    {-# LANGUAGE CPP           #-}
    {-# LANGUAGE DeriveFunctor #-}

    {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}

    {-
    (c) The GRASP/AQUA Project, Glasgow University, 1992-1998

    \section{Tidying up Core}
    -}

    module GHC.Iface.Tidy (
           mkBootModDetailsTc, tidyProgram
       ) where

    #include "HsVersions.h"

    import GHC.Prelude

    import GHC.Driver.Session
    import GHC.Driver.Backend
    import GHC.Driver.Ppr
    import GHC.Driver.Env

    import GHC.Tc.Types

    import GHC.Core
    import GHC.Core.Unfold
    import GHC.Core.Unfold.Make
    import GHC.Core.FVs
    import GHC.Core.Tidy
    import GHC.Core.Opt.Monad
    import GHC.Core.Stats   (coreBindsStats, CoreStats(..))
    import GHC.Core.Seq     (seqBinds)
    import GHC.Core.Lint
    import GHC.Core.Rules
    import GHC.Core.Opt.Arity   ( exprArity, exprBotStrictness_maybe )
    import GHC.Core.InstEnv
    import GHC.Core.Type     ( tidyTopType )
    import GHC.Core.DataCon
    import GHC.Core.TyCon
    import GHC.Core.Class

    import GHC.Iface.Tidy.StaticPtrTable
    import GHC.Iface.Env

    import GHC.Tc.Utils.Env
    import GHC.Tc.Utils.Monad

    import GHC.Utils.Outputable
    import GHC.Utils.Misc( filterOut )
    import GHC.Utils.Panic
    import GHC.Utils.Logger as Logger
    import qualified GHC.Utils.Error as Err

    import GHC.Types.ForeignStubs
    import GHC.Types.Var.Env
    import GHC.Types.Var.Set
    import GHC.Types.Var
    import GHC.Types.Id
    import GHC.Types.Id.Make ( mkDictSelRhs )
    import GHC.Types.Id.Info
    import GHC.Types.Demand  ( isDeadEndAppSig, isTopSig, isDeadEndSig )
    import GHC.Types.Cpr     ( mkCprSig, botCpr )
    import GHC.Types.Basic
    import GHC.Types.Name hiding (varName)
    import GHC.Types.Name.Set
    import GHC.Types.Name.Cache
    import GHC.Types.Name.Ppr
    import GHC.Types.Avail
    import GHC.Types.Unique.Supply
    import GHC.Types.Tickish
    import GHC.Types.TypeEnv

    import GHC.Unit.Module
    import GHC.Unit.Module.ModGuts
    import GHC.Unit.Module.ModDetails
    import GHC.Unit.Module.Deps

    import GHC.Data.Maybe

    import Control.Monad
    import Data.Function
    import Data.List        ( sortBy, mapAccumL )
    import Data.IORef       ( atomicModifyIORef' )

    {-
    Constructing the TypeEnv, Instances, Rules from which the
    ModIface is constructed, and which goes on to subsequent modules in
    --make mode.

    Most of the interface file is obtained simply by serialising the
    TypeEnv.  One important consequence is that if the *interface file*
    has pragma info if and only if the final TypeEnv does. This is not so
    important for *this* module, but it's essential for ghc --make:
    subsequent compilations must not see (e.g.) the arity if the interface
    file does not contain arity If they do, they'll exploit the arity;
    then the arity might change, but the iface file doesn't change =>
    recompilation does not happen => disaster.

    For data types, the final TypeEnv will have a TyThing for the TyCon,
    plus one for each DataCon; the interface file will contain just one
    data type declaration, but it is de-serialised back into a collection
    of TyThings.

    ************************************************************************
    *                                                                      *
                    Plan A: simpleTidyPgm
    *                                                                      *
    ************************************************************************

    Plan A: mkBootModDetails: omit pragmas, make interfaces small
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    * Ignore the bindings

    * Drop all WiredIn things from the TypeEnv
            (we never want them in interface files)

    * Retain all TyCons and Classes in the TypeEnv, to avoid
            having to find which ones are mentioned in the
            types of exported Ids

    * Trim off the constructors of non-exported TyCons, both
            from the TyCon and from the TypeEnv

    * Drop non-exported Ids from the TypeEnv

    * Tidy the types of the DFunIds of Instances,
      make them into GlobalIds, (they already have External Names)
      and add them to the TypeEnv

    * Tidy the types of the (exported) Ids in the TypeEnv,
      make them into GlobalIds (they already have External Names)

    * Drop rules altogether

    * Tidy the bindings, to ensure that the Arity
      information is correct for each top-level binder; the
      code generator needs it. And to ensure that local names have
      distinct OccNames in case of object-file splitting

    * If this an hsig file, drop the instances altogether too (they'll
      get pulled in by the implicit module import.
    -}

    -- This is Plan A: make a small type env when typechecking only,
    -- or when compiling a hs-boot file, or simply when not using -O
    --
    -- We don't look at the bindings at all -- there aren't any
    -- for hs-boot files

    mkBootModDetailsTc :: HscEnv -> TcGblEnv -> IO ModDetails
    mkBootModDetailsTc :: HscEnv -> TcGblEnv -> IO ModDetails
    mkBootModDetailsTc HscEnv
    hsc_env
            TcGblEnv{ tcg_exports :: TcGblEnv -> [AvailInfo]
    tcg_exports          = [AvailInfo]
    exports,
                      tcg_type_env :: TcGblEnv -> TypeEnv
    tcg_type_env         = TypeEnv
    type_env, -- just for the Ids
                      tcg_tcs :: TcGblEnv -> [TyCon]
    tcg_tcs              = [TyCon]
    tcs,
                      tcg_patsyns :: TcGblEnv -> [PatSyn]
    tcg_patsyns          = [PatSyn]
    pat_syns,
                      tcg_insts :: TcGblEnv -> [ClsInst]
    tcg_insts            = [ClsInst]
    insts,
                      tcg_fam_insts :: TcGblEnv -> [FamInst]
    tcg_fam_insts        = [FamInst]
    fam_insts,
                      tcg_complete_matches :: TcGblEnv -> CompleteMatches
    tcg_complete_matches = CompleteMatches
    complete_matches,
                      tcg_mod :: TcGblEnv -> Module
    tcg_mod              = Module
    this_mod
                    }
      = -- This timing isn't terribly useful since the result isn't forced, but
        -- the message is useful to locating oneself in the compilation process.
        forall (m :: * -> *) a.
    MonadIO m =>
    Logger -> DynFlags -> SDoc -> (a -> ()) -> m a -> m a
    Err.withTiming Logger
    logger DynFlags
    dflags
                       (String -> SDoc
    text String
    "CoreTidy"SDoc -> SDoc -> SDoc
    <+>SDoc -> SDoc
    brackets (forall a. Outputable a => a -> SDoc
    ppr Module
    this_mod))
                       (forall a b. a -> b -> a
    const ()) forall a b. (a -> b) -> a -> b
    $
        forall (m :: * -> *) a. Monad m => a -> m a
    return (ModDetails { md_types :: TypeEnv
    md_types            = TypeEnv
    type_env'
                           , md_insts :: [ClsInst]
    md_insts            = [ClsInst]
    insts'
                           , md_fam_insts :: [FamInst]
    md_fam_insts        = [FamInst]
    fam_insts
                           , md_rules :: [CoreRule]
    md_rules            = []
                           , md_anns :: [Annotation]
    md_anns             = []
                           , md_exports :: [AvailInfo]
    md_exports          = [AvailInfo]
    exports
                           , md_complete_matches :: CompleteMatches
    md_complete_matches = CompleteMatches
    complete_matches
                           })
      where
        dflags :: DynFlags
    dflags = HscEnv -> DynFlags
    hsc_dflags HscEnv
    hsc_env
        logger :: Logger
    logger = HscEnv -> Logger
    hsc_logger HscEnv
    hsc_env

        -- Find the LocalIds in the type env that are exported
        -- Make them into GlobalIds, and tidy their types
        --
        -- It's very important to remove the non-exported ones
        -- because we don't tidy the OccNames, and if we don't remove
        -- the non-exported ones we'll get many things with the
        -- same name in the interface file, giving chaos.
        --
        -- Do make sure that we keep Ids that are already Global.
        -- When typechecking an .hs-boot file, the Ids come through as
        -- GlobalIds.
        final_ids :: [Id]
    final_ids = [ Id -> Id
    globaliseAndTidyBootId Id
    id
                    | Id
    id <- TypeEnv -> [Id]
    typeEnvIds TypeEnv
    type_env
                    , Id -> Bool
    keep_it Id
    id ]

        final_tcs :: [TyCon]
    final_tcs  = forall a. (a -> Bool) -> [a] -> [a]
    filterOut forall thing. NamedThing thing => thing -> Bool
    isWiredIn [TyCon]
    tcs
                     -- See Note [Drop wired-in things]
        type_env' :: TypeEnv
    type_env'  = [Id] -> [TyCon] -> [PatSyn] -> [FamInst] -> TypeEnv
    typeEnvFromEntities [Id]
    final_ids [TyCon]
    final_tcs [PatSyn]
    pat_syns [FamInst]
    fam_insts
        insts' :: [ClsInst]
    insts'     = TypeEnv -> [ClsInst] -> [ClsInst]
    mkFinalClsInsts TypeEnv
    type_env' [ClsInst]
    insts

        -- Default methods have their export flag set (isExportedId),
        -- but everything else doesn't (yet), because this is
        -- pre-desugaring, so we must test against the exports too.
        keep_it :: Id -> Bool
    keep_it Id
    id | Name -> Bool
    isWiredInName Name
    id_name           = Bool
    False
                     -- See Note [Drop wired-in things]
                   | Id -> Bool
    isExportedId Id
    id                 = Bool
    True
                   | Name
    id_name Name -> NameSet -> Bool
    `elemNameSet` NameSet
    exp_names = Bool
    True
                   | Bool
    otherwise                       = Bool
    False
                   where
                     id_name :: Name
    id_name = Id -> Name
    idName Id
    id

        exp_names :: NameSet
    exp_names = [AvailInfo] -> NameSet
    availsToNameSet [AvailInfo]
    exports

    lookupFinalId :: TypeEnv -> Id -> Id
    lookupFinalId :: TypeEnv -> Id -> Id
    lookupFinalId TypeEnv
    type_env Id
    id
      = case TypeEnv -> Name -> Maybe TyThing
    lookupTypeEnv TypeEnv
    type_env (Id -> Name
    idName Id
    id) of
          Just (AnId Id
    id') -> Id
    id'
          Maybe TyThing
    _ -> forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "lookup_final_id" (forall a. Outputable a => a -> SDoc
    ppr Id
    id)

    mkFinalClsInsts :: TypeEnv -> [ClsInst] -> [ClsInst]
    mkFinalClsInsts :: TypeEnv -> [ClsInst] -> [ClsInst]
    mkFinalClsInsts TypeEnv
    env = forall a b. (a -> b) -> [a] -> [b]
    map ((Id -> Id) -> ClsInst -> ClsInst
    updateClsInstDFun (TypeEnv -> Id -> Id
    lookupFinalId TypeEnv
    env))

    globaliseAndTidyBootId :: Id -> Id
    -- For a LocalId with an External Name,
    -- makes it into a GlobalId
    --     * unchanged Name (might be Internal or External)
    --     * unchanged details
    --     * VanillaIdInfo (makes a conservative assumption about arity)
    --     * BootUnfolding (see Note [Inlining and hs-boot files] in GHC.CoreToIface)
    globaliseAndTidyBootId :: Id -> Id
    globaliseAndTidyBootId Id
    id
      = (Type -> Type) -> Id -> Id
    updateIdTypeAndMult Type -> Type
    tidyTopType (Id -> Id
    globaliseId Id
    id)
                       Id -> Unfolding -> Id
    `setIdUnfolding` Unfolding
    BootUnfolding

    {-
    ************************************************************************
    *                                                                      *
            Plan B: tidy bindings, make TypeEnv full of IdInfo
    *                                                                      *
    ************************************************************************

    Plan B: include pragmas, make interfaces
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    * Step 1: Figure out which Ids are externally visible
              See Note [Choosing external Ids]

    * Step 2: Gather the externally visible rules, separately from
              the top-level bindings.
              See Note [Finding external rules]

    * Step 3: Tidy the bindings, externalising appropriate Ids
              See Note [Tidy the top-level bindings]

    * Drop all Ids from the TypeEnv, and add all the External Ids from
      the bindings.  (This adds their IdInfo to the TypeEnv; and adds
      floated-out Ids that weren't even in the TypeEnv before.)

