%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnSource]{Main pass of renamer}
\begin{code}
-#include "HsVersions.h"
-
-module RnSource ( rnSource, rnPolyType ) where
+module RnSource (
+ rnSrcDecls, addTcgDUs,
+ rnTyClDecls, checkModDeprec,
+ rnBindGroups, rnBindGroupsAndThen, rnSplice
+ ) where
-import Ubiq
-import RnLoop -- *check* the RnPass4/RnExpr4/RnBinds4 loop-breaking
+#include "HsVersions.h"
import HsSyn
-import HsPragmas
-import RdrHsSyn
+import RdrName ( RdrName, isRdrDataCon, rdrNameOcc, elemLocalRdrEnv )
+import RdrHsSyn ( extractGenericPatTyVars )
import RnHsSyn
-import RnMonad
-import RnBinds ( rnTopBinds, rnMethodBinds )
-
-import Bag ( bagToList )
-import Class ( derivableClassKeys )
-import ListSetOps ( unionLists, minusList )
-import Maybes ( maybeToBool, catMaybes )
-import Name ( isLocallyDefined, isAvarid, getLocalName, ExportFlag(..), RdrName )
-import Pretty
-import SrcLoc ( SrcLoc )
-import Unique ( Unique )
-import UniqFM ( addListToUFM, listToUFM )
-import UniqSet ( UniqSet(..) )
-import Util ( isn'tIn, panic, assertPanic )
-
-rnExports mods Nothing = returnRn (\n -> ExportAll)
-rnExports mods (Just exps) = returnRn (\n -> ExportAll)
+import RnExpr ( rnLExpr, checkTH )
+import RnTypes ( rnLHsType, rnLHsTypes, rnHsSigType, rnHsTypeFVs, rnContext )
+import RnBinds ( rnTopBinds, rnBinds, rnMethodBinds,
+ rnBindsAndThen, renameSigs, checkSigs )
+import RnEnv ( lookupTopBndrRn, lookupTopFixSigNames,
+ lookupLocatedTopBndrRn, lookupLocatedOccRn,
+ lookupOccRn, newLocalsRn,
+ bindLocatedLocalsFV, bindPatSigTyVarsFV,
+ bindTyVarsRn, extendTyVarEnvFVRn,
+ bindLocalNames, newIPNameRn,
+ checkDupNames, mapFvRn,
+ unknownNameErr
+ )
+import TcRnMonad
+
+import BasicTypes ( TopLevelFlag(..) )
+import HscTypes ( FixityEnv, FixItem(..),
+ Deprecations, Deprecs(..), DeprecTxt, plusDeprecs )
+import Class ( FunDep )
+import Name ( Name, nameOccName )
+import NameSet
+import NameEnv
+import Outputable
+import SrcLoc ( Located(..), unLoc, getLoc, noLoc )
+import CmdLineOpts ( DynFlag(..) )
+ -- Warn of unused for-all'd tyvars
+import Maybes ( seqMaybe )
+import Maybe ( catMaybes, isNothing )
\end{code}
-rnSource `renames' the source module and export list.
+@rnSourceDecl@ `renames' declarations.
It simultaneously performs dependency analysis and precedence parsing.
It also does the following error checks:
\begin{enumerate}
\item
Checks that tyvars are used properly. This includes checking
for undefined tyvars, and tyvars in contexts that are ambiguous.
+(Some of this checking has now been moved to module @TcMonoType@,
+since we don't have functional dependency information at this point.)
\item
Checks that all variable occurences are defined.
\item
-Checks the (..) etc constraints in the export list.
+Checks the @(..)@ etc constraints in the export list.
\end{enumerate}
\begin{code}
-rnSource :: [Module] -- imported modules
- -> Bag RenamedFixityDecl -- fixity info for imported names
- -> RdrNameHsModule
- -> RnM s (RenamedHsModule,
- Name -> ExportFlag, -- export info
- Bag (RnName, RdrName)) -- occurrence info
-
-rnSource imp_mods imp_fixes (HsModule mod version exports _ fixes
- ty_decls specdata_sigs class_decls
- inst_decls specinst_sigs defaults
- binds _ src_loc)
-
- = pushSrcLocRn src_loc $
-
- rnExports (mod:imp_mods) exports `thenRn` \ exported_fn ->
- rnFixes fixes `thenRn` \ src_fixes ->
- let
- pair_name inf@(InfixL n _) = (n, inf)
- pair_name inf@(InfixR n _) = (n, inf)
- pair_name inf@(InfixN n _) = (n, inf)
-
- imp_fixes_fm = listToUFM (map pair_name (bagToList imp_fixes))
- all_fixes_fm = addListToUFM imp_fixes_fm (map pair_name src_fixes)
- in
- setExtraRn all_fixes_fm $
-
- mapRn rnTyDecl ty_decls `thenRn` \ new_ty_decls ->
- mapRn rnSpecDataSig specdata_sigs `thenRn` \ new_specdata_sigs ->
- mapRn rnClassDecl class_decls `thenRn` \ new_class_decls ->
- mapRn rnInstDecl inst_decls `thenRn` \ new_inst_decls ->
- mapRn rnSpecInstSig specinst_sigs `thenRn` \ new_specinst_sigs ->
- rnDefaultDecl defaults `thenRn` \ new_defaults ->
- rnTopBinds binds `thenRn` \ new_binds ->
-
- getOccurrenceUpRn `thenRn` \ occ_info ->
-
- returnRn (
- HsModule mod version
- trashed_exports trashed_imports src_fixes
- new_ty_decls new_specdata_sigs new_class_decls
- new_inst_decls new_specinst_sigs new_defaults
- new_binds [] src_loc,
- exported_fn,
- occ_info
- )
- where
- trashed_exports = trace "rnSource:trashed_exports" Nothing
- trashed_imports = trace "rnSource:trashed_imports" []
+rnSrcDecls :: HsGroup RdrName -> RnM (TcGblEnv, HsGroup Name)
+
+rnSrcDecls (HsGroup { hs_valds = [HsBindGroup binds sigs _],
+ hs_tyclds = tycl_decls,
+ hs_instds = inst_decls,
+ hs_fixds = fix_decls,
+ hs_depds = deprec_decls,
+ hs_fords = foreign_decls,
+ hs_defds = default_decls,
+ hs_ruleds = rule_decls })
+
+ = do { -- Deal with deprecations (returns only the extra deprecations)
+ deprecs <- rnSrcDeprecDecls deprec_decls ;
+ updGblEnv (\gbl -> gbl { tcg_deprecs = tcg_deprecs gbl `plusDeprecs` deprecs })
+ $ do {
+
+ -- Deal with top-level fixity decls
+ -- (returns the total new fixity env)
+ fix_env <- rnSrcFixityDecls fix_decls ;
+ updGblEnv (\gbl -> gbl { tcg_fix_env = fix_env })
+ $ do {
+
+ -- Rename other declarations
+ traceRn (text "Start rnmono") ;
+ (rn_val_decls, bind_dus) <- rnTopBinds binds sigs ;
+ traceRn (text "finish rnmono" <+> ppr rn_val_decls) ;
+
+ -- You might think that we could build proper def/use information
+ -- for type and class declarations, but they can be involved
+ -- in mutual recursion across modules, and we only do the SCC
+ -- analysis for them in the type checker.
