X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnBinds.lhs;h=843f28e41c41dc69f7eb68c6331fa2ca543861c5;hb=29da2cf3011c292bc4261601aff85afb13e24d54;hp=3c27d75f93caca4d0b69a64631aa061f91c89d43;hpb=ca5a4a480d10d61e5b7a52eb4d556e8b8c33e69d;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnBinds.lhs b/ghc/compiler/rename/RnBinds.lhs index 3c27d75..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} @@ -9,36 +9,42 @@ type-synonym declarations; those cannot be done at this stage because they may be affected by renaming (which isn't fully worked out yet). \begin{code} -#include "HsVersions.h" - module RnBinds ( - rnTopBinds, - rnMethodBinds, - rnBinds, - FreeVars(..), - DefinedVars(..) + rnTopBinds, rnBinds, rnBindsAndThen, + rnMethodBinds, renameSigs, checkSigs ) where -import Ubiq -import RnLoop -- break the RnPass/RnExpr/RnBinds loops +#include "HsVersions.h" + import HsSyn -import HsPragmas ( isNoGenPragmas, noGenPragmas ) +import HsBinds ( hsSigDoc, eqHsSig ) import RdrHsSyn import RnHsSyn -import RnMonad -import RnExpr ( rnMatch, rnGRHSsAndBinds, rnPat, checkPrecMatch ) - -import CmdLineOpts ( opt_SigsRequired ) -import Digraph ( stronglyConnComp ) -import ErrUtils ( addErrLoc, addShortErrLocLine ) -import Name ( RdrName ) -import Maybes ( catMaybes ) -import Pretty -import UniqSet ( emptyUniqSet, unitUniqSet, mkUniqSet, - unionUniqSets, unionManyUniqSets, - elementOfUniqSet, uniqSetToList, UniqSet(..) ) -import Util ( thenCmp, isIn, removeDups, panic, panic#, assertPanic ) +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 ( 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 @@ -63,30 +69,17 @@ This is precisely what the function @rnBinds@ does. ToDo: deal with case where a single monobinds binds the same variable twice. -Sets of variable names are represented as sets explicitly, rather than lists. - -\begin{code} -type DefinedVars = UniqSet RnName -type FreeVars = UniqSet RnName -\end{code} - -i.e., binders. - 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} %************************************************************************ %* * %* naming conventions * %* * %************************************************************************ + \subsection[name-conventions]{Name conventions} The basic algorithm involves walking over the tree and returning a tuple @@ -110,9 +103,10 @@ a set of variables free in @Exp@ is written @fvExp@ %************************************************************************ %* * -%* analysing polymorphic bindings (HsBinds, Bind, MonoBinds) * +%* analysing polymorphic bindings (HsBindGroup, HsBind) %* * %************************************************************************ + \subsubsection[dep-HsBinds]{Polymorphic bindings} Non-recursive expressions are reconstructed without any changes at top @@ -121,7 +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 @@ -153,345 +147,293 @@ instance declarations. It expects only to see @FunMonoBind@s, and it expects the global environment to contain bindings for the binders (which are all class operations). -\begin{code} -rnTopBinds :: RdrNameHsBinds -> RnM_Fixes s RenamedHsBinds -rnMethodBinds :: RnName{-class-} -> RdrNameMonoBinds -> RnM_Fixes s RenamedMonoBinds -rnBinds :: RdrNameHsBinds -> RnM_Fixes s (RenamedHsBinds, FreeVars, [RnName]) - -rnTopBinds EmptyBinds = returnRn EmptyBinds -rnTopBinds (SingleBind (RecBind bind)) = rnTopMonoBinds bind [] -rnTopBinds (BindWith (RecBind bind) sigs) = rnTopMonoBinds bind sigs - -- the parser doesn't produce other forms - --- ******************************************************************** - -rnMethodBinds class_name EmptyMonoBinds = returnRn EmptyMonoBinds - -rnMethodBinds class_name (AndMonoBinds mb1 mb2) - = andRn AndMonoBinds (rnMethodBinds class_name mb1) - (rnMethodBinds class_name mb2) +%************************************************************************ +%* * +\subsubsection{ Top-level bindings} +%* * +%************************************************************************ -rnMethodBinds class_name (FunMonoBind occname inf matches locn) - = pushSrcLocRn locn $ - lookupClassOp class_name occname `thenRn` \ op_name -> - mapAndUnzipRn rnMatch matches `thenRn` \ (new_matches, _) -> - mapRn (checkPrecMatch inf op_name) new_matches `thenRn_` - returnRn (FunMonoBind op_name inf new_matches locn) +@rnTopMonoBinds@ assumes that the environment already +contains bindings for the binders of this particular binding. -rnMethodBinds class_name (PatMonoBind (VarPatIn occname) grhss_and_binds locn) - = pushSrcLocRn locn $ - lookupClassOp class_name occname `thenRn` \ op_name -> - rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', _) -> - returnRn (PatMonoBind (VarPatIn op_name) grhss_and_binds' locn) +\begin{code} +rnTopBinds :: Bag (LHsBind RdrName) + -> [LSig RdrName] + -> RnM ([HsBindGroup Name], DefUses) --- Can't handle method pattern-bindings which bind multiple methods. -rnMethodBinds _ mbind@(PatMonoBind other_pat _ locn) - = failButContinueRn EmptyMonoBinds (methodBindErr mbind locn) +-- The binders of the binding are in scope already; +-- the top level scope resolution does that --- ******************************************************************** +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 -rnBinds EmptyBinds = returnRn (EmptyBinds,emptyUniqSet,[]) -rnBinds (SingleBind (RecBind bind)) = rnNestedMonoBinds bind [] -rnBinds (BindWith (RecBind bind) sigs) = rnNestedMonoBinds bind sigs - -- the parser doesn't produce other forms + rnBinds TopLevel mbinds sigs \end{code} -@rnNestedMonoBinds@ - - collects up the binders for this declaration group, - - checkes that they form a set - - extends the environment to bind them to new local names - - calls @rnMonoBinds@ to do the real work -In contrast, @rnTopMonoBinds@ doesn't extend the environment, because that's -already done in pass3. All it does is call @rnMonoBinds@ and discards -the free var info. +%************************************************************************ +%* * +%* Nested binds +%* * +%************************************************************************ \begin{code} -rnTopMonoBinds :: RdrNameMonoBinds -> [RdrNameSig] -> RnM_Fixes s RenamedHsBinds - -rnTopMonoBinds EmptyMonoBinds sigs = returnRn EmptyBinds - -rnTopMonoBinds mbs sigs - = rnBindSigs True{-top-level-} (collectMonoBinders mbs) sigs `thenRn` \ siglist -> - rnMonoBinds mbs siglist `thenRn` \ (new_binds, fv_set) -> - returnRn new_binds +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 ] $ -rnNestedMonoBinds :: RdrNameMonoBinds -> [RdrNameSig] - -> RnM_Fixes s (RenamedHsBinds, FreeVars, [RnName]) + -- Do the business + rnBinds NotTopLevel mbinds sigs `thenM` \ (binds, bind_dus) -> -rnNestedMonoBinds EmptyMonoBinds sigs - = returnRn (EmptyBinds, emptyUniqSet, []) + -- Now do the "thing inside" + thing_inside binds `thenM` \ (result,result_fvs) -> -rnNestedMonoBinds mbinds sigs -- 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 + -- Final error checking let - mbinders_w_srclocs = collectMonoBindersAndLocs mbinds - mbinders = map fst mbinders_w_srclocs + all_uses = duUses bind_dus `plusFV` result_fvs + bndrs = duDefs bind_dus + unused_bndrs = nameSetToList (bndrs `minusNameSet` all_uses) in - newLocalNames "variable" - mbinders_w_srclocs `thenRn` \ new_mbinders -> - - extendSS2 new_mbinders ( - rnBindSigs False{-not top- level-} mbinders sigs `thenRn` \ siglist -> - rnMonoBinds mbinds siglist - ) `thenRn` \ (new_binds, fv_set) -> - returnRn (new_binds, fv_set, 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 = collectHsBindLocatedBinders mbinds + doc = text "In the binding group for:" + <+> pprWithCommas ppr (map unLoc mbinders_w_srclocs) \end{code} -@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). -\begin{code} -rnMonoBinds :: RdrNameMonoBinds - -> [RenamedSig] -- Signatures attached to this group - -> RnM_Fixes s (RenamedHsBinds, FreeVars) +%************************************************************************ +%* * +\subsubsection{rnBinds -- the main work is done here} +%* * +%************************************************************************ -rnMonoBinds mbinds 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 0 siglist mbinds `thenRn` \ (_, mbinds_info) -> +@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). - -- Do the SCC analysis - let vertices = mkVertices mbinds_info - edges = mkEdges vertices mbinds_info +\begin{code} +rnBinds :: TopLevelFlag + -> Bag (LHsBind RdrName) + -> [LSig RdrName] + -> RnM ([HsBindGroup Name], DefUses) - scc_result = stronglyConnComp (==) edges vertices +-- Assumes the binders of the binding are in scope already - -- Deal with bound and free-var calculation - rhs_free_vars = foldr f emptyUniqSet mbinds_info +rnBinds top_lvl mbinds sigs + = renameSigs sigs `thenM` \ siglist -> - final_binds = reconstructRec scc_result edges mbinds_info + -- Rename the bindings, returning a [HsBindVertex] + -- which is a list of indivisible vertices so far as + -- the strongly-connected-components (SCC) analysis is concerned + mkBindVertices siglist mbinds `thenM` \ mbinds_info -> - happy_answer = returnRn (final_binds, rhs_free_vars) + -- Do the SCC analysis + 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 - case (inline_sigs_in_recursive_binds final_binds) of - Nothing -> happy_answer - Just names_n_locns -> --- SLPJ: sometimes want recursive INLINE for worker wrapper style stuff --- addErrRn (inlineInRecursiveBindsErr names_n_locns) `thenRn_` - {-not so-}happy_answer - where - f :: (a,b, FreeVars, c,d) -> FreeVars -> FreeVars - - f (_, _, fvs_body, _, _) fvs_sofar = fvs_sofar `unionUniqSets` fvs_body - - inline_sigs_in_recursive_binds (BindWith (RecBind _) sigs) - = case [(n, locn) | (InlineSig n locn) <- sigs ] of - [] -> Nothing - sigh -> -#if OMIT_DEFORESTER - Just sigh -#else - -- Allow INLINEd recursive functions if they are - -- designated DEFORESTable too. - case [(n, locn) | (DeforestSig n locn) <- sigs ] of - [] -> Just sigh - sigh -> Nothing -#endif - - inline_sigs_in_recursive_binds (ThenBinds b1 b2) - = case (inline_sigs_in_recursive_binds b1) of - Nothing -> inline_sigs_in_recursive_binds b2 - Just x -> Just x -- NB: won't report error(s) in b2 - - inline_sigs_in_recursive_binds anything_else = Nothing + -- 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 :: Int -- Next free vertex tag - -> [RenamedSig] -- Signatures - -> RdrNameMonoBinds - -> RnM_Fixes s (Int, FlatMonoBindsInfo) - -flattenMonoBinds uniq sigs EmptyMonoBinds = returnRn (uniq, []) - -flattenMonoBinds uniq sigs (AndMonoBinds mB1 mB2) - = flattenMonoBinds uniq sigs mB1 `thenRn` \ (uniq1, flat1) -> - flattenMonoBinds uniq1 sigs mB2 `thenRn` \ (uniq2, flat2) -> - returnRn (uniq2, flat1 ++ flat2) +mkBindVertices :: [LSig Name] -- Signatures + -> Bag (LHsBind RdrName) + -> RnM [BindVertex] +mkBindVertices sigs = mapM (mkBindVertex sigs) . bagToList -flattenMonoBinds uniq 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 = collectPatBinders pat' - - sigs_etc_for_here = foldl (sig_for_here (\ n -> n `is_elem` names_bound_here)) - [] sigs - - sigs_fvs = foldr sig_fv emptyUniqSet sigs_etc_for_here - - is_elem = isIn "flattenMonoBinds" + names_bound_here = mkNameSet (collectPatBinders pat') in - returnRn ( - uniq + 1, - [(uniq, - mkUniqSet names_bound_here, - fvs `unionUniqSets` sigs_fvs, - PatMonoBind pat' grhss_and_binds' locn, - sigs_etc_for_here - )] - ) - -flattenMonoBinds uniq sigs (FunMonoBind name inf matches locn) - = pushSrcLocRn locn $ - lookupValue name `thenRn` \ name' -> - mapAndUnzipRn rnMatch matches `thenRn` \ (new_matches, fv_lists) -> - mapRn (checkPrecMatch inf name') new_matches `thenRn_` + 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 = unionManyUniqSets fv_lists - - sigs_for_me = foldl (sig_for_here (\ n -> n == name')) [] sigs - - sigs_fvs = foldr sig_fv emptyUniqSet sigs_for_me + plain_name = unLoc new_name + names_bound_here = unitNameSet plain_name in - returnRn ( - uniq + 1, - [(uniq, - unitUniqSet name', - fvs `unionUniqSets` 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} -Grab type-signatures/user-pragmas of interest: -\begin{code} -sig_for_here want_me acc s@(Sig n _ _ _) | want_me n = s:acc -sig_for_here want_me acc s@(InlineSig n _) | want_me n = s:acc -sig_for_here want_me acc s@(DeforestSig n _) | want_me n = s:acc -sig_for_here want_me acc s@(SpecSig n _ _ _) | want_me n = s:acc -sig_for_here want_me acc s@(MagicUnfoldingSig n _ _) - | want_me n = s:acc -sig_for_here want_me acc other_wise = acc - --- 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 `unionUniqSets` unitUniqSet blah -sig_fv _ acc = acc -\end{code} -%************************************************************************ -%* * -\subsection[reconstruct-deps]{Reconstructing dependencies} -%* * -%************************************************************************ +@rnMethodBinds@ is used for the method bindings of a class and an instance +declaration. Like @rnBinds@ but without dependency analysis. -This @MonoBinds@- and @ClassDecls@-specific code is segregated here, -as the two cases are similar. +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. \begin{code} -reconstructRec :: [Cycle] -- Result of SCC analysis; at least one - -> [Edge] -- Original edges - -> FlatMonoBindsInfo - -> RenamedHsBinds - -reconstructRec cycles edges mbi - = foldr1 ThenBinds (map (reconstructCycle mbi) cycles) +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 + + 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 - reconstructCycle :: FlatMonoBindsInfo -> Cycle -> RenamedHsBinds - - reconstructCycle mbi2 cycle - = case [(binds,sigs) | (vertex, _, _, binds, sigs) <- mbi2, vertex `is_elem` cycle] - of { relevant_binds_and_sigs -> - - case (unzip relevant_binds_and_sigs) of { (binds, sig_lists) -> - - case (foldr AndMonoBinds EmptyMonoBinds binds) of { this_gp_binds -> - let - this_gp_sigs = foldr1 (++) sig_lists - have_sigs = not (null sig_lists) - -- ToDo: this might not be the right - -- thing to call this predicate; - -- e.g. "have_sigs [[], [], []]" ??????????? - in - mk_binds this_gp_binds this_gp_sigs (isCyclic edges cycle) have_sigs - }}} - where - is_elem = isIn "reconstructRec" - - mk_binds :: RenamedMonoBinds -> [RenamedSig] - -> Bool -> Bool -> RenamedHsBinds - - mk_binds bs ss True False = SingleBind (RecBind bs) - mk_binds bs ss True True{-have sigs-} = BindWith (RecBind bs) ss - mk_binds bs ss False False = SingleBind (NonRecBind bs) - mk_binds bs ss False True{-have sigs-} = BindWith (NonRecBind bs) ss - - -- moved from Digraph, as this is the only use here - -- (avoid overloading cost). We have to use elem - -- (not FiniteMaps or whatever), because there may be - -- many edges out of one vertex. We give it its own - -- "elem" just for speed. - - isCyclic es [] = panic "isCyclic: empty component" - isCyclic es [v] = (v,v) `elem` es - isCyclic es vs = True - - elem _ [] = False - elem x (y:ys) = x==y || elem x ys + -- 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 + + +-- 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} + %************************************************************************ %* * -%* Manipulating FlatMonoBindInfo * + Strongly connected components %* * %************************************************************************ -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 - = [(VertexTag, -- Identifies the vertex - UniqSet RnName, -- Set of names defined in this vertex - UniqSet RnName, -- Set of names used in this vertex - RenamedMonoBinds, -- Binding for this vertex (always just one binding, either fun or pat) - [RenamedSig]) -- Signatures, if