\begin{code}
module RnBinds (
- rnTopBinds, rnBinds, rnBindsAndThen,
- rnMethodBinds, renameSigs, checkSigs
+ rnTopBinds,
+ rnLocalBindsAndThen, rnValBindsAndThen, rnValBinds, trimWith,
+ rnMethodBinds, renameSigs,
+ rnMatchGroup, rnGRHSs
) where
#include "HsVersions.h"
+import {-# SOURCE #-} RnExpr( rnLExpr, rnStmts )
import HsSyn
-import HsBinds ( hsSigDoc, eqHsSig )
import RdrHsSyn
import RnHsSyn
import TcRnMonad
-import RnTypes ( rnHsSigType, rnLHsType, rnLPat )
-import RnExpr ( rnMatchGroup, rnMatch, rnGRHSs, checkPrecMatch )
+import RnTypes ( rnHsSigType, rnLHsType, rnHsTypeFVs,
+ rnLPat, rnPatsAndThen, patSigErr, checkPrecMatch )
import RnEnv ( bindLocatedLocalsRn, lookupLocatedBndrRn,
- lookupLocatedInstDeclBndr,
+ lookupLocatedInstDeclBndr, newIPNameRn,
lookupLocatedSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV,
bindLocalFixities, bindSigTyVarsFV,
warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn,
)
-import CmdLineOpts ( DynFlag(..) )
-import Digraph ( SCC(..), stronglyConnComp )
+import DynFlags ( DynFlag(..) )
import Name ( Name, nameOccName, nameSrcLoc )
+import NameEnv
import NameSet
import PrelNames ( isUnboundName )
import RdrName ( RdrName, rdrNameOcc )
-import BasicTypes ( RecFlag(..), TopLevelFlag(..), isTopLevel )
-import List ( unzip4 )
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}
contains bindings for the binders of this particular binding.
\begin{code}
-rnTopBinds :: LHsBinds RdrName
- -> [LSig RdrName]
- -> RnM ([HsBindGroup Name], DefUses)
+rnTopBinds :: HsValBinds RdrName -> RnM (HsValBinds Name, DefUses)
-- The binders of the binding are in scope already;
-- the top level scope resolution does that
-rnTopBinds mbinds sigs
+rnTopBinds binds
= do { is_boot <- tcIsHsBoot
- ; if is_boot then
- rnHsBoot mbinds sigs
- else 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 TopLevel mbinds sigs }
-
-rnHsBoot :: LHsBinds RdrName
- -> [LSig RdrName]
- -> RnM ([HsBindGroup Name], DefUses)
+ ; 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
-rnHsBoot mbinds sigs
+rnTopBindsBoot (ValBindsIn mbinds sigs)
= do { checkErr (isEmptyLHsBinds mbinds) (bindsInHsBootFile mbinds)
- ; sigs' <- renameSigs sigs
- ; return ([HsBindGroup emptyLHsBinds sigs' NonRecursive],
- usesOnly (hsSigsFVs sigs')) }
+ ; 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}
+
+
+
+%*********************************************************
+%* *
+ HsLocalBinds
+%* *
+%*********************************************************
+
+\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
%* *
%************************************************************************
\begin{code}
-rnBindsAndThen :: Bag (LHsBind RdrName)
- -> [LSig RdrName]
- -> ([HsBindGroup Name] -> RnM (result, FreeVars))
- -> RnM (result, FreeVars)
+rnValBindsAndThen :: HsValBinds RdrName
+ -> (HsValBinds Name -> RnM (result, FreeVars))
+ -> RnM (result, FreeVars)
-rnBindsAndThen mbinds sigs thing_inside
+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 $ \ _ ->
- bindPatSigTyVarsFV (collectSigTysFromHsBinds (bagToList mbinds)) $
+ 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 ] $
-- Do the business
- rnBinds NotTopLevel mbinds sigs `thenM` \ (binds, bind_dus) ->
+ rnValBinds (trimWith bndrs) binds `thenM` \ (binds, bind_dus) ->
-- Now do the "thing inside"
thing_inside binds `thenM` \ (result,result_fvs) ->
-- Final error checking
let
- all_uses = duUses bind_dus `plusFV` result_fvs
- bndrs = duDefs bind_dus
- unused_bndrs = nameSetToList (bndrs `minusNameSet` all_uses)
- in
- 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:
+ 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_bndrs `thenM_`
+
+ 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)
-\end{code}
+---------------------
+rnValBinds :: (FreeVars -> FreeVars)
+ -> HsValBinds RdrName
+ -> RnM (HsValBinds Name, DefUses)
+-- Assumes the binders of the binding are in scope already
-%************************************************************************
-%* *
-\subsubsection{rnBinds -- the main work is done here}
-%* *
-%************************************************************************
+rnValBinds trim (ValBindsIn mbinds sigs)
+ = do { sigs' <- rename_sigs sigs
-@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).
+ ; binds_w_dus <- mapBagM (rnBind (mkSigTvFn sigs') trim) mbinds
-\begin{code}
-rnBinds :: TopLevelFlag
- -> LHsBinds RdrName
- -> [LSig RdrName]
- -> RnM ([HsBindGroup Name], DefUses)
+ ; let (binds', bind_dus) = depAnalBinds binds_w_dus
--- Assumes the binders of the binding are in scope already
+ -- 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'
-rnBinds top_lvl mbinds sigs
- = renameSigs sigs `thenM` \ siglist ->
+ ; return (ValBindsOut binds' sigs',
+ usesOnly (hsSigsFVs sigs') `plusDU` bind_dus) }
- -- 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 ->
- -- 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
- -- 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}
+---------------------
+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
-@mkBindVertices@ is ever-so-slightly magical in that it sticks
-unique ``vertex tags'' on its output; minor plumbing required.