+ -- So we content ourselves with gathering uses only; that
+ -- means we'll only report a declaration as unused if it isn't
+ -- mentioned at all. Ah well.
+ (rn_tycl_decls, src_fvs1)
+ <- mapFvRn (wrapLocFstM rnTyClDecl) tycl_decls ;
+ (rn_inst_decls, src_fvs2)
+ <- mapFvRn (wrapLocFstM rnSrcInstDecl) inst_decls ;
+ (rn_rule_decls, src_fvs3)
+ <- mapFvRn (wrapLocFstM rnHsRuleDecl) rule_decls ;
+ (rn_foreign_decls, src_fvs4)
+ <- mapFvRn (wrapLocFstM rnHsForeignDecl) foreign_decls ;
+ (rn_default_decls, src_fvs5)
+ <- mapFvRn (wrapLocFstM rnDefaultDecl) default_decls ;
+
+ let {
+ rn_group = HsGroup { hs_valds = rn_val_decls,
+ hs_tyclds = rn_tycl_decls,
+ hs_instds = rn_inst_decls,
+ hs_fixds = [],
+ hs_depds = [],
+ hs_fords = rn_foreign_decls,
+ hs_defds = rn_default_decls,
+ hs_ruleds = rn_rule_decls } ;
+
+ other_fvs = plusFVs [src_fvs1, src_fvs2, src_fvs3,
+ src_fvs4, src_fvs5] ;
+ src_dus = bind_dus `plusDU` usesOnly other_fvs
+ -- Note: src_dus will contain *uses* for locally-defined types
+ -- and classes, but no *defs* for them. (Because rnTyClDecl
+ -- returns only the uses.) This is a little
+ -- surprising but it doesn't actually matter at all.
+ } ;
+
+ traceRn (text "finish rnSrc" <+> ppr rn_group) ;
+ traceRn (text "finish Dus" <+> ppr src_dus ) ;
+ tcg_env <- getGblEnv ;
+ return (tcg_env `addTcgDUs` src_dus, rn_group)
+ }}}
+
+rnTyClDecls :: [LTyClDecl RdrName] -> RnM [LTyClDecl Name]
+rnTyClDecls tycl_decls = do
+ (decls', fvs) <- mapFvRn (wrapLocFstM rnTyClDecl) tycl_decls
+ return decls'
+
+addTcgDUs :: TcGblEnv -> DefUses -> TcGblEnv
+addTcgDUs tcg_env dus = tcg_env { tcg_dus = tcg_dus tcg_env `plusDU` dus }
\end{code}
+
%*********************************************************
-%* *
-\subsection{Type declarations}
-%* *
+%* *
+ Source-code fixity declarations
+%* *
%*********************************************************
-@rnTyDecl@ uses the `global name function' to create a new type
-declaration in which local names have been replaced by their original
-names, reporting any unknown names.
-
-Renaming type variables is a pain. Because they now contain uniques,
-it is necessary to pass in an association list which maps a parsed
-tyvar to its Name representation. In some cases (type signatures of
-values), it is even necessary to go over the type first in order to
-get the set of tyvars used by it, make an assoc list, and then go over
-it again to rename the tyvars! However, we can also do some scoping
-checks at the same time.
-
\begin{code}
-rnTyDecl :: RdrNameTyDecl -> RnM_Fixes s RenamedTyDecl
-
-rnTyDecl (TyData context tycon tyvars condecls derivings pragmas src_loc)
- = pushSrcLocRn src_loc $
- lookupTyCon tycon `thenRn` \ tycon' ->
- mkTyVarNamesEnv src_loc tyvars `thenRn` \ (tv_env, tyvars') ->
- rnContext tv_env context `thenRn` \ context' ->
- rnConDecls tv_env condecls `thenRn` \ condecls' ->
- rn_derivs tycon' src_loc derivings `thenRn` \ derivings' ->
- ASSERT(isNoDataPragmas pragmas)
- returnRn (TyData context' tycon' tyvars' condecls' derivings' noDataPragmas src_loc)
-
-rnTyDecl (TyNew context tycon tyvars condecl derivings pragmas src_loc)
- = pushSrcLocRn src_loc $
- lookupTyCon tycon `thenRn` \ tycon' ->
- mkTyVarNamesEnv src_loc tyvars `thenRn` \ (tv_env, tyvars') ->
- rnContext tv_env context `thenRn` \ context' ->
- rnConDecls tv_env condecl `thenRn` \ condecl' ->
- rn_derivs tycon' src_loc derivings `thenRn` \ derivings' ->
- ASSERT(isNoDataPragmas pragmas)
- returnRn (TyNew context' tycon' tyvars' condecl' derivings' noDataPragmas src_loc)
-
-rnTyDecl (TySynonym name tyvars ty src_loc)
- = pushSrcLocRn src_loc $
- lookupTyCon name `thenRn` \ name' ->
- mkTyVarNamesEnv src_loc tyvars `thenRn` \ (tv_env, tyvars') ->
- rnMonoType tv_env ty `thenRn` \ ty' ->
- returnRn (TySynonym name' tyvars' ty' src_loc)
-
-rn_derivs tycon2 locn Nothing -- derivs not specified
- = returnRn Nothing
-
-rn_derivs tycon2 locn (Just ds)
- = mapRn (rn_deriv tycon2 locn) ds `thenRn` \ derivs ->
- returnRn (Just derivs)
+rnSrcFixityDecls :: [LFixitySig RdrName] -> RnM FixityEnv
+rnSrcFixityDecls fix_decls
+ = getGblEnv `thenM` \ gbl_env ->
+ foldlM rnFixityDecl (tcg_fix_env gbl_env)
+ fix_decls `thenM` \ fix_env ->
+ traceRn (text "fixity env" <+> pprFixEnv fix_env) `thenM_`
+ returnM fix_env
+
+rnFixityDecl :: FixityEnv -> LFixitySig RdrName -> RnM FixityEnv
+rnFixityDecl fix_env (L loc (FixitySig rdr_name fixity))
+ = setSrcSpan loc $
+ -- GHC extension: look up both the tycon and data con
