\begin{code}
module RnBinds (
- rnTopBinds, rnTopMonoBinds,
- rnMethodBinds, renameSigs,
- rnBinds, rnMonoBinds
+ rnTopBinds, rnBinds, rnBindsAndThen,
+ rnMethodBinds, renameSigs, checkSigs
) where
#include "HsVersions.h"
-import {-# SOURCE #-} RnSource ( rnHsSigType )
import HsSyn
-import HsBinds ( sigsForMe )
+import HsBinds ( hsSigDoc, eqHsSig )
import RdrHsSyn
import RnHsSyn
-import RnMonad
-import RnExpr ( rnMatch, rnGRHSs, rnPat, checkPrecMatch )
-import RnEnv ( bindLocatedLocalsRn, lookupBndrRn, lookupOccRn, lookupGlobalOccRn,
- isUnboundName, warnUnusedBinds,
- FreeVars, emptyFVs, plusFV, plusFVs, unitFV
+import TcRnMonad
+import RnTypes ( rnHsSigType, rnLHsType, rnLPat )
+import RnExpr ( rnMatchGroup, rnMatch, rnGRHSs, checkPrecMatch )
+import RnEnv ( bindLocatedLocalsRn, lookupLocatedBndrRn,
+ lookupLocatedInstDeclBndr,
+ lookupLocatedSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV,
+ bindLocalFixities,
+ warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn,
)
-import CmdLineOpts ( opt_WarnMissingSigs )
-import Digraph ( stronglyConnComp, SCC(..) )
-import Name ( OccName, Name )
+import CmdLineOpts ( DynFlag(..) )
+import Digraph ( SCC(..), stronglyConnComp )
+import Name ( Name, nameOccName, nameSrcLoc )
import NameSet
-import BasicTypes ( RecFlag(..), TopLevelFlag(..) )
-import Util ( thenCmp, removeDups )
-import ListSetOps ( minusList )
-import Bag ( bagToList )
+import PrelNames ( isUnboundName )
+import RdrName ( RdrName, rdrNameOcc )
+import BasicTypes ( RecFlag(..), TopLevelFlag(..), isTopLevel )
+import List ( unzip4 )
+import SrcLoc ( mkSrcSpan, Located(..), unLoc )
+import Bag
import Outputable
+import Monad ( foldM )
\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
%************************************************************************
%* *
-%* Top-level bindings
+\subsubsection{ Top-level bindings}
%* *
%************************************************************************
-@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 s (RenamedHsBinds, FreeVars)
+rnTopBinds :: LHsBinds RdrName
+ -> [LSig RdrName]
+ -> RnM ([HsBindGroup Name], DefUses)
-rnTopBinds EmptyBinds = returnRn (EmptyBinds, emptyFVs)
-rnTopBinds (MonoBind bind sigs _) = rnTopMonoBinds bind sigs
- -- The parser doesn't produce other forms
+-- The binders of the binding are in scope already;
+-- the top level scope resolution does that
+rnTopBinds mbinds sigs
+ = bindPatSigTyVars (collectSigTysFromHsBinds (bagToList mbinds)) $ \ _ ->
+ -- Hmm; by analogy with Ids, this doesn't look right
+ -- Top-level bound type vars should really scope over
+ -- everything, but we only scope them over the other bindings
-rnTopMonoBinds EmptyMonoBinds sigs
- = returnRn (EmptyBinds, emptyFVs)
-
-rnTopMonoBinds mbinds sigs
- = mapRn lookupBndrRn binder_rdr_names `thenRn` \ binder_names ->
- let
- binder_set = mkNameSet binder_names
- in
- rn_mono_binds TopLevel binder_set mbinds sigs
- where
- binder_rdr_names = map fst (bagToList (collectMonoBinders mbinds))
+ rnBinds TopLevel mbinds sigs
\end{code}
+
%************************************************************************
%* *
%* Nested binds
%* *
