X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnBinds.lhs;h=13035e72e2831185bc58ee74c632c381ac49b151;hb=876b4ef2093cb9c104db33c7db1200b941b6d079;hp=c5ba50eba0c9aee0d646e0e69cf6fe376c608091;hpb=d1854b8826400244bb6f3ca02d3614d34aa65c90;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnBinds.lhs b/ghc/compiler/rename/RnBinds.lhs index c5ba50e..13035e7 100644 --- a/ghc/compiler/rename/RnBinds.lhs +++ b/ghc/compiler/rename/RnBinds.lhs @@ -10,34 +10,43 @@ they may be affected by renaming (which isn't fully worked out yet). \begin{code} module RnBinds ( - rnTopMonoBinds, rnMonoBinds, rnMonoBindsAndThen, - rnMethodBinds, renameSigs, checkSigs + rnTopBinds, + rnLocalBindsAndThen, rnValBindsAndThen, rnValBinds, trimWith, + rnMethodBinds, renameSigs, + rnMatchGroup, rnGRHSs ) where #include "HsVersions.h" +import {-# SOURCE #-} RnExpr( rnLExpr, rnStmts ) import HsSyn -import HsBinds ( hsSigDoc, sigLoc, eqHsSig ) import RdrHsSyn import RnHsSyn import TcRnMonad -import RnTypes ( rnHsSigType, rnHsType, rnPat ) -import RnExpr ( rnMatch, rnGRHSs, checkPrecMatch ) -import RnEnv ( bindLocatedLocalsRn, lookupBndrRn, lookupInstDeclBndr, - lookupSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV, - bindLocalFixities, +import RnTypes ( rnHsSigType, rnLHsType, rnHsTypeFVs, + rnLPat, rnPatsAndThen, patSigErr, checkPrecMatch ) +import RnEnv ( bindLocatedLocalsRn, lookupLocatedBndrRn, + lookupLocatedInstDeclBndr, newIPNameRn, + lookupLocatedSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV, + bindLocalFixities, bindSigTyVarsFV, warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn, ) -import CmdLineOpts ( DynFlag(..) ) -import Digraph ( SCC(..), stronglyConnComp ) +import DynFlags ( DynFlag(..) ) import Name ( Name, nameOccName, nameSrcLoc ) +import NameEnv import NameSet import PrelNames ( isUnboundName ) import RdrName ( RdrName, rdrNameOcc ) -import BasicTypes ( RecFlag(..), TopLevelFlag(..), isTopLevel ) -import List ( unzip4 ) +import SrcLoc ( mkSrcSpan, Located(..), unLoc ) +import ListSetOps ( findDupsEq ) +import BasicTypes ( RecFlag(..) ) +import Digraph ( SCC(..), stronglyConnComp ) +import Bag import Outputable +import Maybes ( orElse, isJust ) +import Util ( filterOut ) +import Monad ( foldM ) \end{code} -- ToDo: Put the annotations into the monad, so that they arrive in the proper @@ -96,7 +105,7 @@ a set of variables free in @Exp@ is written @fvExp@ %************************************************************************ %* * -%* analysing polymorphic bindings (HsBinds, Bind, MonoBinds) * +%* analysing polymorphic bindings (HsBindGroup, HsBind) %* * %************************************************************************ @@ -150,190 +159,252 @@ it expects the global environment to contain bindings for the binders contains bindings for the binders of this particular binding. \begin{code} -rnTopMonoBinds :: RdrNameMonoBinds - -> [RdrNameSig] - -> RnM (RenamedHsBinds, DefUses) +rnTopBinds :: HsValBinds RdrName -> RnM (HsValBinds Name, DefUses) -- The binders of the binding are in scope already; -- the top level scope resolution does that -rnTopMonoBinds mbinds sigs - = bindPatSigTyVars (collectSigTysFromMonoBinds mbinds) $ \ _ -> - -- Hmm; by analogy with Ids, this doesn't look right - -- Top-level bound type vars should really scope over - -- everything, but we only scope them over the other bindings +rnTopBinds binds + = do { is_boot <- tcIsHsBoot + ; if is_boot then rnTopBindsBoot binds + else rnTopBindsSrc binds } + +rnTopBindsBoot :: HsValBinds RdrName -> RnM (HsValBinds