    {-
    (c) The University of Glasgow, 2000-2006

    -}

    {-# LANGUAGE CPP #-}
    {-# LANGUAGE FlexibleContexts #-}

    -- | Module finder
    module GHC.Unit.Finder (
        FindResult(..),
        InstalledFindResult(..),
        FinderCache,
        flushFinderCaches,
        findImportedModule,
        findPluginModule,
        findExactModule,
        findHomeModule,
        findExposedPackageModule,
        mkHomeModLocation,
        mkHomeModLocation2,
        mkHiOnlyModLocation,
        mkHiPath,
        mkObjPath,
        addHomeModuleToFinder,
        uncacheModule,
        mkStubPaths,

        findObjectLinkableMaybe,
        findObjectLinkable,

      ) where

    #include "HsVersions.h"

    import GHC.Prelude

    import GHC.Driver.Env
    import GHC.Driver.Session

    import GHC.Platform.Ways

    import GHC.Builtin.Names ( gHC_PRIM )

    import GHC.Unit.Types
    import GHC.Unit.Module
    import GHC.Unit.Home
    import GHC.Unit.State
    import GHC.Unit.Finder.Types

    import GHC.Data.FastString
    import GHC.Data.Maybe    ( expectJust )
    import qualified GHC.Data.ShortText as ST

    import GHC.Utils.Misc
    import GHC.Utils.Outputable as Outputable
    import GHC.Utils.Panic

    import GHC.Linker.Types

    import Data.IORef       ( IORef, readIORef, atomicModifyIORef' )
    import System.Directory
    import System.FilePath
    import Control.Monad
    import Data.Time

    type FileExt = String   -- Filename extension
    type BaseName = String  -- Basename of file

    -- -----------------------------------------------------------------------------
    -- The Finder

    -- The Finder provides a thin filesystem abstraction to the rest of
    -- the compiler.  For a given module, it can tell you where the
    -- source, interface, and object files for that module live.

    -- It does *not* know which particular package a module lives in.  Use
    -- Packages.lookupModuleInAllUnits for that.

    -- -----------------------------------------------------------------------------
    -- The finder's cache

    -- remove all the home modules from the cache; package modules are
    -- assumed to not move around during a session.
    flushFinderCaches :: HscEnv -> IO ()
    flushFinderCaches :: HscEnv -> IO ()
    flushFinderCaches HscEnv
    hsc_env =
      forall a b. IORef a -> (a -> (a, b)) -> IO b
    atomicModifyIORef' IORef FinderCache
    fc_ref forall a b. (a -> b) -> a -> b
    $ \FinderCache
    fm -> (forall a.
    (InstalledModule -> a -> Bool)
    -> InstalledModuleEnv a -> InstalledModuleEnv a
    filterInstalledModuleEnv InstalledModule -> InstalledFindResult -> Bool
    is_ext FinderCache
    fm, ())
     where
            fc_ref :: IORef FinderCache
    fc_ref       = HscEnv -> IORef FinderCache
    hsc_FC HscEnv
    hsc_env
            home_unit :: HomeUnit
    home_unit    = HscEnv -> HomeUnit
    hsc_home_unit HscEnv
    hsc_env
            is_ext :: InstalledModule -> InstalledFindResult -> Bool
    is_ext InstalledModule
    mod InstalledFindResult
    _ = Bool -> Bool
    not (forall u. GenHomeUnit u -> InstalledModule -> Bool
    isHomeInstalledModule HomeUnit
    home_unit InstalledModule
    mod)

    addToFinderCache :: IORef FinderCache -> InstalledModule -> InstalledFindResult -> IO ()
    addToFinderCache :: IORef FinderCache
    -> InstalledModule -> InstalledFindResult -> IO ()
    addToFinderCache IORef FinderCache
    ref InstalledModule
    key InstalledFindResult
    val =
      forall a b. IORef a -> (a -> (a, b)) -> IO b
    atomicModifyIORef' IORef FinderCache
    ref forall a b. (a -> b) -> a -> b
    $ \FinderCache
    c -> (forall a.
    InstalledModuleEnv a
    -> InstalledModule -> a -> InstalledModuleEnv a
    extendInstalledModuleEnv FinderCache
    c InstalledModule
    key InstalledFindResult
    val, ())

    removeFromFinderCache :: IORef FinderCache -> InstalledModule -> IO ()
    removeFromFinderCache :: IORef FinderCache -> InstalledModule -> IO ()
    removeFromFinderCache IORef FinderCache
    ref InstalledModule
    key =
      forall a b. IORef a -> (a -> (a, b)) -> IO b
    atomicModifyIORef' IORef FinderCache
    ref forall a b. (a -> b) -> a -> b
    $ \FinderCache
    c -> (forall a.
    InstalledModuleEnv a -> InstalledModule -> InstalledModuleEnv a
    delInstalledModuleEnv FinderCache
    c InstalledModule
    key, ())

    lookupFinderCache :: IORef FinderCache -> InstalledModule -> IO (Maybe InstalledFindResult)
    lookupFinderCache :: IORef FinderCache
    -> InstalledModule -> IO (Maybe InstalledFindResult)
    lookupFinderCache IORef FinderCache
    ref InstalledModule
    key = do
       FinderCache
    c <- forall a. IORef a -> IO a
    readIORef IORef FinderCache
    ref
       forall (m :: * -> *) a. Monad m => a -> m a
    return forall a b. (a -> b) -> a -> b
    $! forall a. InstalledModuleEnv a -> InstalledModule -> Maybe a
    lookupInstalledModuleEnv FinderCache
    c InstalledModule
    key

    -- -----------------------------------------------------------------------------
    -- The three external entry points

    -- | Locate a module that was imported by the user.  We have the
    -- module's name, and possibly a package name.  Without a package
    -- name, this function will use the search path and the known exposed
    -- packages to find the module, if a package is specified then only
    -- that package is searched for the module.

    findImportedModule :: HscEnv -> ModuleName -> Maybe FastString -> IO FindResult
    findImportedModule :: HscEnv -> ModuleName -> Maybe FastString -> IO FindResult
    findImportedModule HscEnv
    hsc_env ModuleName
    mod_name Maybe FastString
    mb_pkg =
      case Maybe FastString
    mb_pkg of
            Maybe FastString
    Nothing                        -> IO FindResult
    unqual_import
            Just FastString
    pkg | FastString
    pkg forall a. Eq a => a -> a -> Bool
    == FilePath -> FastString
    fsLit FilePath
    "this" -> IO FindResult
    home_import -- "this" is special
                     | Bool
    otherwise           -> IO FindResult
    pkg_import
      where
        home_import :: IO FindResult
    home_import   = HscEnv -> ModuleName -> IO FindResult
    findHomeModule HscEnv
    hsc_env ModuleName
    mod_name

        pkg_import :: IO FindResult
    pkg_import    = HscEnv -> ModuleName -> Maybe FastString -> IO FindResult
    findExposedPackageModule HscEnv
    hsc_env ModuleName
    mod_name Maybe FastString
    mb_pkg

        unqual_import :: IO FindResult
    unqual_import = IO FindResult
    home_import
                        forall (m :: * -> *).
    Monad m =>
    m FindResult -> m FindResult -> m FindResult
    `orIfNotFound`
                        HscEnv -> ModuleName -> Maybe FastString -> IO FindResult
    findExposedPackageModule HscEnv
    hsc_env ModuleName
    mod_name forall a. Maybe a
    Nothing