%************************************************************************
-@rnMonoBinds@
- - collects up the binders for this declaration group,
- - checks that they form a set
- - extends the environment to bind them to new local names
- - calls @rnMonoBinds@ to do the real work
-
\begin{code}
-rnBinds :: RdrNameHsBinds
- -> (RenamedHsBinds -> RnMS s (result, FreeVars))
- -> RnMS s (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
-
+rnBindsAndThen :: Bag (LHsBind RdrName)
+ -> [LSig RdrName]
+ -> ([HsBindGroup Name] -> RnM (result, FreeVars))
+ -> RnM (result, FreeVars)
+
+rnBindsAndThen mbinds sigs thing_inside
+ = -- Extract all the binders in this group, and extend the
+ -- current scope, inventing new names for the new binders
+ -- This also checks that the names form a set
+ bindLocatedLocalsRn doc mbinders_w_srclocs $ \ _ ->
+ bindPatSigTyVarsFV (collectSigTysFromHsBinds (bagToList mbinds)) $
-rnMonoBinds :: RdrNameMonoBinds -> [RdrNameSig]
- -> (RenamedHsBinds -> RnMS s (result, FreeVars))
- -> RnMS s (result, FreeVars)
+ -- Then install local fixity declarations
+ -- Notice that they scope over thing_inside too
+ bindLocalFixities [sig | L _ (FixSig sig) <- sigs ] $
-rnMonoBinds EmptyMonoBinds sigs thing_inside = thing_inside EmptyBinds
+ -- Do the business
+ rnBinds NotTopLevel mbinds sigs `thenM` \ (binds, bind_dus) ->
-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
- -- This also checks that the names form a set
- bindLocatedLocalsRn (text "binding group") mbinders_w_srclocs $ \ new_mbinders ->
- let
- binder_set = mkNameSet new_mbinders
- in
- rn_mono_binds NotTopLevel
- binder_set mbinds sigs `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
- unused_binders = nameSetToList (binder_set `minusNameSet` all_fvs)
+ all_uses = duUses bind_dus `plusFV` result_fvs
+ bndrs = duDefs bind_dus
+ unused_bndrs = nameSetToList (bndrs `minusNameSet` all_uses)
in
- warnUnusedBinds unused_binders `thenRn_`
- returnRn (result, delListFromNameSet all_fvs new_mbinders)
+ warnUnusedLocalBinds unused_bndrs `thenM_`
+
+ returnM (result, all_uses `minusNameSet` bndrs)
+ -- duUses: It's important to return all the uses, not the 'real uses' used for
+ -- warning about unused bindings. Otherwise consider:
+ -- x = 3
+ -- y = let p = x in 'x' -- NB: p not used
+ -- If we don't "see" the dependency of 'y' on 'x', we may put the
+ -- bindings in the wrong order, and the type checker will complain
+ -- that x isn't in scope
where
- mbinders_w_srclocs = bagToList (collectMonoBinders mbinds)
+ mbinders_w_srclocs = collectHsBindLocatedBinders mbinds
+ doc = text "In the binding group for:"
+ <+> pprWithCommas ppr (map unLoc mbinders_w_srclocs)
\end{code}
%************************************************************************
%* *
-%* MonoBinds -- the main work is done here
+\subsubsection{rnBinds -- the main work is done here}
%* *
%************************************************************************
-@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).
+@rnMonoBinds@ is used by {\em both} top-level and nested bindings.
+It assumes that all variables bound in this group are already in scope.