Name, DefUses) +-- A hs-boot file has no bindings. +-- Return a single HsBindGroup with empty binds and renamed signatures +rnTopBindsBoot (ValBindsIn mbinds sigs) + = do { checkErr (isEmptyLHsBinds mbinds) (bindsInHsBootFile mbinds) + ; sigs' <- renameSigs okHsBootSig sigs + ; return (ValBindsOut [] sigs', usesOnly (hsSigsFVs sigs')) } + +rnTopBindsSrc :: HsValBinds RdrName -> RnM (HsValBinds Name, DefUses) +rnTopBindsSrc binds@(ValBindsIn mbinds _) + = do { (binds', dus) <- rnValBinds noTrim binds + + -- Warn about missing signatures, + ; let { ValBindsOut _ sigs' = binds' + ; ty_sig_vars = mkNameSet [ unLoc n | L _ (TypeSig n _) <- sigs'] + ; un_sigd_bndrs = duDefs dus `minusNameSet` ty_sig_vars } + + ; warn_missing_sigs <- doptM Opt_WarnMissingSigs + ; ifM (warn_missing_sigs) + (mappM_ missingSigWarn (nameSetToList un_sigd_bndrs)) + + ; return (binds', dus) + } +\end{code} + + - rnMonoBinds TopLevel mbinds sigs +%********************************************************* +%* * + HsLocalBinds +%* * +%********************************************************* + +\begin{code} +rnLocalBindsAndThen + :: HsLocalBinds RdrName + -> (HsLocalBinds 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 +rnLocalBindsAndThen EmptyLocalBinds thing_inside + = thing_inside EmptyLocalBinds + +rnLocalBindsAndThen (HsValBinds val_binds) thing_inside + = rnValBindsAndThen val_binds $ \ val_binds' -> + thing_inside (HsValBinds val_binds') + +rnLocalBindsAndThen (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 (IPBinds ip_binds _no_dict_binds) + = do { (ip_binds', fvs_s) <- mapAndUnzipM (wrapLocFstM rnIPBind) ip_binds + ; return (IPBinds ip_binds' emptyLHsBinds, plusFVs fvs_s) } + +rnIPBind (IPBind n expr) + = newIPNameRn n `thenM` \ name -> + rnLExpr expr `thenM` \ (expr',fvExpr) -> + return (IPBind name expr', fvExpr) \end{code} %************************************************************************ %* * -%* Nested binds + ValBinds %* * %************************************************************************ \begin{code} -rnMonoBindsAndThen :: RdrNameMonoBinds - -> [RdrNameSig] - -> (RenamedHsBinds -> RnM (result, FreeVars)) - -> RnM (result, FreeVars) +rnValBindsAndThen :: HsValBinds RdrName + -> (HsValBinds Name -> RnM (result, FreeVars)) + -> RnM (result, FreeVars) -rnMonoBindsAndThen mbinds sigs thing_inside -- Non-empty monobinds +rnValBindsAndThen binds@(ValBindsIn mbinds sigs) thing_inside = -- Extract all the binders in this group, and extend the -- current scope, inventing new names for the new binders -- This also checks that the names form a set - bindLocatedLocalsRn doc mbinders_w_srclocs $ \ _ -> - bindPatSigTyVarsFV (collectSigTysFromMonoBinds mbinds) $ + bindLocatedLocalsRn doc mbinders_w_srclocs $ \ bndrs -> -- Then install local fixity declarations -- Notice that they scope over thing_inside too - bindLocalFixities [sig | FixSig sig <- sigs ] $ + bindLocalFixities [sig | L _ (FixSig sig) <- sigs ] $ -- Do the business - rnMonoBinds NotTopLevel mbinds sigs `thenM` \ (binds, bind_dus) -> + rnValBinds (trimWith bndrs) binds `thenM` \ (binds, bind_dus) -> -- Now do the "thing inside" thing_inside binds `thenM` \ (result,result_fvs) -> -- Final error checking let - all_uses = duUses bind_dus `plusFV` result_fvs - bndrs = duDefs bind_dus - unused_bndrs = nameSetToList (bndrs `minusNameSet` all_uses) - in - warnUnusedLocalBinds unused_bndrs `thenM_` - - returnM (result, all_uses `minusNameSet` bndrs) - -- duUses: It's important to return all the uses, not the 'real uses' used for - -- warning about