X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnBinds.lhs;h=843f28e41c41dc69f7eb68c6331fa2ca543861c5;hb=29da2cf3011c292bc4261601aff85afb13e24d54;hp=eef7a3fbe3d2c2a4973ed04bf1300562f47433a1;hpb=f36fb2ce821caf594c1db5669dd10ca082f66361;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnBinds.lhs b/ghc/compiler/rename/RnBinds.lhs index eef7a3f..843f28e 100644 --- a/ghc/compiler/rename/RnBinds.lhs +++ b/ghc/compiler/rename/RnBinds.lhs @@ -1,5 +1,5 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[RnBinds]{Renaming and dependency analysis of bindings} @@ -10,38 +10,41 @@ they may be affected by renaming (which isn't fully worked out yet). \begin{code} module RnBinds ( - rnTopBinds, rnTopMonoBinds, - rnMethodBinds, renameSigs, - rnBinds, rnMonoBinds + rnTopBinds, rnBinds, rnBindsAndThen, + rnMethodBinds, renameSigs, checkSigs ) where #include "HsVersions.h" -import {-# SOURCE #-} RnSource ( rnHsSigType ) import HsSyn -import HsBinds ( sigsForMe ) +import HsBinds ( hsSigDoc, eqHsSig ) import RdrHsSyn import RnHsSyn -import RnMonad -import RnExpr ( rnMatch, rnGRHSsAndBinds, rnPat, checkPrecMatch ) -import RnEnv ( bindLocatedLocalsRn, lookupBndrRn, lookupOccRn, lookupGlobalOccRn, - newLocalNames, isUnboundName, warnUnusedBinds +import TcRnMonad +import RnTypes ( rnHsSigType, rnLHsType, rnLPat ) +import RnExpr ( rnMatch, rnGRHSs, checkPrecMatch ) +import RnEnv ( bindLocatedLocalsRn, lookupLocatedBndrRn, + lookupLocatedInstDeclBndr, + lookupLocatedSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV, + bindLocalFixities, + warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn, ) -import CmdLineOpts ( opt_SigsRequired ) -import Digraph ( stronglyConnComp, SCC(..) ) -import Name ( OccName(..), Provenance, - Name, isExportedName, - NameSet, emptyNameSet, mkNameSet, unionNameSets, - minusNameSet, unionManyNameSets, elemNameSet, unitNameSet, nameSetToList - ) -import BasicTypes ( RecFlag(..), TopLevelFlag(..) ) -import Util ( thenCmp, removeDups, panic, panic#, assertPanic ) -import UniqSet ( UniqSet ) -import ListSetOps ( minusList ) -import Bag ( bagToList ) -import UniqFM ( UniqFM ) +import CmdLineOpts ( DynFlag(..) ) +import Digraph ( SCC(..), stronglyConnComp ) +import Name ( Name, nameOccName, nameSrcLoc ) +import NameSet +import PrelNames ( isUnboundName ) +import RdrName ( RdrName, rdrNameOcc ) +import BasicTypes ( RecFlag(..), TopLevelFlag(..), isTopLevel ) +import List ( unzip4 ) +import SrcLoc ( mkSrcSpan, Located(..), unLoc ) +import Bag import Outputable + +import Monad ( foldM ) + +import SrcLoc (getLoc) -- tmp \end{code} -- ToDo: Put the annotations into the monad, so that they arrive in the proper @@ -70,11 +73,6 @@ The vertag tag is a unique @Int@; the tags only need to be unique within one @MonoBinds@, so that unique-Int plumbing is done explicitly (heavy monad machinery not needed). -\begin{code} -type VertexTag = Int -type Cycle = [VertexTag] -type Edge = (VertexTag, VertexTag) -\end{code} %************************************************************************ %* * @@ -105,7 +103,7 @@ a set of variables free in @Exp@ is written @fvExp@ %************************************************************************ %* * -%* analysing polymorphic bindings (HsBinds, Bind, MonoBinds) * +%* analysing polymorphic bindings (HsBindGroup, HsBind) %* * %************************************************************************ @@ -117,7 +115,7 @@ However, non-recursive expressions are currently not expected as \Haskell{} programs, and this code should not be executed. Monomorphic bindings contain information that is returned in a tuple -(a @FlatMonoBindsInfo@) containing: +(a @FlatMonoBinds@) containing: \begin{enumerate} \item @@ -151,282 +149,291 @@ it expects the global environment to contain bindings for the binders %************************************************************************ %* * -%* Top-level bindings +\subsubsection{ Top-level bindings} %* * %************************************************************************ -@rnTopBinds@ assumes that the environment already +@rnTopMonoBinds@ assumes that the environment already contains bindings for the binders of this particular binding. \begin{code} -rnTopBinds :: RdrNameHsBinds -> RnMS s RenamedHsBinds - -rnTopBinds EmptyBinds = returnRn EmptyBinds -rnTopBinds (MonoBind bind sigs _) = rnTopMonoBinds bind sigs - -- The parser doesn't produce other forms +rnTopBinds :: Bag (LHsBind RdrName) + -> [LSig RdrName] + -> RnM ([HsBindGroup Name], DefUses) +-- The binders of the binding are in scope already; +-- the top level scope resolution does that -rnTopMonoBinds EmptyMonoBinds sigs - = returnRn EmptyBinds +rnTopBinds mbinds sigs + = bindPatSigTyVars (collectSigTysFromHsBinds (bagToList 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 -rnTopMonoBinds mbinds sigs - = mapRn lookupBndrRn binder_rdr_names `thenRn` \ binder_names -> - let - binder_set = mkNameSet binder_names - exported_binders = mkNameSet (filter isExportedName binder_names) - in - rn_mono_binds TopLevel - binder_set mbinds sigs `thenRn` \ (new_binds, fv_set) -> - let - unused_binders = binder_set `minusNameSet` (fv_set `unionNameSets` exported_binders) - in - warnUnusedBinds unused_binders `thenRn_` - returnRn new_binds - where - binder_rdr_names = map fst (bagToList (collectMonoBinders mbinds)) + rnBinds TopLevel mbinds sigs \end{code} + %************************************************************************ %* * %* Nested binds %* * %************************************************************************ -@rnMonoBinds@ - - collects up the binders for this declaration group, - - checks that they form a set - - extends the environment to bind them to new local names - - calls @rnMonoBinds@ to do the real work - \begin{code} -rnBinds :: RdrNameHsBinds - -> (RenamedHsBinds -> RnMS s (result, FreeVars)) - -> RnMS s (result, FreeVars) - -rnBinds EmptyBinds thing_inside = thing_inside EmptyBinds -rnBinds (MonoBind bind sigs _) thing_inside = rnMonoBinds bind sigs thing_inside - -- the parser doesn't produce other forms +rnBindsAndThen :: Bag (LHsBind RdrName) + -> [LSig RdrName] + -> ([HsBindGroup Name] -> RnM (result, FreeVars)) + -> RnM (result, FreeVars) + +rnBindsAndThen 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 (collectSigTysFromHsBinds (bagToList mbinds)) $ + -- Then install local fixity declarations + -- Notice that they scope over thing_inside too + bindLocalFixities [sig | L _ (FixSig sig) <- sigs ] $ -rnMonoBinds :: RdrNameMonoBinds -> [RdrNameSig] - -> (RenamedHsBinds -> RnMS s (result, FreeVars)) - -> RnMS s (result, FreeVars) + -- Do the business + rnBinds NotTopLevel mbinds sigs `thenM` \ (binds, bind_dus) -> -rnMonoBinds EmptyMonoBinds sigs thing_inside = thing_inside EmptyBinds + -- Now do the "thing inside" + thing_inside binds `thenM` \ (result,result_fvs) -> -rnMonoBinds mbinds sigs thing_inside -- Non-empty monobinds - = -- Extract all the binders in this group, - -- and extend current scope, inventing new names for the new binders - -- This also checks that the names form a set - bindLocatedLocalsRn (text "binding group") mbinders_w_srclocs $ \ new_mbinders -> + -- Final error checking let - binder_set = mkNameSet new_mbinders + all_uses = duUses bind_dus `plusFV` result_fvs + bndrs = duDefs bind_dus + unused_bndrs = nameSetToList (bndrs `minusNameSet` all_uses) in - rn_mono_binds NotTopLevel - binder_set mbinds sigs `thenRn` \ (binds,bind_fvs) -> - - -- Now do the "thing inside", and deal with the free-variable calculations - thing_inside binds `thenRn` \ (result,result_fvs) -> - let - all_fvs = result_fvs `unionNameSets` bind_fvs - net_fvs = all_fvs `minusNameSet` binder_set - unused_binders = binder_set `minusNameSet` all_fvs - in - warnUnusedBinds unused_binders `thenRn_` - returnRn (result, net_fvs) + 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: + -- 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 where - mbinders_w_srclocs = bagToList (collectMonoBinders mbinds) + mbinders_w_srclocs = collectHsBindLocatedBinders mbinds + doc = text "In the binding group for:" + <+> pprWithCommas ppr (map unLoc mbinders_w_srclocs) \end{code} %************************************************************************ %* * -%* MonoBinds -- the main work is done here +\subsubsection{rnBinds -- the main work is done here} %* * %************************************************************************ -@rnMonoBinds@ is used by *both* top-level and nested bindings. It -assumes that all variables bound in this group are already in scope. -This is done *either* by pass 3 (for the top-level bindings), *or* by -@rnNestedMonoBinds@ (for the nested ones). +@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). \begin{code} -rn_mono_binds :: TopLevelFlag - -> NameSet -- Binders of this group - -> RdrNameMonoBinds - -> [RdrNameSig] -- Signatures attached to this group - -> RnMS s (RenamedHsBinds, -- - FreeVars) -- Free variables - -rn_mono_binds top_lev binders mbinds sigs - = - -- Rename the bindings, returning a MonoBindsInfo +rnBinds :: TopLevelFlag + -> Bag (LHsBind RdrName) + -> [LSig RdrName] + -> RnM ([HsBindGroup Name], DefUses) + +-- Assumes the binders of the binding are in scope already + +rnBinds top_lvl mbinds sigs + = renameSigs sigs `thenM` \ siglist -> + + -- Rename the bindings, returning a [HsBindVertex] -- which is a list of indivisible vertices so far as -- the strongly-connected-components (SCC) analysis is concerned - renameSigs top_lev False binders sigs `thenRn` \ siglist -> - flattenMonoBinds siglist mbinds `thenRn` \ mbinds_info -> + mkBindVertices siglist mbinds `thenM` \ mbinds_info -> -- Do the SCC analysis - let edges = mkEdges (mbinds_info `zip` [(0::Int)..]) - scc_result = stronglyConnComp edges - final_binds = foldr1 ThenBinds (map reconstructCycle scc_result) - - -- Deal with bound and free-var calculation - rhs_fvs = unionManyNameSets [fvs | (_,fvs,_,_) <- mbinds_info] + let + scc_result = rnSCC mbinds_info + (groups, bind_dus_s) = unzip (map reconstructCycle scc_result) + bind_dus = mkDUs bind_dus_s + binders = duDefs bind_dus in - returnRn (final_binds, rhs_fvs) + -- 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 = [ unLoc n | L _ (Sig n _) <- siglist] + un_sigd_binders = filter (not . (`elem` type_sig_vars)) + (nameSetToList binders) + in + mappM_ missingSigWarn un_sigd_binders + else + returnM () + ) `thenM_` + + returnM (groups, bind_dus `plusDU` usesOnly (hsSigsFVs siglist)) \end{code} -@flattenMonoBinds@ is ever-so-slightly magical in that it sticks +@mkBindVertices@ is ever-so-slightly magical in that it sticks unique ``vertex tags'' on its output; minor plumbing required. \begin{code} -flattenMonoBinds :: [RenamedSig] -- Signatures - -> RdrNameMonoBinds - -> RnMS s [FlatMonoBindsInfo] - -flattenMonoBinds sigs EmptyMonoBinds = returnRn [] +mkBindVertices :: [LSig Name] -- Signatures + -> Bag (LHsBind RdrName) + -> RnM [BindVertex] +mkBindVertices sigs = mapM (mkBindVertex sigs) . bagToList -flattenMonoBinds