    -- | Locate a plugin module requested by the user, for a compiler
    -- plugin.  This consults the same set of exposed packages as
    -- 'findImportedModule', unless @-hide-all-plugin-packages@ or
    -- @-plugin-package@ are specified.
    findPluginModule :: HscEnv -> ModuleName -> IO FindResult
    findPluginModule :: HscEnv -> ModuleName -> IO FindResult
    findPluginModule HscEnv
    hsc_env ModuleName
    mod_name =
      HscEnv -> ModuleName -> IO FindResult
    findHomeModule HscEnv
    hsc_env ModuleName
    mod_name
      forall (m :: * -> *).
    Monad m =>
    m FindResult -> m FindResult -> m FindResult
    `orIfNotFound`
      HscEnv -> ModuleName -> IO FindResult
    findExposedPluginPackageModule HscEnv
    hsc_env ModuleName
    mod_name

    -- | Locate a specific 'Module'.  The purpose of this function is to
    -- create a 'ModLocation' for a given 'Module', that is to find out
    -- where the files associated with this module live.  It is used when
    -- reading the interface for a module mentioned by another interface,
    -- for example (a "system import").

    findExactModule :: HscEnv -> InstalledModule -> IO InstalledFindResult
    findExactModule :: HscEnv -> InstalledModule -> IO InstalledFindResult
    findExactModule HscEnv
    hsc_env InstalledModule
    mod =
        let home_unit :: HomeUnit
    home_unit = HscEnv -> HomeUnit
    hsc_home_unit HscEnv
    hsc_env
        in if forall u. GenHomeUnit u -> InstalledModule -> Bool
    isHomeInstalledModule HomeUnit
    home_unit InstalledModule
    mod
           then HscEnv -> ModuleName -> IO InstalledFindResult
    findInstalledHomeModule HscEnv
    hsc_env (forall unit. GenModule unit -> ModuleName
    moduleName InstalledModule
    mod)
           else HscEnv -> InstalledModule -> IO InstalledFindResult
    findPackageModule HscEnv
    hsc_env InstalledModule
    mod

    -- -----------------------------------------------------------------------------
    -- Helpers

    -- | Given a monadic actions @this@ and @or_this@, first execute
    -- @this@.  If the returned 'FindResult' is successful, return
    -- it; otherwise, execute @or_this@.  If both failed, this function
    -- also combines their failure messages in a reasonable way.
    orIfNotFound :: Monad m => m FindResult -> m FindResult -> m FindResult
    orIfNotFound :: forall (m :: * -> *).
    Monad m =>
    m FindResult -> m FindResult -> m FindResult
    orIfNotFound m FindResult
    this m FindResult
    or_this = do
      FindResult
    res <- m FindResult
    this
      case FindResult
    res of
        NotFound { fr_paths :: FindResult -> [FilePath]
    fr_paths = [FilePath]
    paths1, fr_mods_hidden :: FindResult -> [Unit]
    fr_mods_hidden = [Unit]
    mh1
                 , fr_pkgs_hidden :: FindResult -> [Unit]
    fr_pkgs_hidden = [Unit]
    ph1, fr_unusables :: FindResult -> [(Unit, UnusableUnitReason)]
    fr_unusables = [(Unit, UnusableUnitReason)]
    u1, fr_suggestions :: FindResult -> [ModuleSuggestion]
    fr_suggestions = [ModuleSuggestion]
    s1 }
         -> do FindResult
    res2 <- m FindResult
    or_this
               case FindResult
    res2 of
                 NotFound { fr_paths :: FindResult -> [FilePath]
    fr_paths = [FilePath]
    paths2, fr_pkg :: FindResult -> Maybe Unit
    fr_pkg = Maybe Unit
    mb_pkg2, fr_mods_hidden :: FindResult -> [Unit]
    fr_mods_hidden = [Unit]
    mh2
                          , fr_pkgs_hidden :: FindResult -> [Unit]
    fr_pkgs_hidden = [Unit]
    ph2, fr_unusables :: FindResult -> [(Unit, UnusableUnitReason)]
    fr_unusables = [(Unit, UnusableUnitReason)]
    u2
                          , fr_suggestions :: FindResult -> [ModuleSuggestion]
    fr_suggestions = [ModuleSuggestion]
    s2 }
                  -> forall (m :: * -> *) a. Monad m => a -> m a
    return (NotFound { fr_paths :: [FilePath]
    fr_paths = [FilePath]
    paths1 forall a. [a] -> [a] -> [a]
    ++ [FilePath]
    paths2
                                      , fr_pkg :: Maybe Unit
    fr_pkg = Maybe Unit
    mb_pkg2 -- snd arg is the package search
                                      , fr_mods_hidden :: [Unit]
    fr_mods_hidden = [Unit]
    mh1 forall a. [a] -> [a] -> [a]
    ++ [Unit]
    mh2
                                      , fr_pkgs_hidden :: [Unit]
    fr_pkgs_hidden = [Unit]
    ph1 forall a. [a] -> [a] -> [a]
    ++ [Unit]
    ph2
                                      , fr_unusables :: [(Unit, UnusableUnitReason)]
    fr_unusables = [(Unit, UnusableUnitReason)]
    u1 forall a. [a] -> [a] -> [a]
    ++ [(Unit, UnusableUnitReason)]
    u2
                                      , fr_suggestions :: [ModuleSuggestion]
    fr_suggestions = [ModuleSuggestion]
    s1  forall a. [a] -> [a] -> [a]
    ++ [ModuleSuggestion]
    s2 })
                 FindResult
    _other -> forall (m :: * -> *) a. Monad m => a -> m a
    return FindResult
    res2
        FindResult
    _other -> forall (m :: * -> *) a. Monad m => a -> m a
    return FindResult
    res