+ -- for con-like things
+ -- If neither are in scope, report an error; otherwise
+ -- add both to the fixity env
+ addLocM lookupTopFixSigNames rdr_name `thenM` \ names ->
+ if null names then
+ addLocErr rdr_name unknownNameErr `thenM_`
+ returnM fix_env
+ else
+ foldlM add fix_env names
where
- rn_deriv tycon2 locn clas
- = lookupClass clas `thenRn` \ clas_name ->
- addErrIfRn (uniqueOf clas_name `not_elem` derivableClassKeys)
- (derivingNonStdClassErr clas locn)
- `thenRn_`
- returnRn clas_name
+ add fix_env name
+ = case lookupNameEnv fix_env name of
+ Just (FixItem _ _ loc')
+ -> addLocErr rdr_name (dupFixityDecl loc') `thenM_`
+ returnM fix_env
+ Nothing -> returnM (extendNameEnv fix_env name fix_item)
where
- not_elem = isn'tIn "rn_deriv"
+ fix_item = FixItem (nameOccName name) fixity (getLoc rdr_name)
+
+pprFixEnv :: FixityEnv -> SDoc
+pprFixEnv env
+ = pprWithCommas (\ (FixItem n f _) -> ppr f <+> ppr n)
+ (nameEnvElts env)
+
+dupFixityDecl loc rdr_name
+ = vcat [ptext SLIT("Multiple fixity declarations for") <+> quotes (ppr rdr_name),
+ ptext SLIT("also at ") <+> ppr loc
+ ]
\end{code}
-@rnConDecls@ uses the `global name function' to create a new
-constructor in which local names have been replaced by their original
-names, reporting any unknown names.
-\begin{code}
-rnConDecls :: TyVarNamesEnv
- -> [RdrNameConDecl]
- -> RnM_Fixes s [RenamedConDecl]
+%*********************************************************
+%* *
+ Source-code deprecations declarations
+%* *
+%*********************************************************
-rnConDecls tv_env con_decls
- = mapRn rn_decl con_decls
- where
- rn_decl (ConDecl name tys src_loc)
- = pushSrcLocRn src_loc $
- lookupValue name `thenRn` \ new_name ->
- mapRn rn_bang_ty tys `thenRn` \ new_tys ->
- returnRn (ConDecl new_name new_tys src_loc)
-
- rn_decl (ConOpDecl ty1 op ty2 src_loc)
- = pushSrcLocRn src_loc $
- lookupValue op `thenRn` \ new_op ->
- rn_bang_ty ty1 `thenRn` \ new_ty1 ->
- rn_bang_ty ty2 `thenRn` \ new_ty2 ->
- returnRn (ConOpDecl new_ty1 new_op new_ty2 src_loc)
-
- rn_decl (NewConDecl name ty src_loc)
- = pushSrcLocRn src_loc $
- lookupValue name `thenRn` \ new_name ->
- rn_mono_ty ty `thenRn` \ new_ty ->
- returnRn (NewConDecl new_name new_ty src_loc)
-
- rn_decl (RecConDecl con fields src_loc)
- = panic "rnConDecls:RecConDecl"
-
- ----------
- rn_mono_ty = rnMonoType tv_env
-
- rn_bang_ty (Banged ty)
- = rn_mono_ty ty `thenRn` \ new_ty ->
- returnRn (Banged new_ty)
- rn_bang_ty (Unbanged ty)
- = rn_mono_ty ty `thenRn` \ new_ty ->
- returnRn (Unbanged new_ty)
+For deprecations, all we do is check that the names are in scope.
+It's only imported deprecations, dealt with in RnIfaces, that we
+gather them together.
+
+\begin{code}
+rnSrcDeprecDecls :: [LDeprecDecl RdrName] -> RnM Deprecations
+rnSrcDeprecDecls []
+ = returnM NoDeprecs
+
+rnSrcDeprecDecls decls
+ = mappM (addLocM rn_deprec) decls `thenM` \ pairs ->
+ returnM (DeprecSome (mkNameEnv (catMaybes pairs)))
+ where
+ rn_deprec (Deprecation rdr_name txt)
+ = lookupTopBndrRn rdr_name `thenM` \ name ->
+ returnM (Just (name, (rdrNameOcc rdr_name, txt)))
+
+checkModDeprec :: Maybe DeprecTxt -> Deprecations
+-- Check for a module deprecation; done once at top level
+checkModDeprec Nothing = NoDeprecs
+checkModDeprec (Just txt) = DeprecAll txt
\end{code}
%*********************************************************
%* *
-\subsection{SPECIALIZE data pragmas}
+\subsection{Source code declarations}
%* *
%*********************************************************
\begin{code}
-rnSpecDataSig :: RdrNameSpecDataSig
- -> RnM_Fixes s RenamedSpecDataSig
-
-rnSpecDataSig (SpecDataSig tycon ty src_loc)
- = pushSrcLocRn src_loc $
- let
- tyvars = extractMonoTyNames ty
- in
- mkTyVarNamesEnv src_loc tyvars `thenRn` \ (tv_env,_) ->
- lookupTyCon tycon `thenRn` \ tycon' ->
- rnMonoType tv_env ty `thenRn` \ ty' ->
- returnRn (SpecDataSig tycon' ty' src_loc)
+rnDefaultDecl (DefaultDecl tys)
+ = mapFvRn (rnHsTypeFVs doc_str) tys `thenM` \ (tys', fvs) ->
+ returnM (DefaultDecl tys', fvs)
+ where
+ doc_str = text "In a `default' declaration"
\end{code}
%*********************************************************
%* *
-\subsection{Class declarations}
+ Bindings
%* *
%*********************************************************
-@rnClassDecl@ uses the `global name function' to create a new
-class declaration in which local names have been replaced by their
-original names, reporting any unknown names.