+This is done {\em either} by pass 3 (for the top-level bindings),
+{\em or} by @rnMonoBinds@ (for the nested ones).
\begin{code}
-rn_mono_binds :: TopLevelFlag
- -> NameSet -- Binders of this group
- -> RdrNameMonoBinds
- -> [RdrNameSig] -- Signatures attached to this group
- -> RnMS s (RenamedHsBinds, --
- FreeVars) -- Free variables
-
-rn_mono_binds top_lev binders mbinds sigs
- =
- -- Rename the bindings, returning a MonoBindsInfo
+rnBinds :: TopLevelFlag
+ -> LHsBinds RdrName
+ -> [LSig RdrName]
+ -> RnM ([HsBindGroup Name], DefUses)
+
+-- Assumes the binders of the binding are in scope already
+
+rnBinds top_lvl mbinds sigs
+ = renameSigs sigs `thenM` \ siglist ->
+
+ -- Rename the bindings, returning a [HsBindVertex]
-- which is a list of indivisible vertices so far as
-- the strongly-connected-components (SCC) analysis is concerned
- renameSigs top_lev False binders sigs `thenRn` \ siglist ->
- flattenMonoBinds siglist mbinds `thenRn` \ mbinds_info ->
+ mkBindVertices siglist mbinds `thenM` \ mbinds_info ->
-- Do the SCC analysis
- let edges = mkEdges (mbinds_info `zip` [(0::Int)..])
- scc_result = stronglyConnComp edges
- final_binds = foldr1 ThenBinds (map reconstructCycle scc_result)
-
- -- Deal with bound and free-var calculation
- rhs_fvs = plusFVs [fvs | (_,fvs,_,_) <- mbinds_info]
+ 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
- returnRn (final_binds, rhs_fvs)
+ -- Check for duplicate or mis-placed signatures
+ checkSigs (okBindSig binders) siglist `thenM_`
+
+ -- Warn about missing signatures,
+ -- but only at top level, and not in interface mode
+ -- (The latter is important when renaming bindings from 'deriving' clauses.)
+ doptM Opt_WarnMissingSigs `thenM` \ warn_missing_sigs ->
+ (if isTopLevel top_lvl &&
+ warn_missing_sigs
+ then let
+ type_sig_vars = [ unLoc n | L _ (Sig n _) <- siglist]
+ un_sigd_binders = filter (not . (`elem` type_sig_vars))
+ (nameSetToList binders)
+ in
+ mappM_ missingSigWarn un_sigd_binders
+ else
+ returnM ()
+ ) `thenM_`
+
+ returnM (groups, bind_dus `plusDU` usesOnly (hsSigsFVs siglist))
\end{code}
-@flattenMonoBinds@ is ever-so-slightly magical in that it sticks
+@mkBindVertices@ is ever-so-slightly magical in that it sticks
unique ``vertex tags'' on its output; minor plumbing required.
\begin{code}
-flattenMonoBinds :: [RenamedSig] -- Signatures
- -> RdrNameMonoBinds
- -> RnMS s [FlatMonoBindsInfo]
-
-flattenMonoBinds sigs EmptyMonoBinds = returnRn []
+mkBindVertices :: [LSig Name] -- Signatures
+ -> LHsBinds RdrName
+ -> RnM [BindVertex]
+mkBindVertices sigs = mapM (mkBindVertex sigs) . bagToList
-flattenMonoBinds sigs (AndMonoBinds bs1 bs2)
- = flattenMonoBinds sigs bs1 `thenRn` \ flat1 ->
- flattenMonoBinds sigs bs2 `thenRn` \ flat2 ->
- returnRn (flat1 ++ flat2)
-
-flattenMonoBinds sigs (PatMonoBind pat grhss locn)
- = pushSrcLocRn locn $
- rnPat pat `thenRn` \ (pat', pat_fvs) ->
+mkBindVertex :: [LSig Name] -> LHsBind RdrName -> RnM BindVertex
+mkBindVertex sigs (L loc (PatBind pat grhss ty))
+ = setSrcSpan loc $
+ rnLPat pat `thenM` \ (pat', pat_fvs) ->
-- Find which things are bound in this group
let
names_bound_here = mkNameSet (collectPatBinders pat')
- sigs_for_me = sigsForMe (`elemNameSet` names_bound_here) sigs
- sigs_fvs = foldr sig_fv emptyFVs sigs_for_me
