%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[RnBinds]{Renaming and dependency analysis of bindings}
\begin{code}
module RnBinds (
- rnTopBinds, rnTopMonoBinds,
- rnMethodBinds,
- rnBinds, rnMonoBinds
+ rnTopMonoBinds, rnMonoBinds, rnMonoBindsAndThen,
+ rnMethodBinds, renameSigs, checkSigs
) where
#include "HsVersions.h"
-import {-# SOURCE #-} RnSource ( rnHsSigType )
import HsSyn
+import HsBinds ( hsSigDoc, sigLoc, eqHsSig )
import RdrHsSyn
import RnHsSyn
-import RnMonad
-import RnExpr ( rnMatch, rnGRHSsAndBinds, rnPat, checkPrecMatch )
-import RnEnv ( bindLocatedLocalsRn, lookupBndrRn, lookupOccRn,
- newLocalNames, isUnboundName, warnUnusedBinds
+import TcRnMonad
+import RnTypes ( rnHsSigType, rnHsType, rnPat )
+import RnExpr ( rnMatch, rnGRHSs, checkPrecMatch )
+import RnEnv ( bindLocatedLocalsRn, lookupBndrRn, lookupInstDeclBndr,
+ lookupSigOccRn, bindPatSigTyVars, bindPatSigTyVarsFV,
+ bindLocalFixities,
+ warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn,
)
-import CmdLineOpts ( opt_SigsRequired )
-import Digraph ( stronglyConnComp, SCC(..) )
-import Name ( OccName(..), Provenance,
- Name, isExportedName,
- NameSet(..), emptyNameSet, mkNameSet, unionNameSets,
- minusNameSet, unionManyNameSets, elemNameSet, unitNameSet, nameSetToList
- )
-import BasicTypes ( RecFlag(..), TopLevelFlag(..) )
-import Util ( thenCmp, removeDups, panic, panic#, assertPanic )
-import UniqSet ( UniqSet )
-import ListSetOps ( minusList )
-import Bag ( bagToList )
-import UniqFM ( UniqFM )
+import CmdLineOpts ( DynFlag(..) )
+import Digraph ( SCC(..), stronglyConnComp )
+import Name ( Name, nameOccName, nameSrcLoc )
+import NameSet
+import PrelNames ( isUnboundName )
+import RdrName ( RdrName, rdrNameOcc )
+import BasicTypes ( RecFlag(..), TopLevelFlag(..), isTopLevel )
+import List ( unzip4 )
import Outputable
\end{code}
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}
%************************************************************************
%* *
\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
-
-rnTopBinds EmptyBinds = returnRn EmptyBinds
-rnTopBinds (MonoBind bind sigs _) = rnTopMonoBinds bind sigs
- -- The parser doesn't produce other forms
+rnTopMonoBinds :: RdrNameMonoBinds
+ -> [RdrNameSig]
+ -> RnM (RenamedHsBinds, DefUses)
-
-rnTopMonoBinds EmptyMonoBinds sigs
- = returnRn EmptyBinds
+-- The binders of the binding are in scope already;
+-- the top level scope resolution does that
rnTopMonoBinds mbinds sigs
- = mapRn lookupBndrRn binder_rdr_names `thenRn` \ binder_names ->
- let
- binder_set = mkNameSet binder_names
- exported_binders = mkNameSet (filter isExportedName binder_names)
- in
- rn_mono_binds TopLevel
- binder_set mbinds sigs `thenRn` \ (new_binds, fv_set) ->
- let
- unused_binders = binder_set `minusNameSet` (fv_set `unionNameSets` exported_binders)
- in
- warnUnusedBinds unused_binders `thenRn_`
- returnRn new_binds
- where
- binder_rdr_names = map fst (bagToList (collectMonoBinders mbinds))
+ = 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
+
+ rnMonoBinds 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
-
+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 $ \ _ ->
+ bindPatSigTyVarsFV (collectSigTysFromMonoBinds 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 | FixSig sig <- sigs ] $
-rnMonoBinds EmptyMonoBinds sigs thing_inside = thing_inside EmptyBinds
+ -- Do the business
+ rnMonoBinds 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 `unionNameSets` bind_fvs
- net_fvs = all_fvs `minusNameSet` binder_set
- unused_binders = 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, net_fvs)
+ 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 = collectLocatedMonoBinders mbinds
+ doc = text "In the binding group for:"
+ <+> pprWithCommas ppr (map fst mbinders_w_srclocs)
\end{code}
%************************************************************************
%* *
-%* MonoBinds -- the main work is done here
+\subsubsection{ MonoBinds -- 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
+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
- rnBindSigs top_lev binders sigs `thenRn` \ siglist ->
- flattenMonoBinds siglist mbinds `thenRn` \ mbinds_info ->
+ flattenMonoBinds siglist mbinds `thenM` \ mbinds_info ->
-- Do the SCC analysis
- let edges = mkEdges (mbinds_info `zip` [0..])