    Note [Choosing external Ids]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    See also the section "Interface stability" in the
    recompilation-avoidance commentary:
      https://gitlab.haskell.org/ghc/ghc/wikis/commentary/compiler/recompilation-avoidance

    First we figure out which Ids are "external" Ids.  An
    "external" Id is one that is visible from outside the compilation
    unit.  These are
      a) the user exported ones
      b) the ones bound to static forms
      c) ones mentioned in the unfoldings, workers, or
         rules of externally-visible ones

    While figuring out which Ids are external, we pick a "tidy" OccName
    for each one.  That is, we make its OccName distinct from the other
    external OccNames in this module, so that in interface files and
    object code we can refer to it unambiguously by its OccName.  The
    OccName for each binder is prefixed by the name of the exported Id
    that references it; e.g. if "f" references "x" in its unfolding, then
    "x" is renamed to "f_x".  This helps distinguish the different "x"s
    from each other, and means that if "f" is later removed, things that
    depend on the other "x"s will not need to be recompiled.  Of course,
    if there are multiple "f_x"s, then we have to disambiguate somehow; we
    use "f_x0", "f_x1" etc.

    As far as possible we should assign names in a deterministic fashion.
    Each time this module is compiled with the same options, we should end
    up with the same set of external names with the same types.  That is,
    the ABI hash in the interface should not change.  This turns out to be
    quite tricky, since the order of the bindings going into the tidy
    phase is already non-deterministic, as it is based on the ordering of
    Uniques, which are assigned unpredictably.

    To name things in a stable way, we do a depth-first-search of the
    bindings, starting from the exports sorted by name.  This way, as long
    as the bindings themselves are deterministic (they sometimes aren't!),
    the order in which they are presented to the tidying phase does not
    affect the names we assign.

    Note [Tidy the top-level bindings]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Next we traverse the bindings top to bottom.  For each *top-level*
    binder

     1. Make it into a GlobalId; its IdDetails becomes VanillaGlobal,
        reflecting the fact that from now on we regard it as a global,
        not local, Id

     2. Give it a system-wide Unique.
        [Even non-exported things need system-wide Uniques because the
        byte-code generator builds a single Name->BCO symbol table.]

        We use the NameCache kept in the HscEnv as the
        source of such system-wide uniques.

        For external Ids, use the original-name cache in the NameCache
        to ensure that the unique assigned is the same as the Id had
        in any previous compilation run.

     3. Rename top-level Ids according to the names we chose in step 1.
        If it's an external Id, make it have a External Name, otherwise
        make it have an Internal Name.  This is used by the code generator
        to decide whether to make the label externally visible

     4. Give it its UTTERLY FINAL IdInfo; in ptic,
            * its unfolding, if it should have one

            * its arity, computed from the number of visible lambdas

    Finally, substitute these new top-level binders consistently
    throughout, including in unfoldings.  We also tidy binders in
    RHSs, so that they print nicely in interfaces.

    Note [Always expose compulsory unfoldings]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    We must make absolutely sure that unsafeCoerce# is inlined. You might
    think that giving it a compulsory unfolding is enough. However,
    unsafeCoerce# is put in an interface file just like any other definition.
    So, unless we take special precuations
    - If we compiled Unsafe.Coerce with -O0, we might not put the unfolding
      into the interface file.
    - If we compile a module M, that imports Unsafe.Coerce, with -O0 we might
      not read the unfolding out of the interface file.

    So we need to take care, to ensure that Compulsory unfoldings are written
    and read.  That makes sense: they are compulsory, after all. There are
    three places this is actioned:

    * GHC.Iface.Tidy.addExternal.  Export end: expose compulsory
      unfoldings, even with -O0.

    * GHC.IfaceToCore.tcIdInfo.  Import end: when reading in from
      interface file, even with -O0 (fignore-interface-pragmas.)  we must
      load a compulsory unfolding
    -}

    tidyProgram :: HscEnv -> ModGuts -> IO (CgGuts, ModDetails)
    tidyProgram :: HscEnv -> ModGuts -> IO (CgGuts, ModDetails)
    tidyProgram HscEnv
    hsc_env  (ModGuts { mg_module :: ModGuts -> Module
    mg_module           = Module
    mod
                                  , mg_exports :: ModGuts -> [AvailInfo]
    mg_exports          = [AvailInfo]
    exports
                                  , mg_rdr_env :: ModGuts -> GlobalRdrEnv
    mg_rdr_env          = GlobalRdrEnv
    rdr_env
                                  , mg_tcs :: ModGuts -> [TyCon]
    mg_tcs              = [TyCon]
    tcs
                                  , mg_insts :: ModGuts -> [ClsInst]
    mg_insts            = [ClsInst]
    cls_insts
                                  , mg_fam_insts :: ModGuts -> [FamInst]
    mg_fam_insts        = [FamInst]
    fam_insts
                                  , mg_binds :: ModGuts -> CoreProgram
    mg_binds            = CoreProgram
    binds
                                  , mg_patsyns :: ModGuts -> [PatSyn]
    mg_patsyns          = [PatSyn]
    patsyns
                                  , mg_rules :: ModGuts -> [CoreRule]
    mg_rules            = [CoreRule]
    imp_rules
                                  , mg_anns :: ModGuts -> [Annotation]
    mg_anns             = [Annotation]
    anns
                                  , mg_complete_matches :: ModGuts -> CompleteMatches
    mg_complete_matches = CompleteMatches
    complete_matches
                                  , mg_deps :: ModGuts -> Dependencies
    mg_deps             = Dependencies
    deps
                                  , mg_foreign :: ModGuts -> ForeignStubs
    mg_foreign          = ForeignStubs
    foreign_stubs
                                  , mg_foreign_files :: ModGuts -> [(ForeignSrcLang, String)]
    mg_foreign_files    = [(ForeignSrcLang, String)]
    foreign_files
                                  , mg_hpc_info :: ModGuts -> HpcInfo
    mg_hpc_info         = HpcInfo
    hpc_info
                                  , mg_modBreaks :: ModGuts -> Maybe ModBreaks
    mg_modBreaks        = Maybe ModBreaks
    modBreaks
                                  })

      = forall (m :: * -> *) a.
    MonadIO m =>
    Logger -> DynFlags -> SDoc -> (a -> ()) -> m a -> m a
    Err.withTiming Logger
    logger DynFlags
    dflags
                       (String -> SDoc
    text String
    "CoreTidy"SDoc -> SDoc -> SDoc
    <+>SDoc -> SDoc
    brackets (forall a. Outputable a => a -> SDoc
    ppr Module
    mod))
                       (forall a b. a -> b -> a
    const ()) forall a b. (a -> b) -> a -> b
    $
        do  { let { omit_prags :: Bool
    omit_prags = GeneralFlag -> DynFlags -> Bool
    gopt GeneralFlag
    Opt_OmitInterfacePragmas DynFlags
    dflags
                  ; expose_all :: Bool
    expose_all = GeneralFlag -> DynFlags -> Bool
    gopt GeneralFlag
    Opt_ExposeAllUnfoldings  DynFlags
    dflags
                  ; print_unqual :: PrintUnqualified
    print_unqual = UnitEnv -> GlobalRdrEnv -> PrintUnqualified
    mkPrintUnqualified (HscEnv -> UnitEnv
    hsc_unit_env HscEnv
    hsc_env) GlobalRdrEnv
    rdr_env
                  ; implicit_binds :: CoreProgram
    implicit_binds = forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
    concatMap TyCon -> CoreProgram
    getImplicitBinds [TyCon]
    tcs
                  }

            ; (UnfoldEnv
    unfold_env, TidyOccEnv
    tidy_occ_env)
                  <- HscEnv
    -> Module
    -> Bool
    -> Bool
    -> CoreProgram
    -> CoreProgram
    -> [CoreRule]
    -> IO (UnfoldEnv, TidyOccEnv)
    chooseExternalIds HscEnv
    hsc_env Module
    mod Bool
    omit_prags Bool
    expose_all
                                       CoreProgram
    binds CoreProgram
    implicit_binds [CoreRule]
    imp_rules
            ; let { (CoreProgram
    trimmed_binds, [CoreRule]
    trimmed_rules)
                        = Bool
    -> CoreProgram
    -> [CoreRule]
    -> UnfoldEnv
    -> (CoreProgram, [CoreRule])
    findExternalRules Bool
    omit_prags CoreProgram
    binds [CoreRule]
    imp_rules UnfoldEnv
    unfold_env }

            ; let uf_opts :: UnfoldingOpts
    uf_opts = DynFlags -> UnfoldingOpts
    unfoldingOpts DynFlags
    dflags
            ; (TidyEnv
    tidy_env, CoreProgram
    tidy_binds)
                     <- UnfoldingOpts
    -> UnfoldEnv
    -> TidyOccEnv
    -> CoreProgram
    -> IO (TidyEnv, CoreProgram)
    tidyTopBinds UnfoldingOpts
    uf_opts UnfoldEnv
    unfold_env TidyOccEnv
    tidy_occ_env CoreProgram
    trimmed_binds

              -- See Note [Grand plan for static forms] in GHC.Iface.Tidy.StaticPtrTable.
            ; ([SptEntry]
    spt_entries, CoreProgram
    tidy_binds') <-
                 HscEnv -> Module -> CoreProgram -> IO ([SptEntry], CoreProgram)
    sptCreateStaticBinds HscEnv
    hsc_env Module
    mod CoreProgram
    tidy_binds
            ; let { platform :: Platform
    platform = DynFlags -> Platform
    targetPlatform (HscEnv -> DynFlags
    hsc_dflags HscEnv
    hsc_env)
                  ; spt_init_code :: CStub
    spt_init_code = Platform -> Module -> [SptEntry] -> CStub
    sptModuleInitCode Platform
    platform Module
    mod [SptEntry]
    spt_entries
                  ; add_spt_init_code :: ForeignStubs -> ForeignStubs
    add_spt_init_code =
                      case DynFlags -> Backend
    backend DynFlags
    dflags of
                        -- If we are compiling for the interpreter we will insert
                        -- any necessary SPT entries dynamically
                        Backend
    Interpreter -> forall a. a -> a
    id
                        -- otherwise add a C stub to do so
                        Backend
    _              -> (ForeignStubs -> CStub -> ForeignStubs
    `appendStubC` CStub
    spt_init_code)

                  -- The completed type environment is gotten from
                  --      a) the types and classes defined here (plus implicit things)
                  --      b) adding Ids with correct IdInfo, including unfoldings,
                  --              gotten from the bindings
                  -- From (b) we keep only those Ids with External names;
                  --          the CoreTidy pass makes sure these are all and only
                  --          the externally-accessible ones
                  -- This truncates the type environment to include only the
                  -- exported Ids and things needed from them, which saves space
                  --
                  -- See Note [Don't attempt to trim data types]
                  ; final_ids :: [Id]
    final_ids  = [ Bool -> Id -> Id
    trimId Bool
    omit_prags Id
    id
                                 | Id
    id <- forall b. [Bind b] -> [b]
    bindersOfBinds CoreProgram
    tidy_binds
                                 , Name -> Bool
    isExternalName (Id -> Name
    idName Id
    id)
                                 , Bool -> Bool
    not (forall thing. NamedThing thing => thing -> Bool
    isWiredIn Id
    id)
                                 ]   -- See Note [Drop wired-in things]

                  ; final_tcs :: [TyCon]
    final_tcs      = forall a. (a -> Bool) -> [a] -> [a]
    filterOut forall thing. NamedThing thing => thing -> Bool
    isWiredIn [TyCon]
    tcs
                                     -- See Note [Drop wired-in things]
                  ; tidy_type_env :: TypeEnv
    tidy_type_env  = [Id] -> [TyCon] -> [PatSyn] -> [FamInst] -> TypeEnv
    typeEnvFromEntities [Id]
    final_ids [TyCon]
    final_tcs [PatSyn]
    patsyns [FamInst]
    fam_insts
                  ; tidy_cls_insts :: [ClsInst]
    tidy_cls_insts = TypeEnv -> [ClsInst] -> [ClsInst]
    mkFinalClsInsts TypeEnv
    tidy_type_env [ClsInst]
    cls_insts
                  ; tidy_rules :: [CoreRule]
    tidy_rules     = TidyEnv -> [CoreRule] -> [CoreRule]
    tidyRules TidyEnv
    tidy_env [CoreRule]
    trimmed_rules

