{-# LANGUAGE RecordWildCards #-}
----------------------------------------------------------------------------
-- |
-- Module      :  Haddock.Interface.Rename
-- Copyright   :  (c) Simon Marlow 2003-2006,
--                    David Waern  2006-2009
-- License     :  BSD-like
--
-- Maintainer  :  haddock@projects.haskell.org
-- Stability   :  experimental
-- Portability :  portable
-----------------------------------------------------------------------------
module Haddock.Interface.Rename (renameInterface) where


import Data.Traversable (mapM)

import Haddock.GhcUtils
import Haddock.Types

import Bag (emptyBag)
import GHC hiding (NoLink)
import Name

import Control.Applicative
import Control.Monad hiding (mapM)
import Data.List
import qualified Data.Map as Map hiding ( Map )
import Prelude hiding (mapM)


renameInterface :: DynFlags -> LinkEnv -> Bool -> Interface -> ErrMsgM Interface
renameInterface dflags renamingEnv warnings iface =

  -- first create the local env, where every name exported by this module
  -- is mapped to itself, and everything else comes from the global renaming
  -- env
  let localEnv = foldl fn renamingEnv (ifaceVisibleExports iface)
        where fn env name = Map.insert name (ifaceMod iface) env

      -- rename names in the exported declarations to point to things that
      -- are closer to, or maybe even exported by, the current module.
      (renamedExportItems, missingNames1)
        = runRnFM localEnv (renameExportItems (ifaceExportItems iface))

      (rnDocMap, missingNames2) = runRnFM localEnv (mapM renameDoc (ifaceDocMap iface))

      (rnArgMap, missingNames3) = runRnFM localEnv (mapM (mapM renameDoc) (ifaceArgMap iface))

      (renamedOrphanInstances, missingNames4)
        = runRnFM localEnv (mapM renameDocInstance (ifaceOrphanInstances iface))

      (finalModuleDoc, missingNames5)
        = runRnFM localEnv (renameDocumentation (ifaceDoc iface))

      -- combine the missing names and filter out the built-ins, which would
      -- otherwise always be missing.
      missingNames = nub $ filter isExternalName  -- XXX: isExternalName filters out too much
                    (missingNames1 ++ missingNames2 ++ missingNames3
                     ++ missingNames4 ++ missingNames5)

      -- filter out certain built in type constructors using their string
      -- representation. TODO: use the Name constants from the GHC API.
--      strings = filter (`notElem` ["()", "[]", "(->)"])
--                (map pretty missingNames)
      strings = map (pretty dflags) . filter (\n -> not (isSystemName n || isBuiltInSyntax n)) $ missingNames

  in do
    -- report things that we couldn't link to. Only do this for non-hidden
    -- modules.
    unless (OptHide `elem` ifaceOptions iface || null strings || not warnings) $
      tell ["Warning: " ++ moduleString (ifaceMod iface) ++
            ": could not find link destinations for:\n"++
            unwords ("   " : strings) ]

    return $ iface { ifaceRnDoc         = finalModuleDoc,
                     ifaceRnDocMap      = rnDocMap,
                     ifaceRnArgMap      = rnArgMap,
                     ifaceRnExportItems = renamedExportItems,
                     ifaceRnOrphanInstances = renamedOrphanInstances}


--------------------------------------------------------------------------------
-- Monad for renaming
--
-- The monad does two things for us: it passes around the environment for
-- renaming, and it returns a list of names which couldn't be found in
-- the environment.
--------------------------------------------------------------------------------


newtype RnM a =
  RnM { unRn :: (Name -> (Bool, DocName))  -- name lookup function
             -> (a,[Name])
      }

instance Monad RnM where
  (>>=) = thenRn
  return = pure

instance Functor RnM where
  fmap f x = do a <- x; return (f a)

instance Applicative RnM where
  pure = returnRn
  (<*>) = ap

returnRn :: a -> RnM a
returnRn a   = RnM (const (a,[]))
thenRn :: RnM a -> (a -> RnM b) -> RnM b
m `thenRn` k = RnM (\lkp -> case unRn m lkp of
  (a,out1) -> case unRn (k a) lkp of
    (b,out2) -> (b,out1++out2))

