\begin{code}
module RnBinds (
- rnTopBinds, rnTopMonoBinds,
- rnMethodBinds, renameSigs,
- rnBinds,
- unknownSigErr
+ rnTopBinds,
+ rnLocalBindsAndThen, rnValBindsAndThen, rnValBinds, trimWith,
+ rnMethodBinds, renameSigs,
+ rnMatchGroup, rnGRHSs
) where
#include "HsVersions.h"
-import {-# SOURCE #-} RnSource ( rnHsSigType )
+import {-# SOURCE #-} RnExpr( rnLExpr, rnStmts )
import HsSyn
-import HsBinds ( eqHsSig, sigName, hsSigDoc )
import RdrHsSyn
import RnHsSyn
-import RnMonad
-import RnExpr ( rnMatch, rnGRHSs, rnPat, checkPrecMatch )
-import RnEnv ( bindLocatedLocalsRn, lookupBndrRn,
- lookupGlobalOccRn, lookupSigOccRn,
+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,
- FreeVars, emptyFVs, plusFV, plusFVs, unitFV, addOneFV
)
-import CmdLineOpts ( DynFlag(..) )
-import Digraph ( stronglyConnComp, SCC(..) )
-import Name ( OccName, Name, nameOccName )
+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 List ( partition )
+import Digraph ( SCC(..), stronglyConnComp )
+import Bag
import Outputable
-import PrelNames ( isUnboundName )
+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
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}
%************************************************************************
%* *
%************************************************************************
%* *
-%* analysing polymorphic bindings (HsBinds, Bind, MonoBinds) *
+%* analysing polymorphic bindings (HsBindGroup, HsBind)
%* *
%************************************************************************
\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
%* *
%************************************************************************
-@rnTopBinds@ assumes that the environment already
+@rnTopMonoBinds@ assumes that the environment already
contains bindings for the binders of this particular binding.
\begin{code}
-rnTopBinds :: RdrNameHsBinds -> RnMS (RenamedHsBinds, FreeVars)
+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}
-rnTopBinds EmptyBinds = returnRn (EmptyBinds, emptyFVs)
-rnTopBinds (MonoBind bind sigs _) = rnTopMonoBinds bind sigs
- -- The parser doesn't produce other forms
-rnTopMonoBinds mbinds sigs
- = mapRn lookupBndrRn binder_rdr_names `thenRn` \ binder_names ->
- let
- bndr_name_set = mkNameSet binder_names
- in
- renameSigs (okBindSig bndr_name_set) sigs `thenRn` \ (siglist, sig_fvs) ->
- doptRn Opt_WarnMissingSigs `thenRn` \ warnMissing ->
- let
- type_sig_vars = [n | Sig n _ _ <- siglist]
- un_sigd_binders | warnMissing = nameSetToList (delListFromNameSet
- bndr_name_set type_sig_vars)
- | otherwise = []
- in
- mapRn_ (addWarnRn.missingSigWarn) un_sigd_binders `thenRn_`
+%*********************************************************
+%* *
+ HsLocalBinds
+%* *
+%*********************************************************
- rn_mono_binds siglist mbinds `thenRn` \ (final_binds, bind_fvs) ->
- returnRn (final_binds, bind_fvs `plusFV` sig_fvs)
- where
- binder_rdr_names = collectMonoBinders mbinds
+\begin{code}
+rnLocalBindsAndThen
+ :: HsLocalBinds RdrName
+ -> (HsLocalBinds Name -> RnM (result, FreeVars))
+ -> RnM (result, FreeVars)
+-- This version (a) assumes that the binding vars are not already in scope
+-- (b) removes the binders from the free vars of the thing inside
+-- The parser doesn't produce ThenBinds
+rnLocalBindsAndThen EmptyLocalBinds thing_inside
+ = thing_inside EmptyLocalBinds
+
+rnLocalBindsAndThen (HsValBinds val_binds) thing_inside
+ = rnValBindsAndThen val_binds $ \ val_binds' ->
+ thing_inside (HsValBinds val_binds')
+
+rnLocalBindsAndThen (HsIPBinds binds) thing_inside
+ = rnIPBinds binds `thenM` \ (binds',fv_binds) ->