                  ; -- See Note [Injecting implicit bindings]
                    all_tidy_binds :: CoreProgram
    all_tidy_binds = CoreProgram
    implicit_binds forall a. [a] -> [a] -> [a]
    ++ CoreProgram
    tidy_binds'

                  -- Get the TyCons to generate code for.  Careful!  We must use
                  -- the untidied TyCons here, because we need
                  --  (a) implicit TyCons arising from types and classes defined
                  --      in this module
                  --  (b) wired-in TyCons, which are normally removed from the
                  --      TypeEnv we put in the ModDetails
                  --  (c) Constructors even if they are not exported (the
                  --      tidied TypeEnv has trimmed these away)
                  ; alg_tycons :: [TyCon]
    alg_tycons = forall a. (a -> Bool) -> [a] -> [a]
    filter TyCon -> Bool
    isAlgTyCon [TyCon]
    tcs
                  }

            ; HscEnv
    -> PrintUnqualified
    -> CoreToDo
    -> CoreProgram
    -> [CoreRule]
    -> IO ()
    endPassIO HscEnv
    hsc_env PrintUnqualified
    print_unqual CoreToDo
    CoreTidy CoreProgram
    all_tidy_binds [CoreRule]
    tidy_rules

              -- If the endPass didn't print the rules, but ddump-rules is
              -- on, print now
            ; forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    unless (DumpFlag -> DynFlags -> Bool
    dopt DumpFlag
    Opt_D_dump_simpl DynFlags
    dflags) forall a b. (a -> b) -> a -> b
    $
                Logger
    -> DynFlags -> DumpFlag -> String -> DumpFormat -> SDoc -> IO ()
    Logger.dumpIfSet_dyn Logger
    logger DynFlags
    dflags DumpFlag
    Opt_D_dump_rules
                  (DynFlags -> SDoc -> String
    showSDoc DynFlags
    dflags (forall a. Outputable a => a -> SDoc
    ppr CoreToDo
    CoreTidy SDoc -> SDoc -> SDoc
    <+> String -> SDoc
    text String
    "rules"))
                  DumpFormat
    FormatText
                  ([CoreRule] -> SDoc
    pprRulesForUser [CoreRule]
    tidy_rules)

              -- Print one-line size info
            ; let cs :: CoreStats
    cs = CoreProgram -> CoreStats
    coreBindsStats CoreProgram
    tidy_binds
            ; Logger
    -> DynFlags -> DumpFlag -> String -> DumpFormat -> SDoc -> IO ()
    Logger.dumpIfSet_dyn Logger
    logger DynFlags
    dflags DumpFlag
    Opt_D_dump_core_stats String
    "Core Stats"
                DumpFormat
    FormatText
                (String -> SDoc
    text String
    "Tidy size (terms,types,coercions)"
                 SDoc -> SDoc -> SDoc
    <+> forall a. Outputable a => a -> SDoc
    ppr (forall unit. GenModule unit -> ModuleName
    moduleName Module
    mod) SDoc -> SDoc -> SDoc
    <> SDoc
    colon
                 SDoc -> SDoc -> SDoc
    <+> Int -> SDoc
    int (CoreStats -> Int
    cs_tm CoreStats
    cs)
                 SDoc -> SDoc -> SDoc
    <+> Int -> SDoc
    int (CoreStats -> Int
    cs_ty CoreStats
    cs)
                 SDoc -> SDoc -> SDoc
    <+> Int -> SDoc
    int (CoreStats -> Int
    cs_co CoreStats
    cs) )

            ; forall (m :: * -> *) a. Monad m => a -> m a
    return (CgGuts { cg_module :: Module
    cg_module   = Module
    mod,
                               cg_tycons :: [TyCon]
    cg_tycons   = [TyCon]
    alg_tycons,
                               cg_binds :: CoreProgram
    cg_binds    = CoreProgram
    all_tidy_binds,
                               cg_foreign :: ForeignStubs
    cg_foreign  = ForeignStubs -> ForeignStubs
    add_spt_init_code ForeignStubs
    foreign_stubs,
                               cg_foreign_files :: [(ForeignSrcLang, String)]
    cg_foreign_files = [(ForeignSrcLang, String)]
    foreign_files,
                               cg_dep_pkgs :: [UnitId]
    cg_dep_pkgs = forall a b. (a -> b) -> [a] -> [b]
    map forall a b. (a, b) -> a
    fst forall a b. (a -> b) -> a -> b
    $ Dependencies -> [(UnitId, Bool)]
    dep_pkgs Dependencies
    deps,
                               cg_hpc_info :: HpcInfo
    cg_hpc_info = HpcInfo
    hpc_info,
                               cg_modBreaks :: Maybe ModBreaks
    cg_modBreaks = Maybe ModBreaks
    modBreaks,
                               cg_spt_entries :: [SptEntry]
    cg_spt_entries = [SptEntry]
    spt_entries },

                       ModDetails { md_types :: TypeEnv
    md_types            = TypeEnv
    tidy_type_env,
                                    md_rules :: [CoreRule]
    md_rules            = [CoreRule]
    tidy_rules,
                                    md_insts :: [ClsInst]
    md_insts            = [ClsInst]
    tidy_cls_insts,
                                    md_fam_insts :: [FamInst]
    md_fam_insts        = [FamInst]
    fam_insts,
                                    md_exports :: [AvailInfo]
    md_exports          = [AvailInfo]
    exports,
                                    md_anns :: [Annotation]
    md_anns             = [Annotation]
    anns,      -- are already tidy
                                    md_complete_matches :: CompleteMatches
    md_complete_matches = CompleteMatches
    complete_matches
                                  })
            }
      where
        dflags :: DynFlags
    dflags = HscEnv -> DynFlags
    hsc_dflags HscEnv
    hsc_env
        logger :: Logger
    logger = HscEnv -> Logger
    hsc_logger HscEnv
    hsc_env

    --------------------------
    trimId :: Bool -> Id -> Id
    -- With -O0 we now trim off the arity, one-shot-ness, strictness
    -- etc which tidyTopIdInfo retains for the benefit of the code generator
    -- but which we don't want in the interface file or ModIface for
    -- downstream compilations
    trimId :: Bool -> Id -> Id
    trimId Bool
    omit_prags Id
    id
      | Bool
    omit_prags, Bool -> Bool
    not (Id -> Bool
    isImplicitId Id
    id)
      = Id
    id Id -> IdInfo -> Id
    `setIdInfo`      IdInfo
    vanillaIdInfo
           Id -> Unfolding -> Id
    `setIdUnfolding` Id -> Unfolding
    idUnfolding Id
    id
           -- We respect the final unfolding chosen by tidyTopIdInfo.
           -- We have already trimmed it if we don't want it for -O0;
           -- see also Note [Always expose compulsory unfoldings]

      | Bool
    otherwise   -- No trimming
      = Id
    id

    {- Note [Drop wired-in things]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    We never put wired-in TyCons or Ids in an interface file.
    They are wired-in, so the compiler knows about them already.

    Note [Don't attempt to trim data types]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    For some time GHC tried to avoid exporting the data constructors
    of a data type if it wasn't strictly necessary to do so; see #835.
    But "strictly necessary" accumulated a longer and longer list
    of exceptions, and finally I gave up the battle:

        commit 9a20e540754fc2af74c2e7392f2786a81d8d5f11
        Author: Simon Peyton Jones <simonpj@microsoft.com>
        Date:   Thu Dec 6 16:03:16 2012 +0000

        Stop attempting to "trim" data types in interface files

        Without -O, we previously tried to make interface files smaller
        by not including the data constructors of data types.  But
        there are a lot of exceptions, notably when Template Haskell is
        involved or, more recently, DataKinds.

        However #7445 shows that even without TemplateHaskell, using
        the Data class and invoking Language.Haskell.TH.Quote.dataToExpQ
        is enough to require us to expose the data constructors.

        So I've given up on this "optimisation" -- it's probably not
        important anyway.  Now I'm simply not attempting to trim off
        the data constructors.  The gain in simplicity is worth the
        modest cost in interface file growth, which is limited to the
        bits reqd to describe those data constructors.

    ************************************************************************
    *                                                                      *
            Implicit bindings
    *                                                                      *
    ************************************************************************

    Note [Injecting implicit bindings]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    We inject the implicit bindings right at the end, in GHC.Core.Tidy.
    Some of these bindings, notably record selectors, are not
    constructed in an optimised form.  E.g. record selector for
            data T = MkT { x :: {-# UNPACK #-} !Int }
    Then the unfolding looks like
            x = \t. case t of MkT x1 -> let x = I# x1 in x
    This generates bad code unless it's first simplified a bit.  That is
    why GHC.Core.Unfold.mkImplicitUnfolding uses simpleOptExpr to do a bit of
    optimisation first.  (Only matters when the selector is used curried;
    eg map x ys.)  See #2070.

    [Oct 09: in fact, record selectors are no longer implicit Ids at all,
    because we really do want to optimise them properly. They are treated
    much like any other Id.  But doing "light" optimisation on an implicit
    Id still makes sense.]

    At one time I tried injecting the implicit bindings *early*, at the
    beginning of SimplCore.  But that gave rise to real difficulty,
    because GlobalIds are supposed to have *fixed* IdInfo, but the
    simplifier and other core-to-core passes mess with IdInfo all the
    time.  The straw that broke the camels back was when a class selector
    got the wrong arity -- ie the simplifier gave it arity 2, whereas
    importing modules were expecting it to have arity 1 (#2844).
    It's much safer just to inject them right at the end, after tidying.

    Oh: two other reasons for injecting them late:

      - If implicit Ids are already in the bindings when we start tidying,
        we'd have to be careful not to treat them as external Ids (in
        the sense of chooseExternalIds); else the Ids mentioned in *their*
        RHSs will be treated as external and you get an interface file
        saying      a18 = <blah>
        but nothing referring to a18 (because the implicit Id is the
        one that does, and implicit Ids don't appear in interface files).

      - More seriously, the tidied type-envt will include the implicit
        Id replete with a18 in its unfolding; but we won't take account
        of a18 when computing a fingerprint for the class; result chaos.