getLookupRn :: RnM (Name -> (Bool, DocName))
getLookupRn = RnM (\lkp -> (lkp,[]))

outRn :: Name -> RnM ()
outRn name = RnM (const ((),[name]))

lookupRn :: Name -> RnM DocName
lookupRn name = do
  lkp <- getLookupRn
  case lkp name of
    (False,maps_to) -> do outRn name; return maps_to
    (True, maps_to) -> return maps_to


runRnFM :: LinkEnv -> RnM a -> (a,[Name])
runRnFM env rn = unRn rn lkp
  where
    lkp n = case Map.lookup n env of
      Nothing  -> (False, Undocumented n)
      Just mdl -> (True,  Documented n mdl)


--------------------------------------------------------------------------------
-- Renaming
--------------------------------------------------------------------------------


rename :: Name -> RnM DocName
rename = lookupRn


renameL :: Located Name -> RnM (Located DocName)
renameL = mapM rename


renameExportItems :: [ExportItem GHCR] -> RnM [ExportItem DocNameI]
renameExportItems = mapM renameExportItem


renameDocForDecl :: DocForDecl Name -> RnM (DocForDecl DocName)
renameDocForDecl (doc, fnArgsDoc) =
  (,) <$> renameDocumentation doc <*> renameFnArgsDoc fnArgsDoc


renameDocumentation :: Documentation Name -> RnM (Documentation DocName)
renameDocumentation (Documentation mDoc mWarning) =
  Documentation <$> mapM renameDoc mDoc <*> mapM renameDoc mWarning


renameLDocHsSyn :: LHsDocString -> RnM LHsDocString
renameLDocHsSyn = return


renameDoc :: Traversable t => t Name -> RnM (t DocName)
renameDoc = traverse rename

renameFnArgsDoc :: FnArgsDoc Name -> RnM (FnArgsDoc DocName)
renameFnArgsDoc = mapM renameDoc


renameLType :: LHsType GHCR -> RnM (LHsType DocNameI)
renameLType = mapM renameType

renameLSigType :: LHsSigType GHCR -> RnM (LHsSigType DocNameI)
renameLSigType = renameImplicit renameLType

renameLSigWcType :: LHsSigWcType GHCR -> RnM (LHsSigWcType DocNameI)
renameLSigWcType = renameWc (renameImplicit renameLType)

renameLKind :: LHsKind GHCR -> RnM (LHsKind DocNameI)
renameLKind = renameLType

renameMaybeLKind :: Maybe (LHsKind GHCR) -> RnM (Maybe (LHsKind DocNameI))
renameMaybeLKind = traverse renameLKind

renameFamilyResultSig :: LFamilyResultSig GHCR -> RnM (LFamilyResultSig DocNameI)
renameFamilyResultSig (L loc NoSig)
    = return (L loc NoSig)
renameFamilyResultSig (L loc (KindSig ki))
    = do { ki' <- renameLKind ki
         ; return (L loc (KindSig ki')) }
renameFamilyResultSig (L loc (TyVarSig bndr))
    = do { bndr' <- renameLTyVarBndr bndr
         ; return (L loc (TyVarSig bndr')) }

renameInjectivityAnn :: LInjectivityAnn GHCR -> RnM (LInjectivityAnn DocNameI)
renameInjectivityAnn (L loc (InjectivityAnn lhs rhs))
    = do { lhs' <- renameL lhs
         ; rhs' <- mapM renameL rhs
         ; return (L loc (InjectivityAnn lhs' rhs')) }

renameMaybeInjectivityAnn :: Maybe (LInjectivityAnn GHCR)
                          -> RnM (Maybe (LInjectivityAnn DocNameI))
renameMaybeInjectivityAnn = traverse renameInjectivityAnn

renameType :: HsType GHCR -> RnM (HsType DocNameI)
renameType t = case t of
  HsForAllTy { hst_bndrs = tyvars, hst_body = ltype } -> do
    tyvars'   <- mapM renameLTyVarBndr tyvars
    ltype'    <- renameLType ltype
    return (HsForAllTy { hst_bndrs = tyvars', hst_body = ltype' })