sigs (AndMonoBinds bs1 bs2) - = flattenMonoBinds sigs bs1 `thenRn` \ flat1 -> - flattenMonoBinds sigs bs2 `thenRn` \ flat2 -> - returnRn (flat1 ++ flat2) - -flattenMonoBinds sigs (PatMonoBind pat grhss_and_binds locn) - = pushSrcLocRn locn $ - rnPat pat `thenRn` \ pat' -> - rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', fvs) -> +mkBindVertex :: [LSig Name] -> LHsBind RdrName -> RnM BindVertex +mkBindVertex sigs (L loc (PatBind pat grhss)) + = addSrcSpan loc $ + rnLPat pat `thenM` \ (pat', pat_fvs) -> -- Find which things are bound in this group let names_bound_here = mkNameSet (collectPatBinders pat') - sigs_for_me = sigsForMe (`elemNameSet` names_bound_here) sigs - sigs_fvs = foldr sig_fv emptyNameSet sigs_for_me in - returnRn - [(names_bound_here, - fvs `unionNameSets` sigs_fvs, - PatMonoBind pat' grhss_and_binds' locn, - sigs_for_me - )] - -flattenMonoBinds sigs (FunMonoBind name inf matches locn) - = pushSrcLocRn locn $ - mapRn (checkPrecMatch inf name) matches `thenRn_` - lookupBndrRn name `thenRn` \ name' -> - mapAndUnzipRn rnMatch matches `thenRn` \ (new_matches, fv_lists) -> + sigsForMe names_bound_here sigs `thenM` \ sigs_for_me -> + rnGRHSs PatBindRhs grhss `thenM` \ (grhss', fvs) -> + returnM + (names_bound_here, fvs `plusFV` pat_fvs, + L loc (PatBind pat' grhss'), sigs_for_me + ) + +mkBindVertex sigs (L loc (FunBind name inf matches)) + = addSrcSpan loc $ + lookupLocatedBndrRn name `thenM` \ new_name -> let - fvs = unionManyNameSets fv_lists - sigs_for_me = sigsForMe (name' ==) sigs - sigs_fvs = foldr sig_fv emptyNameSet sigs_for_me + plain_name = unLoc new_name + names_bound_here = unitNameSet plain_name in - returnRn - [(unitNameSet name', - fvs `unionNameSets` sigs_fvs, - FunMonoBind name' inf new_matches locn, - sigs_for_me - )] + sigsForMe names_bound_here sigs `thenM` \ sigs_for_me -> + mapFvRn (rnMatch (FunRhs plain_name)) matches `thenM` \ (new_matches, fvs) -> + mappM_ (checkPrecMatch inf plain_name) new_matches `thenM_` + returnM + (unitNameSet plain_name, fvs, + L loc (FunBind new_name inf new_matches), sigs_for_me + ) + +sigsForMe names_bound_here sigs + = foldlM check [] (filter (sigForThisGroup names_bound_here) sigs) + where + -- sigForThisGroup only returns signatures for + -- which sigName returns a Just + eq sig1 sig2 = eqHsSig (unLoc sig1) (unLoc sig2) + + check sigs sig = case filter (eq sig) sigs of + [] -> returnM (sig:sigs) + other -> dupSigDeclErr sig other `thenM_` + returnM sigs \end{code} -@rnMethodBinds@ is used for the method bindings of an instance -declaration. like @rnMonoBinds@ but without dependency analysis. - -\begin{code} -rnMethodBinds :: RdrNameMonoBinds -> RnMS s RenamedMonoBinds - -rnMethodBinds EmptyMonoBinds = returnRn EmptyMonoBinds - -rnMethodBinds (AndMonoBinds mb1 mb2) - = andRn AndMonoBinds (rnMethodBinds mb1) - (rnMethodBinds mb2) +@rnMethodBinds@ is used for the method bindings of a class and an instance +declaration. Like @rnBinds@ but without dependency analysis. -rnMethodBinds (FunMonoBind name inf matches locn) - = pushSrcLocRn locn $ - mapRn (checkPrecMatch inf name) matches `thenRn_` +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: +\begin{verbatim} + instance Foo (T a) where + op x = ... +\end{verbatim} +This might be the {\em sole} occurrence of @op@ for an imported class @Foo@, +and unless @op@ occurs we won't treat the type signature of @op@ in the class +decl for @Foo@ as a source of instance-decl gates. But we should! Indeed, +in many ways the @op@ in an instance decl is just like an occurrence, not +a binder. - lookupGlobalOccRn name `thenRn` \ sel_name -> +\begin{code} +rnMethodBinds :: Name -- Class name + -> [Name] -- Names for generic type variables + -> (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 name inf matches)) + = addSrcSpan loc $ + lookupLocatedInstDeclBndr cls name `thenM` \ sel_name -> + let plain_name = unLoc sel_name in -- We use the selector name as the binder - mapAndUnzipRn rnMatch matches `thenRn` \ (new_matches, _) -> - returnRn (FunMonoBind sel_name inf new_matches locn) + mapFvRn (rn_match plain_name) matches `thenM` \ (new_matches, fvs) -> + mappM_ (checkPrecMatch inf plain_name) new_matches `thenM_` + returnM (unitBag (L loc (FunBind sel_name inf new_matches)), fvs `addOneFV` plain_name) + where + -- 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.unLoc) (extractHsTyRdrTyVars ty) + gen_tvs = [tv | tv <- gen_tyvars, nameOccName tv `elem` tvs] + + rn_match sel_name match = rnMatch (FunRhs sel_name) match -rnMethodBinds (PatMonoBind (VarPatIn name) grhss_and_binds locn) - = pushSrcLocRn locn $ - lookupGlobalOccRn name `thenRn` \ sel_name -> - rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', _) -> - returnRn (PatMonoBind (VarPatIn sel_name) grhss_and_binds' locn) -- Can't handle method pattern-bindings which bind multiple methods. -rnMethodBinds mbind@(PatMonoBind other_pat _ locn) - = pushSrcLocRn locn $ - failWithRn EmptyMonoBinds (methodBindErr mbind) +rnMethodBind cls gen_tyvars mbind@(L loc (PatBind other_pat _)) + = addLocErr mbind methodBindErr `thenM_` + returnM (emptyBag, emptyFVs) \end{code} -\begin{code} --- If a SPECIALIZE pragma is of the "... = blah" form, --- then we'd better make sure "blah" is taken into --- acct in the dependency analysis (or we get an --- unexpected out-of-scope error)! WDP 95/07 - -sig_fv (SpecSig _ _ (Just blah) _) acc = acc `unionNameSets` (unitNameSet blah) -sig_fv _ acc = acc -\end{code} %************************************************************************ %* * -\subsection[reconstruct-deps]{Reconstructing dependencies} + Strongly connected components %* * %************************************************************************ -This @MonoBinds@- and @ClassDecls@-specific code is segregated here, -as the two cases are similar. - \begin{code} -reconstructCycle :: SCC FlatMonoBindsInfo - -> RenamedHsBinds - -reconstructCycle (AcyclicSCC (_, _, binds, sigs)) - = MonoBind binds sigs NonRecursive - -reconstructCycle (CyclicSCC cycle) - = MonoBind this_gp_binds this_gp_sigs Recursive - where - this_gp_binds = foldr1 AndMonoBinds [binds | (_, _, binds, _) <- cycle] - this_gp_sigs = foldr1 (++) [sigs | (_, _, _, sigs) <- cycle] -\end{code} +type BindVertex = (Defs, Uses, LHsBind Name, [LSig Name]) + -- Signatures, if any, for this vertex -%************************************************************************ -%* * -%* Manipulating FlatMonoBindInfo * -%* * -%************************************************************************ +rnSCC :: [BindVertex] -> [SCC BindVertex] +rnSCC nodes = stronglyConnComp (mkEdges nodes) -During analysis a @MonoBinds@ is flattened to a @FlatMonoBindsInfo@. -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 FlatMonoBindsInfo - = (NameSet, -- Set of names defined in this vertex - NameSet, -- Set of names used in this vertex - RenamedMonoBinds, - [RenamedSig]) -- Signatures, if any, for this vertex - -mkEdges :: [(FlatMonoBindsInfo, VertexTag)] -> [(FlatMonoBindsInfo, VertexTag, [VertexTag])] +type VertexTag = Int -mkEdges flat_info - = [ (info, tag, dest_vertices (nameSetToList names_used)) - | (info@(names_defined, names_used, mbind, sigs), tag) <- flat_info +mkEdges :: [BindVertex] -> [(BindVertex, 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 src_mentions = [ target_vertex - | ((names_defined, _, _, _), target_vertex) <- flat_info, - mentioned_name <- src_mentions, - mentioned_name `elemNameSet` names_defined - ] + dest_vertices uses = [ target_vertex + | ((defs, _, _, _), target_vertex) <- tagged_nodes, + defs `intersectsNameSet` uses + ] + +reconstructCycle :: SCC BindVertex -> (HsBindGroup Name, (Defs,Uses)) +reconstructCycle (AcyclicSCC (defs, uses, bind, sigs)) + = (HsBindGroup (unitBag bind) sigs NonRecursive, (defs, uses)) +reconstructCycle (CyclicSCC cycle) + = (HsBindGroup 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 = listToBag binds_s + this_gp_sigs = foldr1 (++) sigs_s \end{code} @@ -436,104 +443,66 @@ mkEdges flat_info %* * %************************************************************************ -@renameSigs@ checks for: (a)~more than one sig for one thing; -(b)~signatures given for things not bound here; (c)~with suitably -flaggery, that all top-level things have type signatures. +@renameSigs@ checks for: +\begin{enumerate} +\item more than one sig for one thing; +\item signatures given for things not bound here; +\item with suitably flaggery, that all top-level things have type signatures. +\end{enumerate} +% +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} -renameSigs :: TopLevelFlag - -> Bool -- True <-> sigs for an instance decl - -- hence SPECIALISE instance prags ok - -> NameSet -- Set of names bound in this group - -> [RdrNameSig] - -> RnMS s [RenamedSig] -- List of Sig constructors - -renameSigs top_lev inst_decl binders sigs - = -- Rename the signatures - mapRn renameSig sigs `thenRn` \ sigs' -> - +checkSigs :: (LSig Name -> Bool) -- OK-sig predicbate + -> [LSig Name] + -> RnM () +checkSigs ok_sig sigs -- Check for (a) duplicate signatures -- (b) signatures for things not in this group - -- (c) optionally, bindings with no signature - let - (goodies, dups) = removeDups cmp_sig (sigsForMe (not . isUnboundName) sigs') - not_this_group = sigsForMe (not . (`elemNameSet` binders)) goodies - spec_inst_sigs = [s | s@(SpecInstSig _ _) <- goodies] - type_sig_vars = [n | Sig n _ _ <- goodies] - sigs_required = case top_lev of {TopLevel -> opt_SigsRequired; NotTopLevel -> False} - un_sigd_binders | sigs_required = nameSetToList binders `minusList` type_sig_vars - | otherwise = [] - in - mapRn dupSigDeclErr dups `thenRn_` - mapRn unknownSigErr not_this_group `thenRn_` - (if not inst_decl then - mapRn unknownSigErr spec_inst_sigs - else - returnRn [] - ) `thenRn_` - mapRn (addErrRn.missingSigErr) un_sigd_binders `thenRn_` - - returnRn sigs' -- bad ones and all: - -- we need bindings of *some* sort for every name - - -renameSig (Sig v ty src_loc) - = pushSrcLocRn src_loc $ - lookupBndrRn v `thenRn` \ new_v -> - rnHsSigType (quotes (ppr v)) ty `thenRn` \ new_ty -> - returnRn (Sig new_v new_ty src_loc) - -renameSig (SpecInstSig ty src_loc) - = pushSrcLocRn src_loc $ - rnHsSigType (text "A SPECIALISE instance pragma") ty `thenRn` \ new_ty -> - returnRn (SpecInstSig new_ty src_loc) - -renameSig (SpecSig v ty using src_loc) - = pushSrcLocRn src_loc $ - lookupBndrRn v `thenRn` \ new_v -> - rnHsSigType (quotes (ppr v)) ty `thenRn` \ new_ty -> - rn_using using `thenRn` \ new_using -> - returnRn (SpecSig new_v new_ty new_using src_loc) + -- Well, I can't see the check for (a)... ToDo! + = mappM_ unknownSigErr (filter bad sigs) where - rn_using Nothing = returnRn Nothing - rn_using (Just x) = lookupOccRn x `thenRn` \ new_x -> - returnRn (Just new_x) - -renameSig (InlineSig v src_loc) - = pushSrcLocRn src_loc $ - lookupBndrRn v `thenRn` \ new_v -> - returnRn (InlineSig new_v src_loc) - -renameSig (NoInlineSig v src_loc) - = pushSrcLocRn src_loc $ - lookupBndrRn v `thenRn` \ new_v -> - returnRn (NoInlineSig new_v src_loc) + 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 + +-- We use lookupSigOccRn in the signatures, which is a little bit unsatisfactory +-- because this won't work for: +-- instance Foo T where +-- {-# INLINE op #-} +-- Baz.op = ... +-- We'll just rename the INLINE prag to refer to whatever other 'op' +-- is in scope. (I'm assuming that Baz.op isn't in scope unqualified.) +-- Doesn't seem worth much trouble to sort this. + +renameSigs :: [LSig RdrName] -> RnM [LSig Name] +renameSigs sigs = mappM (wrapLocM renameSig) (filter (not . isFixitySig . unLoc) sigs) + -- Remove fixity sigs which have been dealt with already + +renameSig :: Sig RdrName -> RnM (Sig Name) +-- FixitSig is renamed elsewhere. +renameSig (Sig v ty) + = lookupLocatedSigOccRn v `thenM` \ new_v -> + rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty -> + returnM (Sig new_v new_ty) + +renameSig (SpecInstSig ty) + = rnLHsType (text "A SPECIALISE instance pragma") ty `thenM` \ new_ty -> + returnM (SpecInstSig new_ty) + +renameSig (SpecSig v ty) + = lookupLocatedSigOccRn v `thenM` \ new_v -> + rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty -> + returnM (SpecSig new_v new_ty) + +renameSig (InlineSig b v p) + = lookupLocatedSigOccRn v `thenM` \ new_v -> + returnM (InlineSig b new_v p) \end{code} -Checking for distinct signatures; oh, so boring - -\begin{code} -cmp_sig :: RenamedSig -> RenamedSig -> Ordering -cmp_sig (Sig n1 _ _) (Sig n2 _ _) = n1 `compare` n2 -cmp_sig (InlineSig n1 _) (InlineSig n2 _) = n1 `compare` n2 -cmp_sig (NoInlineSig n1 _) (NoInlineSig n2 _) = n1 `compare` n2 -cmp_sig (SpecInstSig ty1 _) (SpecInstSig ty2 _) = cmpHsType compare ty1 ty2 -cmp_sig (SpecSig n1 ty1 _ _) (SpecSig n2 ty2 _ _) - = -- may have many specialisations for one value; - -- but not ones that are exactly the same... - thenCmp (n1 `compare` n2) (cmpHsType compare ty1 ty2) - -cmp_sig other_1 other_2 -- Tags *must* be different - | (sig_tag other_1) _LT_ (sig_tag other_2) = LT - | otherwise = GT - -sig_tag (Sig n1 _ _) = (ILIT(1) :: FAST_INT) -sig_tag (SpecSig n1 _ _ _) = ILIT(2) -sig_tag (InlineSig n1 _) = ILIT(3) -sig_tag (NoInlineSig n1 _) = ILIT(4) -sig_tag (SpecInstSig _ _) = ILIT(5) -sig_tag _ = panic# "tag(RnBinds)" -\end{code} %************************************************************************ %* * @@ -542,31 +511,25 @@ sig_tag _ = panic# "tag(RnBinds)" %************************************************************************ \begin{code} -dupSigDeclErr (sig:sigs) - = pushSrcLocRn loc $ - addErrRn (sep [ptext SLIT("Duplicate"), - ptext what_it_is <> colon, - ppr sig]) +dupSigDeclErr (L loc sig) sigs + = addErrAt loc $ + vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon, + nest 2 (vcat (map ppr_sig (L loc sig:sigs)))] where - (what_it_is, loc) = sig_doc sig + what_it_is = hsSigDoc sig + ppr_sig (L loc sig) = ppr loc <> colon <+> ppr sig -unknownSigErr sig - = pushSrcLocRn loc $ - addErrRn (sep [ptext SLIT("Misplaced"), - ptext 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) = sig_doc sig - -sig_doc (Sig _ _ loc) = (SLIT("type signature"),loc) -sig_doc (ClassOpSig _ _ _ loc) = (SLIT("class-method type signature"), loc) -sig_doc (SpecSig _ _ _ loc) = (SLIT("SPECIALISE pragma"),loc) -sig_doc (InlineSig _ loc) = (SLIT("INLINE pragma"),loc) -sig_doc (NoInlineSig _ loc) = (SLIT("NOINLINE pragma"),loc) -sig_doc (SpecInstSig _ loc) = (SLIT("SPECIALISE instance pragma"),loc) + what_it_is = hsSigDoc sig -missingSigErr var - = sep [ptext SLIT("Definition but no type signature for"), quotes (ppr var)] +missingSigWarn 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"))