+ keyd_nodes = bagToList binds_w_dus `zip` [0::Int ..]
-\begin{code}
-mkBindVertices :: [LSig Name] -- Signatures
- -> LHsBinds RdrName
- -> RnM [BindVertex]
-mkBindVertices sigs = mapM (mkBindVertex sigs) . bagToList
+ edges = [ (node, key, [key | n <- nameSetToList uses,
+ Just key <- [lookupNameEnv key_map n] ])
+ | (node@(_,_,uses), key) <- keyd_nodes ]
-mkBindVertex :: [LSig Name] -> LHsBind RdrName -> RnM BindVertex
-mkBindVertex sigs (L loc (PatBind pat grhss ty))
- = setSrcSpan loc $
- rnLPat pat `thenM` \ (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 `thenM` \ sigs_for_me ->
- bindSigTyVarsFV sigs_for_me (
- rnGRHSs PatBindRhs grhss
- ) `thenM` \ (grhss', fvs) ->
- returnM
- (names_bound_here, fvs `plusFV` pat_fvs,
- L loc (PatBind pat' grhss' ty), sigs_for_me
- )
-
-mkBindVertex sigs (L loc (FunBind name inf matches))
- = setSrcSpan loc $
- lookupLocatedBndrRn name `thenM` \ new_name ->
- let
- plain_name = unLoc new_name
- names_bound_here = unitNameSet plain_name
- in
- sigsForMe names_bound_here sigs `thenM` \ sigs_for_me ->
- bindSigTyVarsFV sigs_for_me (
- rnMatchGroup (FunRhs plain_name) matches
- ) `thenM` \ (new_matches, fvs) ->
- 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)
+ 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
- -- 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
+ 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}
(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 (MatchGroup matches _)))
+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
new_group = MatchGroup new_matches placeHolderType
in
checkPrecMatch inf plain_name new_group `thenM_`
- returnM (unitBag (L loc (FunBind sel_name inf new_group)), fvs `addOneFV` plain_name)
+ 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)
-- Can't handle method pattern-bindings which bind multiple methods.
-rnMethodBind cls gen_tyvars mbind@(L loc (PatBind other_pat _ _))
+rnMethodBind cls gen_tyvars mbind@(L loc (PatBind other_pat _ _ _))
= addLocErr mbind methodBindErr `thenM_`
returnM (emptyBag, emptyFVs)
\end{code}
%************************************************************************
%* *
- Strongly connected components
-%* *
-%************************************************************************
-
-\begin{code}
-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
-
-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}
-
-
-%************************************************************************
-%* *
\subsubsection[dep-Sigs]{Signatures (and user-pragmas for values)}
%* *
%************************************************************************
signatures. We'd only need this if we wanted to report unused tyvars.
\begin{code}
-checkSigs :: (LSig Name -> Bool) -- OK-sig predicbate
- -> [LSig Name]
- -> RnM ()
-checkSigs ok_sig sigs
+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
- -- Well, I can't see the check for (a)... ToDo!
- = mappM_ unknownSigErr (filter bad sigs)
+ = do { mappM_ unknownSigErr (filter (not . ok_sig) sigs')
+ ; mappM_ dupSigDeclErr (findDupsEq eqHsSig sigs') }
where
- bad sig = not (ok_sig sig) &&
- case sigName sig of
- Just n | isUnboundName n -> False
- -- Don't complain about an unbound name again
- other -> True
+ -- 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.
-renameSigs :: [LSig RdrName] -> RnM [LSig Name]
-renameSigs sigs = mappM (wrapLocM renameSig) (filter (not . isFixityLSig) sigs)
- -- Remove fixity sigs which have been dealt with already
-
renameSig :: Sig RdrName -> RnM (Sig Name)
-- FixitSig is renamed elsewhere.
-renameSig (Sig v ty)
+renameSig (TypeSig v ty)
= lookupLocatedSigOccRn v `thenM` \ new_v ->
rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty ->
- returnM (Sig new_v 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)
+renameSig (SpecSig v ty inl)
= lookupLocatedSigOccRn v `thenM` \ new_v ->
rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty ->
- returnM (SpecSig new_v new_ty)
+ returnM (SpecSig new_v new_ty inl)
-renameSig (InlineSig b v p)
+renameSig (InlineSig v s)
= lookupLocatedSigOccRn v `thenM` \ new_v ->
- returnM (InlineSig b new_v p)
+ returnM (InlineSig new_v s)
+\end{code}
+
+
+************************************************************************
+* *
+\subsection{Match}
+* *
+************************************************************************
+
+\begin{code}
+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 (L loc sig) sigs
+dupSigDeclErr sigs@(L loc sig : _)
= addErrAt loc $
vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon,
- nest 2 (vcat (map ppr_sig (L loc sig:sigs)))]
+ nest 2 (vcat (map ppr_sig sigs))]
where
what_it_is = hsSigDoc sig
ppr_sig (L loc sig) = ppr loc <> colon <+> ppr sig
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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