- scc_result = stronglyConnComp edges
- final_binds = foldr1 ThenBinds (map reconstructCycle scc_result)
-
- -- Deal with bound and free-var calculation
- rhs_fvs = unionManyNameSets [fvs | (_,_,fvs,_,_) <- mbinds_info]
+ let
+ 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
- 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 = [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
\begin{code}
flattenMonoBinds :: [RenamedSig] -- Signatures
-> RdrNameMonoBinds
- -> RnMS s (Int, [FlatMonoBindsInfo])
+ -> RnM [FlatMonoBinds]
-flattenMonoBinds sigs EmptyMonoBinds = returnRn []
+flattenMonoBinds sigs EmptyMonoBinds = returnM []
flattenMonoBinds sigs (AndMonoBinds bs1 bs2)
- = flattenMonoBinds sigs bs1 `thenRn` \ flat1 ->
- flattenMonoBinds sigs bs2 `thenRn` \ flat2 ->
- returnRn (flat1 ++ flat2)
+ = flattenMonoBinds sigs bs1 `thenM` \ flat1 ->
+ flattenMonoBinds sigs bs2 `thenM` \ flat2 ->
+ returnM (flat1 ++ flat2)
-flattenMonoBinds sigs (PatMonoBind pat grhss_and_binds locn)
- = pushSrcLocRn locn $
- rnPat pat `thenRn` \ pat' ->
- rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', fvs) ->
+flattenMonoBinds sigs (PatMonoBind pat grhss locn)
+ = addSrcLoc locn $
+ rnPat pat `thenM` \ (pat', pat_fvs) ->
-- Find which things are bound in this group
let
names_bound_here = mkNameSet (collectPatBinders pat')
- sigs_for_me = filter ((`elemNameSet` names_bound_here) . sig_name) sigs
- sigs_fvs = foldr sig_fv emptyNameSet sigs_for_me
in
- returnRn
- [(names_bound_here,
- fvs `unionNameSets` sigs_fvs,
- PatMonoBind pat' grhss_and_binds' locn,
- sigs_for_me
- )]
+ sigsForMe names_bound_here sigs `thenM` \ sigs_for_me ->
+ rnGRHSs PatBindRhs grhss `thenM` \ (grhss', fvs) ->
+ returnM
+ [(names_bound_here, fvs `plusFV` pat_fvs,
+ PatMonoBind pat' grhss' locn, sigs_for_me
+ )]
flattenMonoBinds sigs (FunMonoBind name inf matches locn)
- = pushSrcLocRn locn $
- mapRn (checkPrecMatch inf name) matches `thenRn_`
- lookupBndrRn name `thenRn` \ name' ->
- mapAndUnzipRn rnMatch matches `thenRn` \ (new_matches, fv_lists) ->
+ = addSrcLoc locn $
+ lookupBndrRn name `thenM` \ new_name ->
let
- fvs = unionManyNameSets fv_lists
- sigs_for_me = filter ((name' ==) . sig_name) sigs
- sigs_fvs = foldr sig_fv emptyNameSet sigs_for_me
+ names_bound_here = unitNameSet new_name
in
- returnRn
- [(unitNameSet name',
- fvs `unionNameSets` sigs_fvs,
- FunMonoBind name' inf new_matches locn,
- sigs_for_me
- )]
+ sigsForMe names_bound_here sigs `thenM` \ sigs_for_me ->
+ 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
+ )]
+
+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 other `thenM_`
+ returnM sigs
\end{code}
-@rnMethodBinds@ is used for the method bindings of an instance
-declaration. like @rnMonoBinds@ but without dependency analysis.
