they may be affected by renaming (which isn't fully worked out yet).
\begin{code}
-module RnBinds (
- rnTopBinds,
- rnLocalBindsAndThen, rnValBindsAndThen, rnValBinds, trimWith,
- rnMethodBinds, renameSigs, mkSigTvFn,
- rnMatchGroup, rnGRHSs
+module RnBinds (rnTopBinds, rnTopBindsLHS, rnTopBindsRHS, -- use these for top-level bindings
+ rnLocalBindsAndThen, rnValBindsLHS, rnValBindsRHS, -- or these for local bindings
+ rnMethodBinds, renameSigs, mkSigTvFn,
+ rnMatchGroup, rnGRHSs,
+ makeMiniFixityEnv, MiniFixityEnv
) where
-#include "HsVersions.h"
-
import {-# SOURCE #-} RnExpr( rnLExpr, rnStmts )
import HsSyn
import RdrHsSyn
import RnHsSyn
import TcRnMonad
-import RnTypes ( rnHsSigType, rnLHsType, rnHsTypeFVs,
- rnLPat, rnPatsAndThen, patSigErr, checkPrecMatch )
-import RnEnv ( bindLocatedLocalsRn, lookupLocatedBndrRn,
- lookupLocatedInstDeclBndr, newIPNameRn,
- lookupLocatedSigOccRn, bindPatSigTyVarsFV,
- bindLocalFixities, bindSigTyVarsFV,
- warnUnusedLocalBinds, mapFvRn, extendTyVarEnvFVRn,
- )
+import RnTypes ( rnHsSigType, rnLHsType, checkPrecMatch)
+import RnPat (rnPatsAndThen_LocalRightwards, rnBindPat,
+ NameMaker, localRecNameMaker, topRecNameMaker, applyNameMaker
+ )
+
+import RnEnv
+import PrelNames ( mkUnboundName )
import DynFlags ( DynFlag(..) )
import Name
import NameEnv
import NameSet
-import PrelNames ( isUnboundName )
import RdrName ( RdrName, rdrNameOcc )
-import SrcLoc ( Located(..), unLoc )
+import SrcLoc
import ListSetOps ( findDupsEq )
import BasicTypes ( RecFlag(..) )
import Digraph ( SCC(..), stronglyConnComp )
import Bag
import Outputable
+import FastString
+import Data.List ( partition )
import Maybes ( orElse )
-import Util ( filterOut )
-import Monad ( foldM )
+import Monad ( foldM, unless )
\end{code}
-- ToDo: Put the annotations into the monad, so that they arrive in the proper
%* *
%************************************************************************
-@rnTopMonoBinds@ assumes that the environment already
-contains bindings for the binders of this particular binding.
-
\begin{code}
-rnTopBinds :: HsValBinds RdrName -> RnM (HsValBinds Name, DefUses)
-
--- The binders of the binding are in scope already;
--- the top level scope resolution does that
-
-rnTopBinds binds
- = do { is_boot <- tcIsHsBoot
- ; if is_boot then rnTopBindsBoot binds
- else rnTopBindsSrc binds }
-
-rnTopBindsBoot :: HsValBinds RdrName -> RnM (HsValBinds Name, DefUses)
+-- for top-level bindings, we need to make top-level names,
+-- so we have a different entry point than for local bindings
+rnTopBindsLHS :: MiniFixityEnv
+ -> HsValBinds RdrName
+ -> RnM (HsValBindsLR Name RdrName)
+rnTopBindsLHS fix_env binds =
+ (uncurry $ rnValBindsLHSFromDoc (topRecNameMaker fix_env)) (bindersAndDoc binds) binds
+
+rnTopBindsRHS :: [Name] -- the names bound by these binds
+ -> HsValBindsLR Name RdrName
+ -> RnM (HsValBinds Name, DefUses)
+rnTopBindsRHS bound_names binds =
+ do { is_boot <- tcIsHsBoot
+ ; if is_boot
+ then rnTopBindsBoot binds
+ else rnValBindsRHSGen (\x -> x) -- don't trim free vars
+ bound_names binds }
+
+
+-- wrapper if we don't need to do anything in between the left and right,
+-- or anything else in the scope of the left
+--
+-- never used when there are fixity declarations
+rnTopBinds :: HsValBinds RdrName
+ -> RnM (HsValBinds Name, DefUses)
+rnTopBinds b =
+ do nl <- rnTopBindsLHS emptyFsEnv b
+ let bound_names = map unLoc (collectHsValBinders nl)
+ bindLocalNames bound_names $ rnTopBindsRHS bound_names nl
+
+
+rnTopBindsBoot :: HsValBindsLR Name RdrName -> RnM (HsValBinds Name, DefUses)
-- A hs-boot file has no bindings.