    There is one sort of implicit binding that is injected still later,
    namely those for data constructor workers. Reason (I think): it's
    really just a code generation trick.... binding itself makes no sense.
    See Note [Data constructor workers] in "GHC.CoreToStg.Prep".
    -}

    getImplicitBinds :: TyCon -> [CoreBind]
    getImplicitBinds :: TyCon -> CoreProgram
    getImplicitBinds TyCon
    tc = CoreProgram
    cls_binds forall a. [a] -> [a] -> [a]
    ++ TyCon -> CoreProgram
    getTyConImplicitBinds TyCon
    tc
      where
        cls_binds :: CoreProgram
    cls_binds = forall b a. b -> (a -> b) -> Maybe a -> b
    maybe [] Class -> CoreProgram
    getClassImplicitBinds (TyCon -> Maybe Class
    tyConClass_maybe TyCon
    tc)

    getTyConImplicitBinds :: TyCon -> [CoreBind]
    getTyConImplicitBinds :: TyCon -> CoreProgram
    getTyConImplicitBinds TyCon
    tc
      | TyCon -> Bool
    isNewTyCon TyCon
    tc = []  -- See Note [Compulsory newtype unfolding] in GHC.Types.Id.Make
      | Bool
    otherwise     = forall a b. (a -> b) -> [a] -> [b]
    map Id -> CoreBind
    get_defn (forall a b. (a -> Maybe b) -> [a] -> [b]
    mapMaybe DataCon -> Maybe Id
    dataConWrapId_maybe (TyCon -> [DataCon]
    tyConDataCons TyCon
    tc))

    getClassImplicitBinds :: Class -> [CoreBind]
    getClassImplicitBinds :: Class -> CoreProgram
    getClassImplicitBinds Class
    cls
      = [ forall b. b -> Expr b -> Bind b
    NonRec Id
    op (Class -> Int -> CoreExpr
    mkDictSelRhs Class
    cls Int
    val_index)
        | (Id
    op, Int
    val_index) <- Class -> [Id]
    classAllSelIds Class
    cls forall a b. [a] -> [b] -> [(a, b)]
    `zip` [Int
    0..] ]

    get_defn :: Id -> CoreBind
    get_defn :: Id -> CoreBind
    get_defn Id
    id = forall b. b -> Expr b -> Bind b
    NonRec Id
    id (Unfolding -> CoreExpr
    unfoldingTemplate (Id -> Unfolding
    realIdUnfolding Id
    id))

    {-
    ************************************************************************
    *                                                                      *
    \subsection{Step 1: finding externals}
    *                                                                      *
    ************************************************************************

    See Note [Choosing external Ids].
    -}

    type UnfoldEnv  = IdEnv (Name{-new name-}, Bool {-show unfolding-})
      -- Maps each top-level Id to its new Name (the Id is tidied in step 2)
      -- The Unique is unchanged.  If the new Name is external, it will be
      -- visible in the interface file.
      --
      -- Bool => expose unfolding or not.

    chooseExternalIds :: HscEnv
                      -> Module
                      -> Bool -> Bool
                      -> [CoreBind]
                      -> [CoreBind]
                      -> [CoreRule]
                      -> IO (UnfoldEnv, TidyOccEnv)
                      -- Step 1 from the notes above

    chooseExternalIds :: HscEnv
    -> Module
    -> Bool
    -> Bool
    -> CoreProgram
    -> CoreProgram
    -> [CoreRule]
    -> IO (UnfoldEnv, TidyOccEnv)
    chooseExternalIds HscEnv
    hsc_env Module
    mod Bool
    omit_prags Bool
    expose_all CoreProgram
    binds CoreProgram
    implicit_binds [CoreRule]
    imp_id_rules
      = do { (UnfoldEnv
    unfold_env1,TidyOccEnv
    occ_env1) <- [(Id, Id)] -> UnfoldEnv -> TidyOccEnv -> IO (UnfoldEnv, TidyOccEnv)
    search [(Id, Id)]
    init_work_list forall a. VarEnv a
    emptyVarEnv TidyOccEnv
    init_occ_env
           ; let internal_ids :: [Id]
    internal_ids = forall a. (a -> Bool) -> [a] -> [a]
    filter (Bool -> Bool
    not forall b c a. (b -> c) -> (a -> b) -> a -> c
    . (forall a. Id -> VarEnv a -> Bool
    `elemVarEnv` UnfoldEnv
    unfold_env1)) [Id]
    binders
           ; [Id] -> UnfoldEnv -> TidyOccEnv -> IO (UnfoldEnv, TidyOccEnv)
    tidy_internal [Id]
    internal_ids UnfoldEnv
    unfold_env1 TidyOccEnv
    occ_env1 }
     where
      nc_var :: IORef NameCache
    nc_var = HscEnv -> IORef NameCache
    hsc_NC HscEnv
    hsc_env

      -- init_ext_ids is the initial list of Ids that should be
      -- externalised.  It serves as the starting point for finding a
      -- deterministic, tidy, renaming for all external Ids in this
      -- module.
      --
      -- It is sorted, so that it has a deterministic order (i.e. it's the
      -- same list every time this module is compiled), in contrast to the
      -- bindings, which are ordered non-deterministically.
      init_work_list :: [(Id, Id)]
    init_work_list = forall a b. [a] -> [b] -> [(a, b)]
    zip [Id]
    init_ext_ids [Id]
    init_ext_ids
      init_ext_ids :: [Id]
    init_ext_ids   = forall a. (a -> a -> Ordering) -> [a] -> [a]
    sortBy (forall a. Ord a => a -> a -> Ordering
    compare forall b c a. (b -> b -> c) -> (a -> b) -> a -> a -> c
    `on` forall a. NamedThing a => a -> OccName
    getOccName) forall a b. (a -> b) -> a -> b
    $ forall a. (a -> Bool) -> [a] -> [a]
    filter Id -> Bool
    is_external [Id]
    binders

      -- An Id should be external if either (a) it is exported,
      -- (b) it appears in the RHS of a local rule for an imported Id, or
      -- See Note [Which rules to expose]
      is_external :: Id -> Bool
    is_external Id
    id = Id -> Bool
    isExportedId Id
    id Bool -> Bool -> Bool
    || Id
    id Id -> VarSet -> Bool
    `elemVarSet` VarSet
    rule_rhs_vars

      rule_rhs_vars :: VarSet
    rule_rhs_vars  = forall a. (a -> VarSet) -> [a] -> VarSet
    mapUnionVarSet CoreRule -> VarSet
    ruleRhsFreeVars [CoreRule]
    imp_id_rules

      binders :: [Id]
    binders          = forall a b. (a -> b) -> [a] -> [b]
    map forall a b. (a, b) -> a
    fst forall a b. (a -> b) -> a -> b
    $ forall b. [Bind b] -> [(b, Expr b)]
    flattenBinds CoreProgram
    binds
      implicit_binders :: [Id]
    implicit_binders = forall b. [Bind b] -> [b]
    bindersOfBinds CoreProgram
    implicit_binds
      binder_set :: VarSet
    binder_set       = [Id] -> VarSet
    mkVarSet [Id]
    binders

      avoids :: [OccName]
    avoids   = [forall a. NamedThing a => a -> OccName
    getOccName Name
    name | Id
    bndr <- [Id]
    binders forall a. [a] -> [a] -> [a]
    ++ [Id]
    implicit_binders,
                                    let name :: Name
    name = Id -> Name
    idName Id
    bndr,
                                    Name -> Bool
    isExternalName Name
    name ]
                    -- In computing our "avoids" list, we must include
                    --      all implicit Ids
                    --      all things with global names (assigned once and for
                    --                                      all by the renamer)
                    -- since their names are "taken".
                    -- The type environment is a convenient source of such things.
                    -- In particular, the set of binders doesn't include
                    -- implicit Ids at this stage.

            -- We also make sure to avoid any exported binders.  Consider
            --      f{-u1-} = 1     -- Local decl
            --      ...
            --      f{-u2-} = 2     -- Exported decl
            --
            -- The second exported decl must 'get' the name 'f', so we
            -- have to put 'f' in the avoids list before we get to the first
            -- decl.  tidyTopId then does a no-op on exported binders.
      init_occ_env :: TidyOccEnv
    init_occ_env = [OccName] -> TidyOccEnv
    initTidyOccEnv [OccName]
    avoids

      search :: [(Id,Id)]    -- The work-list: (external id, referring id)
                             -- Make a tidy, external Name for the external id,
                             --   add it to the UnfoldEnv, and do the same for the
                             --   transitive closure of Ids it refers to
                             -- The referring id is used to generate a tidy
                             ---  name for the external id
             -> UnfoldEnv    -- id -> (new Name, show_unfold)
             -> TidyOccEnv   -- occ env for choosing new Names
             -> IO (UnfoldEnv, TidyOccEnv)

      search :: [(Id, Id)] -> UnfoldEnv -> TidyOccEnv -> IO (UnfoldEnv, TidyOccEnv)
    search [] UnfoldEnv
    unfold_env TidyOccEnv
    occ_env = forall (m :: * -> *) a. Monad m => a -> m a
    return (UnfoldEnv
    unfold_env, TidyOccEnv
    occ_env)

      search ((Id
    idocc,Id
    referrer) : [(Id, Id)]
    rest) UnfoldEnv
    unfold_env TidyOccEnv
    occ_env
        | Id
    idocc forall a. Id -> VarEnv a -> Bool
    `elemVarEnv` UnfoldEnv
    unfold_env = [(Id, Id)] -> UnfoldEnv -> TidyOccEnv -> IO (UnfoldEnv, TidyOccEnv)
    search [(Id, Id)]
    rest UnfoldEnv
    unfold_env TidyOccEnv
    occ_env
        | Bool
    otherwise = do
          (TidyOccEnv
    occ_env', Name
    name') <- Module
    -> IORef NameCache
    -> Maybe Id
    -> TidyOccEnv
    -> Id
    -> IO (TidyOccEnv, Name)
    tidyTopName Module
    mod IORef NameCache
    nc_var (forall a. a -> Maybe a
    Just Id
    referrer) TidyOccEnv
    occ_env Id
    idocc
          let
              ([Id]
    new_ids, Bool
    show_unfold) = Bool -> Bool -> Id -> ([Id], Bool)
    addExternal Bool
    omit_prags Bool
    expose_all Id
    refined_id

                    -- 'idocc' is an *occurrence*, but we need to see the
                    -- unfolding in the *definition*; so look up in binder_set
              refined_id :: Id
    refined_id = case VarSet -> Id -> Maybe Id
    lookupVarSet VarSet
    binder_set Id
    idocc of
                             Just Id
    id -> Id
    id
                             Maybe Id
    Nothing -> WARN( True, ppr idocc ) idocc

              unfold_env' :: UnfoldEnv
    unfold_env' = forall a. VarEnv a -> Id -> a -> VarEnv a
    extendVarEnv UnfoldEnv
    unfold_env Id
    idocc (Name
    name',Bool
    show_unfold)
              referrer' :: Id
    referrer' | Id -> Bool
    isExportedId Id
    refined_id = Id
    refined_id
                        | Bool
    otherwise               = Id
    referrer
          --
          [(Id, Id)] -> UnfoldEnv -> TidyOccEnv -> IO (UnfoldEnv, TidyOccEnv)
    search (forall a b. [a] -> [b] -> [(a, b)]
    zip [Id]
    new_ids (forall a. a -> [a]
    repeat Id
    referrer') forall a. [a] -> [a] -> [a]
    ++ [(Id, Id)]
    rest) UnfoldEnv
    unfold_env' TidyOccEnv
    occ_env'

      tidy_internal :: [Id] -> UnfoldEnv -> TidyOccEnv
                    -> IO (UnfoldEnv, TidyOccEnv)
      tidy_internal :: [Id] -> UnfoldEnv -> TidyOccEnv -> IO (UnfoldEnv, TidyOccEnv)
    tidy_internal []       UnfoldEnv
    unfold_env TidyOccEnv
    occ_env = forall (m :: * -> *) a. Monad m => a -> m a
    return (UnfoldEnv
    unfold_env,TidyOccEnv
    occ_env)
      tidy_internal (Id
    id:[Id]
    ids) UnfoldEnv
    unfold_env TidyOccEnv
    occ_env = do
          (TidyOccEnv
    occ_env', Name
    name') <- Module
    -> IORef NameCache
    -> Maybe Id
    -> TidyOccEnv
    -> Id
    -> IO (TidyOccEnv, Name)
    tidyTopName Module
    mod IORef NameCache
    nc_var forall a. Maybe a
    Nothing TidyOccEnv
    occ_env Id
    id
          let unfold_env' :: UnfoldEnv
    unfold_env' = forall a. VarEnv a -> Id -> a -> VarEnv a
    extendVarEnv UnfoldEnv
    unfold_env Id
    id (Name
    name',Bool
    False)
          [Id] -> UnfoldEnv -> TidyOccEnv -> IO (UnfoldEnv, TidyOccEnv)
    tidy_internal [Id]
    ids UnfoldEnv
    unfold_env' TidyOccEnv
    occ_env'

    addExternal :: Bool -> Bool -> Id -> ([Id], Bool)
    addExternal :: Bool -> Bool -> Id -> ([Id], Bool)
    addExternal Bool
    omit_prags Bool
    expose_all Id
    id
      | Bool
    omit_prags
      , Bool -> Bool
    not (Unfolding -> Bool
    isCompulsoryUnfolding Unfolding
    unfolding)
      = ([], Bool
    False)  -- See Note [Always expose compulsory unfoldings]
                     -- in GHC.HsToCore

      | Bool
    otherwise
      = ([Id]
    new_needed_ids, Bool
    show_unfold)

      where
        new_needed_ids :: [Id]
    new_needed_ids = Bool -> Id -> [Id]
    bndrFvsInOrder Bool
    show_unfold Id
    id
        idinfo :: IdInfo
    idinfo         = HasDebugCallStack => Id -> IdInfo
    idInfo Id
    id
        unfolding :: Unfolding
    unfolding      = IdInfo -> Unfolding
    unfoldingInfo IdInfo
    idinfo
        show_unfold :: Bool
    show_unfold    = Unfolding -> Bool
    show_unfolding Unfolding
    unfolding
        never_active :: Bool
    never_active   = Activation -> Bool
    isNeverActive (InlinePragma -> Activation
    inlinePragmaActivation (IdInfo -> InlinePragma
    inlinePragInfo IdInfo
    idinfo))
        loop_breaker :: Bool
    loop_breaker   = OccInfo -> Bool
    isStrongLoopBreaker (IdInfo -> OccInfo
    occInfo IdInfo
    idinfo)
        bottoming_fn :: Bool
    bottoming_fn   = StrictSig -> Bool
    isDeadEndSig (IdInfo -> StrictSig
    strictnessInfo IdInfo
    idinfo)