+ thing_inside (HsIPBinds binds') `thenM` \ (thing, fvs_thing) ->
+ returnM (thing, fvs_thing `plusFV` fv_binds)
+
+-------------
+rnIPBinds (IPBinds ip_binds _no_dict_binds)
+ = do { (ip_binds', fvs_s) <- mapAndUnzipM (wrapLocFstM rnIPBind) ip_binds
+ ; return (IPBinds ip_binds' emptyLHsBinds, plusFVs fvs_s) }
+
+rnIPBind (IPBind n expr)
+ = newIPNameRn n `thenM` \ name ->
+ rnLExpr expr `thenM` \ (expr',fvExpr) ->
+ return (IPBind name expr', fvExpr)
\end{code}
+
%************************************************************************
%* *
-%* Nested binds
+ ValBinds
%* *
%************************************************************************
-\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}
-rnBinds :: RdrNameHsBinds
- -> (RenamedHsBinds -> RnMS (result, FreeVars))
- -> RnMS (result, FreeVars)
-
-rnBinds EmptyBinds thing_inside = thing_inside EmptyBinds
-rnBinds (MonoBind bind sigs _) thing_inside = rnMonoBinds bind sigs thing_inside
- -- the parser doesn't produce other forms
-
-
-rnMonoBinds :: RdrNameMonoBinds
- -> [RdrNameSig]
- -> (RenamedHsBinds -> RnMS (result, FreeVars))
- -> RnMS (result, FreeVars)
+rnValBindsAndThen :: HsValBinds RdrName
+ -> (HsValBinds Name -> 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
+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 (text "a binding group")
- mbinders_w_srclocs $ \ new_mbinders ->
- let
- binder_set = mkNameSet new_mbinders
- in
- -- Rename the signatures
- renameSigs (okBindSig binder_set) sigs `thenRn` \ (siglist, sig_fvs) ->
+ bindLocatedLocalsRn doc mbinders_w_srclocs $ \ bndrs ->
- -- 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
- let
- fixity_sigs = [(name,sig) | FixSig sig@(FixitySig name _ _) <- siglist ]
- in
- extendFixityEnv fixity_sigs $
+ bindLocalFixities [sig | L _ (FixSig sig) <- sigs ] $
+
+ -- Do the business
+ rnValBinds (trimWith bndrs) binds `thenM` \ (binds, bind_dus) ->
- rn_mono_binds siglist mbinds `thenRn` \ (binds, bind_fvs) ->
+ -- Now do the "thing inside"
+ thing_inside binds `thenM` \ (result,result_fvs) ->
- -- Now do the "thing inside", and deal with the free-variable calculations
- thing_inside binds `thenRn` \ (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
+ -- duUses: It's important to return all the uses, not the 'real uses'
+ -- used for warning about unused bindings. Otherwise consider:
+ -- x = 3
+ -- y = let p = x in 'x' -- NB: p not used
+ -- If we don't "see" the dependency of 'y' on 'x', we may put the
+ -- bindings in the wrong order, and the type checker will complain
+ -- that x isn't in scope
+
+ unused_bndrs = [ b | b <- bndrs, not (b `elemNameSet` all_uses)]
in
- warnUnusedLocalBinds unused_binders `thenRn_`
- returnRn (result, delListFromNameSet all_fvs new_mbinders)
+ warnUnusedLocalBinds unused_bndrs `thenM_`
+
+ returnM (result, delListFromNameSet all_uses bndrs)
where
- mbinders_w_srclocs = collectLocatedMonoBinders mbinds
-\end{code}
+ mbinders_w_srclocs = collectHsBindLocatedBinders mbinds
+ doc = text "In the binding group for:"
+ <+> pprWithCommas ppr (map unLoc mbinders_w_srclocs)
+---------------------
+rnValBinds :: (FreeVars -> FreeVars)
+ -> HsValBinds RdrName
+ -> RnM (HsValBinds Name, DefUses)
+-- Assumes the binders of the binding are in scope already
-%************************************************************************
-%* *
-\subsubsection{ MonoBinds -- the main work is done here}
-%* *
-%************************************************************************
+rnValBinds trim (ValBindsIn mbinds sigs)
+ = do { sigs' <- rename_sigs sigs
-@rn_mono_binds@ 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).