-- Return a single HsBindGroup with empty binds and renamed signatures
rnTopBindsBoot (ValBindsIn mbinds sigs)
= do { checkErr (isEmptyLHsBinds mbinds) (bindsInHsBootFile mbinds)
- ; sigs' <- renameSigs okHsBootSig sigs
+ ; sigs' <- renameSigs Nothing okHsBootSig sigs
; return (ValBindsOut [] sigs', usesOnly (hsSigsFVs sigs')) }
-
-rnTopBindsSrc :: HsValBinds RdrName -> RnM (HsValBinds Name, DefUses)
-rnTopBindsSrc binds = rnValBinds noTrim binds
+rnTopBindsBoot b = pprPanic "rnTopBindsBoot" (ppr b)
\end{code}
%*********************************************************
\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
+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) ->
+ thing_inside (HsValBinds val_binds')
+
+rnLocalBindsAndThen (HsIPBinds binds) thing_inside = do
+ (binds',fv_binds) <- rnIPBinds binds
+ (thing, fvs_thing) <- thing_inside (HsIPBinds binds')
+ return (thing, fvs_thing `plusFV` fv_binds)
+
+rnIPBinds :: HsIPBinds RdrName -> RnM (HsIPBinds Name, FreeVars)
+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 RdrName -> RnM (IPBind Name, FreeVars)
+rnIPBind (IPBind n expr) = do
+ name <- newIPNameRn n
+ (expr',fvExpr) <- rnLExpr expr
return (IPBind name expr', fvExpr)
\end{code}
%************************************************************************
\begin{code}
-rnValBindsAndThen :: HsValBinds RdrName
- -> (HsValBinds Name -> RnM (result, FreeVars))
- -> RnM (result, FreeVars)
-
-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 $ \ bndrs ->
-
- -- Then install local fixity declarations
- -- Notice that they scope over thing_inside too
- bindLocalFixities [sig | L _ (FixSig sig) <- sigs ] $
-
- -- Do the business
- rnValBinds (trimWith bndrs) binds `thenM` \ (binds, bind_dus) ->
-
- -- Now do the "thing inside"
- thing_inside binds `thenM` \ (result,result_fvs) ->
-
- -- Final error checking
+-- wrapper for local binds
+-- creates the documentation info and calls the helper below
+rnValBindsLHS :: MiniFixityEnv
+ -> HsValBinds RdrName
+ -> RnM (HsValBindsLR Name RdrName)
+rnValBindsLHS fix_env binds =
+ let (boundNames,doc) = bindersAndDoc binds
+ in rnValBindsLHSFromDoc_Local boundNames doc fix_env binds
+
+-- a helper used for local binds that does the duplicates check,
+-- just so we don't forget to do it somewhere
+rnValBindsLHSFromDoc_Local :: [Located RdrName] -- RdrNames of the LHS (so we don't have to gather them twice)
+ -> SDoc -- doc string for dup names and shadowing
+ -> MiniFixityEnv
+ -> HsValBinds RdrName
+ -> RnM (HsValBindsLR Name RdrName)
+
+rnValBindsLHSFromDoc_Local boundNames doc fix_env binds = do
+ -- Do error checking: we need to check for dups here because we
+ -- don't don't bind all of the variables from the ValBinds at once
+ -- with bindLocatedLocals any more.
+ checkDupAndShadowedRdrNames doc boundNames
+
+ -- (Note that we don't want to do this at the top level, since
+ -- sorting out duplicates and shadowing there happens elsewhere.
+ -- The behavior is even different. For example,
+ -- import A(f)
+ -- f = ...
+ -- should not produce a shadowing warning (but it will produce
+ -- an ambiguity warning if you use f), but
+ -- import A(f)
+ -- g = let f = ... in f
+ -- should.
