\begin{code}
module RnBinds (
- rnTopMonoBinds, rnMonoBinds, rnMethodBinds,
- renameSigs, renameSigsFVs, unknownSigErr
+ rnTopMonoBinds, rnMonoBinds, rnMonoBindsAndThen,
+ rnMethodBinds, renameSigs, checkSigs
) where
#include "HsVersions.h"
import HsSyn
-import HsBinds ( eqHsSig, sigName, hsSigDoc )
+import HsBinds ( hsSigDoc, sigLoc, eqHsSig )
import RdrHsSyn
import RnHsSyn
import TcRnMonad
-import RnTypes ( rnHsSigType, rnHsType )
-import RnExpr ( rnMatch, rnGRHSs, rnPat, checkPrecMatch )
+import RnTypes ( rnHsSigType, rnHsType, rnPat )
+import RnExpr ( rnMatch, rnGRHSs, checkPrecMatch )
import RnEnv ( bindLocatedLocalsRn, lookupBndrRn, lookupInstDeclBndr,
- lookupSigOccRn, bindPatSigTyVars, bindLocalFixities,
+ lookupSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV,
+ bindLocalFixities,
warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn,
)
import CmdLineOpts ( DynFlag(..) )
-import Digraph ( stronglyConnComp, SCC(..) )
+import Digraph ( SCC(..), stronglyConnComp )
import Name ( Name, nameOccName, nameSrcLoc )
import NameSet
+import PrelNames ( isUnboundName )
import RdrName ( RdrName, rdrNameOcc )
-import BasicTypes ( RecFlag(..), FixitySig(..) )
-import List ( partition )
+import BasicTypes ( RecFlag(..), TopLevelFlag(..), isTopLevel )
+import List ( unzip4 )
import Outputable
-import PrelNames ( isUnboundName )
\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
-\end{code}
%************************************************************************
%* *
\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
contains bindings for the binders of this particular binding.
\begin{code}
+rnTopMonoBinds :: RdrNameMonoBinds
+ -> [RdrNameSig]
+ -> RnM (RenamedHsBinds, DefUses)
+
+-- The binders of the binding are in scope already;
+-- the top level scope resolution does that
+
rnTopMonoBinds mbinds sigs
- = mappM lookupBndrRn binder_rdr_names `thenM` \ binder_names ->
- bindPatSigTyVars (collectSigTysFromMonoBinds mbinds) $
- let
- bndr_name_set = mkNameSet binder_names
- in
- renameSigsFVs (okBindSig bndr_name_set) sigs `thenM` \ (siglist, sig_fvs) ->
-
- -- Warn about missing signatures, but not in interface mode
- -- (This is important when renaming bindings from 'deriving' clauses.)
- getModeRn `thenM` \ mode ->
- doptM Opt_WarnMissingSigs `thenM` \ warn_missing_sigs ->
- (if warn_missing_sigs && not (isInterfaceMode mode) then
- let
- type_sig_vars = [n | Sig n _ _ <- siglist]
- un_sigd_binders = nameSetToList (delListFromNameSet bndr_name_set type_sig_vars)
- in
- mappM_ missingSigWarn un_sigd_binders
- else
- returnM ()
- ) `thenM_`
+ = bindPatSigTyVars (collectSigTysFromMonoBinds 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
- rn_mono_binds siglist mbinds `thenM` \ (final_binds, bind_fvs) ->
- returnM (final_binds, bind_fvs `plusFV` sig_fvs)
- where
- binder_rdr_names = collectMonoBinders mbinds
+ rnMonoBinds TopLevel mbinds sigs
\end{code}
+
%************************************************************************
%* *
%* Nested binds
%* *
%************************************************************************
-\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}
-rnMonoBinds :: RdrNameMonoBinds
- -> [RdrNameSig]
- -> (RenamedHsBinds -> 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
+rnMonoBindsAndThen :: RdrNameMonoBinds
+ -> [RdrNameSig]
+ -> (RenamedHsBinds -> RnM (result, FreeVars))
+ -> RnM (result, FreeVars)
+
+rnMonoBindsAndThen mbinds sigs thing_inside -- Non-empty monobinds
+ = -- 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 $ \ new_mbinders ->
- bindPatSigTyVars (collectSigTysFromMonoBinds mbinds) $
- let
- binder_set = mkNameSet new_mbinders
- in
- -- Rename the signatures
- renameSigsFVs (okBindSig binder_set) sigs `thenM` \ (siglist, sig_fvs) ->
+ bindLocatedLocalsRn doc mbinders_w_srclocs $ \ _ ->
+ bindPatSigTyVarsFV (collectSigTysFromMonoBinds mbinds) $
- -- 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
- bindLocalFixities [sig | FixSig sig <- siglist ] $
+ bindLocalFixities [sig | FixSig sig <- sigs ] $
- rn_mono_binds siglist mbinds `thenM` \ (binds, bind_fvs) ->
+ -- Do the business
+ rnMonoBinds NotTopLevel mbinds sigs `thenM` \ (binds, bind_dus) ->
- -- Now do the "thing inside", and deal with the free-variable calculations
- thing_inside binds `thenM` \ (result,result_fvs) ->
+ -- Now do the "thing inside"
+ thing_inside binds `thenM` \ (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
+ bndrs = duDefs bind_dus
+ unused_bndrs = nameSetToList (bndrs `minusNameSet` all_uses)
in
- warnUnusedLocalBinds unused_binders `thenM_`
- returnM (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 = collectLocatedMonoBinders mbinds
- doc = text "In the binding group for" <+> pp_bndrs mbinders_w_srclocs
- pp_bndrs [(b,_)] = quotes (ppr b)
- pp_bndrs bs = fsep (punctuate comma [ppr b | (b,_) <- bs])
+ doc = text "In the binding group for:"
+ <+> pprWithCommas ppr (map fst mbinders_w_srclocs)
\end{code}
%* *
%************************************************************************
-@rn_mono_binds@ is used by {\em both} top-level and nested bindings.