            -- Stuff to do with the Id's unfolding
            -- We leave the unfolding there even if there is a worker
            -- In GHCi the unfolding is used by importers

        show_unfolding :: Unfolding -> Bool
    show_unfolding (CoreUnfolding { uf_src :: Unfolding -> UnfoldingSource
    uf_src = UnfoldingSource
    src, uf_guidance :: Unfolding -> UnfoldingGuidance
    uf_guidance = UnfoldingGuidance
    guidance })
           =  Bool
    expose_all         -- 'expose_all' says to expose all
                                 -- unfoldings willy-nilly

           Bool -> Bool -> Bool
    || UnfoldingSource -> Bool
    isStableSource UnfoldingSource
    src     -- Always expose things whose
                                     -- source is an inline rule

           Bool -> Bool -> Bool
    || Bool -> Bool
    not (Bool
    bottoming_fn      -- No need to inline bottom functions
               Bool -> Bool -> Bool
    || Bool
    never_active       -- Or ones that say not to
               Bool -> Bool -> Bool
    || Bool
    loop_breaker       -- Or that are loop breakers
               Bool -> Bool -> Bool
    || UnfoldingGuidance -> Bool
    neverUnfoldGuidance UnfoldingGuidance
    guidance)
        show_unfolding (DFunUnfolding {}) = Bool
    True
        show_unfolding Unfolding
    _                  = Bool
    False

    {-
    ************************************************************************
    *                                                                      *
                   Deterministic free variables
    *                                                                      *
    ************************************************************************

    We want a deterministic free-variable list.  exprFreeVars gives us
    a VarSet, which is in a non-deterministic order when converted to a
    list.  Hence, here we define a free-variable finder that returns
    the free variables in the order that they are encountered.

    See Note [Choosing external Ids]
    -}

    bndrFvsInOrder :: Bool -> Id -> [Id]
    bndrFvsInOrder :: Bool -> Id -> [Id]
    bndrFvsInOrder Bool
    show_unfold Id
    id
      = DFFV () -> [Id]
    run (Bool -> Id -> DFFV ()
    dffvLetBndr Bool
    show_unfold Id
    id)

    run :: DFFV () -> [Id]
    run :: DFFV () -> [Id]
    run (DFFV VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), ())
    m) = case VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), ())
    m VarSet
    emptyVarSet (VarSet
    emptyVarSet, []) of
                     ((VarSet
    _,[Id]
    ids),()
    _) -> [Id]
    ids

    newtype DFFV a
      = DFFV (VarSet              -- Envt: non-top-level things that are in scope
                                  -- we don't want to record these as free vars
          -> (VarSet, [Var])      -- Input State: (set, list) of free vars so far
          -> ((VarSet,[Var]),a))  -- Output state
        deriving (forall a b. a -> DFFV b -> DFFV a
    forall a b. (a -> b) -> DFFV a -> DFFV b
    forall (f :: * -> *).
    (forall a b. (a -> b) -> f a -> f b)
    -> (forall a b. a -> f b -> f a) -> Functor f
    <$ :: forall a b. a -> DFFV b -> DFFV a
    $c<$ :: forall a b. a -> DFFV b -> DFFV a
    fmap :: forall a b. (a -> b) -> DFFV a -> DFFV b
    $cfmap :: forall a b. (a -> b) -> DFFV a -> DFFV b
    Functor)

    instance Applicative DFFV where
        pure :: forall a. a -> DFFV a
    pure a
    a = forall a.
    (VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)) -> DFFV a
    DFFV forall a b. (a -> b) -> a -> b
    $ \VarSet
    _ (VarSet, [Id])
    st -> ((VarSet, [Id])
    st, a
    a)
        <*> :: forall a b. DFFV (a -> b) -> DFFV a -> DFFV b
    (<*>) = forall (m :: * -> *) a b. Monad m => m (a -> b) -> m a -> m b
    ap

    instance Monad DFFV where
      (DFFV VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)
    m) >>= :: forall a b. DFFV a -> (a -> DFFV b) -> DFFV b
    >>= a -> DFFV b
    k = forall a.
    (VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)) -> DFFV a
    DFFV forall a b. (a -> b) -> a -> b
    $ \VarSet
    env (VarSet, [Id])
    st ->
        case VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)
    m VarSet
    env (VarSet, [Id])
    st of
           ((VarSet, [Id])
    st',a
    a) -> case a -> DFFV b
    k a
    a of
                         DFFV VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), b)
    f -> VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), b)
    f VarSet
    env (VarSet, [Id])
    st'

    extendScope :: Var -> DFFV a -> DFFV a
    extendScope :: forall a. Id -> DFFV a -> DFFV a
    extendScope Id
    v (DFFV VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)
    f) = forall a.
    (VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)) -> DFFV a
    DFFV (\VarSet
    env (VarSet, [Id])
    st -> VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)
    f (VarSet -> Id -> VarSet
    extendVarSet VarSet
    env Id
    v) (VarSet, [Id])
    st)

    extendScopeList :: [Var] -> DFFV a -> DFFV a
    extendScopeList :: forall a. [Id] -> DFFV a -> DFFV a
    extendScopeList [Id]
    vs (DFFV VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)
    f) = forall a.
    (VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)) -> DFFV a
    DFFV (\VarSet
    env (VarSet, [Id])
    st -> VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)
    f (VarSet -> [Id] -> VarSet
    extendVarSetList VarSet
    env [Id]
    vs) (VarSet, [Id])
    st)

    insert :: Var -> DFFV ()
    insert :: Id -> DFFV ()
    insert Id
    v = forall a.
    (VarSet -> (VarSet, [Id]) -> ((VarSet, [Id]), a)) -> DFFV a
    DFFV forall a b. (a -> b) -> a -> b
    $ \ VarSet
    env (VarSet
    set, [Id]
    ids) ->
               let keep_me :: Bool
    keep_me = Id -> Bool
    isLocalId Id
    v Bool -> Bool -> Bool
    &&
                             Bool -> Bool
    not (Id
    v Id -> VarSet -> Bool
    `elemVarSet` VarSet
    env) Bool -> Bool -> Bool
    &&
                               Bool -> Bool
    not (Id
    v Id -> VarSet -> Bool
    `elemVarSet` VarSet
    set)
               in if Bool
    keep_me
                  then ((VarSet -> Id -> VarSet
    extendVarSet VarSet
    set Id
    v, Id
    vforall a. a -> [a] -> [a]
    :[Id]
    ids), ())
                  else ((VarSet
    set,                [Id]
    ids),   ())

    dffvExpr :: CoreExpr -> DFFV ()
    dffvExpr :: CoreExpr -> DFFV ()
    dffvExpr (Var Id
    v)              = Id -> DFFV ()
    insert Id
    v
    dffvExpr (App CoreExpr
    e1 CoreExpr
    e2)          = CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e1 forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
    >> CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e2
    dffvExpr (Lam Id
    v CoreExpr
    e)            = forall a. Id -> DFFV a -> DFFV a
    extendScope Id
    v (CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e)
    dffvExpr (Tick (Breakpoint XBreakpoint 'TickishPassCore
    _ Int
    _ [XTickishId 'TickishPassCore]
    ids) CoreExpr
    e) = forall (t :: * -> *) (m :: * -> *) a b.
    (Foldable t, Monad m) =>
    (a -> m b) -> t a -> m ()
    mapM_ Id -> DFFV ()
    insert [XTickishId 'TickishPassCore]
    ids forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
    >> CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e
    dffvExpr (Tick GenTickish 'TickishPassCore
    _other CoreExpr
    e)    = CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e
    dffvExpr (Cast CoreExpr
    e CoercionR
    _)           = CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e
    dffvExpr (Let (NonRec Id
    x CoreExpr
    r) CoreExpr
    e) = (Id, CoreExpr) -> DFFV ()
    dffvBind (Id
    x,CoreExpr
    r) forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
    >> forall a. Id -> DFFV a -> DFFV a
    extendScope Id
    x (CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e)
    dffvExpr (Let (Rec [(Id, CoreExpr)]
    prs) CoreExpr
    e)    = forall a. [Id] -> DFFV a -> DFFV a
    extendScopeList (forall a b. (a -> b) -> [a] -> [b]
    map forall a b. (a, b) -> a
    fst [(Id, CoreExpr)]
    prs) forall a b. (a -> b) -> a -> b
    $
                                    (forall (t :: * -> *) (m :: * -> *) a b.
    (Foldable t, Monad m) =>
    (a -> m b) -> t a -> m ()
    mapM_ (Id, CoreExpr) -> DFFV ()
    dffvBind [(Id, CoreExpr)]
    prs forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
    >> CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e)
    dffvExpr (Case CoreExpr
    e Id
    b Type
    _ [Alt Id]
    as)      = CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    e forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
    >> forall a. Id -> DFFV a -> DFFV a
    extendScope Id
    b (forall (t :: * -> *) (m :: * -> *) a b.
    (Foldable t, Monad m) =>
    (a -> m b) -> t a -> m ()
    mapM_ Alt Id -> DFFV ()
    dffvAlt [Alt Id]
    as)
    dffvExpr CoreExpr
    _other               = forall (m :: * -> *) a. Monad m => a -> m a
    return ()

    dffvAlt :: CoreAlt -> DFFV ()
    dffvAlt :: Alt Id -> DFFV ()
    dffvAlt (Alt AltCon
    _ [Id]
    xs CoreExpr
    r) = forall a. [Id] -> DFFV a -> DFFV a
    extendScopeList [Id]
    xs (CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    r)

    dffvBind :: (Id, CoreExpr) -> DFFV ()
    dffvBind :: (Id, CoreExpr) -> DFFV ()
    dffvBind(Id
    x,CoreExpr
    r)
      | Bool -> Bool
    not (Id -> Bool
    isId Id
    x) = CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    r
      | Bool
    otherwise    = Bool -> Id -> DFFV ()
    dffvLetBndr Bool
    False Id
    x forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
    >> CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    r
                    -- Pass False because we are doing the RHS right here
                    -- If you say True you'll get *exponential* behaviour!