+ rnValBindsLHSFromDoc (localRecNameMaker fix_env) boundNames doc binds
+
+bindersAndDoc :: HsValBinds RdrName -> ([Located RdrName], SDoc)
+bindersAndDoc binds =
let
- 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)]
+ -- the unrenamed bndrs for error checking and reporting
+ orig = collectHsValBinders binds
+ doc = text "In the binding group for:" <+> pprWithCommas ppr (map unLoc orig)
in
- warnUnusedLocalBinds unused_bndrs `thenM_`
+ (orig, doc)
+
+-- renames the left-hand sides
+-- generic version used both at the top level and for local binds
+-- does some error checking, but not what gets done elsewhere at the top level
+rnValBindsLHSFromDoc :: NameMaker
+ -> [Located RdrName] -- RdrNames of the LHS (so we don't have to gather them twice)
+ -> SDoc -- doc string for dup names and shadowing
+ -> HsValBinds RdrName
+ -> RnM (HsValBindsLR Name RdrName)
+rnValBindsLHSFromDoc topP _original_bndrs doc (ValBindsIn mbinds sigs) = do
+ -- rename the LHSes
+ mbinds' <- mapBagM (rnBindLHS topP doc) mbinds
+ return $ ValBindsIn mbinds' sigs
+rnValBindsLHSFromDoc _ _ _ b = pprPanic "rnValBindsLHSFromDoc" (ppr b)
+
+-- General version used both from the top-level and for local things
+-- Assumes the LHS vars are in scope
+--
+-- Does not bind the local fixity declarations
+rnValBindsRHSGen :: (FreeVars -> FreeVars) -- for trimming free var sets
+ -- The trimming function trims the free vars we attach to a
+ -- binding so that it stays reasonably small
+ -> [Name] -- names bound by the LHSes
+ -> HsValBindsLR Name RdrName
+ -> RnM (HsValBinds Name, DefUses)
+
+rnValBindsRHSGen trim bound_names (ValBindsIn mbinds sigs) = do
+ -- rename the sigs
+ env <- getGblEnv
+ traceRn (ptext (sLit "Rename sigs") <+> ppr (tcg_rdr_env env))
+ sigs' <- renameSigs (Just (mkNameSet bound_names)) okBindSig sigs
+ -- rename the RHSes
+ binds_w_dus <- mapBagM (rnBind (mkSigTvFn sigs') trim) mbinds
+ let (anal_binds, anal_dus) = depAnalBinds binds_w_dus
+ (valbind', valbind'_dus) = (ValBindsOut anal_binds sigs',
+ usesOnly (hsSigsFVs sigs') `plusDU` anal_dus)
+ return (valbind', valbind'_dus)
+
+rnValBindsRHSGen _ _ b = pprPanic "rnValBindsRHSGen" (ppr b)
+
+-- Wrapper for local binds
+--
+-- The *client* of this function is responsible for checking for unused binders;
+-- it doesn't (and can't: we don't have the thing inside the binds) happen here
+--
+-- The client is also responsible for bringing the fixities into scope
+rnValBindsRHS :: [Name] -- names bound by the LHSes
+ -> HsValBindsLR Name RdrName
+ -> RnM (HsValBinds Name, DefUses)
+rnValBindsRHS bound_names binds =
+ rnValBindsRHSGen (\ fvs -> -- only keep the names the names from this group
+ intersectNameSet (mkNameSet bound_names) fvs) bound_names binds
- 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)
+
+-- for local binds
+-- wrapper that does both the left- and right-hand sides
+--
+-- here there are no local fixity decls passed in;
+-- the local fixity decls come from the ValBinds sigs
+rnValBindsAndThen :: HsValBinds RdrName
+ -> (HsValBinds Name -> RnM (result, FreeVars))
+ -> RnM (result, FreeVars)
+rnValBindsAndThen binds@(ValBindsIn _ sigs) thing_inside
+ = do { let (original_bndrs, doc) = bindersAndDoc binds
+
+ -- (A) Create the local fixity environment
+ ; new_fixities <- makeMiniFixityEnv [L loc sig | L loc (FixSig sig) <- sigs]
+
+ -- (B) Rename the LHSes
+ ; new_lhs <- rnValBindsLHSFromDoc_Local original_bndrs doc new_fixities binds
+ ; let bound_names = map unLoc $ collectHsValBinders new_lhs
+
+ -- ...and bring them (and their fixities) into scope
+ ; bindLocalNamesFV_WithFixities bound_names new_fixities $ do
+
+ { -- (C) Do the RHS and thing inside
+ (binds', dus) <- rnValBindsRHS bound_names new_lhs
+ ; (result, result_fvs) <- thing_inside binds'
+
+ -- Report unused bindings based on the (accurate)
+ -- findUses. E.g.