- fixity_sigs = [(name,sig) | FixSig sig@(FixitySig name _ _) <- sigs_for_me]
in
- extendFixityEnv fixity_sigs $
- rnGRHSs grhss `thenRn` \ (grhss', fvs) ->
- returnRn
- [(names_bound_here,
- fvs `plusFV` sigs_fvs `plusFV` pat_fvs,
- PatMonoBind pat' grhss' locn,
- sigs_for_me
- )]
-
-flattenMonoBinds sigs (FunMonoBind name inf matches locn)
- = pushSrcLocRn locn $
- lookupBndrRn name `thenRn` \ name' ->
+ sigsForMe names_bound_here sigs `thenM` \ sigs_for_me ->
+ rnGRHSs PatBindRhs grhss `thenM` \ (grhss', fvs) ->
+ returnM
+ (names_bound_here, fvs `plusFV` pat_fvs,
+ L loc (PatBind pat' grhss' ty), sigs_for_me
+ )
+
+mkBindVertex sigs (L loc (FunBind name inf matches))
+ = setSrcSpan loc $
+ lookupLocatedBndrRn name `thenM` \ new_name ->
let
- sigs_for_me = sigsForMe (name' ==) sigs
- sigs_fvs = foldr sig_fv emptyFVs sigs_for_me
- fixity_sigs = [(name,sig) | FixSig sig@(FixitySig name _ _) <- sigs_for_me]
+ plain_name = unLoc new_name
+ names_bound_here = unitNameSet plain_name
in
- extendFixityEnv fixity_sigs $
- mapAndUnzipRn rnMatch matches `thenRn` \ (new_matches, fv_lists) ->
- mapRn (checkPrecMatch inf name') new_matches `thenRn_`
- returnRn
- [(unitNameSet name',
- plusFVs fv_lists `plusFV` sigs_fvs,
- FunMonoBind name' inf new_matches locn,
- sigs_for_me
- )]
+ sigsForMe names_bound_here sigs `thenM` \ 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)
+ where
+ -- sigForThisGroup only returns signatures for
+ -- which sigName returns a Just
+ eq sig1 sig2 = eqHsSig (unLoc sig1) (unLoc sig2)
+
+ check sigs sig = case filter (eq sig) sigs of
+ [] -> returnM (sig:sigs)
+ other -> dupSigDeclErr sig other `thenM_`
+ returnM sigs
\end{code}
-@rnMethodBinds@ is used for the method bindings of an instance
-declaration. like @rnMonoBinds@ but without dependency analysis.
-
-\begin{code}
-rnMethodBinds :: RdrNameMonoBinds -> RnMS s (RenamedMonoBinds, FreeVars)
+@rnMethodBinds@ is used for the method bindings of a class and an instance
+declaration. Like @rnBinds@ but without dependency analysis.
-rnMethodBinds EmptyMonoBinds = returnRn (EmptyMonoBinds, emptyFVs)
-
-rnMethodBinds (AndMonoBinds mb1 mb2)
- = rnMethodBinds mb1 `thenRn` \ (mb1', fvs1) ->
- rnMethodBinds mb2 `thenRn` \ (mb2', fvs2) ->
- returnRn (mb1' `AndMonoBinds` mb2', fvs1 `plusFV` fvs2)
-
-rnMethodBinds (FunMonoBind name inf matches locn)
- = pushSrcLocRn locn $
+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.
- lookupGlobalOccRn name `thenRn` \ sel_name ->
+\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 name inf (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
- mapAndUnzipRn rnMatch matches `thenRn` \ (new_matches, fvs_s) ->
- mapRn (checkPrecMatch inf sel_name) new_matches `thenRn_`
- returnRn (FunMonoBind sel_name inf new_matches locn, plusFVs fvs_s)
+ 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 sel_name inf new_group)), fvs `addOneFV` plain_name)
+ 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]
+
+ rn_match sel_name match = rnMatch (FunRhs sel_name) match
-rnMethodBinds (PatMonoBind (VarPatIn name) grhss locn)
- = pushSrcLocRn locn $
- lookupGlobalOccRn name `thenRn` \ sel_name ->
- rnGRHSs grhss `thenRn` \ (grhss', fvs) ->
- returnRn (PatMonoBind (VarPatIn sel_name) grhss' locn, fvs)
-- Can't handle method pattern-bindings which bind multiple methods.