  HsQualTy { hst_ctxt = lcontext , hst_body = ltype } -> do
    lcontext' <- renameLContext lcontext
    ltype'    <- renameLType ltype
    return (HsQualTy { hst_ctxt = lcontext', hst_body = ltype' })

  HsTyVar ip (L l n) -> return . HsTyVar ip . L l =<< rename n
  HsBangTy b ltype -> return . HsBangTy b =<< renameLType ltype

  HsAppTy a b -> do
    a' <- renameLType a
    b' <- renameLType b
    return (HsAppTy a' b')

  HsFunTy a b -> do
    a' <- renameLType a
    b' <- renameLType b
    return (HsFunTy a' b')

  HsListTy ty -> return . HsListTy =<< renameLType ty
  HsPArrTy ty -> return . HsPArrTy =<< renameLType ty
  HsIParamTy n ty -> liftM (HsIParamTy n) (renameLType ty)
  HsEqTy ty1 ty2 -> liftM2 HsEqTy (renameLType ty1) (renameLType ty2)

  HsTupleTy b ts -> return . HsTupleTy b =<< mapM renameLType ts
  HsSumTy ts -> HsSumTy <$> mapM renameLType ts

  HsOpTy a (L loc op) b -> do
    op' <- rename op
    a'  <- renameLType a
    b'  <- renameLType b
    return (HsOpTy a' (L loc op') b')

  HsParTy ty -> return . HsParTy =<< renameLType ty

  HsKindSig ty k -> do
    ty' <- renameLType ty
    k' <- renameLKind k
    return (HsKindSig ty' k')

  HsDocTy ty doc -> do
    ty' <- renameLType ty
    doc' <- renameLDocHsSyn doc
    return (HsDocTy ty' doc')

  HsTyLit x -> return (HsTyLit x)

  HsRecTy a               -> HsRecTy <$> mapM renameConDeclFieldField a
  HsCoreTy a              -> pure (HsCoreTy a)
  HsExplicitListTy i a b  -> HsExplicitListTy i a <$> mapM renameLType b
  HsExplicitTupleTy a b   -> HsExplicitTupleTy a <$> mapM renameLType b
  HsSpliceTy _ _          -> error "renameType: HsSpliceTy"
  HsWildCardTy a          -> HsWildCardTy <$> renameWildCardInfo a
  HsAppsTy _              -> error "renameType: HsAppsTy"

renameLHsQTyVars :: LHsQTyVars GHCR -> RnM (LHsQTyVars DocNameI)
renameLHsQTyVars (HsQTvs { hsq_implicit = _, hsq_explicit = tvs })
  = do { tvs' <- mapM renameLTyVarBndr tvs
       ; return (HsQTvs { hsq_implicit = error "haddock:renameLHsQTyVars", hsq_explicit = tvs', hsq_dependent = error "haddock:renameLHsQTyVars" }) }
                -- This is rather bogus, but I'm not sure what else to do

renameLTyVarBndr :: LHsTyVarBndr GHCR -> RnM (LHsTyVarBndr DocNameI)
renameLTyVarBndr (L loc (UserTyVar (L l n)))
  = do { n' <- rename n
       ; return (L loc (UserTyVar (L l n'))) }
renameLTyVarBndr (L loc (KindedTyVar (L lv n) kind))
  = do { n' <- rename n
       ; kind' <- renameLKind kind
       ; return (L loc (KindedTyVar (L lv n') kind')) }

renameLContext :: Located [LHsType GHCR] -> RnM (Located [LHsType DocNameI])
renameLContext (L loc context) = do
  context' <- mapM renameLType context
  return (L loc context')

renameWildCardInfo :: HsWildCardInfo GHCR -> RnM (HsWildCardInfo DocNameI)
renameWildCardInfo (AnonWildCard  (L l name)) = AnonWildCard . L l <$> rename name