+ -- let x = x in 3
+ -- should report 'x' unused
+ ; let real_uses = findUses dus result_fvs
+ ; warnUnusedLocalBinds bound_names real_uses
+
+ ; let
+ -- The variables "used" in the val binds are:
+ -- (1) the uses of the binds (duUses)
+ -- (2) the FVs of the thing-inside
+ all_uses = duUses dus `plusFV` result_fvs
+ -- Note [Unused binding hack]
+ -- ~~~~~~~~~~~~~~~~~~~~~~~~~~
+ -- Note that *in contrast* to the above reporting of
+ -- unused bindings, (1) above uses duUses to return *all*
+ -- the uses, even if the binding is unused. 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
+ --
+ -- But note that this means we won't report 'x' as unused,
+ -- whereas we would if we had { x = 3; p = x; y = 'x' }
+
+ ; return (result, all_uses) }}
+ -- The bound names are pruned out of all_uses
+ -- by the bindLocalNamesFV call above
+
+rnValBindsAndThen bs _ = pprPanic "rnValBindsAndThen" (ppr bs)
+
+
+-- Process the fixity declarations, making a FastString -> (Located Fixity) map
+-- (We keep the location around for reporting duplicate fixity declarations.)
+--
+-- Checks for duplicates, but not that only locally defined things are fixed.
+-- Note: for local fixity declarations, duplicates would also be checked in
+-- check_sigs below. But we also use this function at the top level.
+
+makeMiniFixityEnv :: [LFixitySig RdrName] -> RnM MiniFixityEnv
+
+makeMiniFixityEnv decls = foldlM add_one emptyFsEnv decls
+ where
+ add_one env (L loc (FixitySig (L name_loc name) fixity)) = do
+ { -- this fixity decl is a duplicate iff
+ -- the ReaderName's OccName's FastString is already in the env
+ -- (we only need to check the local fix_env because
+ -- definitions of non-local will be caught elsewhere)
+ let { fs = occNameFS (rdrNameOcc name)
+ ; fix_item = L loc fixity };
+
+ case lookupFsEnv env fs of
+ Nothing -> return $ extendFsEnv env fs fix_item
+ Just (L loc' _) -> do
+ { setSrcSpan loc $
+ addLocErr (L name_loc name) (dupFixityDecl loc')
+ ; return env}
+ }
+
+dupFixityDecl :: SrcSpan -> RdrName -> SDoc
+dupFixityDecl loc rdr_name
+ = vcat [ptext (sLit "Multiple fixity declarations for") <+> quotes (ppr rdr_name),
+ ptext (sLit "also at ") <+> ppr loc]
---------------------
-rnValBinds :: (FreeVars -> FreeVars)
- -> HsValBinds RdrName
- -> RnM (HsValBinds Name, DefUses)
--- Assumes the binders of the binding are in scope already
-rnValBinds trim (ValBindsIn mbinds sigs)
- = do { sigs' <- rename_sigs sigs
+-- renaming a single bind
+
+rnBindLHS :: NameMaker
+ -> SDoc
+ -> LHsBind RdrName
+ -- returns the renamed left-hand side,
+ -- and the FreeVars *of the LHS*
+ -- (i.e., any free variables of the pattern)
+ -> RnM (LHsBindLR Name RdrName)
+
+rnBindLHS name_maker _ (L loc (PatBind { pat_lhs = pat,
+ pat_rhs = grhss,
+ pat_rhs_ty=pat_rhs_ty
+ }))
+ = setSrcSpan loc $ do
+ -- we don't actually use the FV processing of rnPatsAndThen here
+ (pat',pat'_fvs) <- rnBindPat name_maker pat
+ return (L loc (PatBind { pat_lhs = pat',
+ pat_rhs = grhss,
+ -- we temporarily store the pat's FVs here;
+ -- gets updated to the FVs of the whole bind
+ -- when doing the RHS below
+ bind_fvs = pat'_fvs,
+ -- these will get ignored in the next pass,
+ -- when we rename the RHS
+ pat_rhs_ty = pat_rhs_ty }))
+
+rnBindLHS name_maker _ (L loc (FunBind { fun_id = name@(L nameLoc _),
+ fun_infix = inf,
+ fun_matches = matches,
+ fun_co_fn = fun_co_fn,
+ fun_tick = fun_tick
+ }))
+ = setSrcSpan loc $
+ do { (newname, _fvs) <- applyNameMaker name_maker name $ \ newname ->
+ return (newname, emptyFVs)
+ ; return (L loc (FunBind { fun_id = L nameLoc newname,
+ fun_infix = inf,