unused bindings. Otherwise consider: + all_uses = duUses bind_dus `plusFV` result_fvs + -- duUses: It's important to return all the uses, not the 'real uses' + -- used for warning about unused bindings. Otherwise consider: -- x = 3 -- y = let p = x in 'x' -- NB: p not used -- If we don't "see" the dependency of 'y' on 'x', we may put the -- bindings in the wrong order, and the type checker will complain -- that x isn't in scope + + unused_bndrs = [ b | b <- bndrs, not (b `elemNameSet` all_uses)] + in + warnUnusedLocalBinds unused_bndrs `thenM_` + + returnM (result, delListFromNameSet all_uses bndrs) where - mbinders_w_srclocs = collectLocatedMonoBinders mbinds + mbinders_w_srclocs = collectHsBindLocatedBinders mbinds doc = text "In the binding group for:" - <+> pprWithCommas ppr (map fst mbinders_w_srclocs) -\end{code} + <+> pprWithCommas ppr (map unLoc mbinders_w_srclocs) +--------------------- +rnValBinds :: (FreeVars -> FreeVars) + -> HsValBinds RdrName + -> RnM (HsValBinds Name, DefUses) +-- Assumes the binders of the binding are in scope already -%************************************************************************ -%* * -\subsubsection{ MonoBinds -- the main work is done here} -%* * -%************************************************************************ - -@rnMonoBinds@ is used by {\em both} top-level and nested bindings. -It assumes that all variables bound in this group are already in scope. -This is done {\em either} by pass 3 (for the top-level bindings), -{\em or} by @rnMonoBinds@ (for the nested ones). +rnValBinds trim (ValBindsIn mbinds sigs) + = do { sigs' <- rename_sigs sigs -\begin{code} -rnMonoBinds :: TopLevelFlag - -> RdrNameMonoBinds - -> [RdrNameSig] - -> RnM (RenamedHsBinds, DefUses) + ; binds_w_dus <- mapBagM (rnBind (mkSigTvFn sigs') trim) mbinds --- Assumes the binders of the binding are in scope already + ; let (binds', bind_dus) = depAnalBinds binds_w_dus -rnMonoBinds top_lvl mbinds sigs - = renameSigs sigs `thenM` \ siglist -> + -- We do the check-sigs after renaming the bindings, + -- so that we have convenient access to the binders + ; check_sigs (okBindSig (duDefs bind_dus)) sigs' - -- Rename the bindings, returning a MonoBindsInfo - -- which is a list of indivisible vertices so far as - -- the strongly-connected-components (SCC) analysis is concerned - flattenMonoBinds siglist mbinds `thenM` \ mbinds_info -> + ; return (ValBindsOut binds' sigs', + usesOnly (hsSigsFVs sigs') `plusDU` bind_dus) } - -- Do the SCC analysis - let - scc_result = rnSCC mbinds_info - (binds_s, bind_dus_s) = unzip (map reconstructCycle scc_result) - bind_dus = mkDUs bind_dus_s - final_binds = foldr ThenBinds EmptyBinds binds_s - binders = duDefs bind_dus - in - -- Check for duplicate or mis-placed signatures - checkSigs (okBindSig binders) siglist `thenM_` - - -- Warn about missing signatures, - -- but only at top level, and not in interface mode - -- (The latter is important when renaming bindings from 'deriving' clauses.) - doptM Opt_WarnMissingSigs `thenM` \ warn_missing_sigs -> - (if isTopLevel top_lvl && - warn_missing_sigs - then let - type_sig_vars = [n | Sig n _ _ <- siglist] - un_sigd_binders = filter (not . (`elem` type_sig_vars)) - (nameSetToList binders) - in - mappM_ missingSigWarn un_sigd_binders - else - returnM () - ) `thenM_` - - returnM (final_binds, bind_dus `plusDU` usesOnly (hsSigsFVs siglist)) -\end{code} -@flattenMonoBinds@ is ever-so-slightly magical in that it sticks -unique ``vertex tags'' on its output; minor plumbing required. +--------------------- +depAnalBinds :: Bag (LHsBind Name, [Name], Uses) + -> ([(RecFlag, LHsBinds Name)], DefUses) +-- Dependency analysis; this is important so that +-- unused-binding reporting is accurate +depAnalBinds binds_w_dus + = (map get_binds sccs, map get_du sccs) + where + sccs = stronglyConnComp edges -\begin{code} -flattenMonoBinds :: [RenamedSig] -- Signatures - -> RdrNameMonoBinds - -> RnM [FlatMonoBinds] + keyd_nodes = bagToList binds_w_dus `zip` [0::Int ..] -flattenMonoBinds sigs EmptyMonoBinds = returnM [] + edges = [ (node, key, [key | n <- nameSetToList uses, + Just key <- [lookupNameEnv key_map n] ]) + | (node@(_,_,uses), key) <- keyd_nodes ] -flattenMonoBinds sigs (AndMonoBinds bs1 bs2) - = flattenMonoBinds sigs bs1 `thenM` \ flat1 -> - flattenMonoBinds sigs bs2 `thenM` \ flat2 -> - returnM (flat1 ++ flat2) + key_map :: NameEnv Int -- Which binding it comes from + key_map = mkNameEnv [(bndr, key) | ((_, bndrs, _), key) <- keyd_nodes + , bndr <- bndrs ] -flattenMonoBinds sigs (PatMonoBind pat grhss locn) - = addSrcLoc locn $ - rnPat pat `thenM` \ (pat', pat_fvs) -> + get_binds (AcyclicSCC (bind, _, _)) = (NonRecursive, unitBag bind) + get_binds (CyclicSCC binds_w_dus) = (Recursive, listToBag [b | (b,d,u) <- binds_w_dus]) - -- Find which things are bound in this group - let - names_bound_here = mkNameSet (collectPatBinders pat') - in - sigsForMe names_bound_here sigs `thenM` \ sigs_for_me -> - rnGRHSs PatBindRhs grhss `thenM` \ (grhss', fvs) -> - returnM - [(names_bound_here, fvs `plusFV` pat_fvs, - PatMonoBind pat' grhss' locn, sigs_for_me - )] - -flattenMonoBinds sigs (FunMonoBind name inf matches locn) - = addSrcLoc locn $ - lookupBndrRn name `thenM` \ new_name -> - let - names_bound_here = unitNameSet new_name - in - sigsForMe names_bound_here sigs `thenM` \ sigs_for_me -> - mapFvRn (rnMatch (FunRhs new_name)) matches `thenM` \ (new_matches, fvs) -> - mappM_ (checkPrecMatch inf new_name) new_matches `thenM_` - returnM - [(unitNameSet new_name, fvs, - FunMonoBind new_name inf new_matches locn, sigs_for_me - )] - -sigsForMe names_bound_here sigs - = foldlM check [] (filter (sigForThisGroup names_bound_here) sigs) + get_du (AcyclicSCC (_, bndrs, uses)) = (Just (mkNameSet bndrs), uses) + get_du (CyclicSCC binds_w_dus) = (Just defs, uses) + where + defs = mkNameSet [b | (_,bs,_) <- binds_w_dus, b <- bs] + uses = unionManyNameSets [u | (_,_,u) <- binds_w_dus] + + +--------------------- +-- Bind the top-level forall'd type variables in the sigs. +-- E.g f :: a -> a +-- f = rhs +-- The 'a' scopes over the rhs +-- +-- NB: there'll usually be just one (for a function binding) +-- but if there are many, one may shadow the rest; too bad! +-- e.g x :: [a] -> [a] +-- y :: [(a,a)] -> a +-- (x,y) = e +-- In e, 'a' will be in scope, and it'll be the one from 'y'! + +mkSigTvFn :: [LSig Name] -> (Name -> [Name]) +-- Return a lookup function that maps an Id Name to the names +-- of the type variables that should scope over its body.. +mkSigTvFn sigs + = \n -> lookupNameEnv env n `orElse` [] where - -- sigForThisGroup only returns signatures for - -- which sigName returns a Just - check sigs sig = case filter (eqHsSig sig) sigs of - [] -> returnM (sig:sigs) - other -> dupSigDeclErr sig other `thenM_` - returnM sigs + env :: NameEnv [Name] + env = mkNameEnv [ (name, map hsLTyVarName ltvs) + | L _ (TypeSig (L _ name) + (L _ (HsForAllTy Explicit ltvs _ _))) <- sigs] + -- Note the pattern-match on "Explicit"; we only bind + -- type variables from signatures with an explicit top-level for-all + +-- The trimming function