    -- | Helper function for 'findHomeModule': this function wraps an IO action
    -- which would look up @mod_name@ in the file system (the home package),
    -- and first consults the 'hsc_FC' cache to see if the lookup has already
    -- been done.  Otherwise, do the lookup (with the IO action) and save
    -- the result in the finder cache and the module location cache (if it
    -- was successful.)
    homeSearchCache :: HscEnv -> ModuleName -> IO InstalledFindResult -> IO InstalledFindResult
    homeSearchCache :: HscEnv
    -> ModuleName -> IO InstalledFindResult -> IO InstalledFindResult
    homeSearchCache HscEnv
    hsc_env ModuleName
    mod_name IO InstalledFindResult
    do_this = do
      let home_unit :: HomeUnit
    home_unit = HscEnv -> HomeUnit
    hsc_home_unit HscEnv
    hsc_env
          mod :: InstalledModule
    mod = forall u. GenHomeUnit u -> ModuleName -> InstalledModule
    mkHomeInstalledModule HomeUnit
    home_unit ModuleName
    mod_name
      HscEnv
    -> InstalledModule
    -> IO InstalledFindResult
    -> IO InstalledFindResult
    modLocationCache HscEnv
    hsc_env InstalledModule
    mod IO InstalledFindResult
    do_this

    findExposedPackageModule :: HscEnv -> ModuleName -> Maybe FastString
                             -> IO FindResult
    findExposedPackageModule :: HscEnv -> ModuleName -> Maybe FastString -> IO FindResult
    findExposedPackageModule HscEnv
    hsc_env ModuleName
    mod_name Maybe FastString
    mb_pkg
      = HscEnv -> LookupResult -> IO FindResult
    findLookupResult HscEnv
    hsc_env
      forall a b. (a -> b) -> a -> b
    $ UnitState -> ModuleName -> Maybe FastString -> LookupResult
    lookupModuleWithSuggestions
            (HscEnv -> UnitState
    hsc_units HscEnv
    hsc_env) ModuleName
    mod_name Maybe FastString
    mb_pkg

    findExposedPluginPackageModule :: HscEnv -> ModuleName
                                   -> IO FindResult
    findExposedPluginPackageModule :: HscEnv -> ModuleName -> IO FindResult
    findExposedPluginPackageModule HscEnv
    hsc_env ModuleName
    mod_name
      = HscEnv -> LookupResult -> IO FindResult
    findLookupResult HscEnv
    hsc_env
      forall a b. (a -> b) -> a -> b
    $ UnitState -> ModuleName -> Maybe FastString -> LookupResult
    lookupPluginModuleWithSuggestions
            (HscEnv -> UnitState
    hsc_units HscEnv
    hsc_env) ModuleName
    mod_name forall a. Maybe a
    Nothing

    findLookupResult :: HscEnv -> LookupResult -> IO FindResult
    findLookupResult :: HscEnv -> LookupResult -> IO FindResult
    findLookupResult HscEnv
    hsc_env LookupResult
    r = case LookupResult
    r of
         LookupFound Module
    m (UnitInfo, ModuleOrigin)
    pkg_conf -> do
           let im :: InstalledModule
    im = forall a b. (a, b) -> a
    fst (Module -> (InstalledModule, Maybe InstantiatedModule)
    getModuleInstantiation Module
    m)
           InstalledFindResult
    r' <- HscEnv -> InstalledModule -> UnitInfo -> IO InstalledFindResult
    findPackageModule_ HscEnv
    hsc_env InstalledModule
    im (forall a b. (a, b) -> a
    fst (UnitInfo, ModuleOrigin)
    pkg_conf)
           case InstalledFindResult
    r' of
            -- TODO: ghc -M is unlikely to do the right thing
            -- with just the location of the thing that was
            -- instantiated; you probably also need all of the
            -- implicit locations from the instances
            InstalledFound ModLocation
    loc   InstalledModule
    _ -> forall (m :: * -> *) a. Monad m => a -> m a
    return (ModLocation -> Module -> FindResult
    Found ModLocation
    loc Module
    m)
            InstalledNoPackage   UnitId
    _ -> forall (m :: * -> *) a. Monad m => a -> m a
    return (Unit -> FindResult
    NoPackage (forall unit. GenModule unit -> unit
    moduleUnit Module
    m))
            InstalledNotFound [FilePath]
    fp Maybe UnitId
    _ -> forall (m :: * -> *) a. Monad m => a -> m a
    return (NotFound{ fr_paths :: [FilePath]
    fr_paths = [FilePath]
    fp, fr_pkg :: Maybe Unit
    fr_pkg = forall a. a -> Maybe a
    Just (forall unit. GenModule unit -> unit
    moduleUnit Module
    m)
                                             , fr_pkgs_hidden :: [Unit]
    fr_pkgs_hidden = []
                                             , fr_mods_hidden :: [Unit]
    fr_mods_hidden = []
                                             , fr_unusables :: [(Unit, UnusableUnitReason)]
    fr_unusables = []
                                             , fr_suggestions :: [ModuleSuggestion]
    fr_suggestions = []})
         LookupMultiple [(Module, ModuleOrigin)]
    rs ->
           forall (m :: * -> *) a. Monad m => a -> m a
    return ([(Module, ModuleOrigin)] -> FindResult
    FoundMultiple [(Module, ModuleOrigin)]
    rs)
         LookupHidden [(Module, ModuleOrigin)]
    pkg_hiddens [(Module, ModuleOrigin)]
    mod_hiddens ->
           forall (m :: * -> *) a. Monad m => a -> m a
    return (NotFound{ fr_paths :: [FilePath]
    fr_paths = [], fr_pkg :: Maybe Unit
    fr_pkg = forall a. Maybe a
    Nothing
                           , fr_pkgs_hidden :: [Unit]
    fr_pkgs_hidden = forall a b. (a -> b) -> [a] -> [b]
    map (forall unit. GenModule unit -> unit
    moduleUnitforall b c a. (b -> c) -> (a -> b) -> a -> c
    .forall a b. (a, b) -> a
    fst) [(Module, ModuleOrigin)]
    pkg_hiddens
                           , fr_mods_hidden :: [Unit]
    fr_mods_hidden = forall a b. (a -> b) -> [a] -> [b]
    map (forall unit. GenModule unit -> unit
    moduleUnitforall b c a. (b -> c) -> (a -> b) -> a -> c
    .forall a b. (a, b) -> a
    fst) [(Module, ModuleOrigin)]
    mod_hiddens
                           , fr_unusables :: [(Unit, UnusableUnitReason)]
    fr_unusables = []
                           , fr_suggestions :: [ModuleSuggestion]
    fr_suggestions = [] })
         LookupUnusable [(Module, ModuleOrigin)]
    unusable ->
           let unusables' :: [(Unit, UnusableUnitReason)]
    unusables' = forall a b. (a -> b) -> [a] -> [b]
    map forall {a}. (GenModule a, ModuleOrigin) -> (a, UnusableUnitReason)
    get_unusable [(Module, ModuleOrigin)]
    unusable
               get_unusable :: (GenModule a, ModuleOrigin) -> (a, UnusableUnitReason)
    get_unusable (GenModule a
    m, ModUnusable UnusableUnitReason
    r) = (forall unit. GenModule unit -> unit
    moduleUnit GenModule a
    m, UnusableUnitReason
    r)
               get_unusable (GenModule a
    _, ModuleOrigin
    r)             =
                 forall a. HasCallStack => FilePath -> SDoc -> a
    pprPanic FilePath
    "findLookupResult: unexpected origin" (forall a. Outputable a => a -> SDoc
    ppr ModuleOrigin
    r)
           in forall (m :: * -> *) a. Monad m => a -> m a
    return (NotFound{ fr_paths :: [FilePath]
    fr_paths = [], fr_pkg :: Maybe Unit
    fr_pkg = forall a. Maybe a
    Nothing
                              , fr_pkgs_hidden :: [Unit]
    fr_pkgs_hidden = []
                              , fr_mods_hidden :: [Unit]
    fr_mods_hidden = []
                              , fr_unusables :: [(Unit, UnusableUnitReason)]
    fr_unusables = [(Unit, UnusableUnitReason)]
    unusables'
                              , fr_suggestions :: [ModuleSuggestion]
    fr_suggestions = [] })
         LookupNotFound [ModuleSuggestion]
    suggest -> do
           let suggest' :: [ModuleSuggestion]
    suggest'
                 | GeneralFlag -> DynFlags -> Bool
    gopt GeneralFlag
    Opt_HelpfulErrors (HscEnv -> DynFlags
    hsc_dflags HscEnv
    hsc_env) = [ModuleSuggestion]
    suggest
                 | Bool
    otherwise = []
           forall (m :: * -> *) a. Monad m => a -> m a
    return (NotFound{ fr_paths :: [FilePath]
    fr_paths = [], fr_pkg :: Maybe Unit
    fr_pkg = forall a. Maybe a
    Nothing
                           , fr_pkgs_hidden :: [Unit]
    fr_pkgs_hidden = []
                           , fr_mods_hidden :: [Unit]
    fr_mods_hidden = []
                           , fr_unusables :: [(Unit, UnusableUnitReason)]
    fr_unusables = []
                           , fr_suggestions :: [ModuleSuggestion]
    fr_suggestions = [ModuleSuggestion]
    suggest' })