+ fun_matches = matches,
+ -- we temporatily store the LHS's FVs (empty in this case) here
+ -- gets updated when doing the RHS below
+ bind_fvs = emptyFVs,
+ -- everything else will get ignored in the next pass
+ fun_co_fn = fun_co_fn,
+ fun_tick = fun_tick
+ })) }
+
+rnBindLHS _ _ b = pprPanic "rnBindLHS" (ppr b)
+
+-- assumes the left-hands-side vars are in scope
+rnBind :: (Name -> [Name]) -- Signature tyvar function
+ -> (FreeVars -> FreeVars) -- Trimming function for rhs free vars
+ -> LHsBindLR Name RdrName
+ -> RnM (LHsBind Name, [Name], Uses)
+rnBind _ trim (L loc (PatBind { pat_lhs = pat,
+ pat_rhs = grhss,
+ -- pat fvs were stored here while
+ -- processing the LHS
+ bind_fvs=pat_fvs }))
+ = setSrcSpan loc $
+ do {let bndrs = collectPatBinders pat
- ; binds_w_dus <- mapBagM (rnBind (mkSigTvFn sigs') trim) mbinds
+ ; (grhss', fvs) <- rnGRHSs PatBindRhs grhss
+ -- No scoped type variables for pattern bindings
- ; let (binds', bind_dus) = depAnalBinds binds_w_dus
+ ; return (L loc (PatBind { pat_lhs = pat,
+ pat_rhs = grhss',
+ pat_rhs_ty = placeHolderType,
+ bind_fvs = trim fvs }),
+ bndrs, pat_fvs `plusFV` fvs) }
- -- 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'
+rnBind sig_fn
+ trim
+ (L loc (FunBind { fun_id = name,
+ fun_infix = inf,
+ fun_matches = matches,
+ -- no pattern FVs
+ bind_fvs = _
+ }))
+ -- invariant: no free vars here when it's a FunBind
+ = setSrcSpan loc $
+ do { let plain_name = unLoc name
- ; return (ValBindsOut binds' sigs',
- usesOnly (hsSigsFVs sigs') `plusDU` bind_dus) }
+ ; (matches', fvs) <- bindSigTyVarsFV (sig_fn plain_name) $
+ -- bindSigTyVars tests for Opt_ScopedTyVars
+ rnMatchGroup (FunRhs plain_name inf) matches
+ ; checkPrecMatch inf plain_name matches'
+ ; return (L loc (FunBind { fun_id = name,
+ fun_infix = inf,
+ fun_matches = matches',
+ bind_fvs = trim fvs,
+ fun_co_fn = idHsWrapper,
+ fun_tick = Nothing }),
+ [plain_name], fvs)
+ }
+
+rnBind _ _ b = pprPanic "rnBind" (ppr b)
+
---------------------
depAnalBinds :: Bag (LHsBind Name, [Name], Uses)
-> ([(RecFlag, LHsBinds Name)], DefUses)
, bndr <- bndrs ]
get_binds (AcyclicSCC (bind, _, _)) = (NonRecursive, unitBag bind)
- get_binds (CyclicSCC binds_w_dus) = (Recursive, listToBag [b | (b,d,u) <- binds_w_dus])
+ get_binds (CyclicSCC binds_w_dus) = (Recursive, listToBag [b | (b,_,_) <- binds_w_dus])
get_du (AcyclicSCC (_, bndrs, uses)) = (Just (mkNameSet bndrs), uses)
get_du (CyclicSCC binds_w_dus) = (Just defs, uses)
(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) <- rnGRHSs PatBindRhs grhss
- -- No scoped type variables for pattern bindings
-
- ; 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) $
- -- bindSigTyVars tests for Opt_ScopedTyVars
- 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 = idHsWrapper, fun_tick = Nothing }),
- [plain_name], fvs)
- }
\end{code}
(bind', fvs_bind) <- rnMethodBind cls sig_fn gen_tyvars bind
return (bind' `unionBags` binds, fvs_bind `plusFV` fvs)
+rnMethodBind :: Name
+ -> (Name -> [Name])
+ -> [Name]
+ -> LHsBindLR RdrName RdrName
+ -> RnM (Bag (LHsBindLR Name Name), FreeVars)
rnMethodBind cls sig_fn gen_tyvars (L loc (FunBind { fun_id = name, fun_infix = inf,
fun_matches = MatchGroup matches _ }))
- = setSrcSpan loc $
- lookupLocatedInstDeclBndr cls name `thenM` \ sel_name ->
- let plain_name = unLoc sel_name in
- -- We use the selector name as the binder
-
- bindSigTyVarsFV (sig_fn plain_name) $
- mapFvRn (rn_match plain_name) matches `thenM` \ (new_matches, fvs) ->
- let
- new_group = MatchGroup new_matches placeHolderType
- in
- checkPrecMatch inf plain_name new_group `thenM_`