renameInstHead :: InstHead GHCR -> RnM (InstHead DocNameI)
renameInstHead InstHead {..} = do
  cname <- rename ihdClsName
  kinds <- mapM renameType ihdKinds
  types <- mapM renameType ihdTypes
  itype <- case ihdInstType of
    ClassInst { .. } -> ClassInst
        <$> mapM renameType clsiCtx
        <*> renameLHsQTyVars clsiTyVars
        <*> mapM renameSig clsiSigs
        <*> mapM renamePseudoFamilyDecl clsiAssocTys
    TypeInst  ts -> TypeInst  <$> traverse renameType ts
    DataInst  dd -> DataInst  <$> renameTyClD dd
  return InstHead
    { ihdClsName = cname
    , ihdKinds = kinds
    , ihdTypes = types
    , ihdInstType = itype
    }

renameLDecl :: LHsDecl GHCR -> RnM (LHsDecl DocNameI)
renameLDecl (L loc d) = return . L loc =<< renameDecl d


renameDecl :: HsDecl GHCR -> RnM (HsDecl DocNameI)
renameDecl decl = case decl of
  TyClD d -> do
    d' <- renameTyClD d
    return (TyClD d')
  SigD s -> do
    s' <- renameSig s
    return (SigD s')
  ForD d -> do
    d' <- renameForD d
    return (ForD d')
  InstD d -> do
    d' <- renameInstD d
    return (InstD d')
  DerivD d -> do
    d' <- renameDerivD d
    return (DerivD d')
  _ -> error "renameDecl"

renameLThing :: (a GHCR -> RnM (a DocNameI)) -> Located (a GHCR) -> RnM (Located (a DocNameI))
renameLThing fn (L loc x) = return . L loc =<< fn x

renameTyClD :: TyClDecl GHCR -> RnM (TyClDecl DocNameI)
renameTyClD d = case d of
--  TyFamily flav lname ltyvars kind tckind -> do
  FamDecl { tcdFam = decl } -> do
    decl' <- renameFamilyDecl decl
    return (FamDecl { tcdFam = decl' })

  SynDecl { tcdLName = lname, tcdTyVars = tyvars, tcdFixity = fixity, tcdRhs = rhs, tcdFVs = _fvs } -> do
    lname'    <- renameL lname
    tyvars'   <- renameLHsQTyVars tyvars
    rhs'     <- renameLType rhs
    return (SynDecl { tcdLName = lname', tcdTyVars = tyvars', tcdFixity = fixity, tcdRhs = rhs', tcdFVs = placeHolderNames })

  DataDecl { tcdLName = lname, tcdTyVars = tyvars, tcdFixity = fixity, tcdDataDefn = defn, tcdFVs = _fvs } -> do
    lname'    <- renameL lname
    tyvars'   <- renameLHsQTyVars tyvars
    defn'     <- renameDataDefn defn
    return (DataDecl { tcdLName = lname', tcdTyVars = tyvars', tcdFixity = fixity, tcdDataDefn = defn', tcdDataCusk = PlaceHolder, tcdFVs = placeHolderNames })

  ClassDecl { tcdCtxt = lcontext, tcdLName = lname, tcdTyVars = ltyvars, tcdFixity = fixity
            , tcdFDs = lfundeps, tcdSigs = lsigs, tcdATs = ats, tcdATDefs = at_defs } -> do
    lcontext' <- renameLContext lcontext
    lname'    <- renameL lname
    ltyvars'  <- renameLHsQTyVars ltyvars
    lfundeps' <- mapM renameLFunDep lfundeps
    lsigs'    <- mapM renameLSig lsigs
    ats'      <- mapM (renameLThing renameFamilyDecl) ats
    at_defs'  <- mapM renameLTyFamDefltEqn at_defs
    -- we don't need the default methods or the already collected doc entities
    return (ClassDecl { tcdCtxt = lcontext', tcdLName = lname', tcdTyVars = ltyvars'
                      , tcdFixity = fixity
                      , tcdFDs = lfundeps', tcdSigs = lsigs', tcdMeths= emptyBag
                      , tcdATs = ats', tcdATDefs = at_defs', tcdDocs = [], tcdFVs = placeHolderNames })

  where
    renameLFunDep (L loc (xs, ys)) = do
      xs' <- mapM rename (map unLoc xs)
      ys' <- mapM rename (map unLoc ys)
      return (L loc (map noLoc xs', map noLoc ys'))