    modLocationCache :: HscEnv -> InstalledModule -> IO InstalledFindResult -> IO InstalledFindResult
    modLocationCache :: HscEnv
    -> InstalledModule
    -> IO InstalledFindResult
    -> IO InstalledFindResult
    modLocationCache HscEnv
    hsc_env InstalledModule
    mod IO InstalledFindResult
    do_this = do
      Maybe InstalledFindResult
    m <- IORef FinderCache
    -> InstalledModule -> IO (Maybe InstalledFindResult)
    lookupFinderCache (HscEnv -> IORef FinderCache
    hsc_FC HscEnv
    hsc_env) InstalledModule
    mod
      case Maybe InstalledFindResult
    m of
        Just InstalledFindResult
    result -> forall (m :: * -> *) a. Monad m => a -> m a
    return InstalledFindResult
    result
        Maybe InstalledFindResult
    Nothing     -> do
            InstalledFindResult
    result <- IO InstalledFindResult
    do_this
            IORef FinderCache
    -> InstalledModule -> InstalledFindResult -> IO ()
    addToFinderCache (HscEnv -> IORef FinderCache
    hsc_FC HscEnv
    hsc_env) InstalledModule
    mod InstalledFindResult
    result
            forall (m :: * -> *) a. Monad m => a -> m a
    return InstalledFindResult
    result

    -- This returns a module because it's more convenient for users
    addHomeModuleToFinder :: HscEnv -> ModuleName -> ModLocation -> IO Module
    addHomeModuleToFinder :: HscEnv -> ModuleName -> ModLocation -> IO Module
    addHomeModuleToFinder HscEnv
    hsc_env ModuleName
    mod_name ModLocation
    loc = do
      let home_unit :: HomeUnit
    home_unit = HscEnv -> HomeUnit
    hsc_home_unit HscEnv
    hsc_env
          mod :: InstalledModule
    mod = forall u. GenHomeUnit u -> ModuleName -> InstalledModule
    mkHomeInstalledModule HomeUnit
    home_unit ModuleName
    mod_name
      IORef FinderCache
    -> InstalledModule -> InstalledFindResult -> IO ()
    addToFinderCache (HscEnv -> IORef FinderCache
    hsc_FC HscEnv
    hsc_env) InstalledModule
    mod (ModLocation -> InstalledModule -> InstalledFindResult
    InstalledFound ModLocation
    loc InstalledModule
    mod)
      forall (m :: * -> *) a. Monad m => a -> m a
    return (HomeUnit -> ModuleName -> Module
    mkHomeModule HomeUnit
    home_unit ModuleName
    mod_name)

    uncacheModule :: HscEnv -> ModuleName -> IO ()
    uncacheModule :: HscEnv -> ModuleName -> IO ()
    uncacheModule HscEnv
    hsc_env ModuleName
    mod_name = do
      let home_unit :: HomeUnit
    home_unit = HscEnv -> HomeUnit
    hsc_home_unit HscEnv
    hsc_env
          mod :: InstalledModule
    mod = forall u. GenHomeUnit u -> ModuleName -> InstalledModule
    mkHomeInstalledModule HomeUnit
    home_unit ModuleName
    mod_name
      IORef FinderCache -> InstalledModule -> IO ()
    removeFromFinderCache (HscEnv -> IORef FinderCache
    hsc_FC HscEnv
    hsc_env) InstalledModule
    mod

    -- -----------------------------------------------------------------------------
    --      The internal workers

    findHomeModule :: HscEnv -> ModuleName -> IO FindResult
    findHomeModule :: HscEnv -> ModuleName -> IO FindResult
    findHomeModule HscEnv
    hsc_env ModuleName
    mod_name = do
      InstalledFindResult
    r <- HscEnv -> ModuleName -> IO InstalledFindResult
    findInstalledHomeModule HscEnv
    hsc_env ModuleName
    mod_name
      forall (m :: * -> *) a. Monad m => a -> m a
    return forall a b. (a -> b) -> a -> b
    $ case InstalledFindResult
    r of
        InstalledFound ModLocation
    loc InstalledModule
    _ -> ModLocation -> Module -> FindResult
    Found ModLocation
    loc (HomeUnit -> ModuleName -> Module
    mkHomeModule HomeUnit
    home_unit ModuleName
    mod_name)
        InstalledNoPackage UnitId
    _ -> Unit -> FindResult
    NoPackage Unit
    uid -- impossible
        InstalledNotFound [FilePath]
    fps Maybe UnitId
    _ -> NotFound {
            fr_paths :: [FilePath]
    fr_paths = [FilePath]
    fps,
            fr_pkg :: Maybe Unit
    fr_pkg = forall a. a -> Maybe a
    Just Unit
    uid,
            fr_mods_hidden :: [Unit]
    fr_mods_hidden = [],
            fr_pkgs_hidden :: [Unit]
    fr_pkgs_hidden = [],
            fr_unusables :: [(Unit, UnusableUnitReason)]
    fr_unusables = [],
            fr_suggestions :: [ModuleSuggestion]
    fr_suggestions = []
          }
     where
      home_unit :: HomeUnit
    home_unit = HscEnv -> HomeUnit
    hsc_home_unit HscEnv
    hsc_env
      uid :: Unit
    uid       = HomeUnit -> Unit
    homeUnitAsUnit HomeUnit
    home_unit