-rnMethodBinds mbind@(PatMonoBind other_pat _ locn)
- = pushSrcLocRn locn $
- failWithRn (EmptyMonoBinds, emptyFVs) (methodBindErr mbind)
+rnMethodBind cls gen_tyvars mbind@(L loc (PatBind other_pat _ _))
+ = addLocErr mbind methodBindErr `thenM_`
+ returnM (emptyBag, emptyFVs)
\end{code}
-\begin{code}
--- 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 `plusFV` unitFV blah
-sig_fv _ acc = acc
-\end{code}
%************************************************************************
%* *
-\subsection[reconstruct-deps]{Reconstructing dependencies}
+ Strongly connected components
%* *
%************************************************************************
-This @MonoBinds@- and @ClassDecls@-specific code is segregated here,
-as the two cases are similar.
-
\begin{code}
-reconstructCycle :: SCC FlatMonoBindsInfo
- -> RenamedHsBinds
+type BindVertex = (Defs, Uses, LHsBind Name, [LSig Name])
+ -- Signatures, if any, for this vertex
-reconstructCycle (AcyclicSCC (_, _, binds, sigs))
- = MonoBind binds sigs NonRecursive
+rnSCC :: [BindVertex] -> [SCC BindVertex]
+rnSCC nodes = stronglyConnComp (mkEdges nodes)
-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}
-
-%************************************************************************
-%* *
-%* 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])]
+type VertexTag = Int
-mkEdges flat_info
- = [ (info, tag, dest_vertices (nameSetToList names_used))
- | (info@(names_defined, names_used, mbind, sigs), tag) <- flat_info
+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 src_mentions = [ target_vertex
- | ((names_defined, _, _, _), target_vertex) <- flat_info,
- mentioned_name <- src_mentions,
- mentioned_name `elemNameSet` names_defined
- ]
+ dest_vertices uses = [ target_vertex
+ | ((defs, _, _, _), target_vertex) <- tagged_nodes,
+ defs `intersectsNameSet` uses
+ ]
+
+reconstructCycle :: SCC 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}
%* *
%************************************************************************
-@renameSigs@ checks for: (a)~more than one sig for one thing;
-(b)~signatures given for things not bound here; (c)~with suitably
-flaggery, that all top-level things have type signatures.
-
+@renameSigs@ checks for:
+\begin{enumerate}
+\item more than one sig for one thing;
+\item signatures given for things not bound here;
+\item with suitably flaggery, that all top-level things have type signatures.
+\end{enumerate}
+%
At the moment we don't gather free-var info from the types in
-sigatures. We'd only need this if we wanted to report unused tyvars.
+signatures. We'd only need this if we wanted to report unused tyvars.
\begin{code}
-renameSigs :: TopLevelFlag
- -> Bool -- True <-> sigs for an instance decl
- -- hence SPECIALISE instance prags ok
- -> NameSet -- Set of names bound in this group
- -> [RdrNameSig]
- -> RnMS s [RenamedSig] -- List of Sig constructors
-
-renameSigs top_lev inst_decl binders sigs
- = -- Rename the signatures
- mapRn renameSig sigs `thenRn` \ sigs' ->
-
+checkSigs :: (LSig Name -> Bool) -- OK-sig predicbate
+ -> [LSig Name]
+ -> RnM ()
+checkSigs ok_sig sigs
-- Check for (a) duplicate signatures
-- (b) signatures for things not in this group
- -- (c) optionally, bindings with no signature
- let
- (goodies, dups) = removeDups cmp_sig (sigsForMe (not . isUnboundName) sigs')
- not_this_group = sigsForMe (not . (`elemNameSet` binders)) goodies
- spec_inst_sigs = [s | s@(SpecInstSig _ _) <- goodies]
- type_sig_vars = [n | Sig n _ _ <- goodies]
- fixes = [f | f@(FixSig _) <- goodies]
- idecl_type_sigs = [s | s@(Sig _ _ _) <- goodies]
- sigs_required = case top_lev of {TopLevel -> opt_WarnMissingSigs; NotTopLevel -> False}
- un_sigd_binders | sigs_required = nameSetToList binders `minusList` type_sig_vars
- | otherwise = []
- in
- mapRn dupSigDeclErr dups `thenRn_`
- mapRn unknownSigErr not_this_group `thenRn_`
- (if not inst_decl then
- mapRn unknownSigErr spec_inst_sigs
- else
- -- We're being strict here, outlawing the presence
- -- of type signatures within an instance declaration.
