, -- The dfun id + iBinds :: InstBindings + } + +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 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 = tcTyConAppTyCon (simpleInstInfoTy inst) \end{code} +%************************************************************************ +%* * +\subsection{Errors} +%* * +%************************************************************************ + +\begin{code} +badCon con_id = quotes (ppr con_id) <+> ptext SLIT("is not a data constructor") + +notFound wheRe name = failWithTc (text wheRe <> colon <+> quotes (ppr name) <+> + ptext SLIT("is not in scope")) +\end{code}