+@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 :: [RenamedSig] -- Signatures attached to this group
- -> RdrNameMonoBinds
- -> RnM (RenamedHsBinds, -- Dependency analysed
- FreeVars) -- Free variables
-
-rn_mono_binds siglist mbinds
- =
- -- Rename the bindings, returning a MonoBindsInfo
+rnMonoBinds :: TopLevelFlag
+ -> RdrNameMonoBinds
+ -> [RdrNameSig]
+ -> RnM (RenamedHsBinds, DefUses)
+
+-- Assumes the binders of the binding are in scope already
+
+rnMonoBinds top_lvl mbinds sigs
+ = renameSigs sigs `thenM` \ 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 siglist mbinds `thenM` \ mbinds_info ->
+ flattenMonoBinds siglist mbinds `thenM` \ 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
-
- -- Deal with bound and free-var calculation
- rhs_fvs = plusFVs [fvs | (_,fvs,_,_) <- mbinds_info]
+ scc_result = rnSCC mbinds_info
+ (binds_s, bind_dus_s) = unzip (map reconstructCycle scc_result)
+ bind_dus = mkDUs bind_dus_s
+ final_binds = foldr ThenBinds EmptyBinds binds_s
+ binders = duDefs bind_dus
in
- returnM (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 = [n | Sig n _ _ <- siglist]
+ un_sigd_binders = filter (not . (`elem` type_sig_vars))
+ (nameSetToList binders)
+ in
+ mappM_ missingSigWarn un_sigd_binders
+ else
+ returnM ()
+ ) `thenM_`
+
+ returnM (final_binds, bind_dus `plusDU` usesOnly (hsSigsFVs siglist))
\end{code}
@flattenMonoBinds@ is ever-so-slightly magical in that it sticks
unique ``vertex tags'' on its output; minor plumbing required.
-Sigh --- need to pass along the signatures for the group of bindings,
-in case any of them \fbox{\ ???\ }
-
\begin{code}
flattenMonoBinds :: [RenamedSig] -- Signatures
-> RdrNameMonoBinds
- -> RnM [FlatMonoBindsInfo]
+ -> RnM [FlatMonoBinds]
flattenMonoBinds sigs EmptyMonoBinds = returnM []
names_bound_here = mkNameSet (collectPatBinders pat')
in
sigsForMe names_bound_here sigs `thenM` \ sigs_for_me ->
- rnGRHSs grhss `thenM` \ (grhss', fvs) ->
+ rnGRHSs PatBindRhs grhss `thenM` \ (grhss', fvs) ->
returnM
- [(names_bound_here,
- fvs `plusFV` pat_fvs,
- PatMonoBind pat' grhss' locn,
- sigs_for_me
- )]
+ [(names_bound_here, fvs `plusFV` pat_fvs,
+ PatMonoBind pat' grhss' locn, sigs_for_me
+ )]
flattenMonoBinds sigs (FunMonoBind name inf matches locn)
= addSrcLoc locn $
names_bound_here = unitNameSet new_name
in
sigsForMe names_bound_here sigs `thenM` \ sigs_for_me ->
- mapFvRn (rnMatch (FunRhs name)) matches `thenM` \ (new_matches, fvs) ->
+ mapFvRn (rnMatch (FunRhs new_name)) matches `thenM` \ (new_matches, fvs) ->
mappM_ (checkPrecMatch inf new_name) new_matches `thenM_`
returnM
- [(unitNameSet new_name,
- fvs,
- FunMonoBind new_name inf new_matches locn,
- sigs_for_me
- )]
-
+ [(unitNameSet new_name, fvs,
+ FunMonoBind new_name inf new_matches locn, 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
check sigs sig = case filter (eqHsSig sig) sigs of
[] -> returnM (sig:sigs)
- other -> dupSigDeclErr sig `thenM_`
+ other -> dupSigDeclErr sig other `thenM_`
returnM sigs
\end{code}
lookupInstDeclBndr cls name `thenM` \ sel_name ->
-- We use the selector name as the binder
- mapFvRn rn_match matches `thenM` \ (new_matches, fvs) ->
+ mapFvRn (rn_match sel_name) matches `thenM` \ (new_matches, fvs) ->
mappM_ (checkPrecMatch inf sel_name) new_matches `thenM_`
returnM (FunMonoBind sel_name inf new_matches locn, fvs `addOneFV` sel_name)
where
-- Gruesome; bring into scope the correct members of the generic type variables
-- See comments in RnSource.rnSourceDecl(ClassDecl)
- rn_match match@(Match (TypePat ty : _) _ _)
- = extendTyVarEnvFVRn gen_tvs (rnMatch (FunRhs name) match)
+ rn_match sel_name match@(Match (TypePat ty : _) _ _)
+ = extendTyVarEnvFVRn gen_tvs $
+ rnMatch (FunRhs sel_name) match
where
- tvs = map rdrNameOcc (extractHsTyRdrNames ty)
+ tvs = map rdrNameOcc (extractHsTyRdrTyVars ty)
gen_tvs = [tv | tv <- gen_tyvars, nameOccName tv `elem` tvs]
- rn_match match = rnMatch (FunRhs name) match
+ rn_match sel_name match = rnMatch (FunRhs sel_name) match
-- Can't handle method pattern-bindings which bind multiple methods.