    -- | Implements the search for a module name in the home package only.  Calling
    -- this function directly is usually *not* what you want; currently, it's used
    -- as a building block for the following operations:
    --
    --  1. When you do a normal package lookup, we first check if the module
    --  is available in the home module, before looking it up in the package
    --  database.
    --
    --  2. When you have a package qualified import with package name "this",
    --  we shortcut to the home module.
    --
    --  3. When we look up an exact 'Module', if the unit id associated with
    --  the module is the current home module do a look up in the home module.
    --
    --  4. Some special-case code in GHCi (ToDo: Figure out why that needs to
    --  call this.)
    findInstalledHomeModule :: HscEnv -> ModuleName -> IO InstalledFindResult
    findInstalledHomeModule :: HscEnv -> ModuleName -> IO InstalledFindResult
    findInstalledHomeModule HscEnv
    hsc_env ModuleName
    mod_name =
       HscEnv
    -> ModuleName -> IO InstalledFindResult -> IO InstalledFindResult
    homeSearchCache HscEnv
    hsc_env ModuleName
    mod_name forall a b. (a -> b) -> a -> b
    $
       let
         dflags :: DynFlags
    dflags = HscEnv -> DynFlags
    hsc_dflags HscEnv
    hsc_env
         home_unit :: HomeUnit
    home_unit = HscEnv -> HomeUnit
    hsc_home_unit HscEnv
    hsc_env
         home_path :: [FilePath]
    home_path = DynFlags -> [FilePath]
    importPaths DynFlags
    dflags
         hisuf :: FilePath
    hisuf = DynFlags -> FilePath
    hiSuf DynFlags
    dflags
         mod :: InstalledModule
    mod = forall u. GenHomeUnit u -> ModuleName -> InstalledModule
    mkHomeInstalledModule HomeUnit
    home_unit ModuleName
    mod_name

         source_exts :: [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    source_exts =
          [ (FilePath
    "hs",   DynFlags
    -> ModuleName -> FilePath -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocationSearched DynFlags
    dflags ModuleName
    mod_name FilePath
    "hs")
          , (FilePath
    "lhs",  DynFlags
    -> ModuleName -> FilePath -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocationSearched DynFlags
    dflags ModuleName
    mod_name FilePath
    "lhs")
          , (FilePath
    "hsig",  DynFlags
    -> ModuleName -> FilePath -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocationSearched DynFlags
    dflags ModuleName
    mod_name FilePath
    "hsig")
          , (FilePath
    "lhsig",  DynFlags
    -> ModuleName -> FilePath -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocationSearched DynFlags
    dflags ModuleName
    mod_name FilePath
    "lhsig")
          ]

         -- we use mkHomeModHiOnlyLocation instead of mkHiOnlyModLocation so that
         -- when hiDir field is set in dflags, we know to look there (see #16500)
         hi_exts :: [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    hi_exts = [ (FilePath
    hisuf,                DynFlags -> ModuleName -> FilePath -> FilePath -> IO ModLocation
    mkHomeModHiOnlyLocation DynFlags
    dflags ModuleName
    mod_name)
                   , (FilePath -> FilePath
    addBootSuffix FilePath
    hisuf,  DynFlags -> ModuleName -> FilePath -> FilePath -> IO ModLocation
    mkHomeModHiOnlyLocation DynFlags
    dflags ModuleName
    mod_name)
                   ]

            -- In compilation manager modes, we look for source files in the home
            -- package because we can compile these automatically.  In one-shot
            -- compilation mode we look for .hi and .hi-boot files only.
         exts :: [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    exts | GhcMode -> Bool
    isOneShot (DynFlags -> GhcMode
    ghcMode DynFlags
    dflags) = [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    hi_exts
              | Bool
    otherwise                  = [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    source_exts
       in

      -- special case for GHC.Prim; we won't find it in the filesystem.
      -- This is important only when compiling the base package (where GHC.Prim
      -- is a home module).
      if InstalledModule
    mod InstalledModule -> Module -> Bool
    `installedModuleEq` Module
    gHC_PRIM
            then forall (m :: * -> *) a. Monad m => a -> m a
    return (ModLocation -> InstalledModule -> InstalledFindResult
    InstalledFound (forall a. HasCallStack => FilePath -> a
    error FilePath
    "GHC.Prim ModLocation") InstalledModule
    mod)
            else [FilePath]
    -> InstalledModule
    -> [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    -> IO InstalledFindResult
    searchPathExts [FilePath]
    home_path InstalledModule
    mod [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    exts

    -- | Search for a module in external packages only.
    findPackageModule :: HscEnv -> InstalledModule -> IO InstalledFindResult
    findPackageModule :: HscEnv -> InstalledModule -> IO InstalledFindResult
    findPackageModule HscEnv
    hsc_env InstalledModule
    mod = do
      let pkg_id :: UnitId
    pkg_id = forall unit. GenModule unit -> unit
    moduleUnit InstalledModule
    mod
      case UnitState -> UnitId -> Maybe UnitInfo
    lookupUnitId (HscEnv -> UnitState
    hsc_units HscEnv
    hsc_env) UnitId
    pkg_id of
         Maybe UnitInfo
    Nothing -> forall (m :: * -> *) a. Monad m => a -> m a
    return (UnitId -> InstalledFindResult
    InstalledNoPackage UnitId
    pkg_id)
         Just UnitInfo
    u  -> HscEnv -> InstalledModule -> UnitInfo -> IO InstalledFindResult
    findPackageModule_ HscEnv
    hsc_env InstalledModule
    mod UnitInfo
    u