- returnM (unitBag (L loc (FunBind {
- fun_id = sel_name, fun_infix = inf,
- fun_matches = new_group,
- bind_fvs = fvs, fun_co_fn = idHsWrapper,
- fun_tick = Nothing })),
- fvs `addOneFV` plain_name)
- -- The 'fvs' field isn't used for method binds
+ = setSrcSpan loc $ do
+ sel_name <- lookupInstDeclBndr cls name
+ let plain_name = unLoc sel_name
+ -- We use the selector name as the binder
+
+ bindSigTyVarsFV (sig_fn plain_name) $ do
+ (new_matches, fvs) <- mapFvRn (rn_match plain_name) matches
+ let
+ new_group = MatchGroup new_matches placeHolderType
+
+ checkPrecMatch inf plain_name new_group
+ return (unitBag (L loc (FunBind {
+ fun_id = sel_name, fun_infix = inf,
+ fun_matches = new_group,
+ bind_fvs = fvs, fun_co_fn = idHsWrapper,
+ fun_tick = Nothing })),
+ 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)
rn_match sel_name match@(L _ (Match (L _ (TypePat ty) : _) _ _))
= extendTyVarEnvFVRn gen_tvs $
- rnMatch (FunRhs sel_name) match
+ rnMatch (FunRhs sel_name inf) 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
+ rn_match sel_name match = rnMatch (FunRhs sel_name inf) match
-- Can't handle method pattern-bindings which bind multiple methods.
-rnMethodBind cls sig_fn gen_tyvars mbind@(L loc (PatBind other_pat _ _ _))
- = addLocErr mbind methodBindErr `thenM_`
- returnM (emptyBag, emptyFVs)
+rnMethodBind _ _ _ mbind@(L _ (PatBind _ _ _ _)) = do
+ addLocErr mbind methodBindErr
+ return (emptyBag, emptyFVs)
+
+rnMethodBind _ _ _ b = pprPanic "rnMethodBind" (ppr b)
\end{code}
\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}
-renameSigs :: (LSig Name -> Bool) -> [LSig RdrName] -> RnM [LSig Name]
+renameSigs :: Maybe NameSet -- If (Just ns) complain if the sig isn't for one of ns
+ -> (Sig RdrName -> Bool) -- Complain about the wrong kind of signature if this is False
+ -> [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' }
+renameSigs mb_names ok_sig sigs
+ = do { let (good_sigs, bad_sigs) = partition (ok_sig . unLoc) sigs
+ ; mapM_ unknownSigErr bad_sigs -- Misplaced
+ ; mapM_ dupSigDeclErr (findDupsEq eqHsSig sigs) -- Duplicate
+ ; sigs' <- mapM (wrapLocM (renameSig mb_names)) good_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
- = do { mappM_ unknownSigErr (filter (not . ok_sig) sigs')
- ; mappM_ dupSigDeclErr (findDupsEq eqHsSig sigs') }
- where
- -- Don't complain about an unbound name again
- sigs' = filterOut bad_name sigs
- bad_name sig = case sigName sig of
- Just n -> isUnboundName n
- other -> False
-
--- We use lookupLocatedSigOccRn in the signatures, which is a little bit unsatisfactory
+-- We use lookupSigOccRn in the signatures, which is a little bit unsatisfactory
-- because this won't work for:
-- instance Foo T where
-- {-# INLINE op #-}
-- is in scope. (I'm assuming that Baz.op isn't in scope unqualified.)
-- Doesn't seem worth much trouble to sort this.
-renameSig :: Sig RdrName -> RnM (Sig Name)
--- FixitSig is renamed elsewhere.
-renameSig (TypeSig v ty)
- = lookupLocatedSigOccRn v `thenM` \ new_v ->
- rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty ->
- returnM (TypeSig new_v new_ty)
-
-renameSig (SpecInstSig ty)
- = rnLHsType (text "A SPECIALISE instance pragma") ty `thenM` \ new_ty ->
- returnM (SpecInstSig new_ty)
-
-renameSig (SpecSig v ty inl)
- = lookupLocatedSigOccRn v `thenM` \ new_v ->
- rnHsSigType (quotes (ppr v)) ty `thenM` \ new_ty ->
- returnM (SpecSig new_v new_ty inl)
-
-renameSig (InlineSig v s)
- = lookupLocatedSigOccRn v `thenM` \ new_v ->
- returnM (InlineSig new_v s)
+renameSig :: Maybe NameSet -> Sig RdrName -> RnM (Sig Name)
+-- FixitySig is renamed elsewhere.