- mapRn unknownSigErr (fixes ++ idecl_type_sigs)
- ) `thenRn_`
- mapRn (addWarnRn.missingSigWarn) un_sigd_binders `thenRn_`
-
- returnRn sigs' -- bad ones and all:
- -- we need bindings of *some* sort for every name
-
-
-renameSig (Sig v ty src_loc)
- = pushSrcLocRn src_loc $
- lookupBndrRn v `thenRn` \ new_v ->
- rnHsSigType (quotes (ppr v)) ty `thenRn` \ (new_ty,_) ->
- returnRn (Sig new_v new_ty src_loc)
-
-renameSig (SpecInstSig ty src_loc)
- = pushSrcLocRn src_loc $
- rnHsSigType (text "A SPECIALISE instance pragma") ty `thenRn` \ (new_ty, _) ->
- returnRn (SpecInstSig new_ty src_loc)
-
-renameSig (SpecSig v ty using src_loc)
- = pushSrcLocRn src_loc $
- lookupBndrRn v `thenRn` \ new_v ->
- rnHsSigType (quotes (ppr v)) ty `thenRn` \ (new_ty,_) ->
- rn_using using `thenRn` \ new_using ->
- returnRn (SpecSig new_v new_ty new_using src_loc)
+ -- Well, I can't see the check for (a)... ToDo!
+ = mappM_ unknownSigErr (filter bad sigs)
where
- rn_using Nothing = returnRn Nothing
- rn_using (Just x) = lookupOccRn x `thenRn` \ new_x ->
- returnRn (Just new_x)
-
-renameSig (InlineSig v src_loc)
- = pushSrcLocRn src_loc $
- lookupBndrRn v `thenRn` \ new_v ->
- returnRn (InlineSig new_v src_loc)
-
-renameSig (FixSig (FixitySig v fix src_loc))
- = pushSrcLocRn src_loc $
- lookupBndrRn v `thenRn` \ new_v ->
- returnRn (FixSig (FixitySig new_v fix src_loc))
-
-renameSig (NoInlineSig v src_loc)
- = pushSrcLocRn src_loc $
- lookupBndrRn v `thenRn` \ new_v ->
- returnRn (NoInlineSig new_v src_loc)
+ bad sig = not (ok_sig sig) &&
+ case sigName sig of
+ Just n | isUnboundName n -> False
+ -- Don't complain about an unbound name again
+ other -> True
+
+-- We use lookupSigOccRn in the signatures, which is a little bit unsatisfactory
+-- because this won't work for:
+-- instance Foo T where
+-- {-# INLINE op #-}
+-- Baz.op = ...
+-- We'll just rename the INLINE prag to refer to whatever other 'op'
+-- is in scope. (I'm assuming that Baz.op isn't in scope unqualified.)
+-- Doesn't seem worth much trouble to sort this.
+
+renameSigs :: [LSig RdrName] -> RnM [LSig Name]
+renameSigs sigs = mappM (wrapLocM renameSig) (filter (not . isFixitySig . unLoc) sigs)
+ -- Remove fixity sigs which have been dealt with already
+
+renameSig :: Sig RdrName -> RnM (Sig Name)
+-- FixitSig is renamed elsewhere.