    dffvLetBndr :: Bool -> Id -> DFFV ()
    -- Gather the free vars of the RULES and unfolding of a binder
    -- We always get the free vars of a *stable* unfolding, but
    -- for a *vanilla* one (InlineRhs), the flag controls what happens:
    --   True <=> get fvs of even a *vanilla* unfolding
    --   False <=> ignore an InlineRhs
    -- For nested bindings (call from dffvBind) we always say "False" because
    --       we are taking the fvs of the RHS anyway
    -- For top-level bindings (call from addExternal, via bndrFvsInOrder)
    --       we say "True" if we are exposing that unfolding
    dffvLetBndr :: Bool -> Id -> DFFV ()
    dffvLetBndr Bool
    vanilla_unfold Id
    id
      = do { Unfolding -> DFFV ()
    go_unf (IdInfo -> Unfolding
    unfoldingInfo IdInfo
    idinfo)
           ; forall (t :: * -> *) (m :: * -> *) a b.
    (Foldable t, Monad m) =>
    (a -> m b) -> t a -> m ()
    mapM_ CoreRule -> DFFV ()
    go_rule (RuleInfo -> [CoreRule]
    ruleInfoRules (IdInfo -> RuleInfo
    ruleInfo IdInfo
    idinfo)) }
      where
        idinfo :: IdInfo
    idinfo = HasDebugCallStack => Id -> IdInfo
    idInfo Id
    id

        go_unf :: Unfolding -> DFFV ()
    go_unf (CoreUnfolding { uf_tmpl :: Unfolding -> CoreExpr
    uf_tmpl = CoreExpr
    rhs, uf_src :: Unfolding -> UnfoldingSource
    uf_src = UnfoldingSource
    src })
           = case UnfoldingSource
    src of
               UnfoldingSource
    InlineRhs | Bool
    vanilla_unfold -> CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    rhs
                         | Bool
    otherwise      -> forall (m :: * -> *) a. Monad m => a -> m a
    return ()
               UnfoldingSource
    _                          -> CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    rhs

        go_unf (DFunUnfolding { df_bndrs :: Unfolding -> [Id]
    df_bndrs = [Id]
    bndrs, df_args :: Unfolding -> [CoreExpr]
    df_args = [CoreExpr]
    args })
                 = forall a. [Id] -> DFFV a -> DFFV a
    extendScopeList [Id]
    bndrs forall a b. (a -> b) -> a -> b
    $ forall (t :: * -> *) (m :: * -> *) a b.
    (Foldable t, Monad m) =>
    (a -> m b) -> t a -> m ()
    mapM_ CoreExpr -> DFFV ()
    dffvExpr [CoreExpr]
    args
        go_unf Unfolding
    _ = forall (m :: * -> *) a. Monad m => a -> m a
    return ()

        go_rule :: CoreRule -> DFFV ()
    go_rule (BuiltinRule {}) = forall (m :: * -> *) a. Monad m => a -> m a
    return ()
        go_rule (Rule { ru_bndrs :: CoreRule -> [Id]
    ru_bndrs = [Id]
    bndrs, ru_rhs :: CoreRule -> CoreExpr
    ru_rhs = CoreExpr
    rhs })
          = forall a. [Id] -> DFFV a -> DFFV a
    extendScopeList [Id]
    bndrs (CoreExpr -> DFFV ()
    dffvExpr CoreExpr
    rhs)

    {-
    ************************************************************************
    *                                                                      *
                   findExternalRules
    *                                                                      *
    ************************************************************************

    Note [Finding external rules]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    The complete rules are gotten by combining
       a) local rules for imported Ids
       b) rules embedded in the top-level Ids

    There are two complications:
      * Note [Which rules to expose]
      * Note [Trimming auto-rules]

    Note [Which rules to expose]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    The function 'expose_rule' filters out rules that mention, on the LHS,
    Ids that aren't externally visible; these rules can't fire in a client
    module.

    The externally-visible binders are computed (by chooseExternalIds)
    assuming that all orphan rules are externalised (see init_ext_ids in
    function 'search'). So in fact it's a bit conservative and we may
    export more than we need.  (It's a sort of mutual recursion.)

    Note [Trimming auto-rules]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Second, with auto-specialisation we may specialise local or imported
    dfuns or INLINE functions, and then later inline them.  That may leave
    behind something like
       RULE "foo" forall d. f @ Int d = f_spec
    where f is either local or imported, and there is no remaining
    reference to f_spec except from the RULE.

    Now that RULE *might* be useful to an importing module, but that is
    purely speculative, and meanwhile the code is taking up space and
    codegen time.  I found that binary sizes jumped by 6-10% when I
    started to specialise INLINE functions (again, Note [Inline
    specialisations] in GHC.Core.Opt.Specialise).

    So it seems better to drop the binding for f_spec, and the rule
    itself, if the auto-generated rule is the *only* reason that it is
    being kept alive.

    (The RULE still might have been useful in the past; that is, it was
    the right thing to have generated it in the first place.  See Note
    [Inline specialisations] in GHC.Core.Opt.Specialise. But now it has
    served its purpose, and can be discarded.)

    So findExternalRules does this:
      * Remove all bindings that are kept alive *only* by isAutoRule rules
          (this is done in trim_binds)
      * Remove all auto rules that mention bindings that have been removed
          (this is done by filtering by keep_rule)

    NB: if a binding is kept alive for some *other* reason (e.g. f_spec is
    called in the final code), we keep the rule too.

    This stuff is the only reason for the ru_auto field in a Rule.
    -}

    findExternalRules :: Bool       -- Omit pragmas
                      -> [CoreBind]
                      -> [CoreRule] -- Local rules for imported fns
                      -> UnfoldEnv  -- Ids that are exported, so we need their rules
                      -> ([CoreBind], [CoreRule])
    -- See Note [Finding external rules]
    findExternalRules :: Bool
    -> CoreProgram
    -> [CoreRule]
    -> UnfoldEnv
    -> (CoreProgram, [CoreRule])
    findExternalRules Bool
    omit_prags CoreProgram
    binds [CoreRule]
    imp_id_rules UnfoldEnv
    unfold_env
      = (CoreProgram
    trimmed_binds, forall a. (a -> Bool) -> [a] -> [a]
    filter CoreRule -> Bool
    keep_rule [CoreRule]
    all_rules)
      where
        imp_rules :: [CoreRule]
    imp_rules         = forall a. (a -> Bool) -> [a] -> [a]
    filter CoreRule -> Bool
    expose_rule [CoreRule]
    imp_id_rules
        imp_user_rule_fvs :: VarSet
    imp_user_rule_fvs = forall a. (a -> VarSet) -> [a] -> VarSet
    mapUnionVarSet CoreRule -> VarSet
    user_rule_rhs_fvs [CoreRule]
    imp_rules

        user_rule_rhs_fvs :: CoreRule -> VarSet
    user_rule_rhs_fvs CoreRule
    rule | CoreRule -> Bool
    isAutoRule CoreRule
    rule = VarSet
    emptyVarSet
                               | Bool
    otherwise       = CoreRule -> VarSet
    ruleRhsFreeVars CoreRule
    rule

        (CoreProgram
    trimmed_binds, VarSet
    local_bndrs, VarSet
    _, [CoreRule]
    all_rules) = CoreProgram -> (CoreProgram, VarSet, VarSet, [CoreRule])
    trim_binds CoreProgram
    binds

        keep_rule :: CoreRule -> Bool
    keep_rule CoreRule
    rule = CoreRule -> VarSet
    ruleFreeVars CoreRule
    rule VarSet -> VarSet -> Bool
    `subVarSet` VarSet
    local_bndrs
            -- Remove rules that make no sense, because they mention a
            -- local binder (on LHS or RHS) that we have now discarded.
            -- (NB: ruleFreeVars only includes LocalIds)
            --
            -- LHS: we have already filtered out rules that mention internal Ids
            --     on LHS but that isn't enough because we might have by now
            --     discarded a binding with an external Id. (How?
            --     chooseExternalIds is a bit conservative.)
            --
            -- RHS: the auto rules that might mention a binder that has
            --      been discarded; see Note [Trimming auto-rules]

        expose_rule :: CoreRule -> Bool
    expose_rule CoreRule
    rule
            | Bool
    omit_prags = Bool
    False
            | Bool
    otherwise  = forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
    all Id -> Bool
    is_external_id (CoreRule -> [Id]
    ruleLhsFreeIdsList CoreRule
    rule)
                    -- Don't expose a rule whose LHS mentions a locally-defined
                    -- Id that is completely internal (i.e. not visible to an
                    -- importing module).  NB: ruleLhsFreeIds only returns LocalIds.
                    -- See Note [Which rules to expose]

        is_external_id :: Id -> Bool
    is_external_id Id
    id = case forall a. VarEnv a -> Id -> Maybe a
    lookupVarEnv UnfoldEnv
    unfold_env Id
    id of
                              Just (Name
    name, Bool
    _) -> Name -> Bool
    isExternalName Name
    name
                              Maybe (Name, Bool)
    Nothing        -> Bool
    False

        trim_binds :: [CoreBind]
                   -> ( [CoreBind]   -- Trimmed bindings
                      , VarSet       -- Binders of those bindings
                      , VarSet       -- Free vars of those bindings + rhs of user rules
                                     -- (we don't bother to delete the binders)
                      , [CoreRule])  -- All rules, imported + from the bindings
        -- This function removes unnecessary bindings, and gathers up rules from
        -- the bindings we keep.  See Note [Trimming auto-rules]
        trim_binds :: CoreProgram -> (CoreProgram, VarSet, VarSet, [CoreRule])
    trim_binds []  -- Base case, start with imp_user_rule_fvs
           = ([], VarSet
    emptyVarSet, VarSet
    imp_user_rule_fvs, [CoreRule]
    imp_rules)

        trim_binds (CoreBind
    bind:CoreProgram
    binds)
           | forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Bool
    any Id -> Bool
    needed [Id]
    bndrs    -- Keep binding
           = ( CoreBind
    bind forall a. a -> [a] -> [a]
    : CoreProgram
    binds', VarSet
    bndr_set', VarSet
    needed_fvs', [CoreRule]
    local_rules forall a. [a] -> [a] -> [a]
    ++ [CoreRule]
    rules )
           | Bool
    otherwise           -- Discard binding altogether
           = (CoreProgram, VarSet, VarSet, [CoreRule])
    stuff
           where
             stuff :: (CoreProgram, VarSet, VarSet, [CoreRule])
    stuff@(CoreProgram
    binds', VarSet
    bndr_set, VarSet
    needed_fvs, [CoreRule]
    rules)
                           = CoreProgram -> (CoreProgram, VarSet, VarSet, [CoreRule])
    trim_binds CoreProgram
    binds
             needed :: Id -> Bool
    needed Id
    bndr   = Id -> Bool
    isExportedId Id
    bndr Bool -> Bool -> Bool
    || Id
    bndr Id -> VarSet -> Bool
    `elemVarSet` VarSet
    needed_fvs

             bndrs :: [Id]
    bndrs         = forall b. Bind b -> [b]
    bindersOf  CoreBind
    bind
             rhss :: [CoreExpr]
    rhss          = forall b. Bind b -> [Expr b]
    rhssOfBind CoreBind
    bind
             bndr_set' :: VarSet
    bndr_set'     = VarSet
    bndr_set VarSet -> [Id] -> VarSet
    `extendVarSetList` [Id]
    bndrs

             needed_fvs' :: VarSet
    needed_fvs'   = VarSet
    needed_fvs                                   VarSet -> VarSet -> VarSet
    `unionVarSet`
                             forall a. (a -> VarSet) -> [a] -> VarSet
    mapUnionVarSet Id -> VarSet
    idUnfoldingVars   [Id]
    bndrs       VarSet -> VarSet -> VarSet
    `unionVarSet`
                                  -- Ignore type variables in the type of bndrs
                             forall a. (a -> VarSet) -> [a] -> VarSet
    mapUnionVarSet CoreExpr -> VarSet
    exprFreeVars      [CoreExpr]
    rhss        VarSet -> VarSet -> VarSet
    `unionVarSet`
                             forall a. (a -> VarSet) -> [a] -> VarSet
    mapUnionVarSet CoreRule -> VarSet
    user_rule_rhs_fvs [CoreRule]
    local_rules
                -- In needed_fvs', we don't bother to delete binders from the fv set

             local_rules :: [CoreRule]
    local_rules  = [ CoreRule
    rule
                            | Id
    id <- [Id]
    bndrs
                            , Id -> Bool
    is_external_id Id
    id   -- Only collect rules for external Ids
                            , CoreRule
    rule <- Id -> [CoreRule]
    idCoreRules Id
    id
                            , CoreRule -> Bool
    expose_rule CoreRule
    rule ]  -- and ones that can fire in a client

    {-
    ************************************************************************
    *                                                                      *
                   tidyTopName
    *                                                                      *
    ************************************************************************

    This is where we set names to local/global based on whether they really are
    externally visible (see comment at the top of this module).  If the name
    was previously local, we have to give it a unique occurrence name if
    we intend to externalise it.
    -}

    tidyTopName :: Module -> IORef NameCache -> Maybe Id -> TidyOccEnv
                -> Id -> IO (TidyOccEnv, Name)
    tidyTopName :: Module
    -> IORef NameCache
    -> Maybe Id
    -> TidyOccEnv
    -> Id
    -> IO (TidyOccEnv, Name)
    tidyTopName Module
    mod IORef NameCache
    nc_var Maybe Id
    maybe_ref TidyOccEnv
    occ_env Id
    id
      | Bool
    global Bool -> Bool -> Bool
    && Bool
    internal = forall (m :: * -> *) a. Monad m => a -> m a
    return (TidyOccEnv
    occ_env, Name -> Name
    localiseName Name
    name)

      | Bool
    global Bool -> Bool -> Bool
    && Bool
    external = forall (m :: * -> *) a. Monad m => a -> m a
    return (TidyOccEnv
    occ_env, Name
    name)
            -- Global names are assumed to have been allocated by the renamer,
            -- so they already have the "right" unique
            -- And it's a system-wide unique too

