X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnBinds.lhs;h=13035e72e2831185bc58ee74c632c381ac49b151;hb=876b4ef2093cb9c104db33c7db1200b941b6d079;hp=ced653a84e8a67973618dbb3fd83b637e2020fb3;hpb=f7ecf7234c224489be8a5e63fced903b655d92ee;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnBinds.lhs b/ghc/compiler/rename/RnBinds.lhs index ced653a..13035e7 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} @@ -9,37 +9,44 @@ 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, - SYN_IE(FreeVars), - SYN_IE(DefinedVars) + rnTopBinds, + rnLocalBindsAndThen, rnValBindsAndThen, rnValBinds, trimWith, + rnMethodBinds, renameSigs, + rnMatchGroup, rnGRHSs ) where -IMP_Ubiq() -IMPORT_DELOOPER(RnLoop) -- break the RnPass/RnExpr/RnBinds loops +#include "HsVersions.h" + +import {-# SOURCE #-} RnExpr( rnLExpr, rnStmts ) import HsSyn -import HsPragmas ( isNoGenPragmas, noGenPragmas ) 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 ( getLocalName, RdrName ) -import Maybes ( catMaybes ) ---import PprStyle--ToDo:rm -import Pretty -import UniqSet ( emptyUniqSet, unitUniqSet, mkUniqSet, - unionUniqSets, unionManyUniqSets, - elementOfUniqSet, uniqSetToList, SYN_IE(UniqSet) ) -import Util ( thenCmp, isIn, removeDups, panic, panic#, assertPanic ) +import TcRnMonad +import RnTypes ( rnHsSigType, rnLHsType, rnHsTypeFVs, + rnLPat, rnPatsAndThen, patSigErr, checkPrecMatch ) +import RnEnv ( bindLocatedLocalsRn, lookupLocatedBndrRn, + lookupLocatedInstDeclBndr, newIPNameRn, + lookupLocatedSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV, + bindLocalFixities, bindSigTyVarsFV, + warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn, + ) +import DynFlags ( DynFlag(..) ) +import Name ( Name, nameOccName, nameSrcLoc ) +import NameEnv +import NameSet +import PrelNames ( isUnboundName ) +import RdrName ( RdrName, rdrNameOcc ) +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 @@ -64,30 +71,17 @@ 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 @@ -111,9 +105,10 @@ 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 @@ -122,7 +117,7 @@ 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 @@ -154,494 +149,474 @@ 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 +%************************************************************************ +%* * +\subsubsection{ Top-level bindings} +%* * +%************************************************************************ -rnMethodBinds class_name (AndMonoBinds mb1 mb2) - = andRn AndMonoBinds (rnMethodBinds class_name mb1) - (rnMethodBinds class_name mb2) +@rnTopMonoBinds@ assumes that the environment already +contains bindings for the binders of this particular binding. -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) +\begin{code} +rnTopBinds :: HsValBinds RdrName -> RnM (HsValBinds Name, DefUses) + +-- The binders of the binding are in scope already; +-- the top level scope resolution does that + +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} -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) --- Can't handle method pattern-bindings which bind multiple methods. -rnMethodBinds _ mbind@(PatMonoBind other_pat _ locn) - = failButContinueRn EmptyMonoBinds (methodBindErr mbind locn) --- ******************************************************************** +%********************************************************* +%* * + HsLocalBinds +%* * +%********************************************************* -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 +\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} -@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. +%************************************************************************ +%* * + ValBinds +%* * +%************************************************************************ \begin{code} -rnTopMonoBinds :: RdrNameMonoBinds -> [RdrNameSig] -> RnM_Fixes s RenamedHsBinds +rnValBindsAndThen :: HsValBinds RdrName + -> (HsValBinds Name -> RnM (result, FreeVars)) + -> RnM (result, FreeVars) -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 +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 $ \ bndrs -> + -- 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 + rnValBinds (trimWith bndrs) binds `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 + -- 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 - 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) -\end{code} + warnUnusedLocalBinds