+ ; binds_w_dus <- mapBagM (rnBind (mkSigTvFn sigs') trim) mbinds
-\begin{code}
-rn_mono_binds :: [RenamedSig] -- Signatures attached to this group
- -> RdrNameMonoBinds
- -> RnMS (RenamedHsBinds, --
- FreeVars) -- Free variables
-
-rn_mono_binds siglist mbinds
- =
- -- 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 `thenRn` \ 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
+ ; let (binds', bind_dus) = depAnalBinds binds_w_dus
- -- Deal with bound and free-var calculation
- rhs_fvs = plusFVs [fvs | (_,fvs,_,_) <- mbinds_info]
- in
- returnRn (final_binds, rhs_fvs)
-\end{code}
+ -- 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'
-@flattenMonoBinds@ is ever-so-slightly magical in that it sticks
-unique ``vertex tags'' on its output; minor plumbing required.
+ ; return (ValBindsOut binds' sigs',
+ usesOnly (hsSigsFVs sigs') `plusDU` bind_dus) }
-Sigh --- need to pass along the signatures for the group of bindings,
-in case any of them \fbox{\ ???\ }
-\begin{code}
-flattenMonoBinds :: [RenamedSig] -- Signatures
- -> RdrNameMonoBinds
- -> RnMS [FlatMonoBindsInfo]
+---------------------
+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
-flattenMonoBinds sigs EmptyMonoBinds = returnRn []
+ keyd_nodes = bagToList binds_w_dus `zip` [0::Int ..]
-flattenMonoBinds sigs (AndMonoBinds bs1 bs2)
- = flattenMonoBinds sigs bs1 `thenRn` \ flat1 ->
- flattenMonoBinds sigs bs2 `thenRn` \ flat2 ->
- returnRn (flat1 ++ flat2)
+ edges = [ (node, key, [key | n <- nameSetToList uses,
+ Just key <- [lookupNameEnv key_map n] ])
+ | (node@(_,_,uses), key) <- keyd_nodes ]
-flattenMonoBinds sigs (PatMonoBind pat grhss locn)
- = pushSrcLocRn locn $
- rnPat pat `thenRn` \ (pat', pat_fvs) ->
+ key_map :: NameEnv Int -- Which binding it comes from
+ key_map = mkNameEnv [(bndr, key) | ((_, bndrs, _), key) <- keyd_nodes
+ , bndr <- bndrs ]
- -- Find which things are bound in this group
- let
- names_bound_here = mkNameSet (collectPatBinders pat')
- in
- sigsForMe names_bound_here sigs `thenRn` \ sigs_for_me ->
- rnGRHSs grhss `thenRn` \ (grhss', fvs) ->
- returnRn
- [(names_bound_here,
- fvs `plusFV` pat_fvs,
- PatMonoBind pat' grhss' locn,
- sigs_for_me
- )]
-
-flattenMonoBinds sigs (FunMonoBind name inf matches locn)
- = pushSrcLocRn locn $
- lookupBndrRn name `thenRn` \ new_name ->
- let
- names_bound_here = unitNameSet new_name
- in
- sigsForMe names_bound_here sigs `thenRn` \ sigs_for_me ->
- mapFvRn rnMatch matches `thenRn` \ (new_matches, fvs) ->
- mapRn_ (checkPrecMatch inf new_name) new_matches `thenRn_`
- returnRn
- [(unitNameSet new_name,
- fvs,
- FunMonoBind new_name inf new_matches locn,
- sigs_for_me
- )]
-
-
-sigsForMe names_bound_here sigs
- = foldlRn check [] (filter (sigForThisGroup names_bound_here) sigs)
+ 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
- check sigs sig = case filter (eqHsSig sig) sigs of
- [] -> returnRn (sig:sigs)
- other -> dupSigDeclErr sig `thenRn_`
- returnRn sigs
+ env :: NameEnv [Name]
+ env = mkNameEnv [ (name, map hsLTyVarName ltvs)
+ | L _ (TypeSig (L _ name)
+ (L _ (HsForAllTy Explicit ltvs _ _))) <- sigs]
+ -- Note the pattern-match on "Explicit"; we only bind
+ -- type variables from signatures with an explicit top-level for-all
+
+-- The trimming function trims the free vars we attach to a
+-- binding so that it stays reasonably small
+noTrim :: FreeVars -> FreeVars
+noTrim fvs = fvs -- Used at top level
+
+trimWith :: [Name] -> FreeVars -> FreeVars