    -- | Look up the interface file associated with module @mod@.  This function
    -- requires a few invariants to be upheld: (1) the 'Module' in question must
    -- be the module identifier of the *original* implementation of a module,
    -- not a reexport (this invariant is upheld by "GHC.Unit.State") and (2)
    -- the 'UnitInfo' must be consistent with the unit id in the 'Module'.
    -- The redundancy is to avoid an extra lookup in the package state
    -- for the appropriate config.
    findPackageModule_ :: HscEnv -> InstalledModule -> UnitInfo -> IO InstalledFindResult
    findPackageModule_ :: HscEnv -> InstalledModule -> UnitInfo -> IO InstalledFindResult
    findPackageModule_ HscEnv
    hsc_env InstalledModule
    mod UnitInfo
    pkg_conf =
      ASSERT2( moduleUnit mod == unitId pkg_conf, ppr (moduleUnit mod) <+> ppr (unitId pkg_conf) )
      HscEnv
    -> InstalledModule
    -> IO InstalledFindResult
    -> IO InstalledFindResult
    modLocationCache HscEnv
    hsc_env InstalledModule
    mod forall a b. (a -> b) -> a -> b
    $

      -- special case for GHC.Prim; we won't find it in the filesystem.
      if InstalledModule
    mod InstalledModule -> Module -> Bool
    `installedModuleEq` Module
    gHC_PRIM
            then forall (m :: * -> *) a. Monad m => a -> m a
    return (ModLocation -> InstalledModule -> InstalledFindResult
    InstalledFound (forall a. HasCallStack => FilePath -> a
    error FilePath
    "GHC.Prim ModLocation") InstalledModule
    mod)
            else

      let
         dflags :: DynFlags
    dflags = HscEnv -> DynFlags
    hsc_dflags HscEnv
    hsc_env
         tag :: FilePath
    tag = Ways -> FilePath
    waysBuildTag (DynFlags -> Ways
    ways DynFlags
    dflags)

               -- hi-suffix for packages depends on the build tag.
         package_hisuf :: FilePath
    package_hisuf | forall (t :: * -> *) a. Foldable t => t a -> Bool
    null FilePath
    tag  = FilePath
    "hi"
                       | Bool
    otherwise = FilePath
    tag forall a. [a] -> [a] -> [a]
    ++ FilePath
    "_hi"

         mk_hi_loc :: FilePath -> FilePath -> IO ModLocation
    mk_hi_loc = DynFlags -> FilePath -> FilePath -> FilePath -> IO ModLocation
    mkHiOnlyModLocation DynFlags
    dflags FilePath
    package_hisuf

         import_dirs :: [FilePath]
    import_dirs = forall a b. (a -> b) -> [a] -> [b]
    map ShortText -> FilePath
    ST.unpack forall a b. (a -> b) -> a -> b
    $ forall compid srcpkgid srcpkgname uid modulename mod.
    GenericUnitInfo compid srcpkgid srcpkgname uid modulename mod
    -> [ShortText]
    unitImportDirs UnitInfo
    pkg_conf
          -- we never look for a .hi-boot file in an external package;
          -- .hi-boot files only make sense for the home package.
      in
      case [FilePath]
    import_dirs of
        [FilePath
    one] | GhcMode
    MkDepend <- DynFlags -> GhcMode
    ghcMode DynFlags
    dflags -> do
              -- there's only one place that this .hi file can be, so
              -- don't bother looking for it.
              let basename :: FilePath
    basename = ModuleName -> FilePath
    moduleNameSlashes (forall unit. GenModule unit -> ModuleName
    moduleName InstalledModule
    mod)
              ModLocation
    loc <- FilePath -> FilePath -> IO ModLocation
    mk_hi_loc FilePath
    one FilePath
    basename
              forall (m :: * -> *) a. Monad m => a -> m a
    return (ModLocation -> InstalledModule -> InstalledFindResult
    InstalledFound ModLocation
    loc InstalledModule
    mod)
        [FilePath]
    _otherwise ->
              [FilePath]
    -> InstalledModule
    -> [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    -> IO InstalledFindResult
    searchPathExts [FilePath]
    import_dirs InstalledModule
    mod [(FilePath
    package_hisuf, FilePath -> FilePath -> IO ModLocation
    mk_hi_loc)]

    -- -----------------------------------------------------------------------------
    -- General path searching

    searchPathExts :: [FilePath]      -- paths to search
                   -> InstalledModule -- module name
                   -> [ (
                         FileExt,                                -- suffix
                         FilePath -> BaseName -> IO ModLocation  -- action
                        )
                      ]
                   -> IO InstalledFindResult

    searchPathExts :: [FilePath]
    -> InstalledModule
    -> [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    -> IO InstalledFindResult
    searchPathExts [FilePath]
    paths InstalledModule
    mod [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    exts = [(FilePath, IO ModLocation)] -> IO InstalledFindResult
    search [(FilePath, IO ModLocation)]
    to_search
      where
        basename :: FilePath
    basename = ModuleName -> FilePath
    moduleNameSlashes (forall unit. GenModule unit -> ModuleName
    moduleName InstalledModule
    mod)

        to_search :: [(FilePath, IO ModLocation)]
        to_search :: [(FilePath, IO ModLocation)]
    to_search = [ (FilePath
    file, FilePath -> FilePath -> IO ModLocation
    fn FilePath
    path FilePath
    basename)
                    | FilePath
    path <- [FilePath]
    paths,
                      (FilePath
    ext,FilePath -> FilePath -> IO ModLocation
    fn) <- [(FilePath, FilePath -> FilePath -> IO ModLocation)]
    exts,
                      let base :: FilePath
    base | FilePath
    path forall a. Eq a => a -> a -> Bool
    == FilePath
    "." = FilePath
    basename
                               | Bool
    otherwise   = FilePath
    path FilePath -> FilePath -> FilePath
    </> FilePath
    basename
                          file :: FilePath
    file = FilePath
    base FilePath -> FilePath -> FilePath
    <.> FilePath
    ext
                    ]

        search :: [(FilePath, IO ModLocation)] -> IO InstalledFindResult
    search [] = forall (m :: * -> *) a. Monad m => a -> m a
    return ([FilePath] -> Maybe UnitId -> InstalledFindResult
    InstalledNotFound (forall a b. (a -> b) -> [a] -> [b]
    map forall a b. (a, b) -> a
    fst [(FilePath, IO ModLocation)]
    to_search) (forall a. a -> Maybe a
    Just (forall unit. GenModule unit -> unit
    moduleUnit InstalledModule
    mod)))

        search ((FilePath
    file, IO ModLocation
    mk_result) : [(FilePath, IO ModLocation)]
    rest) = do
          Bool
    b <- FilePath -> IO Bool
    doesFileExist FilePath
    file
          if Bool
    b
            then do { ModLocation
    loc <- IO ModLocation
    mk_result; forall (m :: * -> *) a. Monad m => a -> m a
    return (ModLocation -> InstalledModule -> InstalledFindResult
    InstalledFound ModLocation
    loc InstalledModule
    mod) }
            else [(FilePath, IO ModLocation)] -> IO InstalledFindResult
    search [(FilePath, IO ModLocation)]
    rest

    mkHomeModLocationSearched :: DynFlags -> ModuleName -> FileExt
                              -> FilePath -> BaseName -> IO ModLocation
    mkHomeModLocationSearched :: DynFlags
    -> ModuleName -> FilePath -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocationSearched DynFlags
    dflags ModuleName
    mod FilePath
    suff FilePath
    path FilePath
    basename =
      DynFlags -> ModuleName -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocation2 DynFlags
    dflags ModuleName
    mod (FilePath
    path FilePath -> FilePath -> FilePath
    </> FilePath
    basename) FilePath
    suff