    renameLSig (L loc sig) = return . L loc =<< renameSig sig

renameFamilyDecl :: FamilyDecl GHCR -> RnM (FamilyDecl DocNameI)
renameFamilyDecl (FamilyDecl { fdInfo = info, fdLName = lname
                             , fdTyVars = ltyvars
                             , fdFixity = fixity
                             , fdResultSig = result
                             , fdInjectivityAnn = injectivity }) = do
    info'        <- renameFamilyInfo info
    lname'       <- renameL lname
    ltyvars'     <- renameLHsQTyVars ltyvars
    result'      <- renameFamilyResultSig result
    injectivity' <- renameMaybeInjectivityAnn injectivity
    return (FamilyDecl { fdInfo = info', fdLName = lname'
                       , fdTyVars = ltyvars'
                       , fdFixity = fixity
                       , fdResultSig = result'
                       , fdInjectivityAnn = injectivity' })


renamePseudoFamilyDecl :: PseudoFamilyDecl GHCR
                       -> RnM (PseudoFamilyDecl DocNameI)
renamePseudoFamilyDecl (PseudoFamilyDecl { .. }) =  PseudoFamilyDecl
    <$> renameFamilyInfo pfdInfo
    <*> renameL pfdLName
    <*> mapM renameLType pfdTyVars
    <*> renameFamilyResultSig pfdKindSig


renameFamilyInfo :: FamilyInfo GHCR -> RnM (FamilyInfo DocNameI)
renameFamilyInfo DataFamily     = return DataFamily
renameFamilyInfo OpenTypeFamily = return OpenTypeFamily
renameFamilyInfo (ClosedTypeFamily eqns)
  = do { eqns' <- mapM (mapM renameLTyFamInstEqn) eqns
       ; return $ ClosedTypeFamily eqns' }

renameDataDefn :: HsDataDefn GHCR -> RnM (HsDataDefn DocNameI)
renameDataDefn (HsDataDefn { dd_ND = nd, dd_ctxt = lcontext, dd_cType = cType
                           , dd_kindSig = k, dd_cons = cons }) = do
    lcontext' <- renameLContext lcontext
    k'        <- renameMaybeLKind k
    cons'     <- mapM (mapM renameCon) cons
    -- I don't think we need the derivings, so we return Nothing
    return (HsDataDefn { dd_ND = nd, dd_ctxt = lcontext', dd_cType = cType
                       , dd_kindSig = k', dd_cons = cons'
                       , dd_derivs = noLoc [] })

renameCon :: ConDecl GHCR -> RnM (ConDecl DocNameI)
renameCon decl@(ConDeclH98 { con_name = lname, con_qvars = ltyvars
                           , con_cxt = lcontext, con_details = details
                           , con_doc = mbldoc }) = do
      lname'    <- renameL lname
      ltyvars'  <- traverse renameLHsQTyVars ltyvars
      lcontext' <- traverse renameLContext lcontext
      details'  <- renameDetails details
      mbldoc'   <- mapM renameLDocHsSyn mbldoc
      return (decl { con_name = lname', con_qvars = ltyvars', con_cxt = lcontext'
                   , con_details = details', con_doc = mbldoc' })

  where
    renameDetails (RecCon (L l fields)) = do
      fields' <- mapM renameConDeclFieldField fields
      return (RecCon (L l fields'))
    renameDetails (PrefixCon ps) = return . PrefixCon =<< mapM renameLType ps
    renameDetails (InfixCon a b) = do
      a' <- renameLType a
      b' <- renameLType b
      return (InfixCon a' b')

renameCon decl@(ConDeclGADT { con_names = lnames
                            , con_type = lty
                            , con_doc = mbldoc }) = do
      lnames'   <- mapM renameL lnames
      lty'      <- renameLSigType lty
      mbldoc'   <- mapM renameLDocHsSyn mbldoc
      return (decl { con_names = lnames'
                   , con_type = lty', con_doc = mbldoc' })

renameConDeclFieldField :: LConDeclField GHCR -> RnM (LConDeclField DocNameI)
renameConDeclFieldField (L l (ConDeclField names t doc)) = do
  names' <- mapM renameLFieldOcc names
  t'   <- renameLType t
  doc' <- mapM renameLDocHsSyn doc
  return $ L l (ConDeclField names' t' doc')