trims the free vars we attach to a +-- binding so that it stays reasonably small +noTrim :: FreeVars -> FreeVars +noTrim fvs = fvs -- Used at top level + +trimWith :: [Name] -> FreeVars -> FreeVars +-- Nested bindings; trim by intersection with the names bound here +trimWith bndrs = intersectNameSet (mkNameSet bndrs) + +--------------------- +rnBind :: (Name -> [Name]) -- Signature tyvar function + -> (FreeVars -> FreeVars) -- Trimming function for rhs free vars + -> LHsBind RdrName + -> RnM (LHsBind Name, [Name], Uses) +rnBind sig_fn trim (L loc (PatBind { pat_lhs = pat, pat_rhs = grhss })) + = setSrcSpan loc $ + do { (pat', pat_fvs) <- rnLPat pat + + ; let bndrs = collectPatBinders pat' + + ; (grhss', fvs) <- bindSigTyVarsFV (concatMap sig_fn bndrs) $ + rnGRHSs PatBindRhs grhss + + ; return (L loc (PatBind { pat_lhs = pat', pat_rhs = grhss', + pat_rhs_ty = placeHolderType, bind_fvs = trim fvs }), + bndrs, pat_fvs `plusFV` fvs) } + +rnBind sig_fn trim (L loc (FunBind { fun_id = name, fun_infix = inf, fun_matches = matches })) + = setSrcSpan loc $ + do { new_name <- lookupLocatedBndrRn name + ; let plain_name = unLoc new_name + + ; (matches', fvs) <- bindSigTyVarsFV (sig_fn plain_name) $ + rnMatchGroup (FunRhs plain_name) matches + + ; checkPrecMatch inf plain_name matches' + + ; return (L loc (FunBind { fun_id = new_name, fun_infix = inf, fun_matches = matches', + bind_fvs = trim fvs, fun_co_fn = idCoercion }), + [plain_name], fvs) + } \end{code} @rnMethodBinds@ is used for the method bindings of a class and an instance -declaration. Like @rnMonoBinds@ but without dependency analysis. +declaration. Like @rnBinds@ but without dependency analysis. NOTA BENE: we record each {\em binder} of a method-bind group as a free variable. That's crucial when dealing with an instance decl: @@ -350,92 +421,48 @@ a binder. \begin{code} rnMethodBinds :: Name -- Class name -> [Name] -- Names for generic type variables - -> RdrNameMonoBinds - -> RnM (RenamedMonoBinds, FreeVars) - -rnMethodBinds cls gen_tyvars EmptyMonoBinds = returnM (EmptyMonoBinds, emptyFVs) - -rnMethodBinds cls gen_tyvars (AndMonoBinds mb1 mb2) - = rnMethodBinds cls gen_tyvars mb1 `thenM` \ (mb1', fvs1) -> - rnMethodBinds cls gen_tyvars mb2 `thenM` \ (mb2', fvs2) -> - returnM (mb1' `AndMonoBinds` mb2', fvs1 `plusFV` fvs2) - -rnMethodBinds cls gen_tyvars (FunMonoBind name inf matches locn) - = addSrcLoc locn $ - - lookupInstDeclBndr cls name `thenM` \ sel_name -> + -> LHsBinds RdrName + -> RnM (LHsBinds Name, FreeVars) + +rnMethodBinds cls gen_tyvars binds + = foldM do_one (emptyBag,emptyFVs) (bagToList binds) + where do_one (binds,fvs) bind = do + (bind', fvs_bind) <- rnMethodBind cls gen_tyvars bind + return (bind' `unionBags` binds, fvs_bind `plusFV` fvs) + +rnMethodBind cls gen_tyvars (L loc (FunBind { fun_id = name, fun_infix = inf, + fun_matches = MatchGroup matches _ })) + = setSrcSpan loc $ + lookupLocatedInstDeclBndr cls name `thenM` \ sel_name -> + let plain_name = unLoc sel_name in -- We use the selector name as the binder - mapFvRn (rn_match sel_name) matches `thenM` \ (new_matches, fvs) -> - mappM_ (checkPrecMatch inf sel_name) new_matches `thenM_` - returnM (FunMonoBind sel_name inf new_matches locn, fvs `addOneFV` sel_name) + mapFvRn (rn_match plain_name) matches `thenM` \ (new_matches, fvs) -> + let + new_group = MatchGroup new_matches placeHolderType + in + checkPrecMatch inf plain_name new_group `thenM_` + returnM (unitBag (L loc (FunBind { fun_id = sel_name, fun_infix = inf, fun_matches = new_group, + bind_fvs = fvs, fun_co_fn = idCoercion })), + fvs `addOneFV` plain_name) + -- The 'fvs' field isn't used for method binds where - -- Gruesome; bring into scope the correct members of the generic type variables - -- See comments in RnSource.rnSourceDecl(ClassDecl) - rn_match sel_name match@(Match (TypePat ty : _) _ _) + -- Truly gruesome; bring into scope the correct members of the generic + -- type variables. See comments in RnSource.rnSourceDecl(ClassDecl) + rn_match sel_name match@(L _ (Match (L _ (TypePat ty) : _) _ _)) = extendTyVarEnvFVRn gen_tvs $ rnMatch (FunRhs sel_name) match where - tvs = map rdrNameOcc (extractHsTyRdrTyVars ty) + tvs = map (rdrNameOcc.unLoc) (extractHsTyRdrTyVars ty) gen_tvs = [tv | tv <- gen_tyvars, nameOccName tv `elem` tvs] rn_match sel_name match = rnMatch (FunRhs sel_name) match - --- Can't handle method pattern-bindings which bind multiple methods. -rnMethodBinds cls gen_tyvars mbind@(PatMonoBind other_pat _ locn) - = addSrcLoc locn (addErr (methodBindErr mbind)) `thenM_` - returnM (EmptyMonoBinds, emptyFVs) -\end{code} - - -%************************************************************************ -%* * - Strongly connected components - -%* * -%************************************************************************ - -During analysis a @MonoBinds@ is flattened to a @FlatMonoBinds@. -The @RenamedMonoBinds@ is always an empty bind, a pattern binding or -a function binding, and has itself been dependency-analysed and -renamed. - -\begin{code} -type FlatMonoBinds = (Defs, Uses, RenamedMonoBinds, [RenamedSig]) - -- Signatures, if any, for this vertex - -rnSCC :: [FlatMonoBinds] -> [SCC FlatMonoBinds] -rnSCC nodes = stronglyConnComp (mkEdges nodes) - -type VertexTag = Int -mkEdges :: [FlatMonoBinds] -> [(FlatMonoBinds, VertexTag, [VertexTag])] - -- We keep the uses with the binding, - -- so we can track unused bindings better -mkEdges nodes - = [ (thing, tag, dest_vertices uses) - | (thing@(_, uses, _, _), tag) <- tagged_nodes - ] - where - tagged_nodes = nodes `zip` [0::VertexTag ..] - - -- An edge (v,v') indicates that v depends on v' - dest_vertices uses = [ target_vertex - | ((defs, _, _, _), target_vertex) <- tagged_nodes, - defs `intersectsNameSet` uses - ] - -reconstructCycle :: SCC FlatMonoBinds -> (RenamedHsBinds, (Defs,Uses)) -reconstructCycle (AcyclicSCC (defs, uses, binds, sigs)) - = (MonoBind binds sigs NonRecursive, (defs, uses)) -reconstructCycle (CyclicSCC cycle) - = (MonoBind this_gp_binds this_gp_sigs Recursive, - (unionManyNameSets defs_s, unionManyNameSets uses_s)) - where - (defs_s, uses_s, binds_s, sigs_s) = unzip4 cycle - this_gp_binds = foldr1 AndMonoBinds binds_s - this_gp_sigs = foldr1 (++) sigs_s +-- Can't handle method pattern-bindings which bind multiple methods. +rnMethodBind cls gen_tyvars mbind@(L loc (PatBind other_pat _ _ _)) + = addLocErr mbind methodBindErr `thenM_` + returnM (emptyBag, emptyFVs) \end{code} @@ -456,21 +483,35 @@ At the moment we don't gather free-var info from the types in signatures. We'd only need this if we wanted to report unused tyvars. \begin{code} -checkSigs :: (RenamedSig -> Bool) -- OK-sig predicbate - -> [RenamedSig] - -> RnM () -checkSigs ok_sig sigs +renameSigs :: (LSig Name -> Bool) -> [LSig RdrName] -> RnM [LSig Name] +-- Renames the signatures and performs error checks +renameSigs ok_sig sigs + = do { sigs' <- rename_sigs sigs + ; check_sigs ok_sig sigs' + ; return sigs' } + +---------------------- +rename_sigs :: [LSig RdrName] -> RnM [LSig Name] +rename_sigs sigs = mappM (wrapLocM renameSig) + (filter (not . isFixityLSig) sigs) + -- Remove fixity sigs which have been dealt with already + +---------------------- +check_sigs :: (LSig Name -> Bool) -> [LSig Name] -> RnM () +-- Used for class and instance decls, as well as regular bindings +check_sigs ok_sig sigs -- Check for (a) duplicate signatures -- (b) signatures for things not in this group - -- Well, I can't see the check for (a)... ToDo! - = mappM_ unknownSigErr (filter bad sigs) + = do { mappM_ unknownSigErr (filter (not . ok_sig) sigs') + ; mappM_ dupSigDeclErr (findDupsEq eqHsSig sigs') } where - bad sig = not (ok_sig sig) && - case sigName sig of - Just n | isUnboundName n -> False -- Don't complain about an unbound name again - other -> True + -- Don't complain about an unbound name again + sigs' = filterOut bad_name sigs + bad_name sig = case sigName sig of + Just n -> isUnboundName n + other -> False --- We use lookupSigOccRn in the signatures, which is a little bit unsatisfactory +-- We use lookupLocatedSigOccRn in the signatures, which is a little bit unsatisfactory -- because this won't work for: -- instance Foo T where -- {-# INLINE op #-} @@ -479,63 +520,141 @@ checkSigs ok_sig sigs -- is in scope. (I'm assuming that Baz.op isn't in scope unqualified.) -- Doesn't seem worth much trouble to sort this. -renameSigs :: [Sig RdrName] -> RnM [Sig Name] -renameSigs sigs = mappM renameSig (filter (not . isFixitySig) sigs) - -- Remove fixity sigs which have been dealt with already - renameSig :: Sig RdrName -> RnM (Sig Name) -- FixitSig is renamed elsewhere. -renameSig (Sig v ty src_loc) - = addSrcLoc src_loc $ - lookupSigOccRn v `thenM` \ new_v -> +renameSig (TypeSig v ty) + = lookupLocatedSigOccRn v `thenM` \ new_v -> rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty -> - returnM (Sig new_v new_ty src_loc) + returnM (TypeSig new_v new_ty) -renameSig (SpecInstSig ty src_loc) - = addSrcLoc src_loc $ - rnHsType (text "A SPECIALISE instance pragma") ty `thenM` \ new_ty -> - returnM (SpecInstSig new_ty src_loc) +renameSig (SpecInstSig ty) + = rnLHsType (text "A SPECIALISE instance pragma") ty `thenM` \ new_ty -> + returnM (SpecInstSig new_ty) -renameSig (SpecSig v ty src_loc) - = addSrcLoc src_loc $ - lookupSigOccRn v `thenM` \ new_v -> +renameSig (SpecSig v ty inl) + = lookupLocatedSigOccRn v `thenM` \ new_v -> rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty -> - returnM (SpecSig new_v new_ty src_loc) + returnM (SpecSig new_v new_ty inl) -renameSig (InlineSig b v p src_loc) - = addSrcLoc src_loc $ - lookupSigOccRn v `thenM` \ new_v -> - returnM (InlineSig b new_v p src_loc) +renameSig (InlineSig v s) + = lookupLocatedSigOccRn v `thenM` \ new_v -> + returnM (InlineSig new_v s) +\end{code} + + +************************************************************************ +* * +\subsection{Match} +* * +************************************************************************ + +\begin{code} +rnMatchGroup :: HsMatchContext Name -> MatchGroup RdrName -> RnM (MatchGroup Name, FreeVars) +rnMatchGroup ctxt (MatchGroup ms _) + = mapFvRn (rnMatch ctxt) ms `thenM` \ (new_ms, ms_fvs) -> + returnM (MatchGroup new_ms placeHolderType, ms_fvs) + +rnMatch :: HsMatchContext Name -> LMatch RdrName -> RnM (LMatch Name, FreeVars) +rnMatch ctxt = wrapLocFstM (rnMatch' ctxt) + +rnMatch' ctxt match@(Match pats maybe_rhs_sig grhss) + = + -- Deal with the rhs type signature + bindPatSigTyVarsFV rhs_sig_tys $ + doptM Opt_GlasgowExts `thenM` \ opt_GlasgowExts -> + (case maybe_rhs_sig of + Nothing -> returnM (Nothing, emptyFVs) + Just ty | opt_GlasgowExts -> rnHsTypeFVs