+These chaps are here, rather than in TcBinds, so that there
+is just one hi-boot file (for RnSource). rnSrcDecls is part
+of the loop too, and it must be defined in this module.
\begin{code}
-rnClassDecl :: RdrNameClassDecl -> RnM_Fixes s RenamedClassDecl
-
-rnClassDecl (ClassDecl context cname tyvar sigs mbinds pragmas src_loc)
- = pushSrcLocRn src_loc $
- mkTyVarNamesEnv src_loc [tyvar] `thenRn` \ (tv_env, [tyvar']) ->
- rnContext tv_env context `thenRn` \ context' ->
- lookupClass cname `thenRn` \ cname' ->
- mapRn (rn_op cname' tv_env) sigs `thenRn` \ sigs' ->
- rnMethodBinds cname' mbinds `thenRn` \ mbinds' ->
- ASSERT(isNoClassPragmas pragmas)
- returnRn (ClassDecl context' cname' tyvar' sigs' mbinds' NoClassPragmas src_loc)
- where
- rn_op clas tv_env (ClassOpSig op ty pragmas locn)
- = pushSrcLocRn locn $
- lookupClassOp clas op `thenRn` \ op_name ->
- rnPolyType tv_env ty `thenRn` \ new_ty ->
-
-{-
-*** Please check here that tyvar' appears in new_ty ***
-*** (used to be in tcClassSig, but it's better here)
-*** not_elem = isn'tIn "tcClassSigs"
-*** -- Check that the class type variable is mentioned
-*** checkTc (clas_tyvar `not_elem` extractTyVarTemplatesFromTy local_ty)
-*** (methodTypeLacksTyVarErr clas_tyvar (_UNPK_ op_name) src_loc) `thenTc_`
--}
-
- ASSERT(isNoClassOpPragmas pragmas)
- returnRn (ClassOpSig op_name new_ty noClassOpPragmas locn)
+rnBindGroups :: [HsBindGroup RdrName] -> RnM ([HsBindGroup Name], DefUses)
+-- This version assumes that the binders are already in scope
+-- It's used only in 'mdo'
+rnBindGroups []
+ = returnM ([], emptyDUs)
+rnBindGroups [HsBindGroup bind sigs _]
+ = rnBinds NotTopLevel bind sigs
+rnBindGroups b@[HsIPBinds bind]
+ = do addErr (badIpBinds b)
+ returnM ([], emptyDUs)
+rnBindGroups _
+ = panic "rnBindGroups"
+
+rnBindGroupsAndThen
+ :: [HsBindGroup RdrName]
+ -> ([HsBindGroup Name] -> RnM (result, FreeVars))
+ -> RnM (result, FreeVars)
+-- This version (a) assumes that the binding vars are not already in scope
+-- (b) removes the binders from the free vars of the thing inside
+-- The parser doesn't produce ThenBinds
+rnBindGroupsAndThen [] thing_inside
+ = thing_inside []
+rnBindGroupsAndThen [HsBindGroup bind sigs _] thing_inside
+ = rnBindsAndThen bind sigs $ \ groups -> thing_inside groups
+rnBindGroupsAndThen [HsIPBinds binds] thing_inside
+ = rnIPBinds binds `thenM` \ (binds',fv_binds) ->
+ thing_inside [HsIPBinds binds'] `thenM` \ (thing, fvs_thing) ->
+ returnM (thing, fvs_thing `plusFV` fv_binds)
+
+rnIPBinds [] = returnM ([], emptyFVs)
+rnIPBinds (bind : binds)
+ = wrapLocFstM rnIPBind bind `thenM` \ (bind', fvBind) ->
+ rnIPBinds binds `thenM` \ (binds',fvBinds) ->
+ returnM (bind' : binds', fvBind `plusFV` fvBinds)
+
+rnIPBind (IPBind n expr)
+ = newIPNameRn n `thenM` \ name ->
+ rnLExpr expr `thenM` \ (expr',fvExpr) ->
+ return (IPBind name expr', fvExpr)
+
+badIpBinds binds
+ = hang (ptext SLIT("Implicit-parameter bindings illegal in 'mdo':")) 4
+ (ppr binds)
\end{code}
%*********************************************************
%* *
-\subsection{Instance declarations}
+\subsection{Foreign declarations}
%* *
%*********************************************************
+\begin{code}
+rnHsForeignDecl (ForeignImport name ty spec isDeprec)
+ = lookupLocatedTopBndrRn name `thenM` \ name' ->
+ rnHsTypeFVs (fo_decl_msg name) ty `thenM` \ (ty', fvs) ->
+ returnM (ForeignImport name' ty' spec isDeprec, fvs)
+
+rnHsForeignDecl (ForeignExport name ty spec isDeprec)
+ = lookupLocatedOccRn name `thenM` \ name' ->
+ rnHsTypeFVs (fo_decl_msg name) ty `thenM` \ (ty', fvs) ->
+ returnM (ForeignExport name' ty' spec isDeprec, fvs )
+ -- NB: a foreign export is an *occurrence site* for name, so
+ -- we add it to the free-variable list. It might, for example,
+ -- be imported from another module
+
+fo_decl_msg name = ptext SLIT("In the foreign declaration for") <+> ppr name
+\end{code}
+
-@rnInstDecl@ uses the `global name function' to create a new of
-instance declaration in which local names have been replaced by their
-original names, reporting any unknown names.
+%*********************************************************
+%* *
+\subsection{Instance declarations}
+%* *
+%*********************************************************
\begin{code}
-rnInstDecl :: RdrNameInstDecl -> RnM_Fixes s RenamedInstDecl
+rnSrcInstDecl (InstDecl inst_ty mbinds uprags)
+ -- Used for both source and interface file decls
+ = rnHsSigType (text "an instance decl") inst_ty `thenM` \ inst_ty' ->
-rnInstDecl (InstDecl cname ty mbinds from_here modname uprags pragmas src_loc)
- = pushSrcLocRn src_loc $
- lookupClass cname `thenRn` \ cname' ->
+ -- Rename the bindings
+ -- The typechecker (not the renamer) checks that all
+ -- the bindings are for the right class
+ let
+ meth_doc = text "In the bindings in an instance declaration"
+ meth_names = collectHsBindLocatedBinders mbinds
+ (inst_tyvars, _, cls,_) = splitHsInstDeclTy (unLoc inst_ty')
+ in
+ checkDupNames meth_doc meth_names `thenM_`
+ extendTyVarEnvForMethodBinds inst_tyvars (
+ -- (Slightly strangely) the forall-d tyvars scope over
+ -- the method bindings too
+ rnMethodBinds cls [] mbinds
+ ) `thenM` \ (mbinds', meth_fvs) ->
+ -- Rename the prags and signatures.