any, for this vertex - ] +type BindVertex = (Defs, Uses, LHsBind Name, [LSig Name]) + -- Signatures, if any, for this vertex + +rnSCC :: [BindVertex] -> [SCC BindVertex] +rnSCC nodes = stronglyConnComp (mkEdges nodes) + +type VertexTag = Int -mkVertices :: FlatMonoBindsInfo -> [VertexTag] -mkVertices info = [ vertex | (vertex,_,_,_,_) <- info] - -mkEdges :: [VertexTag] -> FlatMonoBindsInfo -> [Edge] - -mkEdges vertices flat_info - -- An edge (v,v') indicates that v depends on v' - = [ (source_vertex, target_vertex) - | (source_vertex, _, used_names, _, _) <- flat_info, - target_name <- uniqSetToList used_names, - target_vertex <- vertices_defining target_name flat_info - ] - where - -- If each name only has one binding in this group, then - -- vertices_defining will always return the empty list, or a - -- singleton. The case when there is more than one binding (an - -- error) needs more thought. - - vertices_defining name flat_info2 - = [ vertex | (vertex, names_defined, _, _, _) <- flat_info2, - name `elementOfUniqSet` names_defined - ] +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 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} @@ -501,143 +443,67 @@ mkEdges vertices flat_info %* * %************************************************************************ -@rnBindSigs@ 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} -rnBindSigs :: Bool -- True <=> top-level binders - -> [RdrName] -- Binders for this decl group - -> [RdrNameSig] - -> RnM_Fixes s [RenamedSig] -- List of Sig constructors - -rnBindSigs is_toplev binder_occnames sigs - = - -- Rename the signatures - -- Will complain about sigs for variables not in this group - mapRn rename_sig sigs `thenRn` \ sigs_maybe -> - let - sigs' = catMaybes sigs_maybe - - -- Discard unbound ones we've already complained about, so we - -- complain about duplicate ones. - - (goodies, dups) = removeDups compare (filter not_unbound sigs') - in - mapRn (addErrRn . dupSigDeclErr) dups `thenRn_` - - getSrcLocRn `thenRn` \ locn -> - - (if (is_toplev && opt_SigsRequired) then - let - sig_frees = catMaybes (map (sig_free sigs) binder_occnames) - in - mapRn (addErrRn . missingSigErr locn) sig_frees - else - returnRn [] - ) `thenRn_` - - returnRn sigs' -- bad ones and all: - -- we need bindings of *some* sort for every name +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 + -- Well, I can't see the check for (a)... ToDo! + = mappM_ unknownSigErr (filter bad sigs) where - rename_sig (Sig v ty pragmas src_loc) - = pushSrcLocRn src_loc $ - if not (v `elem` binder_occnames) then - addErrRn (unknownSigDeclErr "type signature" v src_loc) `thenRn_` - returnRn Nothing - else - lookupValue v `thenRn` \ new_v -> - rnPolyType nullTyVarNamesEnv ty `thenRn` \ new_ty -> - - ASSERT(isNoGenPragmas pragmas) - returnRn (Just (Sig new_v new_ty noGenPragmas src_loc)) - - -- and now, the various flavours of value-modifying user-pragmas: - - rename_sig (SpecSig v ty using src_loc) - = pushSrcLocRn src_loc $ - if not (v `elem` binder_occnames) then - addErrRn (unknownSigDeclErr "SPECIALIZE pragma" v src_loc) `thenRn_` - returnRn Nothing - else - lookupValue v `thenRn` \ new_v -> - rnPolyType nullTyVarNamesEnv ty `thenRn` \ new_ty -> - rn_using using `thenRn` \ new_using -> - returnRn (Just (SpecSig new_v new_ty new_using src_loc)) - where - rn_using Nothing = returnRn Nothing - rn_using (Just x) = lookupValue x `thenRn` \ new_x -> - returnRn (Just new_x) - - rename_sig (InlineSig v src_loc) - = pushSrcLocRn src_loc $ - if not (v `elem` binder_occnames) then - addErrRn (unknownSigDeclErr "INLINE pragma" v src_loc) `thenRn_` - returnRn Nothing - else - lookupValue v `thenRn` \ new_v -> - returnRn (Just (InlineSig new_v src_loc)) - - rename_sig (DeforestSig v src_loc) - = pushSrcLocRn src_loc $ - if not (v `elem` binder_occnames) then - addErrRn (unknownSigDeclErr "DEFOREST pragma" v