      -- Now we get to the real reason that all this is in the IO Monad:
      -- we have to update the name cache in a nice atomic fashion

      | Bool
    local  Bool -> Bool -> Bool
    && Bool
    internal = do { Name
    new_local_name <- forall a b. IORef a -> (a -> (a, b)) -> IO b
    atomicModifyIORef' IORef NameCache
    nc_var NameCache -> (NameCache, Name)
    mk_new_local
                                ; forall (m :: * -> *) a. Monad m => a -> m a
    return (TidyOccEnv
    occ_env', Name
    new_local_name) }
            -- Even local, internal names must get a unique occurrence, because
            -- if we do -split-objs we externalise the name later, in the code generator
            --
            -- Similarly, we must make sure it has a system-wide Unique, because
            -- the byte-code generator builds a system-wide Name->BCO symbol table

      | Bool
    local  Bool -> Bool -> Bool
    && Bool
    external = do { Name
    new_external_name <- forall a b. IORef a -> (a -> (a, b)) -> IO b
    atomicModifyIORef' IORef NameCache
    nc_var NameCache -> (NameCache, Name)
    mk_new_external
                                ; forall (m :: * -> *) a. Monad m => a -> m a
    return (TidyOccEnv
    occ_env', Name
    new_external_name) }

      | Bool
    otherwise = forall a. String -> a
    panic String
    "tidyTopName"
      where
        name :: Name
    name        = Id -> Name
    idName Id
    id
        external :: Bool
    external    = forall a. Maybe a -> Bool
    isJust Maybe Id
    maybe_ref
        global :: Bool
    global      = Name -> Bool
    isExternalName Name
    name
        local :: Bool
    local       = Bool -> Bool
    not Bool
    global
        internal :: Bool
    internal    = Bool -> Bool
    not Bool
    external
        loc :: SrcSpan
    loc         = Name -> SrcSpan
    nameSrcSpan Name
    name

        old_occ :: OccName
    old_occ     = Name -> OccName
    nameOccName Name
    name
        new_occ :: OccName
    new_occ | Just Id
    ref <- Maybe Id
    maybe_ref
                , Id
    ref forall a. Eq a => a -> a -> Bool
    /= Id
    id
                = NameSpace -> String -> OccName
    mkOccName (OccName -> NameSpace
    occNameSpace OccName
    old_occ) forall a b. (a -> b) -> a -> b
    $
                       let
                           ref_str :: String
    ref_str = OccName -> String
    occNameString (forall a. NamedThing a => a -> OccName
    getOccName Id
    ref)
                           occ_str :: String
    occ_str = OccName -> String
    occNameString OccName
    old_occ
                       in
                       case String
    occ_str of
                         Char
    '$':Char
    'w':String
    _ -> String
    occ_str
                            -- workers: the worker for a function already
                            -- includes the occname for its parent, so there's
                            -- no need to prepend the referrer.
                         String
    _other | Name -> Bool
    isSystemName Name
    name -> String
    ref_str
                                | Bool
    otherwise         -> String
    ref_str forall a. [a] -> [a] -> [a]
    ++ Char
    '_' forall a. a -> [a] -> [a]
    : String
    occ_str
                            -- If this name was system-generated, then don't bother
                            -- to retain its OccName, just use the referrer.  These
                            -- system-generated names will become "f1", "f2", etc. for
                            -- a referrer "f".
                | Bool
    otherwise = OccName
    old_occ

        (TidyOccEnv
    occ_env', OccName
    occ') = TidyOccEnv -> OccName -> (TidyOccEnv, OccName)
    tidyOccName TidyOccEnv
    occ_env OccName
    new_occ

        mk_new_local :: NameCache -> (NameCache, Name)
    mk_new_local NameCache
    nc = (NameCache
    nc { nsUniqs :: UniqSupply
    nsUniqs = UniqSupply
    us }, Unique -> OccName -> SrcSpan -> Name
    mkInternalName Unique
    uniq OccName
    occ' SrcSpan
    loc)
                        where
                          (Unique
    uniq, UniqSupply
    us) = UniqSupply -> (Unique, UniqSupply)
    takeUniqFromSupply (NameCache -> UniqSupply
    nsUniqs NameCache
    nc)

        mk_new_external :: NameCache -> (NameCache, Name)
    mk_new_external NameCache
    nc = NameCache -> Module -> OccName -> SrcSpan -> (NameCache, Name)
    allocateGlobalBinder NameCache
    nc Module
    mod OccName
    occ' SrcSpan
    loc
            -- If we want to externalise a currently-local name, check
            -- whether we have already assigned a unique for it.
            -- If so, use it; if not, extend the table.
            -- All this is done by allcoateGlobalBinder.
            -- This is needed when *re*-compiling a module in GHCi; we must
            -- use the same name for externally-visible things as we did before.

    {-
    ************************************************************************
    *                                                                      *
    \subsection{Step 2: top-level tidying}
    *                                                                      *
    ************************************************************************
    -}

    -- TopTidyEnv: when tidying we need to know
    --   * nc_var: The NameCache, containing a unique supply and any pre-ordained Names.
    --        These may have arisen because the
    --        renamer read in an interface file mentioning M.$wf, say,
    --        and assigned it unique r77.  If, on this compilation, we've
    --        invented an Id whose name is $wf (but with a different unique)
    --        we want to rename it to have unique r77, so that we can do easy
    --        comparisons with stuff from the interface file
    --
    --   * occ_env: The TidyOccEnv, which tells us which local occurrences
    --     are 'used'
    --
    --   * subst_env: A Var->Var mapping that substitutes the new Var for the old

    tidyTopBinds :: UnfoldingOpts
                 -> UnfoldEnv
                 -> TidyOccEnv
                 -> CoreProgram
                 -> IO (TidyEnv, CoreProgram)

    tidyTopBinds :: UnfoldingOpts
    -> UnfoldEnv
    -> TidyOccEnv
    -> CoreProgram
    -> IO (TidyEnv, CoreProgram)
    tidyTopBinds UnfoldingOpts
    uf_opts UnfoldEnv
    unfold_env TidyOccEnv
    init_occ_env CoreProgram
    binds
      = do let result :: (TidyEnv, CoreProgram)
    result = TidyEnv -> CoreProgram -> (TidyEnv, CoreProgram)
    tidy TidyEnv
    init_env CoreProgram
    binds
           CoreProgram -> ()
    seqBinds (forall a b. (a, b) -> b
    snd (TidyEnv, CoreProgram)
    result) seq :: forall a b. a -> b -> b
    `seq` forall (m :: * -> *) a. Monad m => a -> m a
    return (TidyEnv, CoreProgram)
    result
           -- This seqBinds avoids a spike in space usage (see #13564)
      where
        init_env :: TidyEnv
    init_env = (TidyOccEnv
    init_occ_env, forall a. VarEnv a
    emptyVarEnv)

        tidy :: TidyEnv -> CoreProgram -> (TidyEnv, CoreProgram)
    tidy = forall (t :: * -> *) s a b.
    Traversable t =>
    (s -> a -> (s, b)) -> s -> t a -> (s, t b)
    mapAccumL (UnfoldingOpts
    -> UnfoldEnv -> TidyEnv -> CoreBind -> (TidyEnv, CoreBind)
    tidyTopBind UnfoldingOpts
    uf_opts UnfoldEnv
    unfold_env)

    ------------------------
    tidyTopBind  :: UnfoldingOpts
                 -> UnfoldEnv
                 -> TidyEnv
                 -> CoreBind
                 -> (TidyEnv, CoreBind)

    tidyTopBind :: UnfoldingOpts
    -> UnfoldEnv -> TidyEnv -> CoreBind -> (TidyEnv, CoreBind)
    tidyTopBind UnfoldingOpts
    uf_opts UnfoldEnv
    unfold_env
                (TidyOccEnv
    occ_env,VarEnv Id
    subst1) (NonRec Id
    bndr CoreExpr
    rhs)
      = (TidyEnv
    tidy_env2,  forall b. b -> Expr b -> Bind b
    NonRec Id
    bndr' CoreExpr
    rhs')
      where
        Just (Name
    name',Bool
    show_unfold) = forall a. VarEnv a -> Id -> Maybe a
    lookupVarEnv UnfoldEnv
    unfold_env Id
    bndr
        (Id
    bndr', CoreExpr
    rhs') = UnfoldingOpts
    -> Bool -> TidyEnv -> Name -> (Id, CoreExpr) -> (Id, CoreExpr)
    tidyTopPair UnfoldingOpts
    uf_opts Bool
    show_unfold TidyEnv
    tidy_env2 Name
    name' (Id
    bndr, CoreExpr
    rhs)
        subst2 :: VarEnv Id
    subst2        = forall a. VarEnv a -> Id -> a -> VarEnv a
    extendVarEnv VarEnv Id
    subst1 Id
    bndr Id
    bndr'
        tidy_env2 :: TidyEnv
    tidy_env2     = (TidyOccEnv
    occ_env, VarEnv Id
    subst2)

    tidyTopBind UnfoldingOpts
    uf_opts UnfoldEnv
    unfold_env (TidyOccEnv
    occ_env, VarEnv Id
    subst1) (Rec [(Id, CoreExpr)]
    prs)
      = (TidyEnv
    tidy_env2, forall b. [(b, Expr b)] -> Bind b
    Rec [(Id, CoreExpr)]
    prs')
      where
        prs' :: [(Id, CoreExpr)]
    prs' = [ UnfoldingOpts
    -> Bool -> TidyEnv -> Name -> (Id, CoreExpr) -> (Id, CoreExpr)
    tidyTopPair UnfoldingOpts
    uf_opts Bool
    show_unfold TidyEnv
    tidy_env2 Name
    name' (Id
    id,CoreExpr
    rhs)
               | (Id
    id,CoreExpr
    rhs) <- [(Id, CoreExpr)]
    prs,
                 let (Name
    name',Bool
    show_unfold) =
                        forall a. HasCallStack => String -> Maybe a -> a
    expectJust String
    "tidyTopBind" forall a b. (a -> b) -> a -> b
    $ forall a. VarEnv a -> Id -> Maybe a
    lookupVarEnv UnfoldEnv
    unfold_env Id
    id
               ]

        subst2 :: VarEnv Id
    subst2    = forall a. VarEnv a -> [(Id, a)] -> VarEnv a
    extendVarEnvList VarEnv Id
    subst1 ([Id]
    bndrs forall a b. [a] -> [b] -> [(a, b)]
    `zip` forall a b. (a -> b) -> [a] -> [b]
    map forall a b. (a, b) -> a
    fst [(Id, CoreExpr)]
    prs')
        tidy_env2 :: TidyEnv
    tidy_env2 = (TidyOccEnv
    occ_env, VarEnv Id
    subst2)

        bndrs :: [Id]
    bndrs = forall a b. (a -> b) -> [a] -> [b]
    map forall a b. (a, b) -> a
    fst [(Id, CoreExpr)]
    prs