+ -- Note that the type variables are not in scope here,
+ -- so that instance Eq a => Eq (T a) where
+ -- {-# SPECIALISE instance Eq a => Eq (T [a]) #-}
+ -- works OK.
+ --
+ -- But the (unqualified) method names are in scope
+ let
+ binders = collectHsBindBinders mbinds'
+ in
+ bindLocalNames binders (renameSigs uprags) `thenM` \ uprags' ->
+ checkSigs (okInstDclSig (mkNameSet binders)) uprags' `thenM_`
- rnPolyType [] ty `thenRn` \ ty' ->
- -- [] tv_env ensures that tyvars will be foralled
+ returnM (InstDecl inst_ty' mbinds' uprags',
+ meth_fvs `plusFV` hsSigsFVs uprags'
+ `plusFV` extractHsTyNames inst_ty')
+\end{code}
- rnMethodBinds cname' mbinds `thenRn` \ mbinds' ->
- mapRn (rn_uprag cname') uprags `thenRn` \ new_uprags ->
+For the method bindings in class and instance decls, we extend the
+type variable environment iff -fglasgow-exts
- ASSERT(isNoInstancePragmas pragmas)
- returnRn (InstDecl cname' ty' mbinds'
- from_here modname new_uprags noInstancePragmas src_loc)
- where
- rn_uprag class_name (SpecSig op ty using locn)
- = pushSrcLocRn src_loc $
- lookupClassOp class_name op `thenRn` \ op_name ->
- rnPolyType nullTyVarNamesEnv ty `thenRn` \ new_ty ->
- rn_using using `thenRn` \ new_using ->
- returnRn (SpecSig op_name new_ty new_using locn)
-
- rn_uprag class_name (InlineSig op locn)
- = pushSrcLocRn locn $
- lookupClassOp class_name op `thenRn` \ op_name ->
- returnRn (InlineSig op_name locn)
-
- rn_uprag class_name (DeforestSig op locn)
- = pushSrcLocRn locn $
- lookupClassOp class_name op `thenRn` \ op_name ->
- returnRn (DeforestSig op_name locn)
-
- rn_uprag class_name (MagicUnfoldingSig op str locn)
- = pushSrcLocRn locn $
- lookupClassOp class_name op `thenRn` \ op_name ->
- returnRn (MagicUnfoldingSig op_name str locn)
-
- rn_using Nothing
- = returnRn Nothing
- rn_using (Just v)
- = lookupValue v `thenRn` \ new_v ->
- returnRn (Just new_v)
+\begin{code}
+extendTyVarEnvForMethodBinds tyvars thing_inside
+ = doptM Opt_GlasgowExts `thenM` \ opt_GlasgowExts ->
+ if opt_GlasgowExts then
+ extendTyVarEnvFVRn (map hsLTyVarName tyvars) thing_inside
+ else
+ thing_inside
\end{code}
+
%*********************************************************
%* *
-\subsection{@SPECIALIZE instance@ user-pragmas}
+\subsection{Rules}
%* *
%*********************************************************
\begin{code}
-rnSpecInstSig :: RdrNameSpecInstSig
- -> RnM_Fixes s RenamedSpecInstSig
+rnHsRuleDecl (HsRule rule_name act vars lhs rhs)
+ = bindPatSigTyVarsFV (collectRuleBndrSigTys vars) $
+
+ bindLocatedLocalsFV doc (map get_var vars) $ \ ids ->
+ mapFvRn rn_var (vars `zip` ids) `thenM` \ (vars', fv_vars) ->
-rnSpecInstSig (SpecInstSig clas ty src_loc)
- = pushSrcLocRn src_loc $
+ rnLExpr lhs `thenM` \ (lhs', fv_lhs) ->
+ rnLExpr rhs `thenM` \ (rhs', fv_rhs) ->
let
- tyvars = extractMonoTyNames ty
+ mb_bad = validRuleLhs ids lhs'
in
- mkTyVarNamesEnv src_loc tyvars `thenRn` \ (tv_env,_) ->
- lookupClass clas `thenRn` \ new_clas ->
- rnMonoType tv_env ty `thenRn` \ new_ty ->
- returnRn (SpecInstSig new_clas new_ty src_loc)
+ checkErr (isNothing mb_bad)
+ (badRuleLhsErr rule_name lhs' mb_bad) `thenM_`
+ let
+ bad_vars = [var | var <- ids, not (var `elemNameSet` fv_lhs)]
+ in
+ mappM (addErr . badRuleVar rule_name) bad_vars `thenM_`
+ returnM (HsRule rule_name act vars' lhs' rhs',
+ fv_vars `plusFV` fv_lhs `plusFV` fv_rhs)
+ where
+ doc = text "In the transformation rule" <+> ftext rule_name
+
+ get_var (RuleBndr v) = v
+ get_var (RuleBndrSig v _) = v
+
+ rn_var (RuleBndr (L loc v), id)
+ = returnM (RuleBndr (L loc id), emptyFVs)
+ rn_var (RuleBndrSig (L loc v) t, id)
+ = rnHsTypeFVs doc t `thenM` \ (t', fvs) ->
+ returnM (RuleBndrSig (L loc id) t', fvs)
+\end{code}
+
+Check the shape of a transformation rule LHS. Currently
+we only allow LHSs of the form @(f e1 .. en)@, where @f@ is
+not one of the @forall@'d variables. We also restrict the form of the LHS so
+that it may be plausibly matched. Basically you only get to write ordinary
+applications. (E.g. a case expression is not allowed: too elaborate.)