    -- -----------------------------------------------------------------------------
    -- Constructing a home module location

    -- This is where we construct the ModLocation for a module in the home
    -- package, for which we have a source file.  It is called from three
    -- places:
    --
    --  (a) Here in the finder, when we are searching for a module to import,
    --      using the search path (-i option).
    --
    --  (b) The compilation manager, when constructing the ModLocation for
    --      a "root" module (a source file named explicitly on the command line
    --      or in a :load command in GHCi).
    --
    --  (c) The driver in one-shot mode, when we need to construct a
    --      ModLocation for a source file named on the command-line.
    --
    -- Parameters are:
    --
    -- mod
    --      The name of the module
    --
    -- path
    --      (a): The search path component where the source file was found.
    --      (b) and (c): "."
    --
    -- src_basename
    --      (a): (moduleNameSlashes mod)
    --      (b) and (c): The filename of the source file, minus its extension
    --
    -- ext
    --      The filename extension of the source file (usually "hs" or "lhs").

    mkHomeModLocation :: DynFlags -> ModuleName -> FilePath -> IO ModLocation
    mkHomeModLocation :: DynFlags -> ModuleName -> FilePath -> IO ModLocation
    mkHomeModLocation DynFlags
    dflags ModuleName
    mod FilePath
    src_filename = do
       let (FilePath
    basename,FilePath
    extension) = FilePath -> (FilePath, FilePath)
    splitExtension FilePath
    src_filename
       DynFlags -> ModuleName -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocation2 DynFlags
    dflags ModuleName
    mod FilePath
    basename FilePath
    extension

    mkHomeModLocation2 :: DynFlags
                       -> ModuleName
                       -> FilePath  -- Of source module, without suffix
                       -> String    -- Suffix
                       -> IO ModLocation
    mkHomeModLocation2 :: DynFlags -> ModuleName -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocation2 DynFlags
    dflags ModuleName
    mod FilePath
    src_basename FilePath
    ext = do
       let mod_basename :: FilePath
    mod_basename = ModuleName -> FilePath
    moduleNameSlashes ModuleName
    mod

           obj_fn :: FilePath
    obj_fn = DynFlags -> FilePath -> FilePath -> FilePath
    mkObjPath  DynFlags
    dflags FilePath
    src_basename FilePath
    mod_basename
           hi_fn :: FilePath
    hi_fn  = DynFlags -> FilePath -> FilePath -> FilePath
    mkHiPath   DynFlags
    dflags FilePath
    src_basename FilePath
    mod_basename
           hie_fn :: FilePath
    hie_fn = DynFlags -> FilePath -> FilePath -> FilePath
    mkHiePath  DynFlags
    dflags FilePath
    src_basename FilePath
    mod_basename

       forall (m :: * -> *) a. Monad m => a -> m a
    return (ModLocation{ ml_hs_file :: Maybe FilePath
    ml_hs_file   = forall a. a -> Maybe a
    Just (FilePath
    src_basename FilePath -> FilePath -> FilePath
    <.> FilePath
    ext),
                            ml_hi_file :: FilePath
    ml_hi_file   = FilePath
    hi_fn,
                            ml_obj_file :: FilePath
    ml_obj_file  = FilePath
    obj_fn,
                            ml_hie_file :: FilePath
    ml_hie_file  = FilePath
    hie_fn })

    mkHomeModHiOnlyLocation :: DynFlags
                            -> ModuleName
                            -> FilePath
                            -> BaseName
                            -> IO ModLocation
    mkHomeModHiOnlyLocation :: DynFlags -> ModuleName -> FilePath -> FilePath -> IO ModLocation
    mkHomeModHiOnlyLocation DynFlags
    dflags ModuleName
    mod FilePath
    path FilePath
    basename = do
       ModLocation
    loc <- DynFlags -> ModuleName -> FilePath -> FilePath -> IO ModLocation
    mkHomeModLocation2 DynFlags
    dflags ModuleName
    mod (FilePath
    path FilePath -> FilePath -> FilePath
    </> FilePath
    basename) FilePath
    ""
       forall (m :: * -> *) a. Monad m => a -> m a
    return ModLocation
    loc { ml_hs_file :: Maybe FilePath
    ml_hs_file = forall a. Maybe a
    Nothing }

    mkHiOnlyModLocation :: DynFlags -> Suffix -> FilePath -> String
                        -> IO ModLocation
    mkHiOnlyModLocation :: DynFlags -> FilePath -> FilePath -> FilePath -> IO ModLocation
    mkHiOnlyModLocation DynFlags
    dflags FilePath
    hisuf FilePath
    path FilePath
    basename
     = do let full_basename :: FilePath
    full_basename = FilePath
    path FilePath -> FilePath -> FilePath
    </> FilePath
    basename
              obj_fn :: FilePath
    obj_fn = DynFlags -> FilePath -> FilePath -> FilePath
    mkObjPath  DynFlags
    dflags FilePath
    full_basename FilePath
    basename
              hie_fn :: FilePath
    hie_fn = DynFlags -> FilePath -> FilePath -> FilePath
    mkHiePath  DynFlags
    dflags FilePath
    full_basename FilePath
    basename
          forall (m :: * -> *) a. Monad m => a -> m a
    return ModLocation{    ml_hs_file :: Maybe FilePath
    ml_hs_file   = forall a. Maybe a
    Nothing,
                                 ml_hi_file :: FilePath
    ml_hi_file   = FilePath
    full_basename FilePath -> FilePath -> FilePath
    <.> FilePath
    hisuf,
                                    -- Remove the .hi-boot suffix from
                                    -- hi_file, if it had one.  We always
                                    -- want the name of the real .hi file
                                    -- in the ml_hi_file field.
                                 ml_obj_file :: FilePath
    ml_obj_file  = FilePath
    obj_fn,
                                 ml_hie_file :: FilePath
    ml_hie_file  = FilePath
    hie_fn
                      }