+renameSig (Sig v ty)
+ = lookupLocatedSigOccRn v `thenM` \ new_v ->
+ rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty ->
+ returnM (Sig new_v new_ty)
+
+renameSig (SpecInstSig ty)
+ = rnLHsType (text "A SPECIALISE instance pragma") ty `thenM` \ new_ty ->
+ returnM (SpecInstSig new_ty)
+
+renameSig (SpecSig v ty)
+ = lookupLocatedSigOccRn v `thenM` \ new_v ->
+ rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty ->
+ returnM (SpecSig new_v new_ty)
+
+renameSig (InlineSig b v p)
+ = lookupLocatedSigOccRn v `thenM` \ new_v ->
+ returnM (InlineSig b new_v p)
\end{code}
-Checking for distinct signatures; oh, so boring
-
-\begin{code}
-cmp_sig :: RenamedSig -> RenamedSig -> Ordering
-cmp_sig (Sig n1 _ _) (Sig n2 _ _) = n1 `compare` n2
-cmp_sig (InlineSig n1 _) (InlineSig n2 _) = n1 `compare` n2
-cmp_sig (NoInlineSig n1 _) (NoInlineSig n2 _) = n1 `compare` n2
-cmp_sig (SpecInstSig ty1 _) (SpecInstSig ty2 _) = cmpHsType compare ty1 ty2
-cmp_sig (SpecSig n1 ty1 _ _) (SpecSig n2 ty2 _ _)
- = -- may have many specialisations for one value;
- -- but not ones that are exactly the same...
- thenCmp (n1 `compare` n2) (cmpHsType compare ty1 ty2)
-
-cmp_sig other_1 other_2 -- Tags *must* be different
- | (sig_tag other_1) _LT_ (sig_tag other_2) = LT
- | otherwise = GT
-
-sig_tag (Sig n1 _ _) = (ILIT(1) :: FAST_INT)
-sig_tag (SpecSig n1 _ _ _) = ILIT(2)
-sig_tag (InlineSig n1 _) = ILIT(3)
-sig_tag (NoInlineSig n1 _) = ILIT(4)
-sig_tag (SpecInstSig _ _) = ILIT(5)
-sig_tag (FixSig _) = ILIT(6)
-sig_tag _ = panic# "tag(RnBinds)"
-\end{code}
%************************************************************************
%* *
%************************************************************************
\begin{code}
-dupSigDeclErr (sig:sigs)
- = pushSrcLocRn loc $
- addErrRn (sep [ptext SLIT("Duplicate"),
- ptext what_it_is <> colon,
- ppr sig])
+dupSigDeclErr (L loc sig) sigs
+ = addErrAt loc $
+ vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon,
+ nest 2 (vcat (map ppr_sig (L loc sig:sigs)))]
where
- (what_it_is, loc) = sig_doc 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) = sig_doc sig
-
-sig_doc (Sig _ _ loc) = (SLIT("type signature"),loc)
-sig_doc (ClassOpSig _ _ _ loc) = (SLIT("class-method type signature"), loc)
-sig_doc (SpecSig _ _ _ loc) = (SLIT("SPECIALISE pragma"),loc)
-sig_doc (InlineSig _ loc) = (SLIT("INLINE pragma"),loc)
-sig_doc (NoInlineSig _ loc) = (SLIT("NOINLINE pragma"),loc)
-sig_doc (SpecInstSig _ loc) = (SLIT("SPECIALISE instance pragma"),loc)
-sig_doc (FixSig (FixitySig _ _ loc)) = (SLIT("fixity declaration"), loc)
+ 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"))
+ = hang (ptext SLIT("Pattern bindings (except simple variables) not allowed in instance declarations"))
4 (ppr mbind)
\end{code}
projects / ghc-hetmet.git / blobdiff