%************************************************************************
%* *
-\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
+ Strongly connected components
-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@.
+During analysis a @MonoBinds@ is flattened to a @FlatMonoBinds@.
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
+type FlatMonoBinds = (Defs, Uses, RenamedMonoBinds, [RenamedSig])
+ -- Signatures, if any, for this vertex
-mkEdges :: [(FlatMonoBindsInfo, VertexTag)] -> [(FlatMonoBindsInfo, VertexTag, [VertexTag])]
+rnSCC :: [FlatMonoBinds] -> [SCC FlatMonoBinds]
+rnSCC nodes = stronglyConnComp (mkEdges nodes)
+
+type VertexTag = Int
-mkEdges flat_info
- = [ (info, tag, dest_vertices (nameSetToList names_used))
- | (info@(names_defined, names_used, mbind, sigs), tag) <- flat_info
+mkEdges :: [FlatMonoBinds] -> [(FlatMonoBinds, 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 FlatMonoBinds -> (RenamedHsBinds, (Defs,Uses))
+reconstructCycle (AcyclicSCC (defs, uses, binds, sigs))
+ = (MonoBind binds sigs NonRecursive, (defs, uses))
+reconstructCycle (CyclicSCC cycle)
+ = (MonoBind 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 = foldr1 AndMonoBinds binds_s
+ this_gp_sigs = foldr1 (++) sigs_s
\end{code}
signatures. We'd only need this if we wanted to report unused tyvars.
\begin{code}
-renameSigsFVs ok_sig sigs
- = renameSigs ok_sig sigs `thenM` \ sigs' ->
- returnM (sigs', hsSigsFVs sigs')
-
-renameSigs :: (RenamedSig -> Bool) -- OK-sig predicate
- -> [RdrNameSig]
- -> RnM [RenamedSig]
-
-renameSigs ok_sig [] = returnM []
-
-renameSigs ok_sig sigs
- = -- Rename the signatures
- mappM renameSig sigs `thenM` \ sigs' ->
-
+checkSigs :: (RenamedSig -> Bool) -- OK-sig predicbate
+ -> [RenamedSig]
+ -> RnM ()
+checkSigs 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
- mappM_ unknownSigErr bads `thenM_`
- returnM goods
+ -- Well, I can't see the check for (a)... ToDo!
+ = mappM_ unknownSigErr (filter bad 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
-- We use lookupSigOccRn in the signatures, which is a little bit unsatisfactory
-- because this won't work for:
-- is in scope. (I'm assuming that Baz.op isn't in scope unqualified.)
-- Doesn't seem worth much trouble to sort this.
+renameSigs :: [Sig RdrName] -> RnM [Sig Name]
+renameSigs sigs = mappM renameSig (filter (not . isFixitySig) sigs)
+ -- Remove fixity sigs which have been dealt with already
+
renameSig :: Sig RdrName -> RnM (Sig Name)
--- ClassOpSig is renamed elsewhere.
+-- FixitSig is renamed elsewhere.
renameSig (Sig v ty src_loc)
= addSrcLoc src_loc $
lookupSigOccRn v `thenM` \ new_v ->
rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty ->
returnM (SpecSig new_v new_ty src_loc)
-renameSig (FixSig (FixitySig v fix src_loc))
- = addSrcLoc src_loc $
- lookupSigOccRn v `thenM` \ new_v ->
- returnM (FixSig (FixitySig new_v fix src_loc))
-
renameSig (InlineSig b v p src_loc)
= addSrcLoc src_loc $
lookupSigOccRn v `thenM` \ new_v ->
%************************************************************************
\begin{code}
-dupSigDeclErr sig
+dupSigDeclErr sig sigs
= addSrcLoc loc $
- addErr (sep [ptext SLIT("Duplicate") <+> what_it_is <> colon,
- ppr sig])
+ addErr (vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon,
+ nest 2 (vcat (map ppr_sig (sig:sigs)))])
where
(what_it_is, loc) = hsSigDoc sig
+ ppr_sig sig = ppr (sigLoc sig) <> colon <+> ppr sig
unknownSigErr sig
= addSrcLoc loc $
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