X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnBinds.lhs;h=9f7e690707cea9a1efcb5f78e2bbc52adaed998d;hb=8fc898cb0b722e72c08dce3acadbc4b2aa2249ff;hp=070abdaf61342d4f335384021e9cb217b36fb778;hpb=2b0496812b16d3ce91c02455e497cb5eae5e397d;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnBinds.lhs b/ghc/compiler/rename/RnBinds.lhs index 070abda..9f7e690 100644 --- a/ghc/compiler/rename/RnBinds.lhs +++ b/ghc/compiler/rename/RnBinds.lhs @@ -10,33 +10,34 @@ they may be affected by renaming (which isn't fully worked out yet). \begin{code} module RnBinds ( - rnTopMonoBinds, rnMonoBinds, rnMethodBinds, - renameSigs, renameSigsFVs, unknownSigErr + rnTopMonoBinds, rnMonoBinds, rnMonoBindsAndThen, + rnMethodBinds, renameSigs, checkSigs, unknownSigErr ) where #include "HsVersions.h" import HsSyn -import HsBinds ( eqHsSig, sigName, hsSigDoc ) +import HsBinds ( hsSigDoc, sigLoc, eqHsSig ) import RdrHsSyn import RnHsSyn import TcRnMonad -import RnTypes ( rnHsSigType, rnHsType ) -import RnExpr ( rnMatch, rnGRHSs, rnPat, checkPrecMatch ) +import RnTypes ( rnHsSigType, rnHsType, rnPat ) +import RnExpr ( rnMatch, rnGRHSs, checkPrecMatch ) import RnEnv ( bindLocatedLocalsRn, lookupBndrRn, lookupInstDeclBndr, - lookupSigOccRn, bindPatSigTyVars, bindLocalFixities, + lookupSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV, + bindLocalFixities, warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn, ) import CmdLineOpts ( DynFlag(..) ) -import Digraph ( stronglyConnComp, SCC(..) ) +import Digraph ( SCC(..), stronglyConnComp ) import Name ( Name, nameOccName, nameSrcLoc ) import NameSet +import PrelNames ( isUnboundName ) import RdrName ( RdrName, rdrNameOcc ) -import BasicTypes ( RecFlag(..), FixitySig(..) ) -import List ( partition ) +import BasicTypes ( RecFlag(..), TopLevelFlag(..), isTopLevel ) +import List ( unzip4 ) import Outputable -import PrelNames ( isUnboundName ) \end{code} -- ToDo: Put the annotations into the monad, so that they arrive in the proper @@ -65,9 +66,6 @@ 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 -\end{code} %************************************************************************ %* * @@ -110,7 +108,7 @@ 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 @@ -152,89 +150,72 @@ 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) + +-- The binders of the binding are in scope already; +-- the top level scope resolution does that + rnTopMonoBinds mbinds sigs - = mappM lookupBndrRn binder_rdr_names `thenM` \ binder_names -> - bindPatSigTyVars (collectSigTysFromMonoBinds mbinds) $ - let - bndr_name_set = mkNameSet binder_names - in - renameSigsFVs (okBindSig bndr_name_set) sigs `thenM` \ (siglist, sig_fvs) -> - - -- Warn about missing signatures, but not in interface mode - -- (This is important when renaming bindings from 'deriving' clauses.) - getModeRn `thenM` \ mode -> - doptM Opt_WarnMissingSigs `thenM` \ warn_missing_sigs -> - (if warn_missing_sigs && not (isInterfaceMode mode) then - let - type_sig_vars = [n | Sig n _ _ <- siglist] - un_sigd_binders = nameSetToList (delListFromNameSet bndr_name_set type_sig_vars) - in - mappM_ missingSigWarn un_sigd_binders - else - returnM () - ) `thenM_` + = 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 - rn_mono_binds siglist mbinds `thenM` \ (final_binds, bind_fvs) -> - returnM (final_binds, bind_fvs `plusFV` sig_fvs) - where - binder_rdr_names = collectMonoBinders mbinds + rnMonoBinds TopLevel mbinds sigs \end{code} + %************************************************************************ %* * %* Nested binds %* * %************************************************************************ -\subsubsection{Nested binds} - -@rnMonoBinds@ -\begin{itemize} -\item collects up the binders for this declaration group, -\item checks that they form a set -\item extends the environment to bind them to new local names -\item calls @rnMonoBinds@ to do the real work -\end{itemize} -% \begin{code} -rnMonoBinds :: RdrNameMonoBinds - -> [RdrNameSig] - -> (RenamedHsBinds -> RnM (result, FreeVars)) - -> RnM (result, FreeVars) - -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 +rnMonoBindsAndThen :: RdrNameMonoBinds + -> [RdrNameSig] + -> (RenamedHsBinds -> RnM (result, FreeVars)) + -> RnM (result, FreeVars) + +rnMonoBindsAndThen mbinds sigs thing_inside -- Non-empty monobinds + = -- 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 $ \ new_mbinders -> - bindPatSigTyVars (collectSigTysFromMonoBinds mbinds) $ - let - binder_set = mkNameSet new_mbinders - in - -- Rename the signatures - renameSigsFVs (okBindSig