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Diffstat (limited to 'compiler/rename/RnSource.lhs')
| -rw-r--r-- | compiler/rename/RnSource.lhs | 722 |
1 files changed, 722 insertions, 0 deletions
diff --git a/compiler/rename/RnSource.lhs b/compiler/rename/RnSource.lhs new file mode 100644 index 0000000000..9150440aee --- /dev/null +++ b/compiler/rename/RnSource.lhs @@ -0,0 +1,722 @@ +% +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 +% +\section[RnSource]{Main pass of renamer} + +\begin{code} +module RnSource ( + rnSrcDecls, addTcgDUs, + rnTyClDecls, checkModDeprec, + rnSplice, checkTH + ) where + +#include "HsVersions.h" + +import {-# SOURCE #-} RnExpr( rnLExpr ) + +import HsSyn +import RdrName ( RdrName, isRdrDataCon, elemLocalRdrEnv, globalRdrEnvElts, + GlobalRdrElt(..), isLocalGRE ) +import RdrHsSyn ( extractGenericPatTyVars, extractHsRhoRdrTyVars ) +import RnHsSyn +import RnTypes ( rnLHsType, rnLHsTypes, rnHsSigType, rnHsTypeFVs, rnContext ) +import RnBinds ( rnTopBinds, rnMethodBinds, renameSigs ) +import RnEnv ( lookupLocalDataTcNames, + lookupLocatedTopBndrRn, lookupLocatedOccRn, + lookupOccRn, newLocalsRn, + bindLocatedLocalsFV, bindPatSigTyVarsFV, + bindTyVarsRn, extendTyVarEnvFVRn, + bindLocalNames, checkDupNames, mapFvRn + ) +import TcRnMonad + +import HscTypes ( FixityEnv, FixItem(..), + Deprecations, Deprecs(..), DeprecTxt, plusDeprecs ) +import Class ( FunDep ) +import Name ( Name, nameOccName ) +import NameSet +import NameEnv +import OccName ( occEnvElts ) +import Outputable +import SrcLoc ( Located(..), unLoc, getLoc, noLoc ) +import DynFlags ( DynFlag(..) ) +import Maybes ( seqMaybe ) +import Maybe ( isNothing ) +import BasicTypes ( Boxity(..) ) +\end{code} + +@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. +\end{enumerate} + + +\begin{code} +rnSrcDecls :: HsGroup RdrName -> RnM (TcGblEnv, HsGroup Name) + +rnSrcDecls (HsGroup { hs_valds = val_decls, + 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 <- rnSrcFixityDeclsEnv fix_decls ; + rn_fix_decls <- 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 val_decls ; + 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 = rn_fix_decls, + 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} + + +%********************************************************* +%* * + Source-code fixity declarations +%* * +%********************************************************* + +\begin{code} +rnSrcFixityDecls :: [LFixitySig RdrName] -> RnM [LFixitySig Name] +rnSrcFixityDecls fix_decls + = do fix_decls <- mapM rnFixityDecl fix_decls + return (concat fix_decls) + +rnFixityDecl :: LFixitySig RdrName -> RnM [LFixitySig Name] +rnFixityDecl (L loc (FixitySig (L nameLoc rdr_name) fixity)) + = do names <- lookupLocalDataTcNames rdr_name + return [ L loc (FixitySig (L nameLoc name) fixity) + | name <- names ] + +rnSrcFixityDeclsEnv :: [LFixitySig RdrName] -> RnM FixityEnv +rnSrcFixityDeclsEnv fix_decls + = getGblEnv `thenM` \ gbl_env -> + foldlM rnFixityDeclEnv (tcg_fix_env gbl_env) + fix_decls `thenM` \ fix_env -> + traceRn (text "fixity env" <+> pprFixEnv fix_env) `thenM_` + returnM fix_env + +rnFixityDeclEnv :: FixityEnv -> LFixitySig RdrName -> RnM FixityEnv +rnFixityDeclEnv 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 lookupLocalDataTcNames rdr_name `thenM` \ names -> + foldlM add fix_env names + where + 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 + 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} + + +%********************************************************* +%* * + Source-code deprecations declarations +%* * +%********************************************************* + +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_s -> + returnM (DeprecSome (mkNameEnv (concat pairs_s))) + where + rn_deprec (Deprecation rdr_name txt) + = lookupLocalDataTcNames rdr_name `thenM` \ names -> + returnM [(name, (nameOccName name, txt)) | name <- names] + +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{Source code declarations} +%* * +%********************************************************* + +\begin{code} +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{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} + + +%********************************************************* +%* * +\subsection{Instance declarations} +%* * +%********************************************************* + +\begin{code} +rnSrcInstDecl (InstDecl inst_ty mbinds uprags) + -- Used for both source and interface file decls + = rnHsSigType (text "an instance decl") inst_ty `thenM` \ inst_ty' -> + + -- 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' + ok_sig = okInstDclSig (mkNameSet binders) + in + bindLocalNames binders (renameSigs ok_sig uprags) `thenM` \ uprags' -> + + returnM (InstDecl inst_ty' mbinds' uprags', + meth_fvs `plusFV` hsSigsFVs uprags' + `plusFV` extractHsTyNames inst_ty') +\end{code} + +For the method bindings in class and instance decls, we extend the +type variable environment iff -fglasgow-exts + +\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{Rules} +%* * +%********************************************************* + +\begin{code} +rnHsRuleDecl (HsRule rule_name act vars lhs fv_lhs rhs fv_rhs) + = bindPatSigTyVarsFV (collectRuleBndrSigTys vars) $ + + bindLocatedLocalsFV doc (map get_var vars) $ \ ids -> + mapFvRn rn_var (vars `zip` ids) `thenM` \ (vars', fv_vars) -> + + rnLExpr lhs `thenM` \ (lhs', fv_lhs') -> + rnLExpr rhs `thenM` \ (rhs', fv_rhs') -> + let + mb_bad = validRuleLhs ids lhs' + in + 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' fv_lhs' rhs' fv_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{Type, class and iface sig 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} +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 + = do { tycon' <- lookupLocatedTopBndrRn tycon + ; checkTc (null (unLoc context)) (badGadtStupidTheta 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) } + + where + is_vanilla = case condecls of -- Yuk + [] -> True + L _ (ConDecl { con_res = ResTyH98 }) : _ -> 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 _ c) = con_name c + + 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 okClsDclSig 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 _ (TypeSig op _) <- sigs] + in + checkDupNames sig_doc sig_rdr_names_w_locs `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 + +badGadtStupidTheta tycon + = vcat [ptext SLIT("No context is allowed on a GADT-style data declaration"), + ptext SLIT("(You can put a context on each contructor, though.)")] +\end{code} + +%********************************************************* +%* * +\subsection{Support code for type/data declarations} +%* * +%********************************************************* + +\begin{code} +rnConDecls :: Name -> [LConDecl RdrName] -> RnM [LConDecl Name] +rnConDecls tycon condecls + = mappM (wrapLocM rnConDecl) condecls + +rnConDecl :: ConDecl RdrName -> RnM (ConDecl Name) +rnConDecl (ConDecl name expl tvs cxt details res_ty) + = do { addLocM checkConName name + + ; new_name <- lookupLocatedTopBndrRn name + ; name_env <- getLocalRdrEnv + + -- For H98 syntax, the tvs are the existential ones + -- For GADT syntax, the tvs are all the quantified tyvars + -- Hence the 'filter' in the ResTyH98 case only + ; let not_in_scope = not . (`elemLocalRdrEnv` name_env) . unLoc + arg_tys = hsConArgs details + implicit_tvs = case res_ty of + ResTyH98 -> filter not_in_scope $ + get_rdr_tvs arg_tys + ResTyGADT ty -> get_rdr_tvs (ty : arg_tys) + tvs' = case expl of + Explicit -> tvs + Implicit -> userHsTyVarBndrs implicit_tvs + + ; bindTyVarsRn doc tvs' $ \new_tyvars -> do + { new_context <- rnContext doc cxt + ; new_details <- rnConDetails doc details + ; new_res_ty <- rnConResult doc res_ty + ; let rv = ConDecl new_name expl new_tyvars new_context new_details new_res_ty + ; traceRn (text "****** - autrijus" <> ppr rv) + ; return rv } } + where + doc = text "In the definition of data constructor" <+> quotes (ppr name) + get_rdr_tvs tys = extractHsRhoRdrTyVars cxt (noLoc (HsTupleTy Boxed tys)) + +rnConResult _ ResTyH98 = return ResTyH98 +rnConResult doc (ResTyGADT ty) = do + ty' <- rnHsSigType doc ty + return $ ResTyGADT ty' + +rnConDetails doc (PrefixCon tys) + = mappM (rnLHsType doc) tys `thenM` \ new_tys -> + returnM (PrefixCon new_tys) + +rnConDetails doc (InfixCon ty1 ty2) + = rnLHsType doc ty1 `thenM` \ new_ty1 -> + rnLHsType doc ty2 `thenM` \ new_ty2 -> + returnM (InfixCon new_ty1 new_ty2) + +rnConDetails doc (RecCon fields) + = checkDupNames doc field_names `thenM_` + mappM (rnField doc) fields `thenM` \ new_fields -> + returnM (RecCon new_fields) + where + 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)] +\end{code} + + +%********************************************************* +%* * +\subsection{Support code to rename types} +%* * +%********************************************************* + +\begin{code} +rnFds :: SDoc -> [Located (FunDep RdrName)] -> RnM [Located (FunDep Name)] + +rnFds doc fds + = mappM (wrapLocM rn_fds) fds + where + 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} + + +%********************************************************* +%* * + Splices +%* * +%********************************************************* + +Note [Splices] +~~~~~~~~~~~~~~ +Consider + f = ... + h = ...$(thing "f")... + +The splice can expand into literally anything, so when we do dependency +analysis we must assume that it might mention 'f'. So we simply treat +all locally-defined names as mentioned by any splice. This is terribly +brutal, but I don't see what else to do. For example, it'll mean +that every locally-defined thing will appear to be used, so no unused-binding +warnings. But if we miss the dependency, then we might typecheck 'h' before 'f', +and that will crash the type checker because 'f' isn't in scope. + +Currently, I'm not treating a splice as also mentioning every import, +which is a bit inconsistent -- but there are a lot of them. We might +thereby get some bogus unused-import warnings, but we won't crash the +type checker. Not very satisfactory really. + +\begin{code} +rnSplice :: HsSplice RdrName -> RnM (HsSplice Name, FreeVars) +rnSplice (HsSplice n expr) + = do { checkTH expr "splice" + ; loc <- getSrcSpanM + ; [n'] <- newLocalsRn [L loc n] + ; (expr', fvs) <- rnLExpr expr + + -- Ugh! See Note [Splices] above + ; lcl_rdr <- getLocalRdrEnv + ; gbl_rdr <- getGlobalRdrEnv + ; let gbl_names = mkNameSet [gre_name gre | gre <- globalRdrEnvElts gbl_rdr, + isLocalGRE gre] + lcl_names = mkNameSet (occEnvElts lcl_rdr) + + ; return (HsSplice n' expr', fvs `plusFV` lcl_names `plusFV` gbl_names) } + +#ifdef GHCI +checkTH e what = returnM () -- OK +#else +checkTH e what -- Raise an error in a stage-1 compiler + = addErr (vcat [ptext SLIT("Template Haskell") <+> text what <+> + ptext SLIT("illegal in a stage-1 compiler"), + nest 2 (ppr e)]) +#endif +\end{code} |