+@rnMethodBinds@ is used for the method bindings of a class and an instance
+declaration. Like @rnMonoBinds@ but without dependency analysis.
-\begin{code}
-rnMethodBinds :: RdrNameMonoBinds -> RnMS s RenamedMonoBinds
+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.
-rnMethodBinds EmptyMonoBinds = returnRn EmptyMonoBinds
+\begin{code}
+rnMethodBinds :: Name -- Class name
+ -> [Name] -- Names for generic type variables
+ -> RdrNameMonoBinds
+ -> RnM (RenamedMonoBinds, FreeVars)
-rnMethodBinds (AndMonoBinds mb1 mb2)
- = andRn AndMonoBinds (rnMethodBinds mb1)
- (rnMethodBinds mb2)
+rnMethodBinds cls gen_tyvars EmptyMonoBinds = returnM (EmptyMonoBinds, emptyFVs)
-rnMethodBinds (FunMonoBind occname inf matches locn)
- = pushSrcLocRn locn $
- mapRn (checkPrecMatch inf occname) matches `thenRn_`
+rnMethodBinds cls gen_tyvars (AndMonoBinds mb1 mb2)
+ = rnMethodBinds cls gen_tyvars mb1 `thenM` \ (mb1', fvs1) ->
+ rnMethodBinds cls gen_tyvars mb2 `thenM` \ (mb2', fvs2) ->
+ returnM (mb1' `AndMonoBinds` mb2', fvs1 `plusFV` fvs2)
- newLocalNames [(occname, locn)] `thenRn` \ [op_name] ->
- -- Make a fresh local for the bound variable; it must be different
- -- to occurrences of the same thing on the LHS, which refer to the global
- -- selectors.
+rnMethodBinds cls gen_tyvars (FunMonoBind name inf matches locn)
+ = addSrcLoc locn $
- mapAndUnzipRn rnMatch matches `thenRn` \ (new_matches, _) ->
- returnRn (FunMonoBind op_name inf new_matches locn)
+ lookupInstDeclBndr cls name `thenM` \ sel_name ->
+ -- We use the selector name as the binder
-rnMethodBinds (PatMonoBind (VarPatIn occname) grhss_and_binds locn)
- = pushSrcLocRn locn $
- newLocalNames [(occname, locn)] `thenRn` \ [op_name] ->
- rnGRHSsAndBinds grhss_and_binds `thenRn` \ (grhss_and_binds', _) ->
- returnRn (PatMonoBind (VarPatIn op_name) grhss_and_binds' locn)
+ 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 sel_name match@(Match (TypePat ty : _) _ _)
+ = extendTyVarEnvFVRn gen_tvs $
+ rnMatch (FunRhs sel_name) match
+ where
+ tvs = map rdrNameOcc (extractHsTyRdrTyVars ty)
+ gen_tvs = [tv | tv <- gen_tyvars, nameOccName tv `elem` tvs]
+
+ rn_match sel_name match = rnMatch (FunRhs sel_name) match
+
-- Can't handle method pattern-bindings which bind multiple methods.
-rnMethodBinds mbind@(PatMonoBind other_pat _ locn)
- = pushSrcLocRn locn $
- failWithRn EmptyMonoBinds (methodBindErr mbind)
+rnMethodBinds cls gen_tyvars mbind@(PatMonoBind other_pat _ locn)
+ = addSrcLoc locn (addErr (methodBindErr mbind)) `thenM_`
+ returnM (EmptyMonoBinds, 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 `unionNameSets` (unitNameSet 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
-
-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}
-
-%************************************************************************
-%* *
-%* 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)
-mkEdges flat_info
- = [ (info, tag, dest_vertices (nameSetToList names_used))
- | (info@(names_defined, names_used, mbind, sigs), tag) <- flat_info
+type VertexTag = Int
+
+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}
%* *
%************************************************************************
-@rnBindSigs@ checks for: (a)~more than one sig for one thing;
-(b)~signatures given for things not bound here; (c)~with suitably
-flaggery, that all top-level things have type signatures.
+@renameSigs@ checks for:
+\begin{enumerate}
+\item more than one sig for one thing;
+\item signatures given for things not bound here;
+\item with suitably flaggery, that all top-level things have type signatures.