src_loc) `thenRn_` - returnRn Nothing - else - lookupValue v `thenRn` \ new_v -> - returnRn (Just (DeforestSig new_v src_loc)) - - rename_sig (MagicUnfoldingSig v str src_loc) - = pushSrcLocRn src_loc $ - if not (v `elem` binder_occnames) then - addErrRn (unknownSigDeclErr "MAGIC_UNFOLDING pragma" v src_loc) `thenRn_` - returnRn Nothing - else - lookupValue v `thenRn` \ new_v -> - returnRn (Just (MagicUnfoldingSig new_v str src_loc)) - - not_unbound :: RenamedSig -> Bool - - not_unbound (Sig n _ _ _) = not (isRnUnbound n) - not_unbound (SpecSig n _ _ _) = not (isRnUnbound n) - not_unbound (InlineSig n _) = not (isRnUnbound n) - not_unbound (DeforestSig n _) = not (isRnUnbound n) - not_unbound (MagicUnfoldingSig n _ _) = not (isRnUnbound n) - - ------------------------------------- - sig_free :: [RdrNameSig] -> RdrName -> Maybe RdrName - -- Return "Just x" if "x" has no type signature in - -- sigs. Nothing, otherwise. - - sig_free [] ny = Just ny - sig_free (Sig nx _ _ _ : rest) ny - = if (nx == ny) then Nothing else sig_free rest ny - sig_free (_ : rest) ny = sig_free rest ny - - ------------------------------------- - compare :: RenamedSig -> RenamedSig -> TAG_ - compare (Sig n1 _ _ _) (Sig n2 _ _ _) = n1 `cmp` n2 - compare (InlineSig n1 _) (InlineSig n2 _) = n1 `cmp` n2 - compare (MagicUnfoldingSig n1 _ _) (MagicUnfoldingSig n2 _ _) = n1 `cmp` n2 - compare (SpecSig n1 ty1 _ _) (SpecSig n2 ty2 _ _) - = -- may have many specialisations for one value; - -- but not ones that are exactly the same... - thenCmp (n1 `cmp` n2) (cmpPolyType cmp ty1 ty2) - - compare other_1 other_2 -- tags *must* be different - = let tag1 = tag other_1 - tag2 = tag other_2 - in - if tag1 _LT_ tag2 then LT_ else GT_ - - tag (Sig n1 _ _ _) = (ILIT(1) :: FAST_INT) - tag (SpecSig n1 _ _ _) = ILIT(2) - tag (InlineSig n1 _) = ILIT(3) - tag (MagicUnfoldingSig n1 _ _) = ILIT(4) - tag (DeforestSig n1 _) = ILIT(5) - tag _ = panic# "tag(RnBinds)" + 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} + %************************************************************************ %* * \subsection{Error messages} @@ -645,46 +511,27 @@ rnBindSigs is_toplev binder_occnames sigs %************************************************************************ \begin{code} -dupSigDeclErr sigs - = let - undup_sigs = fst (removeDups cmp_sig sigs) - in - addErrLoc locn1 - ("more than one "++what_it_is++"\n\thas been given for these variables") ( \ sty -> - ppAboves (map (ppr sty) undup_sigs) ) +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 = hsSigDoc sig + ppr_sig (L loc sig) = ppr loc <> colon <+> ppr sig + +unknownSigErr (L loc sig) + = addErrAt loc $ + sep [ptext SLIT("Misplaced") <+> what_it_is <> colon, ppr sig] where - (what_it_is, locn1) - = case (head sigs) of - Sig _ _ _ loc -> ("type signature",loc) - ClassOpSig _ _ _ loc -> ("class-method type signature", loc) - SpecSig _ _ _ loc -> ("SPECIALIZE pragma",loc) - InlineSig _ loc -> ("INLINE pragma",loc) - MagicUnfoldingSig _ _ loc -> ("MAGIC_UNFOLDING pragma",loc) - - cmp_sig a b = get_name a `cmp` get_name b - - get_name (Sig n _ _ _) = n - get_name (ClassOpSig n _ _ _) = n - get_name (SpecSig n _ _ _) = n - get_name (InlineSig n _) = n - get_name (MagicUnfoldingSig n _ _) = n - ------------------------- -methodBindErr mbind locn - = addErrLoc locn "Can't handle multiple methods defined by one pattern binding" - (\ sty -> ppr sty mbind) - --------------------------- -missingSigErr locn var - = addShortErrLocLine locn ( \ sty -> - ppBesides [ppStr "a definition but no type signature for `", - ppr sty var, - ppStr "'."]) - --------------------------------- -unknownSigDeclErr flavor var locn - = addShortErrLocLine locn ( \ sty -> - ppBesides [ppStr flavor, ppStr " but no definition for `", - ppr sty var, - ppStr "'."]) + what_it_is = hsSigDoc sig + +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")) + 4 (ppr mbind) \end{code}