+renameSig mb_names sig@(TypeSig v ty)
+ = do { new_v <- lookupSigOccRn mb_names sig v
+ ; new_ty <- rnHsSigType (quotes (ppr v)) ty
+ ; return (TypeSig new_v new_ty) }
+
+renameSig _ (SpecInstSig ty)
+ = do { new_ty <- rnLHsType (text "A SPECIALISE instance pragma") ty
+ ; return (SpecInstSig new_ty) }
+
+renameSig mb_names sig@(SpecSig v ty inl)
+ = do { new_v <- lookupSigOccRn mb_names sig v
+ ; new_ty <- rnHsSigType (quotes (ppr v)) ty
+ ; return (SpecSig new_v new_ty inl) }
+
+renameSig mb_names sig@(InlineSig v s)
+ = do { new_v <- lookupSigOccRn mb_names sig v
+ ; return (InlineSig new_v s) }
+
+renameSig mb_names sig@(FixSig (FixitySig v f))
+ = do { new_v <- lookupSigOccRn mb_names sig v
+ ; return (FixSig (FixitySig new_v f)) }
+
+-- lookupSigOccRn is used for type signatures and pragmas
+-- Is this valid?
+-- module A
+-- import M( f )
+-- f :: Int -> Int
+-- f x = x
+-- It's clear that the 'f' in the signature must refer to A.f
+-- The Haskell98 report does not stipulate this, but it will!
+-- So we must treat the 'f' in the signature in the same way
+-- as the binding occurrence of 'f', using lookupBndrRn
+--
+-- However, consider this case:
+-- import M( f )
+-- f :: Int -> Int
+-- g x = x
+-- We don't want to say 'f' is out of scope; instead, we want to
+-- return the imported 'f', so that later on the reanamer will
+-- correctly report "misplaced type sig".
+
+lookupSigOccRn :: Maybe NameSet -> Sig RdrName -> Located RdrName -> RnM (Located Name)
+lookupSigOccRn mb_names sig (L loc v)
+ = do { mb_n <- lookupBndrRn_maybe v
+ ; case mb_n of {
+ Just n -> case mb_names of {
+ Nothing -> return (L loc n) ;
+ Just ns | n `elemNameSet` ns -> return (L loc n)
+ | otherwise -> bale_out_with local_msg } ;
+
+ Nothing -> do
+ { mb_n <- lookupGreRn_maybe v
+ ; case mb_n of
+ Just _ -> bale_out_with import_msg
+ Nothing -> bale_out_with empty
+ } }}
+ where
+ bale_out_with msg
+ = do { addErr (sep [ ptext (sLit "The") <+> hsSigDoc sig
+ <+> ptext (sLit "for") <+> quotes (ppr v)
+ , nest 2 $ ptext (sLit "lacks an accompanying binding")]
+ $$ nest 2 msg)
+ ; return (L loc (mkUnboundName v)) }
+
+ local_msg = parens $ ptext (sLit "The") <+> hsSigDoc sig <+> ptext (sLit "must be given where")
+ <+> quotes (ppr v) <+> ptext (sLit "is declared")
+
+ import_msg = parens $ ptext (sLit "You cannot give a") <+> hsSigDoc sig
+ <+> ptext (sLit "an imported value")
\end{code}
\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)
+rnMatchGroup ctxt (MatchGroup ms _) = do
+ (new_ms, ms_fvs) <- mapFvRn (rnMatch ctxt) ms
+ return (MatchGroup new_ms placeHolderType, ms_fvs)
rnMatch :: HsMatchContext Name -> LMatch RdrName -> RnM (LMatch Name, FreeVars)
rnMatch ctxt = wrapLocFstM (rnMatch' ctxt)
+rnMatch' :: HsMatchContext Name -> Match RdrName -> RnM (Match Name, FreeVars)
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)
+ = do { -- Result type signatures are no longer supported
+ case maybe_rhs_sig of
+ Nothing -> return ()
+ Just ty -> addLocErr ty (resSigErr ctxt match)
+
+
+ -- Now the main event
+ -- note that there are no local ficity decls for matches
+ ; rnPatsAndThen_LocalRightwards ctxt pats $ \ pats' -> do
+ { (grhss', grhss_fvs) <- rnGRHSs ctxt grhss
+