binder_set) sigs `thenM` \ (siglist, sig_fvs) -> + bindLocatedLocalsRn doc mbinders_w_srclocs $ \ _ -> + bindPatSigTyVarsFV (collectSigTysFromMonoBinds mbinds) $ - -- Report the fixity declarations in this group that - -- don't refer to any of the group's binders. - -- Then install the fixity declarations that do apply here + -- Then install local fixity declarations -- Notice that they scope over thing_inside too - bindLocalFixities [sig | FixSig sig <- siglist ] $ + bindLocalFixities [sig | FixSig sig <- sigs ] $ - rn_mono_binds siglist mbinds `thenM` \ (binds, bind_fvs) -> + -- Do the business + rnMonoBinds NotTopLevel mbinds sigs `thenM` \ (binds, bind_dus) -> - -- Now do the "thing inside", and deal with the free-variable calculations - thing_inside binds `thenM` \ (result,result_fvs) -> + -- Now do the "thing inside" + thing_inside binds `thenM` \ (result,result_fvs) -> + + -- Final error checking let - all_fvs = result_fvs `plusFV` bind_fvs `plusFV` sig_fvs - unused_binders = nameSetToList (binder_set `minusNameSet` all_fvs) + all_uses = duUses bind_dus `plusFV` result_fvs + bndrs = duDefs bind_dus + unused_bndrs = nameSetToList (bndrs `minusNameSet` all_uses) in - warnUnusedLocalBinds unused_binders `thenM_` - returnM (result, delListFromNameSet all_fvs new_mbinders) + 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 = collectLocatedMonoBinders mbinds - doc = text "In the binding group for" <+> pp_bndrs mbinders_w_srclocs - pp_bndrs [(b,_)] = quotes (ppr b) - pp_bndrs bs = fsep (punctuate comma [ppr b | (b,_) <- bs]) + doc = text "In the binding group for:" + <+> pprWithCommas ppr (map fst mbinders_w_srclocs) \end{code} @@ -244,46 +225,64 @@ rnMonoBinds mbinds sigs thing_inside -- Non-empty monobinds %* * %************************************************************************ -@rn_mono_binds@ is used by {\em both} top-level and nested bindings. +@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 :: [RenamedSig] -- Signatures attached to this group - -> RdrNameMonoBinds - -> RnM (RenamedHsBinds, -- Dependency analysed - FreeVars) -- Free variables - -rn_mono_binds siglist mbinds - = - -- Rename the bindings, returning a MonoBindsInfo +rnMonoBinds :: TopLevelFlag + -> RdrNameMonoBinds + -> [RdrNameSig] + -> RnM (RenamedHsBinds, DefUses) + +-- Assumes the binders of the binding are in scope already + +rnMonoBinds top_lvl mbinds sigs + = renameSigs sigs `thenM` \ siglist -> + + -- 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 -> + flattenMonoBinds siglist mbinds `thenM` \ mbinds_info -> -- Do the SCC analysis let - edges = mkEdges (mbinds_info `zip` [(0::Int)..]) - scc_result = stronglyConnComp edges - final_binds = foldr (ThenBinds . reconstructCycle) EmptyBinds scc_result - - -- Deal with bound and free-var calculation - rhs_fvs = plusFVs [fvs | (_,fvs,_,_) <- mbinds_info] + 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 - returnM (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 = [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. -Sigh --- need to pass along the signatures for the group of bindings, -in case any of them \fbox{\ ???\ } - \begin{code} flattenMonoBinds :: [RenamedSig] -- Signatures -> RdrNameMonoBinds - -> RnM [FlatMonoBindsInfo] + -> RnM [FlatMonoBinds] flattenMonoBinds sigs EmptyMonoBinds = returnM [] @@ -301,13 +300,11 @@ flattenMonoBinds sigs (PatMonoBind pat grhss locn) names_bound_here = mkNameSet (collectPatBinders pat') in sigsForMe names_bound_here sigs `thenM` \ sigs_for_me -> - rnGRHSs grhss `thenM` \ (grhss', fvs) -> + rnGRHSs PatBindRhs grhss `thenM` \ (grhss', fvs) -> returnM - [(names_bound_here, - fvs `plusFV` pat_fvs, - PatMonoBind pat' grhss' locn, - sigs_for_me - )] + [(names_bound_here, fvs `plusFV` pat_fvs, + PatMonoBind pat' grhss' locn, sigs_for_me + )] flattenMonoBinds sigs (FunMonoBind name inf matches locn) = addSrcLoc locn $ @@ -316,22 +313,21 @@ flattenMonoBinds sigs (FunMonoBind name inf matches locn) names_bound_here = unitNameSet new_name in sigsForMe names_bound_here sigs `thenM` \ sigs_for_me -> - mapFvRn (rnMatch (FunRhs name)) matches `thenM` \ (new_matches, fvs) -> + 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 - )] - + [(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) 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 `thenM_` + other -> dupSigDeclErr sig other `thenM_` returnM sigs \end{code} @@ -370,19 +366,20 @@ rnMethodBinds cls gen_tyvars (FunMonoBind name inf matches locn) lookupInstDeclBndr cls name `thenM` \ sel_name -> -- We use the selector name as the binder - mapFvRn rn_match