    -- | Constructs the filename of a .o file for a given source file.
    -- Does /not/ check whether the .o file exists
    mkObjPath
      :: DynFlags
      -> FilePath           -- the filename of the source file, minus the extension
      -> String             -- the module name with dots replaced by slashes
      -> FilePath
    mkObjPath :: DynFlags -> FilePath -> FilePath -> FilePath
    mkObjPath DynFlags
    dflags FilePath
    basename FilePath
    mod_basename = FilePath
    obj_basename FilePath -> FilePath -> FilePath
    <.> FilePath
    osuf
      where
                    odir :: Maybe FilePath
    odir = DynFlags -> Maybe FilePath
    objectDir DynFlags
    dflags
                    osuf :: FilePath
    osuf = DynFlags -> FilePath
    objectSuf DynFlags
    dflags

                    obj_basename :: FilePath
    obj_basename | Just FilePath
    dir <- Maybe FilePath
    odir = FilePath
    dir FilePath -> FilePath -> FilePath
    </> FilePath
    mod_basename
                                 | Bool
    otherwise        = FilePath
    basename

    -- | Constructs the filename of a .hi file for a given source file.
    -- Does /not/ check whether the .hi file exists
    mkHiPath
      :: DynFlags
      -> FilePath           -- the filename of the source file, minus the extension
      -> String             -- the module name with dots replaced by slashes
      -> FilePath
    mkHiPath :: DynFlags -> FilePath -> FilePath -> FilePath
    mkHiPath DynFlags
    dflags FilePath
    basename FilePath
    mod_basename = FilePath
    hi_basename FilePath -> FilePath -> FilePath
    <.> FilePath
    hisuf
     where
                    hidir :: Maybe FilePath
    hidir = DynFlags -> Maybe FilePath
    hiDir DynFlags
    dflags
                    hisuf :: FilePath
    hisuf = DynFlags -> FilePath
    hiSuf DynFlags
    dflags

                    hi_basename :: FilePath
    hi_basename | Just FilePath
    dir <- Maybe FilePath
    hidir = FilePath
    dir FilePath -> FilePath -> FilePath
    </> FilePath
    mod_basename
                                | Bool
    otherwise         = FilePath
    basename

    -- | Constructs the filename of a .hie file for a given source file.
    -- Does /not/ check whether the .hie file exists
    mkHiePath
      :: DynFlags
      -> FilePath           -- the filename of the source file, minus the extension
      -> String             -- the module name with dots replaced by slashes
      -> FilePath
    mkHiePath :: DynFlags -> FilePath -> FilePath -> FilePath
    mkHiePath DynFlags
    dflags FilePath
    basename FilePath
    mod_basename = FilePath
    hie_basename FilePath -> FilePath -> FilePath
    <.> FilePath
    hiesuf
     where
                    hiedir :: Maybe FilePath
    hiedir = DynFlags -> Maybe FilePath
    hieDir DynFlags
    dflags
                    hiesuf :: FilePath
    hiesuf = DynFlags -> FilePath
    hieSuf DynFlags
    dflags

                    hie_basename :: FilePath
    hie_basename | Just FilePath
    dir <- Maybe FilePath
    hiedir = FilePath
    dir FilePath -> FilePath -> FilePath
    </> FilePath
    mod_basename
                                 | Bool
    otherwise          = FilePath
    basename

    -- -----------------------------------------------------------------------------
    -- Filenames of the stub files

    -- We don't have to store these in ModLocations, because they can be derived
    -- from other available information, and they're only rarely needed.

    mkStubPaths
      :: DynFlags
      -> ModuleName
      -> ModLocation
      -> FilePath

    mkStubPaths :: DynFlags -> ModuleName -> ModLocation -> FilePath
    mkStubPaths DynFlags
    dflags ModuleName
    mod ModLocation
    location
      = let
            stubdir :: Maybe FilePath
    stubdir = DynFlags -> Maybe FilePath
    stubDir DynFlags
    dflags

            mod_basename :: FilePath
    mod_basename = ModuleName -> FilePath
    moduleNameSlashes ModuleName
    mod
            src_basename :: FilePath
    src_basename = FilePath -> FilePath
    dropExtension forall a b. (a -> b) -> a -> b
    $ forall a. HasCallStack => FilePath -> Maybe a -> a
    expectJust FilePath
    "mkStubPaths"
                                                      (ModLocation -> Maybe FilePath
    ml_hs_file ModLocation
    location)

            stub_basename0 :: FilePath
    stub_basename0
                | Just FilePath
    dir <- Maybe FilePath
    stubdir = FilePath
    dir FilePath -> FilePath -> FilePath
    </> FilePath
    mod_basename
                | Bool
    otherwise           = FilePath
    src_basename

            stub_basename :: FilePath
    stub_basename = FilePath
    stub_basename0 forall a. [a] -> [a] -> [a]
    ++ FilePath
    "_stub"
         in
            FilePath
    stub_basename FilePath -> FilePath -> FilePath
    <.> FilePath
    "h"

    -- -----------------------------------------------------------------------------
    -- findLinkable isn't related to the other stuff in here,
    -- but there's no other obvious place for it

    findObjectLinkableMaybe :: Module -> ModLocation -> IO (Maybe Linkable)
    findObjectLinkableMaybe :: Module -> ModLocation -> IO (Maybe Linkable)
    findObjectLinkableMaybe Module
    mod ModLocation
    locn
       = do let obj_fn :: FilePath
    obj_fn = ModLocation -> FilePath
    ml_obj_file ModLocation
    locn
            Maybe UTCTime
    maybe_obj_time <- FilePath -> IO (Maybe UTCTime)
    modificationTimeIfExists FilePath
    obj_fn
            case Maybe UTCTime
    maybe_obj_time of
              Maybe UTCTime
    Nothing -> forall (m :: * -> *) a. Monad m => a -> m a
    return forall a. Maybe a
    Nothing
              Just UTCTime
    obj_time -> forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r
    liftM forall a. a -> Maybe a
    Just (Module -> FilePath -> UTCTime -> IO Linkable
    findObjectLinkable Module
    mod FilePath
    obj_fn UTCTime
    obj_time)

    -- Make an object linkable when we know the object file exists, and we know
    -- its modification time.
    findObjectLinkable :: Module -> FilePath -> UTCTime -> IO Linkable
    findObjectLinkable :: Module -> FilePath -> UTCTime -> IO Linkable
    findObjectLinkable Module
    mod FilePath
    obj_fn UTCTime
    obj_time = forall (m :: * -> *) a. Monad m => a -> m a
    return (UTCTime -> Module -> [Unlinked] -> Linkable
    LM UTCTime
    obj_time Module
    mod [FilePath -> Unlinked
    DotO FilePath
    obj_fn])
      -- We used to look for _stub.o files here, but that was a bug (#706)
      -- Now GHC merges the stub.o into the main .o (#3687)