+\end{enumerate}
+%
+At the moment we don't gather free-var info from the types in
+signatures. We'd only need this if we wanted to report unused tyvars.
\begin{code}
-rnBindSigs :: TopLevelFlag
- -> NameSet -- Set of names bound in this group
- -> [RdrNameSig]
- -> RnMS s [RenamedSig] -- List of Sig constructors
-
-rnBindSigs top_lev binders sigs
- = -- Rename the signatures
- mapRn renameSig sigs `thenRn` \ 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
- -- (c) optionally, bindings with no signature
- let
- (goodies, dups) = removeDups cmp_sig (filter (not.isUnboundName.sig_name) sigs')
- not_this_group = filter (\sig -> not (sig_name sig `elemNameSet` binders)) goodies
- type_sig_vars = [n | Sig n _ _ <- goodies]
- sigs_required = case top_lev of {TopLevel -> opt_SigsRequired; 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_`
- mapRn (addErrRn.missingSigErr) 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 (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 (MagicUnfoldingSig v str src_loc)
- = pushSrcLocRn src_loc $
- lookupBndrRn v `thenRn` \ new_v ->
- returnRn (MagicUnfoldingSig new_v str 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 :: [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)
+-- 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 (Sig new_v new_ty src_loc)
+
+renameSig (SpecInstSig ty src_loc)
+ = addSrcLoc src_loc $
+ rnHsType (text "A SPECIALISE instance pragma") ty `thenM` \ new_ty ->
+ returnM (SpecInstSig new_ty src_loc)
+
+renameSig (SpecSig 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 (InlineSig b v p src_loc)
+ = addSrcLoc src_loc $
+ lookupSigOccRn v `thenM` \ new_v ->
+ returnM (InlineSig b new_v p src_loc)
\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 (MagicUnfoldingSig n1 _ _) (MagicUnfoldingSig n2 _ _) = n1 `compare` n2
-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 (MagicUnfoldingSig n1 _ _) = ILIT(4)
-sig_tag _ = panic# "tag(RnBinds)"
-
-sig_name (Sig n _ _) = n
-sig_name (ClassOpSig n _ _ _) = n
-sig_name (SpecSig n _ _ _) = n
-sig_name (InlineSig n _) = n
-sig_name (MagicUnfoldingSig n _ _) = n
-\end{code}
%************************************************************************
%* *
%************************************************************************
\begin{code}
-dupSigDeclErr (sig:sigs)
- = pushSrcLocRn loc $
- addErrRn (sep [ptext SLIT("more than one"),
- ptext what_it_is, ptext SLIT("given for"),
- quotes (ppr (sig_name sig))])
+dupSigDeclErr sig sigs
+ = addSrcLoc loc $
+ addErr (vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon,
+ nest 2 (vcat (map ppr_sig (sig:sigs)))])
where
- (what_it_is, loc) = sig_doc sig
+ (what_it_is, loc) = hsSigDoc sig
+ ppr_sig sig = ppr (sigLoc sig) <> colon <+> ppr sig
unknownSigErr sig
- = pushSrcLocRn loc $
- addErrRn (sep [ptext flavour, ptext SLIT("but no definition for"),
- quotes (ppr (sig_name sig))])
+ = addSrcLoc loc $
+ addErr (sep [ptext SLIT("Misplaced") <+> what_it_is <> colon,
+ ppr sig])
where
- (flavour, 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("SPECIALIZE pragma"),loc)
-sig_doc (InlineSig _ loc) = (SLIT("INLINE pragma"),loc)
-sig_doc (MagicUnfoldingSig _ _ loc) = (SLIT("MAGIC_UNFOLDING pragma"),loc)
+ (what_it_is, loc) = hsSigDoc sig
-missingSigErr var
- = sep [ptext SLIT("Definition but no type signature for"), quotes (ppr var)]
+missingSigWarn var
+ = addSrcLoc (nameSrcLoc var) $
+ addWarn (sep [ptext SLIT("Definition but no type signature for"), quotes (ppr var)])
methodBindErr mbind
= hang (ptext SLIT("Can't handle multiple methods defined by one pattern binding"))
projects / ghc-hetmet.git / blobdiff