+-- Nested bindings; trim by intersection with the names bound here
+trimWith bndrs = intersectNameSet (mkNameSet bndrs)
+
+---------------------
+rnBind :: (Name -> [Name]) -- Signature tyvar function
+ -> (FreeVars -> FreeVars) -- Trimming function for rhs free vars
+ -> LHsBind RdrName
+ -> RnM (LHsBind Name, [Name], Uses)
+rnBind sig_fn trim (L loc (PatBind { pat_lhs = pat, pat_rhs = grhss }))
+ = setSrcSpan loc $
+ do { (pat', pat_fvs) <- rnLPat pat
+
+ ; let bndrs = collectPatBinders pat'
+
+ ; (grhss', fvs) <- bindSigTyVarsFV (concatMap sig_fn bndrs) $
+ rnGRHSs PatBindRhs grhss
+
+ ; return (L loc (PatBind { pat_lhs = pat', pat_rhs = grhss',
+ pat_rhs_ty = placeHolderType, bind_fvs = trim fvs }),
+ bndrs, pat_fvs `plusFV` fvs) }
+
+rnBind sig_fn trim (L loc (FunBind { fun_id = name, fun_infix = inf, fun_matches = matches }))
+ = setSrcSpan loc $
+ do { new_name <- lookupLocatedBndrRn name
+ ; let plain_name = unLoc new_name
+
+ ; (matches', fvs) <- bindSigTyVarsFV (sig_fn plain_name) $
+ rnMatchGroup (FunRhs plain_name) matches
+
+ ; checkPrecMatch inf plain_name matches'
+
+ ; return (L loc (FunBind { fun_id = new_name, fun_infix = inf, fun_matches = matches',
+ bind_fvs = trim fvs, fun_co_fn = idCoercion }),
+ [plain_name], fvs)
+ }
\end{code}
@rnMethodBinds@ is used for the method bindings of a class and an instance
-declaration. Like @rnMonoBinds@ but without dependency analysis.
+declaration. Like @rnBinds@ but without dependency analysis.
NOTA BENE: we record each {\em binder} of a method-bind group as a free variable.
That's crucial when dealing with an instance decl:
a binder.
\begin{code}
-rnMethodBinds :: [Name] -- Names for generic type variables
- -> RdrNameMonoBinds
- -> RnMS (RenamedMonoBinds, FreeVars)
-
-rnMethodBinds gen_tyvars EmptyMonoBinds = returnRn (EmptyMonoBinds, emptyFVs)
-
-rnMethodBinds gen_tyvars (AndMonoBinds mb1 mb2)
- = rnMethodBinds gen_tyvars mb1 `thenRn` \ (mb1', fvs1) ->
- rnMethodBinds gen_tyvars mb2 `thenRn` \ (mb2', fvs2) ->
- returnRn (mb1' `AndMonoBinds` mb2', fvs1 `plusFV` fvs2)
-
-rnMethodBinds gen_tyvars (FunMonoBind name inf matches locn)
- = pushSrcLocRn locn $
-
- lookupGlobalOccRn name `thenRn` \ sel_name ->
+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 matches `thenRn` \ (new_matches, fvs) ->
- mapRn_ (checkPrecMatch inf sel_name) new_matches `thenRn_`
- returnRn (FunMonoBind sel_name inf new_matches locn, fvs `addOneFV` sel_name)
+ mapFvRn (rn_match plain_name) matches `thenM` \ (new_matches, fvs) ->
+ let
+ new_group = MatchGroup new_matches placeHolderType
+ in
+ checkPrecMatch inf plain_name new_group `thenM_`
+ returnM (unitBag (L loc (FunBind { fun_id = sel_name, fun_infix = inf, fun_matches = new_group,
+ bind_fvs = fvs, fun_co_fn = idCoercion })),
+ fvs `addOneFV` plain_name)
+ -- The 'fvs' field isn't used for method binds
where
- -- Gruesome; bring into scope the correct members of the generic type variables
- -- See comments in RnSource.rnDecl(ClassDecl)
- rn_match match@(Match _ (TypePatIn ty : _) _ _)
- = extendTyVarEnvFVRn gen_tvs (rnMatch match)
+ -- 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 (extractHsTyRdrNames ty)
+ tvs = map (rdrNameOcc.unLoc) (extractHsTyRdrTyVars ty)
gen_tvs = [tv | tv <- gen_tyvars, nameOccName tv `elem` tvs]
- rn_match match = rnMatch match
-
+ rn_match sel_name match = rnMatch (FunRhs sel_name) match
--- Can't handle method pattern-bindings which bind multiple methods.