renameLFieldOcc :: LFieldOcc GHCR -> RnM (LFieldOcc DocNameI)
renameLFieldOcc (L l (FieldOcc lbl sel)) = do
  sel' <- rename sel
  return $ L l (FieldOcc lbl sel')

renameSig :: Sig GHCR -> RnM (Sig DocNameI)
renameSig sig = case sig of
  TypeSig lnames ltype -> do
    lnames' <- mapM renameL lnames
    ltype' <- renameLSigWcType ltype
    return (TypeSig lnames' ltype')
  ClassOpSig is_default lnames sig_ty -> do
    lnames' <- mapM renameL lnames
    ltype' <- renameLSigType sig_ty
    return (ClassOpSig is_default lnames' ltype')
  PatSynSig lnames sig_ty -> do
    lnames' <- mapM renameL lnames
    sig_ty' <- renameLSigType sig_ty
    return $ PatSynSig lnames' sig_ty'
  FixSig (FixitySig lnames fixity) -> do
    lnames' <- mapM renameL lnames
    return $ FixSig (FixitySig lnames' fixity)
  MinimalSig src (L l s) -> do
    s' <- traverse renameL s
    return $ MinimalSig src (L l s')
  -- we have filtered out all other kinds of signatures in Interface.Create
  _ -> error "expected TypeSig"


renameForD :: ForeignDecl GHCR -> RnM (ForeignDecl DocNameI)
renameForD (ForeignImport lname ltype co x) = do
  lname' <- renameL lname
  ltype' <- renameLSigType ltype
  return (ForeignImport lname' ltype' co x)
renameForD (ForeignExport lname ltype co x) = do
  lname' <- renameL lname
  ltype' <- renameLSigType ltype
  return (ForeignExport lname' ltype' co x)


renameInstD :: InstDecl GHCR -> RnM (InstDecl DocNameI)
renameInstD (ClsInstD { cid_inst = d }) = do
  d' <- renameClsInstD d
  return (ClsInstD { cid_inst = d' })
renameInstD (TyFamInstD { tfid_inst = d }) = do
  d' <- renameTyFamInstD d
  return (TyFamInstD { tfid_inst = d' })
renameInstD (DataFamInstD { dfid_inst = d }) = do
  d' <- renameDataFamInstD d
  return (DataFamInstD { dfid_inst = d' })

renameDerivD :: DerivDecl GHCR -> RnM (DerivDecl DocNameI)
renameDerivD (DerivDecl { deriv_type = ty
                        , deriv_strategy = strat
                        , deriv_overlap_mode = omode }) = do
  ty' <- renameLSigType ty
  return (DerivDecl { deriv_type = ty'
                    , deriv_strategy = strat
                    , deriv_overlap_mode = omode })

renameClsInstD :: ClsInstDecl GHCR -> RnM (ClsInstDecl DocNameI)
renameClsInstD (ClsInstDecl { cid_overlap_mode = omode
                            , cid_poly_ty =ltype, cid_tyfam_insts = lATs
                            , cid_datafam_insts = lADTs }) = do
  ltype' <- renameLSigType ltype
  lATs'  <- mapM (mapM renameTyFamInstD) lATs
  lADTs' <- mapM (mapM renameDataFamInstD) lADTs
  return (ClsInstDecl { cid_overlap_mode = omode
                      , cid_poly_ty = ltype', cid_binds = emptyBag
                      , cid_sigs = []
                      , cid_tyfam_insts = lATs', cid_datafam_insts = lADTs' })


renameTyFamInstD :: TyFamInstDecl GHCR -> RnM (TyFamInstDecl DocNameI)
renameTyFamInstD (TyFamInstDecl { tfid_eqn = eqn })
  = do { eqn' <- renameLTyFamInstEqn eqn
       ; return (TyFamInstDecl { tfid_eqn = eqn'
                               , tfid_fvs = placeHolderNames }) }