matches `thenM` \ (new_matches, fvs) -> + 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) where -- Gruesome; bring into scope the correct members of the generic type variables -- See comments in RnSource.rnSourceDecl(ClassDecl) - rn_match match@(Match (TypePat ty : _) _ _) - = extendTyVarEnvFVRn gen_tvs (rnMatch (FunRhs name) match) + rn_match sel_name match@(Match (TypePat ty : _) _ _) + = extendTyVarEnvFVRn gen_tvs $ + rnMatch (FunRhs sel_name) match where - tvs = map rdrNameOcc (extractHsTyRdrNames ty) + tvs = map rdrNameOcc (extractHsTyRdrTyVars ty) gen_tvs = [tv | tv <- gen_tyvars, nameOccName tv `elem` tvs] - rn_match match = rnMatch (FunRhs name) match + rn_match sel_name match = rnMatch (FunRhs sel_name) match -- Can't handle method pattern-bindings which bind multiple methods. @@ -394,58 +391,51 @@ rnMethodBinds cls gen_tyvars mbind@(PatMonoBind other_pat _ locn) %************************************************************************ %* * -\subsection[reconstruct-deps]{Reconstructing dependencies} -%* * -%************************************************************************ - -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 + Strongly connected components -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} - -%************************************************************************ -%* * -\subsubsection{ Manipulating FlatMonoBindInfo} %* * %************************************************************************ -During analysis a @MonoBinds@ is flattened to a @FlatMonoBindsInfo@. +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 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 +type FlatMonoBinds = (Defs, Uses, RenamedMonoBinds, [RenamedSig]) + -- Signatures, if any, for this vertex -mkEdges :: [(FlatMonoBindsInfo, VertexTag)] -> [(FlatMonoBindsInfo, VertexTag, [VertexTag])] +rnSCC :: [FlatMonoBinds] -> [SCC FlatMonoBinds] +rnSCC nodes = stronglyConnComp (mkEdges nodes) + +type VertexTag = Int -mkEdges flat_info - = [ (info, tag, dest_vertices (nameSetToList names_used)) - | (info@(names_defined, names_used, mbind, sigs), tag) <- flat_info +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 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 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 \end{code} @@ -466,31 +456,19 @@ 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} -renameSigsFVs ok_sig sigs - = renameSigs ok_sig sigs `thenM` \ sigs' -> - returnM (sigs', hsSigsFVs sigs') - -renameSigs :: (RenamedSig -> Bool) -- OK-sig predicate - -> [RdrNameSig] - -> RnM [RenamedSig] - -renameSigs ok_sig [] = returnM [] - -renameSigs ok_sig sigs - = -- Rename the signatures - mappM renameSig sigs `thenM` \ sigs' -> - +checkSigs :: (RenamedSig -> Bool) -- OK-sig predicbate + -> [RenamedSig] + -> RnM () +checkSigs ok_sig sigs -- Check for (a) duplicate signatures -- (b) signatures for things not in this group - let - in_scope = filter is_in_scope sigs' - is_in_scope sig = case sigName sig of - Just n -> not (isUnboundName n) - Nothing -> True - (goods, bads) = partition ok_sig in_scope - in - mappM_ unknownSigErr bads `thenM_` - returnM goods + -- Well, I can't see the check for (a)... ToDo! + = mappM_ unknownSigErr (filter bad 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 -- We use lookupSigOccRn in the signatures, which is a little bit unsatisfactory -- because this won't work for: @@ -501,8 +479,12 @@ renameSigs 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) --- ClassOpSig is renamed elsewhere. +-- FixitSig is renamed elsewhere. renameSig (Sig v ty src_loc) = addSrcLoc src_loc $ lookupSigOccRn v `thenM` \ new_v -> @@ -520,11 +502,6 @@ renameSig (SpecSig v ty src_loc) rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty -> returnM (SpecSig new_v new_ty src_loc) -renameSig (FixSig (FixitySig v fix src_loc)) - = addSrcLoc src_loc $ - lookupSigOccRn v `thenM` \ new_v -> - returnM (FixSig (FixitySig new_v fix src_loc)) - renameSig (InlineSig b v p src_loc) = addSrcLoc src_loc $ lookupSigOccRn v `thenM` \ new_v -> @@ -539,12 +516,13 @@ renameSig (InlineSig b v p src_loc) %************************************************************************ \begin{code} -dupSigDeclErr sig +dupSigDeclErr sig sigs = addSrcLoc loc $ - addErr (sep [ptext SLIT("Duplicate") <+> what_it_is <> colon, - ppr sig]) + addErr (vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon, + nest 2 (vcat (map ppr_sig (sig:sigs)))]) where (what_it_is, loc) = hsSigDoc sig + ppr_sig sig = ppr (sigLoc sig) <> colon <+> ppr sig unknownSigErr sig = addSrcLoc loc $