-rnMethodBinds gen_tyvars mbind@(PatMonoBind other_pat _ locn)
- = pushSrcLocRn locn $
- failWithRn (EmptyMonoBinds, emptyFVs) (methodBindErr mbind)
-\end{code}
-
-
-%************************************************************************
-%* *
-\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
-
-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@.
-The @RenamedMonoBinds@ is always an empty bind, a pattern binding or
-a function binding, and has itself been dependency-analysed and
-renamed.
-\begin{code}
-type FlatMonoBindsInfo
- = (NameSet, -- Set of names defined in this vertex
- NameSet, -- Set of names used in this vertex
- RenamedMonoBinds,
- [RenamedSig]) -- Signatures, if any, for this vertex
-
-mkEdges :: [(FlatMonoBindsInfo, VertexTag)] -> [(FlatMonoBindsInfo, VertexTag, [VertexTag])]
-
-mkEdges flat_info
- = [ (info, tag, dest_vertices (nameSetToList names_used))
- | (info@(names_defined, names_used, mbind, sigs), tag) <- flat_info
- ]
- where
- -- 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
- ]
+-- 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}
signatures. We'd only need this if we wanted to report unused tyvars.
\begin{code}
-renameSigs :: (RenamedSig -> Bool) -- OK-sig predicate
- -> [RdrNameSig]
- -> RnMS ([RenamedSig], FreeVars)
-
-renameSigs ok_sig [] = returnRn ([], emptyFVs) -- Common shortcut
-
-renameSigs ok_sig sigs
- = -- Rename the signatures
- mapFvRn renameSig sigs `thenRn` \ (sigs', fvs) ->
-
+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
- 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
- mapRn_ unknownSigErr bads `thenRn_`
- returnRn (goods, fvs)
+ = do { mappM_ unknownSigErr (filter (not . ok_sig) sigs')
+ ; mappM_ dupSigDeclErr (findDupsEq eqHsSig sigs') }
+ where
+ -- Don't complain about an unbound name again
+ sigs' = filterOut bad_name sigs
+ bad_name sig = case sigName sig of
+ Just n -> isUnboundName n
+ other -> False
--- We use lookupSigOccRn in the signatures, which is a little bit unsatisfactory
+-- We use lookupLocatedSigOccRn in the signatures, which is a little bit unsatisfactory
-- because this won't work for:
-- instance Foo T where
-- {-# INLINE op #-}
-- 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 -> RnMS (Sig Name, FreeVars)
--- ClassOpSig is renamed elsewhere.