+
+NB: if you add new cases here, make sure you add new ones to TcRule.ruleLhsTvs
+
+\begin{code}
+validRuleLhs :: [Name] -> LHsExpr Name -> Maybe (HsExpr Name)
+-- Nothing => OK
+-- Just e => Not ok, and e is the offending expression
+validRuleLhs foralls lhs
+ = checkl lhs
+ where
+ checkl (L loc e) = check e
+
+ check (OpApp e1 op _ e2) = checkl op `seqMaybe` checkl_e e1 `seqMaybe` checkl_e e2
+ check (HsApp e1 e2) = checkl e1 `seqMaybe` checkl_e e2
+ check (HsVar v) | v `notElem` foralls = Nothing
+ check other = Just other -- Failure
+
+ checkl_e (L loc e) = check_e e
+
+ check_e (HsVar v) = Nothing
+ check_e (HsPar e) = checkl_e e
+ check_e (HsLit e) = Nothing
+ check_e (HsOverLit e) = Nothing
+
+ check_e (OpApp e1 op _ e2) = checkl_e e1 `seqMaybe` checkl_e op `seqMaybe` checkl_e e2
+ check_e (HsApp e1 e2) = checkl_e e1 `seqMaybe` checkl_e e2
+ check_e (NegApp e _) = checkl_e e
+ check_e (ExplicitList _ es) = checkl_es es
+ check_e (ExplicitTuple es _) = checkl_es es
+ check_e other = Just other -- Fails
+
+ checkl_es es = foldr (seqMaybe . checkl_e) Nothing es
+
+badRuleLhsErr name lhs (Just bad_e)
+ = sep [ptext SLIT("Rule") <+> ftext name <> colon,
+ nest 4 (vcat [ptext SLIT("Illegal expression:") <+> ppr bad_e,
+ ptext SLIT("in left-hand side:") <+> ppr lhs])]
+ $$
+ ptext SLIT("LHS must be of form (f e1 .. en) where f is not forall'd")
+
+badRuleVar name var
+ = sep [ptext SLIT("Rule") <+> doubleQuotes (ftext name) <> colon,
+ ptext SLIT("Forall'd variable") <+> quotes (ppr var) <+>
+ ptext SLIT("does not appear on left hand side")]
\end{code}
+
%*********************************************************
%* *
-\subsection{Default declarations}
+\subsection{Type, class and iface sig declarations}
%* *
%*********************************************************
-@rnDefaultDecl@ uses the `global name function' to create a new set
-of default declarations in which local names have been replaced by
-their original names, reporting any unknown names.
-
-\begin{code}
-rnDefaultDecl :: [RdrNameDefaultDecl] -> RnM_Fixes s [RenamedDefaultDecl]
-
-rnDefaultDecl [] = returnRn []
-rnDefaultDecl [DefaultDecl tys src_loc]
- = pushSrcLocRn src_loc $
- mapRn (rnMonoType nullTyVarNamesEnv) tys `thenRn` \ tys' ->
- returnRn [DefaultDecl tys' src_loc]
-rnDefaultDecl defs@(d:ds)
- = addErrRn (dupDefaultDeclErr defs) `thenRn_`
- rnDefaultDecl [d]
-\end{code}
+@rnTyDecl@ uses the `global name function' to create a new type
+declaration in which local names have been replaced by their original
+names, reporting any unknown names.
-%*************************************************************************
-%* *
-\subsection{Fixity declarations}
-%* *
-%*************************************************************************
+Renaming type variables is a pain. Because they now contain uniques,
+it is necessary to pass in an association list which maps a parsed
+tyvar to its @Name@ representation.
+In some cases (type signatures of values),
+it is even necessary to go over the type first
+in order to get the set of tyvars used by it, make an assoc list,
+and then go over it again to rename the tyvars!
+However, we can also do some scoping checks at the same time.
\begin{code}
-rnFixes :: [RdrNameFixityDecl] -> RnM s [RenamedFixityDecl]
+rnTyClDecl (ForeignType {tcdLName = name, tcdFoType = fo_type, tcdExtName = ext_name})
+ = lookupLocatedTopBndrRn name `thenM` \ name' ->
+ returnM (ForeignType {tcdLName = name', tcdFoType = fo_type, tcdExtName = ext_name},
+ emptyFVs)
+
+rnTyClDecl (TyData {tcdND = new_or_data, tcdCtxt = context, tcdLName = tycon,
+ tcdTyVars = tyvars, tcdCons = condecls,
+ tcdKindSig = sig, tcdDerivs = derivs})
+ | is_vanilla -- Normal Haskell data type decl
+ = ASSERT( isNothing sig ) -- In normal H98 form, kind signature on the
+ -- data type is syntactically illegal
+ bindTyVarsRn data_doc tyvars $ \ tyvars' ->
+ do { tycon' <- lookupLocatedTopBndrRn tycon
+ ; context' <- rnContext data_doc context
+ ; (derivs', deriv_fvs) <- rn_derivs derivs
+ ; checkDupNames data_doc con_names
+ ; condecls' <- rnConDecls (unLoc tycon') condecls
+ ; returnM (TyData {tcdND = new_or_data, tcdCtxt = context', tcdLName = tycon',
+ tcdTyVars = tyvars', tcdKindSig = Nothing, tcdCons = condecls',
+ tcdDerivs = derivs'},
+ delFVs (map hsLTyVarName tyvars') $
+ extractHsCtxtTyNames context' `plusFV`
+ plusFVs (map conDeclFVs condecls') `plusFV`
+ deriv_fvs) }
+
+ | otherwise -- GADT
+ = ASSERT( null (unLoc context) )
+ do { tycon' <- lookupLocatedTopBndrRn tycon
+ ; tyvars' <- bindTyVarsRn data_doc tyvars
+ (\ tyvars' -> return tyvars')
+ -- For GADTs, the type variables in the declaration
+ -- do not scope over the constructor signatures
+ -- data T a where { T1 :: forall b. b-> b }
+ ; (derivs', deriv_fvs) <- rn_derivs derivs
+ ; checkDupNames data_doc con_names
+ ; condecls' <- rnConDecls (unLoc tycon') condecls
+ ; returnM (TyData {tcdND = new_or_data, tcdCtxt = noLoc [], tcdLName = tycon',
+ tcdTyVars = tyvars', tcdCons = condecls', tcdKindSig = sig,
+ tcdDerivs = derivs'},