renameLTyFamInstEqn :: LTyFamInstEqn GHCR -> RnM (LTyFamInstEqn DocNameI)
renameLTyFamInstEqn (L loc (TyFamEqn { tfe_tycon = tc, tfe_pats = pats, tfe_fixity = fixity, tfe_rhs = rhs }))
  = do { tc' <- renameL tc
       ; pats' <- renameImplicit (mapM renameLType) pats
       ; rhs' <- renameLType rhs
       ; return (L loc (TyFamEqn { tfe_tycon = tc'
                                 , tfe_pats = pats'
                                 , tfe_fixity = fixity
                                 , tfe_rhs = rhs' })) }

renameLTyFamDefltEqn :: LTyFamDefltEqn GHCR -> RnM (LTyFamDefltEqn DocNameI)
renameLTyFamDefltEqn (L loc (TyFamEqn { tfe_tycon = tc, tfe_pats = tvs, tfe_fixity = fixity, tfe_rhs = rhs }))
  = do { tc'  <- renameL tc
       ; tvs' <- renameLHsQTyVars tvs
       ; rhs' <- renameLType rhs
       ; return (L loc (TyFamEqn { tfe_tycon = tc'
                                 , tfe_pats = tvs'
                                 , tfe_fixity = fixity
                                 , tfe_rhs = rhs' })) }

renameDataFamInstD :: DataFamInstDecl GHCR -> RnM (DataFamInstDecl DocNameI)
renameDataFamInstD (DataFamInstDecl { dfid_tycon = tc, dfid_pats = pats, dfid_fixity = fixity, dfid_defn = defn })
  = do { tc' <- renameL tc
       ; pats' <- renameImplicit (mapM renameLType) pats
       ; defn' <- renameDataDefn defn
       ; return (DataFamInstDecl { dfid_tycon = tc'
                                 , dfid_pats = pats'
                                 , dfid_fixity = fixity
                                 , dfid_defn = defn', dfid_fvs = placeHolderNames }) }

renameImplicit :: (in_thing -> RnM out_thing)
               -> HsImplicitBndrs GHCR in_thing
               -> RnM (HsImplicitBndrs DocNameI out_thing)
renameImplicit rn_thing (HsIB { hsib_body = thing })
  = do { thing' <- rn_thing thing
       ; return (HsIB { hsib_body = thing'
                      , hsib_vars = PlaceHolder
                      , hsib_closed = PlaceHolder }) }

renameWc :: (in_thing -> RnM out_thing)
         -> HsWildCardBndrs GHCR in_thing
         -> RnM (HsWildCardBndrs DocNameI out_thing)
renameWc rn_thing (HsWC { hswc_body = thing })
  = do { thing' <- rn_thing thing
       ; return (HsWC { hswc_body = thing'
                      , hswc_wcs = PlaceHolder }) }

renameDocInstance :: DocInstance GHCR -> RnM (DocInstance DocNameI)
renameDocInstance (inst, idoc, L l n) = do
  inst' <- renameInstHead inst
  n' <- rename n
  idoc' <- mapM renameDoc idoc
  return (inst', idoc',L l n')

renameExportItem :: ExportItem GHCR -> RnM (ExportItem DocNameI)
renameExportItem item = case item of
  ExportModule mdl -> return (ExportModule mdl)
  ExportGroup lev id_ doc -> do
    doc' <- renameDoc doc
    return (ExportGroup lev id_ doc')
  ExportDecl decl doc subs instances fixities splice -> do
    decl' <- renameLDecl decl
    doc'  <- renameDocForDecl doc
    subs' <- mapM renameSub subs
    instances' <- forM instances renameDocInstance
    fixities' <- forM fixities $ \(name, fixity) -> do
      name' <- lookupRn name
      return (name', fixity)
    return (ExportDecl decl' doc' subs' instances' fixities' splice)
  ExportNoDecl x subs -> do
    x'    <- lookupRn x
    subs' <- mapM lookupRn subs
    return (ExportNoDecl x' subs')
  ExportDoc doc -> do
    doc' <- renameDoc doc
    return (ExportDoc doc')


renameSub :: (Name, DocForDecl Name) -> RnM (DocName, DocForDecl DocName)
renameSub (n,doc) = do
  n' <- rename n
  doc' <- renameDocForDecl doc
  return (n', doc')