unused_bndrs `thenM_` -@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). + returnM (result, delListFromNameSet all_uses bndrs) + where + mbinders_w_srclocs = collectHsBindLocatedBinders mbinds + doc = text "In the binding group for:" + <+> pprWithCommas ppr (map unLoc mbinders_w_srclocs) -\begin{code} -rnMonoBinds :: RdrNameMonoBinds - -> [RenamedSig] -- Signatures attached to this group - -> RnM_Fixes s (RenamedHsBinds, FreeVars) +--------------------- +rnValBinds :: (FreeVars -> FreeVars) + -> HsValBinds RdrName + -> RnM (HsValBinds Name, DefUses) +-- Assumes the binders of the binding are in scope already -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) -> +rnValBinds trim (ValBindsIn mbinds sigs) + = do { sigs' <- rename_sigs sigs - -- Do the SCC analysis - let vertices = mkVertices mbinds_info - edges = mkEdges mbinds_info + ; binds_w_dus <- mapBagM (rnBind (mkSigTvFn sigs') trim) mbinds - scc_result = stronglyConnComp (==) edges vertices + ; let (binds', bind_dus) = depAnalBinds binds_w_dus - -- Deal with bound and free-var calculation - rhs_free_vars = foldr f emptyUniqSet mbinds_info + -- 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' - final_binds = reconstructRec scc_result edges mbinds_info + ; return (ValBindsOut binds' sigs', + usesOnly (hsSigsFVs sigs') `plusDU` bind_dus) } - happy_answer = returnRn (final_binds, rhs_free_vars) - 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 + +--------------------- +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 + + keyd_nodes = bagToList binds_w_dus `zip` [0::Int ..] + + edges = [ (node, key, [key | n <- nameSetToList uses, + Just key <- [lookupNameEnv key_map n] ]) + | (node@(_,_,uses), key) <- keyd_nodes ] + + key_map :: NameEnv Int -- Which binding it comes from + key_map = mkNameEnv [(bndr, key) | ((_, bndrs, _), key) <- keyd_nodes + , bndr <- bndrs ] + + get_binds (AcyclicSCC (bind, _, _)) = (NonRecursive, unitBag bind) + get_binds (CyclicSCC binds_w_dus) = (Recursive, listToBag [b | (b,d,u) <- binds_w_dus]) + + 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 - 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 + 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} -@flattenMonoBinds@ 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 bs1 bs2) - = flattenMonoBinds uniq sigs bs1 `thenRn` \ (uniq1, flat1) -> - flattenMonoBinds uniq1 sigs bs2 `thenRn` \ (uniq2, flat2) -> - returnRn (uniq2, flat1 ++ flat2) - -flattenMonoBinds uniq sigs (PatMonoBind pat grhss_and_binds locn) - = pushSrcLocRn locn $ - rnPat pat `thenRn` \ pat' -> - rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', 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 +@rnMethodBinds@ is used for the method bindings of a class and an instance +declaration. Like @rnBinds@ but without dependency analysis. - sigs_fvs = foldr sig_fv emptyUniqSet sigs_etc_for_here +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. - is_elem = isIn "flattenMonoBinds" +\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 { 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 plain_name) matches `thenM` \ (new_matches, fvs) -> + let + new_group = MatchGroup new_matches placeHolderType 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_` - let - fvs = unionManyUniqSets fv_lists + 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 + -- 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.unLoc) (extractHsTyRdrTyVars ty) + gen_tvs = [tv | tv <- gen_tyvars, nameOccName tv `elem` tvs] - sigs_for_me = foldl (sig_for_here (\ n -> n == name')) [] sigs + rn_match sel_name match = rnMatch (FunRhs sel_name) match - sigs_fvs = foldr sig_fv emptyUniqSet sigs_for_me - in - returnRn ( - uniq + 1, - [(uniq, - unitUniqSet name', - fvs `unionUniqSets` sigs_fvs, - FunMonoBind name' inf new_matches locn, - sigs_for_me - )] - ) -\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 +-- 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} + %************************************************************************ %* * -\subsection[reconstruct-deps]{Reconstructing dependencies} +\subsubsection[dep-Sigs]{Signatures (and user-pragmas for values)} %* * %************************************************************************ -This @MonoBinds@- and @ClassDecls@-specific code is segregated here, -as the two cases