+ plusFVs (map conDeclFVs condecls') `plusFV` deriv_fvs) }
-rnFixes fixities
- = mapRn rn_fixity fixities `thenRn` \ fixes_maybe ->
- returnRn (catMaybes fixes_maybe)
where
- rn_fixity fix@(InfixL name i)
- = rn_fixity_pieces InfixL name i fix
- rn_fixity fix@(InfixR name i)
- = rn_fixity_pieces InfixR name i fix
- rn_fixity fix@(InfixN name i)
- = rn_fixity_pieces InfixN name i fix
-
- rn_fixity_pieces mk_fixity name i fix
- = lookupValueMaybe name `thenRn` \ maybe_res ->
- case maybe_res of
- Just res | isLocallyDefined res
- -> returnRn (Just (mk_fixity res i))
- _ -> failButContinueRn Nothing (undefinedFixityDeclErr fix)
-
+ is_vanilla = case condecls of -- Yuk
+ [] -> True
+ L _ (ConDecl {}) : _ -> True
+ other -> False
+
+ data_doc = text "In the data type declaration for" <+> quotes (ppr tycon)
+ con_names = map con_names_helper condecls
+
+ con_names_helper (L _ (ConDecl n _ _ _)) = n
+ con_names_helper (L _ (GadtDecl n _)) = n
+
+ rn_derivs Nothing = returnM (Nothing, emptyFVs)
+ rn_derivs (Just ds) = rnLHsTypes data_doc ds `thenM` \ ds' ->
+ returnM (Just ds', extractHsTyNames_s ds')
+
+rnTyClDecl (TySynonym {tcdLName = name, tcdTyVars = tyvars, tcdSynRhs = ty})
+ = lookupLocatedTopBndrRn name `thenM` \ name' ->
+ bindTyVarsRn syn_doc tyvars $ \ tyvars' ->
+ rnHsTypeFVs syn_doc ty `thenM` \ (ty', fvs) ->
+ returnM (TySynonym {tcdLName = name', tcdTyVars = tyvars',
+ tcdSynRhs = ty'},
+ delFVs (map hsLTyVarName tyvars') fvs)
+ where
+ syn_doc = text "In the declaration for type synonym" <+> quotes (ppr name)
+
+rnTyClDecl (ClassDecl {tcdCtxt = context, tcdLName = cname,
+ tcdTyVars = tyvars, tcdFDs = fds, tcdSigs = sigs,
+ tcdMeths = mbinds})
+ = lookupLocatedTopBndrRn cname `thenM` \ cname' ->
+
+ -- Tyvars scope over superclass context and method signatures
+ bindTyVarsRn cls_doc tyvars ( \ tyvars' ->
+ rnContext cls_doc context `thenM` \ context' ->
+ rnFds cls_doc fds `thenM` \ fds' ->
+ renameSigs sigs `thenM` \ sigs' ->
+ returnM (tyvars', context', fds', sigs')
+ ) `thenM` \ (tyvars', context', fds', sigs') ->
+
+ -- Check the signatures
+ -- First process the class op sigs (op_sigs), then the fixity sigs (non_op_sigs).
+ let
+ sig_rdr_names_w_locs = [op | L _ (Sig op _) <- sigs]
+ in
+ checkDupNames sig_doc sig_rdr_names_w_locs `thenM_`
+ checkSigs okClsDclSig sigs' `thenM_`
+ -- Typechecker is responsible for checking that we only
+ -- give default-method bindings for things in this class.
+ -- The renamer *could* check this for class decls, but can't
+ -- for instance decls.
+
+ -- The newLocals call is tiresome: given a generic class decl
+ -- class C a where
+ -- op :: a -> a
+ -- op {| x+y |} (Inl a) = ...
+ -- op {| x+y |} (Inr b) = ...
+ -- op {| a*b |} (a*b) = ...
+ -- we want to name both "x" tyvars with the same unique, so that they are
+ -- easy to group together in the typechecker.
+ extendTyVarEnvForMethodBinds tyvars' (
+ getLocalRdrEnv `thenM` \ name_env ->
+ let
+ meth_rdr_names_w_locs = collectHsBindLocatedBinders mbinds
+ gen_rdr_tyvars_w_locs =
+ [ tv | tv <- extractGenericPatTyVars mbinds,
+ not (unLoc tv `elemLocalRdrEnv` name_env) ]
+ in
+ checkDupNames meth_doc meth_rdr_names_w_locs `thenM_`
+ newLocalsRn gen_rdr_tyvars_w_locs `thenM` \ gen_tyvars ->
+ rnMethodBinds (unLoc cname') gen_tyvars mbinds
+ ) `thenM` \ (mbinds', meth_fvs) ->
+
+ returnM (ClassDecl { tcdCtxt = context', tcdLName = cname', tcdTyVars = tyvars',
+ tcdFDs = fds', tcdSigs = sigs', tcdMeths = mbinds'},
+ delFVs (map hsLTyVarName tyvars') $
+ extractHsCtxtTyNames context' `plusFV`
+ plusFVs (map extractFunDepNames (map unLoc fds')) `plusFV`
+ hsSigsFVs sigs' `plusFV`
+ meth_fvs)
+ where
+ meth_doc = text "In the default-methods for class" <+> ppr cname
+ cls_doc = text "In the declaration for class" <+> ppr cname
+ sig_doc = text "In the signatures for class" <+> ppr cname
\end{code}
%*********************************************************
%* *
-\subsection{Support code to rename types}
+\subsection{Support code for type/data declarations}
%* *
%*********************************************************
\begin{code}
-rnPolyType :: TyVarNamesEnv
- -> RdrNamePolyType
- -> RnM_Fixes s RenamedPolyType
-
-rnPolyType tv_env (HsForAllTy tvs ctxt ty)
- = rn_poly_help tv_env tvs ctxt ty
+rnConDecls :: Name -> [LConDecl RdrName] -> RnM [LConDecl Name]
+rnConDecls tycon condecls
+ = -- Check that there's at least one condecl,
+ -- or else we're reading an interface file, or -fglasgow-exts
+ (if null condecls then
+ doptM Opt_GlasgowExts `thenM` \ glaExts ->
+ checkErr glaExts (emptyConDeclsErr tycon)
+ else returnM ()
+ ) `thenM_`
+ mappM (wrapLocM rnConDecl) condecls
+
+rnConDecl :: ConDecl RdrName -> RnM (ConDecl Name)
+rnConDecl (ConDecl name tvs cxt details)
+ = addLocM checkConName name `thenM_`
+ lookupLocatedTopBndrRn name `thenM` \ new_name ->
+
+ bindTyVarsRn doc tvs $ \ new_tyvars ->
+ rnContext doc cxt `thenM` \ new_context ->
+ rnConDetails doc details `thenM` \ new_details ->
+ returnM (ConDecl new_name new_tyvars new_context new_details)
+ where