doc_sig ty `thenM` \ (ty', ty_fvs) -> + returnM (Just ty', ty_fvs) + | otherwise -> addLocErr ty patSigErr `thenM_` + returnM (Nothing, emptyFVs) + ) `thenM` \ (maybe_rhs_sig', ty_fvs) -> + + -- Now the main event + rnPatsAndThen ctxt pats $ \ pats' -> + rnGRHSs ctxt grhss `thenM` \ (grhss', grhss_fvs) -> + + returnM (Match pats' maybe_rhs_sig' grhss', grhss_fvs `plusFV` ty_fvs) + -- The bindPatSigTyVarsFV and rnPatsAndThen will remove the bound FVs + where + rhs_sig_tys = case maybe_rhs_sig of + Nothing -> [] + Just ty -> [ty] + doc_sig = text "In a result type-signature" \end{code} %************************************************************************ %* * +\subsubsection{Guarded right-hand sides (GRHSs)} +%* * +%************************************************************************ + +\begin{code} +rnGRHSs :: HsMatchContext Name -> GRHSs RdrName -> RnM (GRHSs Name, FreeVars) + +rnGRHSs ctxt (GRHSs grhss binds) + = rnLocalBindsAndThen binds $ \ binds' -> + mapFvRn (rnGRHS ctxt) grhss `thenM` \ (grhss', fvGRHSs) -> + returnM (GRHSs grhss' binds', fvGRHSs) + +rnGRHS :: HsMatchContext Name -> LGRHS RdrName -> RnM (LGRHS Name, FreeVars) +rnGRHS ctxt = wrapLocFstM (rnGRHS' ctxt) + +rnGRHS' ctxt (GRHS guards rhs) + = do { opt_GlasgowExts <- doptM Opt_GlasgowExts + ; ((guards', rhs'), fvs) <- rnStmts (PatGuard ctxt) guards $ + rnLExpr rhs + + ; checkM (opt_GlasgowExts || is_standard_guard guards') + (addWarn (nonStdGuardErr guards')) + + ; return (GRHS guards' rhs', fvs) } + where + -- Standard Haskell 1.4 guards are just a single boolean + -- expression, rather than a list of qualifiers as in the + -- Glasgow extension + is_standard_guard [] = True + is_standard_guard [L _ (ExprStmt _ _ _)] = True + is_standard_guard other = False +\end{code} + +%************************************************************************ +%* * \subsection{Error messages} %* * %************************************************************************ \begin{code} -dupSigDeclErr sig sigs - = addSrcLoc loc $ - addErr (vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon, - nest 2 (vcat (map ppr_sig (sig:sigs)))]) +dupSigDeclErr sigs@(L loc sig : _) + = addErrAt loc $ + vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon, + nest 2 (vcat (map ppr_sig sigs))] where - (what_it_is, loc) = hsSigDoc sig - ppr_sig sig = ppr (sigLoc sig) <> colon <+> ppr sig + what_it_is = hsSigDoc sig + ppr_sig (L loc sig) = ppr loc <> colon <+> ppr sig -unknownSigErr sig - = addSrcLoc loc $ - addErr (sep [ptext SLIT("Misplaced") <+> what_it_is <> colon, - ppr sig]) +unknownSigErr (L loc sig) + = addErrAt loc $ + sep [ptext SLIT("Misplaced") <+> what_it_is <> colon, ppr sig] where - (what_it_is, loc) = hsSigDoc sig + what_it_is = hsSigDoc sig missingSigWarn var - = addSrcLoc (nameSrcLoc var) $ - addWarn (sep [ptext SLIT("Definition but no type signature for"), quotes (ppr var)]) + = addWarnAt (mkSrcSpan loc loc) $ + sep [ptext SLIT("Definition but no type signature for"), quotes (ppr var)] + where + loc = nameSrcLoc var -- TODO: make a proper span methodBindErr mbind - = hang (ptext SLIT("Can't handle multiple methods defined by one pattern binding")) - 4 (ppr mbind) + = hang (ptext SLIT("Pattern bindings (except simple variables) not allowed in instance declarations")) + 2 (ppr mbind) + +bindsInHsBootFile mbinds + = hang (ptext SLIT("Bindings in hs-boot files are not allowed")) + 2 (ppr mbinds) + +nonStdGuardErr guards + = hang (ptext SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)")) + 4 (interpp'SP guards) \end{code}