are similar. +@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} -reconstructRec :: [Cycle] -- Result of SCC analysis; at least one - -> [Edge] -- Original edges - -> FlatMonoBindsInfo - -> RenamedHsBinds - -reconstructRec cycles edges mbi - = foldr1 ThenBinds (map (reconstructCycle mbi) cycles) +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 + = do { mappM_ unknownSigErr (filter (not . ok_sig) sigs') + ; mappM_ dupSigDeclErr (findDupsEq eqHsSig sigs') } 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 + -- 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 lookupLocatedSigOccRn 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. + +renameSig :: Sig RdrName -> RnM (Sig Name) +-- FixitSig is renamed elsewhere. +renameSig (TypeSig v ty) + = lookupLocatedSigOccRn v `thenM` \ new_v -> + rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty -> + returnM (TypeSig 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 inl) + = lookupLocatedSigOccRn v `thenM` \ new_v -> + rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty -> + returnM (SpecSig new_v new_ty inl) + +renameSig (InlineSig v s) + = lookupLocatedSigOccRn v `thenM` \ new_v -> + returnM (InlineSig new_v s) \end{code} -%************************************************************************ -%* * -%* Manipulating FlatMonoBindInfo * -%* * -%************************************************************************ -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. +************************************************************************ +* * +\subsection{Match} +* * +************************************************************************ \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 - ] - -mkVertices :: FlatMonoBindsInfo -> [VertexTag] -mkEdges :: FlatMonoBindsInfo -> [Edge] - -mkVertices info = [ vertex | (vertex,_,_,_,_) <- info] - -mkEdges flat_info - -- An edge (v,v') indicates that v depends on v' - = -- pprTrace "mkEdges:" (ppAboves [ppAboves[ppInt v, ppCat [ppr PprDebug d|d <- uniqSetToList defd], ppCat [ppr PprDebug u|u <- uniqSetToList used]] | (v,defd,used,_,_) <- flat_info]) $ - [ (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 - ] +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[dep-Sigs]{Signatures (and user-pragmas for values)} +\subsubsection{Guarded right-hand sides (GRHSs)} %* * %************************************************************************ -@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. - \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 +rnGRHSs :: HsMatchContext Name -> GRHSs RdrName -> RnM (GRHSs Name, FreeVars) - -- Discard unbound ones we've already complained about, so we - -- complain about duplicate ones. +rnGRHSs ctxt (GRHSs grhss binds) + = rnLocalBindsAndThen binds $ \ binds' -> + mapFvRn (rnGRHS ctxt) grhss `thenM` \ (grhss', fvGRHSs) -> + returnM (GRHSs grhss' binds', fvGRHSs) - (goodies, dups) = removeDups compare (filter (\ x -> not_unbound x && not_main x) sigs') - in - mapRn (addErrRn . dupSigDeclErr) dups `thenRn_` +rnGRHS :: HsMatchContext Name -> LGRHS RdrName -> RnM (LGRHS Name, FreeVars) +rnGRHS ctxt = wrapLocFstM (rnGRHS' ctxt) - getSrcLocRn `thenRn` \ locn -> +rnGRHS' ctxt (GRHS guards rhs) + = do { opt_GlasgowExts <- doptM Opt_GlasgowExts + ; ((guards', rhs'), fvs) <- rnStmts (PatGuard ctxt) guards $ + rnLExpr rhs - (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_` + ; checkM (opt_GlasgowExts || is_standard_guard guards') + (addWarn (nonStdGuardErr guards')) - returnRn sigs' -- bad ones and all: - -- we need bindings of *some* sort for every name + ; return (GRHS guards' rhs', fvs) } 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, not_main :: 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) - - not_main (Sig n _ _ _) = let str = getLocalName n in - not (str == SLIT("main") || str == SLIT("mainPrimIO")) - not_main _ = True - - ------------------------------------- - 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)" + -- 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} %************************************************************************ @@ -651,46 +626,35 @@ 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 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 = 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("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}