    -----------------------------------------------------------
    tidyTopPair :: UnfoldingOpts
                -> Bool  -- show unfolding
                -> TidyEnv  -- The TidyEnv is used to tidy the IdInfo
                            -- It is knot-tied: don't look at it!
                -> Name             -- New name
                -> (Id, CoreExpr)   -- Binder and RHS before tidying
                -> (Id, CoreExpr)
            -- This function is the heart of Step 2
            -- The rec_tidy_env is the one to use for the IdInfo
            -- It's necessary because when we are dealing with a recursive
            -- group, a variable late in the group might be mentioned
            -- in the IdInfo of one early in the group

    tidyTopPair :: UnfoldingOpts
    -> Bool -> TidyEnv -> Name -> (Id, CoreExpr) -> (Id, CoreExpr)
    tidyTopPair UnfoldingOpts
    uf_opts Bool
    show_unfold TidyEnv
    rhs_tidy_env Name
    name' (Id
    bndr, CoreExpr
    rhs)
      = (Id
    bndr1, CoreExpr
    rhs1)
      where
        bndr1 :: Id
    bndr1    = IdDetails -> Name -> Type -> IdInfo -> Id
    mkGlobalId IdDetails
    details Name
    name' Type
    ty' IdInfo
    idinfo'
        details :: IdDetails
    details  = Id -> IdDetails
    idDetails Id
    bndr   -- Preserve the IdDetails
        ty' :: Type
    ty'      = Type -> Type
    tidyTopType (Id -> Type
    idType Id
    bndr)
        rhs1 :: CoreExpr
    rhs1     = TidyEnv -> CoreExpr -> CoreExpr
    tidyExpr TidyEnv
    rhs_tidy_env CoreExpr
    rhs
        idinfo' :: IdInfo
    idinfo'  = UnfoldingOpts
    -> TidyEnv
    -> Name
    -> CoreExpr
    -> CoreExpr
    -> IdInfo
    -> Bool
    -> IdInfo
    tidyTopIdInfo UnfoldingOpts
    uf_opts TidyEnv
    rhs_tidy_env Name
    name' CoreExpr
    rhs CoreExpr
    rhs1 (HasDebugCallStack => Id -> IdInfo
    idInfo Id
    bndr)
                                 Bool
    show_unfold

    -- tidyTopIdInfo creates the final IdInfo for top-level
    -- binders.  The delicate piece:
    --
    --  * Arity.  After CoreTidy, this arity must not change any more.
    --      Indeed, CorePrep must eta expand where necessary to make
    --      the manifest arity equal to the claimed arity.
    --
    tidyTopIdInfo :: UnfoldingOpts -> TidyEnv -> Name -> CoreExpr -> CoreExpr
                  -> IdInfo -> Bool -> IdInfo
    tidyTopIdInfo :: UnfoldingOpts
    -> TidyEnv
    -> Name
    -> CoreExpr
    -> CoreExpr
    -> IdInfo
    -> Bool
    -> IdInfo
    tidyTopIdInfo UnfoldingOpts
    uf_opts TidyEnv
    rhs_tidy_env Name
    name CoreExpr
    orig_rhs CoreExpr
    tidy_rhs IdInfo
    idinfo Bool
    show_unfold
      | Bool -> Bool
    not Bool
    is_external     -- For internal Ids (not externally visible)
      = IdInfo
    vanillaIdInfo       -- we only need enough info for code generation
                            -- Arity and strictness info are enough;
                            --      c.f. GHC.Core.Tidy.tidyLetBndr
            IdInfo -> Int -> IdInfo
    `setArityInfo`      Int
    arity
            IdInfo -> StrictSig -> IdInfo
    `setStrictnessInfo` StrictSig
    final_sig
            IdInfo -> CprSig -> IdInfo
    `setCprInfo`        CprSig
    final_cpr
            IdInfo -> Unfolding -> IdInfo
    `setUnfoldingInfo`  Unfolding
    minimal_unfold_info  -- See note [Preserve evaluatedness]
                                                     -- in GHC.Core.Tidy

      | Bool
    otherwise           -- Externally-visible Ids get the whole lot
      = IdInfo
    vanillaIdInfo
            IdInfo -> Int -> IdInfo
    `setArityInfo`         Int
    arity
            IdInfo -> StrictSig -> IdInfo
    `setStrictnessInfo`    StrictSig
    final_sig
            IdInfo -> CprSig -> IdInfo
    `setCprInfo`           CprSig
    final_cpr
            IdInfo -> OccInfo -> IdInfo
    `setOccInfo`           OccInfo
    robust_occ_info
            IdInfo -> InlinePragma -> IdInfo
    `setInlinePragInfo`    (IdInfo -> InlinePragma
    inlinePragInfo IdInfo
    idinfo)
            IdInfo -> Unfolding -> IdInfo
    `setUnfoldingInfo`     Unfolding
    unfold_info
                    -- NB: we throw away the Rules
                    -- They have already been extracted by findExternalRules
      where
        is_external :: Bool
    is_external = Name -> Bool
    isExternalName Name
    name

        --------- OccInfo ------------
        robust_occ_info :: OccInfo
    robust_occ_info = OccInfo -> OccInfo
    zapFragileOcc (IdInfo -> OccInfo
    occInfo IdInfo
    idinfo)
        -- It's important to keep loop-breaker information
        -- when we are doing -fexpose-all-unfoldings

        --------- Strictness ------------
        mb_bot_str :: Maybe (Int, StrictSig)
    mb_bot_str = CoreExpr -> Maybe (Int, StrictSig)
    exprBotStrictness_maybe CoreExpr
    orig_rhs

        sig :: StrictSig
    sig = IdInfo -> StrictSig
    strictnessInfo IdInfo
    idinfo
        final_sig :: StrictSig
    final_sig | Bool -> Bool
    not forall a b. (a -> b) -> a -> b
    $ StrictSig -> Bool
    isTopSig StrictSig
    sig
                  = WARN( _bottom_hidden sig , ppr name ) sig
                  -- try a cheap-and-cheerful bottom analyser
                  | Just (Int
    _, StrictSig
    nsig) <- Maybe (Int, StrictSig)
    mb_bot_str = StrictSig
    nsig
                  | Bool
    otherwise                    = StrictSig
    sig

        cpr :: CprSig
    cpr = IdInfo -> CprSig
    cprInfo IdInfo
    idinfo
        final_cpr :: CprSig
    final_cpr | Just (Int, StrictSig)
    _ <- Maybe (Int, StrictSig)
    mb_bot_str
                  = Int -> Cpr -> CprSig
    mkCprSig Int
    arity Cpr
    botCpr
                  | Bool
    otherwise
                  = CprSig
    cpr

        _bottom_hidden :: StrictSig -> Bool
    _bottom_hidden StrictSig
    id_sig = case Maybe (Int, StrictSig)
    mb_bot_str of
                                      Maybe (Int, StrictSig)
    Nothing         -> Bool
    False
                                      Just (Int
    arity, StrictSig
    _) -> Bool -> Bool
    not (StrictSig -> Int -> Bool
    isDeadEndAppSig StrictSig
    id_sig Int
    arity)

        --------- Unfolding ------------
        unf_info :: Unfolding
    unf_info = IdInfo -> Unfolding
    unfoldingInfo IdInfo
    idinfo
        unfold_info :: Unfolding
    unfold_info
          | Unfolding -> Bool
    isCompulsoryUnfolding Unfolding
    unf_info Bool -> Bool -> Bool
    || Bool
    show_unfold
          = TidyEnv -> Unfolding -> Unfolding -> Unfolding
    tidyUnfolding TidyEnv
    rhs_tidy_env Unfolding
    unf_info Unfolding
    unf_from_rhs
          | Bool
    otherwise
          = Unfolding
    minimal_unfold_info
        minimal_unfold_info :: Unfolding
    minimal_unfold_info = Unfolding -> Unfolding
    zapUnfolding Unfolding
    unf_info
        unf_from_rhs :: Unfolding
    unf_from_rhs = UnfoldingOpts
    -> UnfoldingSource -> StrictSig -> CoreExpr -> Unfolding
    mkFinalUnfolding UnfoldingOpts
    uf_opts UnfoldingSource
    InlineRhs StrictSig
    final_sig CoreExpr
    tidy_rhs
        -- NB: do *not* expose the worker if show_unfold is off,
        --     because that means this thing is a loop breaker or
        --     marked NOINLINE or something like that
        -- This is important: if you expose the worker for a loop-breaker
        -- then you can make the simplifier go into an infinite loop, because
        -- in effect the unfolding is exposed.  See #1709
        --
        -- You might think that if show_unfold is False, then the thing should
        -- not be w/w'd in the first place.  But a legitimate reason is this:
        --    the function returns bottom
        -- In this case, show_unfold will be false (we don't expose unfoldings
        -- for bottoming functions), but we might still have a worker/wrapper
        -- split (see Note [Worker-wrapper for bottoming functions] in
        -- GHC.Core.Opt.WorkWrap)

        --------- Arity ------------
        -- Usually the Id will have an accurate arity on it, because
        -- the simplifier has just run, but not always.
        -- One case I found was when the last thing the simplifier
        -- did was to let-bind a non-atomic argument and then float
        -- it to the top level. So it seems more robust just to
        -- fix it here.
        arity :: Int
    arity = CoreExpr -> Int
    exprArity CoreExpr
    orig_rhs

    {-
    ************************************************************************
    *                                                                      *
                      Old, dead, type-trimming code
    *                                                                      *
    ************************************************************************

    We used to try to "trim off" the constructors of data types that are
    not exported, to reduce the size of interface files, at least without
    -O.  But that is not always possible: see the old Note [When we can't
    trim types] below for exceptions.

    Then (#7445) I realised that the TH problem arises for any data type
    that we have deriving( Data ), because we can invoke
       Language.Haskell.TH.Quote.dataToExpQ
    to get a TH Exp representation of a value built from that data type.
    You don't even need {-# LANGUAGE TemplateHaskell #-}.

    At this point I give up. The pain of trimming constructors just
    doesn't seem worth the gain.  So I've dumped all the code, and am just
    leaving it here at the end of the module in case something like this
    is ever resurrected.

    Note [When we can't trim types]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    The basic idea of type trimming is to export algebraic data types
    abstractly (without their data constructors) when compiling without
    -O, unless of course they are explicitly exported by the user.

    We always export synonyms, because they can be mentioned in the type
    of an exported Id.  We could do a full dependency analysis starting
    from the explicit exports, but that's quite painful, and not done for
    now.

    But there are some times we can't do that, indicated by the 'no_trim_types' flag.

    First, Template Haskell.  Consider (#2386) this
            module M(T, makeOne) where
              data T = Yay String
              makeOne = [| Yay "Yep" |]
    Notice that T is exported abstractly, but makeOne effectively exports it too!
    A module that splices in $(makeOne) will then look for a declaration of Yay,
    so it'd better be there.  Hence, brutally but simply, we switch off type
    constructor trimming if TH is enabled in this module.

    Second, data kinds.  Consider (#5912)
         {-# LANGUAGE DataKinds #-}
         module M() where
         data UnaryTypeC a = UnaryDataC a
         type Bug = 'UnaryDataC
    We always export synonyms, so Bug is exposed, and that means that
    UnaryTypeC must be too, even though it's not explicitly exported.  In
    effect, DataKinds means that we'd need to do a full dependency analysis
    to see what data constructors are mentioned.  But we don't do that yet.

    In these two cases we just switch off type trimming altogether.

    mustExposeTyCon :: Bool         -- Type-trimming flag
                    -> NameSet      -- Exports
                    -> TyCon        -- The tycon
                    -> Bool         -- Can its rep be hidden?
    -- We are compiling without -O, and thus trying to write as little as
    -- possible into the interface file.  But we must expose the details of
    -- any data types whose constructors or fields are exported
    mustExposeTyCon no_trim_types exports tc
      | no_trim_types               -- See Note [When we can't trim types]
      = True

      | not (isAlgTyCon tc)         -- Always expose synonyms (otherwise we'd have to
                                    -- figure out whether it was mentioned in the type
                                    -- of any other exported thing)
      = True

      | isEnumerationTyCon tc       -- For an enumeration, exposing the constructors
      = True                        -- won't lead to the need for further exposure

      | isFamilyTyCon tc            -- Open type family
      = True

      -- Below here we just have data/newtype decls or family instances

      | null data_cons              -- Ditto if there are no data constructors
      = True                        -- (NB: empty data types do not count as enumerations
                                    -- see Note [Enumeration types] in GHC.Core.TyCon

      | any exported_con data_cons  -- Expose rep if any datacon or field is exported
      = True

      | isNewTyCon tc && isFFITy (snd (newTyConRhs tc))
      = True   -- Expose the rep for newtypes if the rep is an FFI type.
               -- For a very annoying reason.  'Foreign import' is meant to
               -- be able to look through newtypes transparently, but it
               -- can only do that if it can "see" the newtype representation

      | otherwise
      = False
      where
        data_cons = tyConDataCons tc
        exported_con con = any (`elemNameSet` exports)
                               (dataConName con : dataConFieldLabels con)
    -}