-renameSig (Sig v ty src_loc)
- = pushSrcLocRn src_loc $
- lookupSigOccRn v `thenRn` \ new_v ->
- rnHsSigType (quotes (ppr v)) ty `thenRn` \ (new_ty,fvs) ->
- returnRn (Sig new_v new_ty src_loc, fvs `addOneFV` new_v)
-
-renameSig (SpecInstSig ty src_loc)
- = pushSrcLocRn src_loc $
- rnHsSigType (text "A SPECIALISE instance pragma") ty `thenRn` \ (new_ty, fvs) ->
- returnRn (SpecInstSig new_ty src_loc, fvs)
-
-renameSig (SpecSig v ty src_loc)
- = pushSrcLocRn src_loc $
- lookupSigOccRn v `thenRn` \ new_v ->
- rnHsSigType (quotes (ppr v)) ty `thenRn` \ (new_ty,fvs) ->
- returnRn (SpecSig new_v new_ty src_loc, fvs `addOneFV` new_v)
-
-renameSig (FixSig (FixitySig v fix src_loc))
- = pushSrcLocRn src_loc $
- lookupSigOccRn v `thenRn` \ new_v ->
- returnRn (FixSig (FixitySig new_v fix src_loc), unitFV new_v)
-
-renameSig (InlineSig v p src_loc)
- = pushSrcLocRn src_loc $
- lookupSigOccRn v `thenRn` \ new_v ->
- returnRn (InlineSig new_v p src_loc, unitFV new_v)
-
-renameSig (NoInlineSig v p src_loc)
- = pushSrcLocRn src_loc $
- lookupSigOccRn v `thenRn` \ new_v ->
- returnRn (NoInlineSig new_v p src_loc, unitFV new_v)
+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}
+
+************************************************************************
+* *
+\subsection{Match}
+* *
+************************************************************************
+
\begin{code}
-renameIE :: (RdrName -> RnMS Name) -> IE RdrName -> RnMS (IE Name, FreeVars)
-renameIE lookup_occ_nm (IEVar v)
- = lookup_occ_nm v `thenRn` \ new_v ->
- returnRn (IEVar new_v, unitFV new_v)
-
-renameIE lookup_occ_nm (IEThingAbs v)
- = lookup_occ_nm v `thenRn` \ new_v ->
- returnRn (IEThingAbs new_v, unitFV new_v)
-
-renameIE lookup_occ_nm (IEThingAll v)
- = lookup_occ_nm v `thenRn` \ new_v ->
- returnRn (IEThingAll new_v, unitFV new_v)
-
-renameIE lookup_occ_nm (IEThingWith v vs)
- = lookup_occ_nm v `thenRn` \ new_v ->
- mapRn lookup_occ_nm vs `thenRn` \ new_vs ->
- returnRn (IEThingWith new_v new_vs, plusFVs [ unitFV x | x <- new_v:new_vs ])
-
-renameIE lookup_occ_nm (IEModuleContents m)
- = returnRn (IEModuleContents m, emptyFVs)
+rnMatchGroup :: HsMatchContext Name -> MatchGroup RdrName -> RnM (MatchGroup Name, FreeVars)
+rnMatchGroup ctxt (MatchGroup ms _)
+ = mapFvRn (rnMatch ctxt) ms `thenM` \ (new_ms, ms_fvs) ->
+ returnM (MatchGroup new_ms placeHolderType, ms_fvs)
+
+rnMatch :: HsMatchContext Name -> LMatch RdrName -> RnM (LMatch Name, FreeVars)
+rnMatch ctxt = wrapLocFstM (rnMatch' ctxt)
+
+rnMatch' ctxt match@(Match pats maybe_rhs_sig grhss)
+ =
+ -- Deal with the rhs type signature
+ bindPatSigTyVarsFV rhs_sig_tys $
+ doptM Opt_GlasgowExts `thenM` \ opt_GlasgowExts ->
+ (case maybe_rhs_sig of
+ Nothing -> returnM (Nothing, emptyFVs)
+ Just ty | opt_GlasgowExts -> rnHsTypeFVs doc_sig ty `thenM` \ (ty', ty_fvs) ->
+ returnM (Just ty', ty_fvs)
+ | otherwise -> addLocErr ty patSigErr `thenM_`
+ returnM (Nothing, emptyFVs)
+ ) `thenM` \ (maybe_rhs_sig', ty_fvs) ->
+
+ -- Now the main event
+ rnPatsAndThen ctxt pats $ \ pats' ->
+ rnGRHSs ctxt grhss `thenM` \ (grhss', grhss_fvs) ->
+
+ returnM (Match pats' maybe_rhs_sig' grhss', grhss_fvs `plusFV` ty_fvs)