+ ; return (Match pats' Nothing grhss', grhss_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"
+
+resSigErr :: HsMatchContext Name -> Match RdrName -> HsType RdrName -> SDoc
+resSigErr ctxt match ty
+ = vcat [ ptext (sLit "Illegal result type signature") <+> quotes (ppr ty)
+ , nest 2 $ ptext (sLit "Result signatures are no longer supported in pattern matches")
+ , pprMatchInCtxt ctxt match ]
\end{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)
+ = rnLocalBindsAndThen binds $ \ binds' -> do
+ (grhss', fvGRHSs) <- mapFvRn (rnGRHS ctxt) grhss
+ return (GRHSs grhss' binds', fvGRHSs)
rnGRHS :: HsMatchContext Name -> LGRHS RdrName -> RnM (LGRHS Name, FreeVars)
rnGRHS ctxt = wrapLocFstM (rnGRHS' ctxt)
+rnGRHS' :: HsMatchContext Name -> GRHS RdrName -> RnM (GRHS Name, FreeVars)
rnGRHS' ctxt (GRHS guards rhs)
- = do { opt_GlasgowExts <- doptM Opt_GlasgowExts
+ = do { pattern_guards_allowed <- doptM Opt_PatternGuards
; ((guards', rhs'), fvs) <- rnStmts (PatGuard ctxt) guards $
rnLExpr rhs
- ; checkM (opt_GlasgowExts || is_standard_guard guards')
+ ; unless (pattern_guards_allowed || is_standard_guard guards')
(addWarn (nonStdGuardErr guards'))
; return (GRHS guards' rhs', fvs) }
-- Glasgow extension
is_standard_guard [] = True
is_standard_guard [L _ (ExprStmt _ _ _)] = True
- is_standard_guard other = False
+ is_standard_guard _ = False
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
+dupSigDeclErr :: [LSig RdrName] -> RnM ()
dupSigDeclErr sigs@(L loc sig : _)
= addErrAt loc $
- vcat [ptext SLIT("Duplicate") <+> what_it_is <> colon,
+ vcat [ptext (sLit "Duplicate") <+> what_it_is <> colon,
nest 2 (vcat (map ppr_sig sigs))]
where
what_it_is = hsSigDoc sig
ppr_sig (L loc sig) = ppr loc <> colon <+> ppr sig
+dupSigDeclErr [] = panic "dupSigDeclErr"
+unknownSigErr :: LSig RdrName -> RnM ()
unknownSigErr (L loc sig)
- = do { mod <- getModule
- ; addErrAt loc $
- vcat [sep [ptext SLIT("Misplaced") <+> what_it_is <> colon, ppr sig],
- extra_stuff mod sig] }
- where
- what_it_is = hsSigDoc sig
- extra_stuff mod (TypeSig (L _ n) _)
- | nameIsLocalOrFrom mod n
- = ptext SLIT("The type signature must be given where")
- <+> quotes (ppr n) <+> ptext SLIT("is declared")
- | otherwise
- = ptext SLIT("You cannot give a type signature for an imported value")
-
- extra_stuff mod other = empty
+ = addErrAt loc $
+ sep [ptext (sLit "Misplaced") <+> hsSigDoc sig <> colon, ppr sig]
+methodBindErr :: HsBindLR RdrName RdrName -> SDoc
methodBindErr mbind
- = hang (ptext SLIT("Pattern bindings (except simple variables) not allowed in instance declarations"))
+ = hang (ptext (sLit "Pattern bindings (except simple variables) not allowed in instance declarations"))
2 (ppr mbind)
+bindsInHsBootFile :: LHsBindsLR Name RdrName -> SDoc
bindsInHsBootFile mbinds
- = hang (ptext SLIT("Bindings in hs-boot files are not allowed"))
+ = hang (ptext (sLit "Bindings in hs-boot files are not allowed"))
2 (ppr mbinds)
+nonStdGuardErr :: [LStmtLR Name Name] -> SDoc
nonStdGuardErr guards
- = hang (ptext SLIT("accepting non-standard pattern guards (-fglasgow-exts to suppress this message)"))
+ = hang (ptext (sLit "accepting non-standard pattern guards (use -XPatternGuards to suppress this message)"))
4 (interpp'SP guards)
\end{code}
projects / ghc-hetmet.git / blobdiff