+ doc = text "In the definition of data constructor" <+> quotes (ppr name)
-rnPolyType tv_env poly_ty@(HsPreForAllTy ctxt ty)
- = rn_poly_help tv_env forall_tyvars ctxt ty
+rnConDecl (GadtDecl name ty)
+ = addLocM checkConName name `thenM_`
+ lookupLocatedTopBndrRn name `thenM` \ new_name ->
+ rnHsSigType doc ty `thenM` \ new_ty ->
+ returnM (GadtDecl new_name new_ty)
where
- mentioned_tyvars = extract_poly_ty_names poly_ty
- forall_tyvars = mentioned_tyvars `minusList` domTyVarNamesEnv tv_env
-
-------------
-extract_poly_ty_names (HsPreForAllTy ctxt ty)
- = extractCtxtTyNames ctxt
- `unionLists`
- extractMonoTyNames ty
-
-------------
-rn_poly_help :: TyVarNamesEnv
- -> [RdrName]
- -> RdrNameContext
- -> RdrNameMonoType
- -> RnM_Fixes s RenamedPolyType
-
-rn_poly_help tv_env tyvars ctxt ty
- = getSrcLocRn `thenRn` \ src_loc ->
- mkTyVarNamesEnv src_loc tyvars `thenRn` \ (tv_env1, new_tyvars) ->
- let
- tv_env2 = catTyVarNamesEnvs tv_env1 tv_env
- in
- rnContext tv_env2 ctxt `thenRn` \ new_ctxt ->
- rnMonoType tv_env2 ty `thenRn` \ new_ty ->
- returnRn (HsForAllTy new_tyvars new_ctxt new_ty)
-\end{code}
+ doc = text "In the definition of data constructor" <+> quotes (ppr name)
-\begin{code}
-rnMonoType :: TyVarNamesEnv
- -> RdrNameMonoType
- -> RnM_Fixes s RenamedMonoType
-
-rnMonoType tv_env (MonoTyVar tyvar)
- = lookupTyVarName tv_env tyvar `thenRn` \ tyvar' ->
- returnRn (MonoTyVar tyvar')
-
-rnMonoType tv_env (MonoListTy ty)
- = rnMonoType tv_env ty `thenRn` \ ty' ->
- returnRn (MonoListTy ty')
-
-rnMonoType tv_env (MonoFunTy ty1 ty2)
- = andRn MonoFunTy (rnMonoType tv_env ty1)
- (rnMonoType tv_env ty2)
-
-rnMonoType tv_env (MonoTupleTy tys)
- = mapRn (rnMonoType tv_env) tys `thenRn` \ tys' ->
- returnRn (MonoTupleTy tys')
-
-rnMonoType tv_env (MonoTyApp name tys)
- = let
- lookup_fn = if isAvarid (getLocalName name)
- then lookupTyVarName tv_env
- else lookupTyCon
- in
- lookup_fn name `thenRn` \ name' ->
- mapRn (rnMonoType tv_env) tys `thenRn` \ tys' ->
- returnRn (MonoTyApp name' tys')
-\end{code}
+rnConDetails doc (PrefixCon tys)
+ = mappM (rnLHsType doc) tys `thenM` \ new_tys ->
+ returnM (PrefixCon new_tys)
-\begin{code}
-rnContext :: TyVarNamesEnv -> RdrNameContext -> RnM_Fixes s RenamedContext
+rnConDetails doc (InfixCon ty1 ty2)
+ = rnLHsType doc ty1 `thenM` \ new_ty1 ->
+ rnLHsType doc ty2 `thenM` \ new_ty2 ->
+ returnM (InfixCon new_ty1 new_ty2)
-rnContext tv_env ctxt
- = mapRn rn_ctxt ctxt
+rnConDetails doc (RecCon fields)
+ = checkDupNames doc field_names `thenM_`
+ mappM (rnField doc) fields `thenM` \ new_fields ->
+ returnM (RecCon new_fields)
where
- rn_ctxt (clas, tyvar)
- = lookupClass clas `thenRn` \ clas_name ->
- lookupTyVarName tv_env tyvar `thenRn` \ tyvar_name ->
- returnRn (clas_name, tyvar_name)
+ field_names = [fld | (fld, _) <- fields]
+
+rnField doc (name, ty)
+ = lookupLocatedTopBndrRn name `thenM` \ new_name ->
+ rnLHsType doc ty `thenM` \ new_ty ->
+ returnM (new_name, new_ty)
+
+-- This data decl will parse OK
+-- data T = a Int
+-- treating "a" as the constructor.
+-- It is really hard to make the parser spot this malformation.
+-- So the renamer has to check that the constructor is legal
+--
+-- We can get an operator as the constructor, even in the prefix form:
+-- data T = :% Int Int
+-- from interface files, which always print in prefix form
+
+checkConName name = checkErr (isRdrDataCon name) (badDataCon name)
+
+badDataCon name
+ = hsep [ptext SLIT("Illegal data constructor name"), quotes (ppr name)]
+
+emptyConDeclsErr tycon
+ = sep [quotes (ppr tycon) <+> ptext SLIT("has no constructors"),
+ nest 4 (ptext SLIT("(-fglasgow-exts permits this)"))]
\end{code}
+%*********************************************************
+%* *
+\subsection{Support code to rename types}
+%* *
+%*********************************************************
+
\begin{code}
-derivingNonStdClassErr clas locn sty
- = ppHang (ppStr "Non-standard class in deriving")
- 4 (ppCat [ppr sty clas, ppr sty locn])
+rnFds :: SDoc -> [Located (FunDep RdrName)] -> RnM [Located (FunDep Name)]
-dupDefaultDeclErr defs sty
- = ppHang (ppStr "Duplicate default declarations")
- 4 (ppAboves (map pp_def_loc defs))
+rnFds doc fds
+ = mappM (wrapLocM rn_fds) fds
where
- pp_def_loc (DefaultDecl _ src_loc) = ppr sty src_loc
+ rn_fds (tys1, tys2)
+ = rnHsTyVars doc tys1 `thenM` \ tys1' ->
+ rnHsTyVars doc tys2 `thenM` \ tys2' ->
+ returnM (tys1', tys2')
+
+rnHsTyVars doc tvs = mappM (rnHsTyvar doc) tvs
+rnHsTyvar doc tyvar = lookupOccRn tyvar
+\end{code}
+
-undefinedFixityDeclErr decl sty
- = ppHang (ppStr "Fixity declaration for unknown operator")
- 4 (ppr sty decl)
+%*********************************************************
+%* *
+ Splices
+%* *
+%*********************************************************
+
+\begin{code}
+rnSplice :: HsSplice RdrName -> RnM (HsSplice Name, FreeVars)
+rnSplice (HsSplice n expr)
+ = checkTH expr "splice" `thenM_`
+ getSrcSpanM `thenM` \ loc ->
+ newLocalsRn [L loc n] `thenM` \ [n'] ->
+ rnLExpr expr `thenM` \ (expr', fvs) ->
+ returnM (HsSplice n' expr', fvs)
\end{code}