+ -- The bindPatSigTyVarsFV and rnPatsAndThen will remove the bound FVs
+ where
+ rhs_sig_tys = case maybe_rhs_sig of
+ Nothing -> []
+ Just ty -> [ty]
+ doc_sig = text "In a result type-signature"
\end{code}
%************************************************************************
%* *
+\subsubsection{Guarded right-hand sides (GRHSs)}
+%* *
+%************************************************************************
+
+\begin{code}
+rnGRHSs :: HsMatchContext Name -> GRHSs RdrName -> RnM (GRHSs Name, FreeVars)
+
+rnGRHSs ctxt (GRHSs grhss binds)
+ = rnLocalBindsAndThen binds $ \ binds' ->
+ mapFvRn (rnGRHS ctxt) grhss `thenM` \ (grhss', fvGRHSs) ->
+ returnM (GRHSs grhss' binds', fvGRHSs)
+
+rnGRHS :: HsMatchContext Name -> LGRHS RdrName -> RnM (LGRHS Name, FreeVars)
+rnGRHS ctxt = wrapLocFstM (rnGRHS' ctxt)
+
+rnGRHS' ctxt (GRHS guards rhs)
+ = do { opt_GlasgowExts <- doptM Opt_GlasgowExts
+ ; ((guards', rhs'), fvs) <- rnStmts (PatGuard ctxt) guards $
+ rnLExpr rhs
+
+ ; checkM (opt_GlasgowExts || is_standard_guard guards')
+ (addWarn (nonStdGuardErr guards'))
+
+ ; return (GRHS guards' rhs', fvs) }
+ where
+ -- Standard Haskell 1.4 guards are just a single boolean
+ -- expression, rather than a list of qualifiers as in the
+ -- Glasgow extension
+ is_standard_guard [] = True
+ is_standard_guard [L _ (ExprStmt _ _ _)] = True
+ is_standard_guard other = False
+\end{code}
+
+%************************************************************************
+%* *
\subsection{Error messages}
%* *
%************************************************************************
\begin{code}
-dupSigDeclErr sig
- = pushSrcLocRn loc $
- addErrRn (sep [ptext SLIT("Duplicate") <+> ptext what_it_is <> colon,
- ppr sig])
+dupSigDeclErr sigs@(L loc sig : _)
+ = addErrAt loc $
+ vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon,
+ nest 2 (vcat (map ppr_sig sigs))]
where
- (what_it_is, loc) = hsSigDoc sig
+ what_it_is = hsSigDoc sig
+ ppr_sig (L loc sig) = ppr loc <> colon <+> ppr sig
-unknownSigErr sig
- = pushSrcLocRn loc $
- addErrRn (sep [ptext SLIT("Misplaced") <+> ptext what_it_is <> colon,
- ppr sig])
+unknownSigErr (L loc sig)
+ = addErrAt loc $
+ sep [ptext SLIT("Misplaced") <+> what_it_is <> colon, ppr sig]
where
- (what_it_is, loc) = hsSigDoc sig
+ what_it_is = hsSigDoc sig
missingSigWarn var
- = sep [ptext SLIT("definition but no type signature for"), quotes (ppr var)]
+ = addWarnAt (mkSrcSpan loc loc) $
+ sep [ptext SLIT("Definition but no type signature for"), quotes (ppr var)]
+ where
+ loc = nameSrcLoc var -- TODO: make a proper span
methodBindErr mbind
- = hang (ptext SLIT("Can't handle multiple methods defined by one pattern binding"))
- 4 (ppr mbind)
+ = hang (ptext SLIT("Pattern bindings (except simple variables) not allowed in instance declarations"))
+ 2 (ppr mbind)
+
+bindsInHsBootFile mbinds
+ = hang (ptext SLIT("Bindings in hs-boot files are not allowed"))
+ 2 (ppr mbinds)
+
+nonStdGuardErr guards
+ = hang (ptext SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)"))
+ 4 (interpp'SP guards)
\end{code}
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